Mini Thesis - Copy

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National Institute of Construction Management and Research, Pune

Department: PG-PEM

Mini Thesis

On

“ Energy Eciency Analysis of RMC Plant “

Guided y!

Prof. P.M.Deshpande

"u#mitted y!

Anoop Nimkande P91107

Ajinka !"#karni P9107$

%ijadatta Pati# P91119

a#le of Contentsapter 1: 'ntrod"(tion..........................................................................................)

.1 Genera#......................................................................................................... )

.* +",,estions for e(o-e(ien(......................................................................)

.) Materia# so"r(in,..........................................................................................



.).1 /ater.........................................................................................................

.).1.1 Genera#...................................................................................................

.).1.* +",,estions for e(o-e(ien(................................................................

.).* &ement......................................................................................................

.).*.1 Genera#...................................................................................................

.).*.* +",,estions for e(o-e(ien(................................................................

.).) A,,re,ates................................................................................................

.).).1 Genera#...................................................................................................

.).).* +",,estions for e(o-e(ien(................................................................

.). e((#ed (onstr"(tion materia#s 2se(ondar (onstr"(tion materia#s3........

.). Minera# additions4 in(#"din, 5 ash4 added dire(t# to (on(rete................

.)..1 Genera#...................................................................................................

.)..* +",,estions for e(o-e(ien(................................................................6

.).6 Ener,....................................................................................................... 6

.).6.1 Genera#...................................................................................................6

.).6.* +",,estions for e(o-e(ien(................................................................6

. istor.......................................................................................................... 7

. De8e#opment in 'ndia...................................................................................7

apter *: iterat"re e8ie................................................................................. $

.1 %ario"s tpes of M& p#ants.........................................................................$

.* Parts of ;pi(a# M& P#ant.............................................................................$

.) Merits and Demerits of M&.........................................................................$

. Man"fa(t"res in 'ndia................................................................................... 9

apter ): ;heor<Methodo#o,............................................................................ 9

apter : Ana#sis................................................................................................ 9

apter : &ase +t"d......................................................................................... 10

apter 6: &on(#"sion = emarks.......................................................................10

hapter 1: 'ntrod"(tion

$ Generalen a ne M& p#ant is p#anned or an e>istin, M& p#ant modi?ed or "p,raded4 a## the app#i(a@#e #e,a#

"irements m"st @e (onsidered. P#annin, a#so oBers the opport"nit to in-(orporate en8ironmenta# aspe(ts

o the pro(ess. /hen en8ironmenta# (riteria are in(#"ded in the p#annin, phase4 the eBe(t is espe(ia##

ne?(ia# and (ost eBe(ti8e.

fore a M& p#ant is @"i#t the ?nan(ia# aspe(ts m"st @e st"died.

e((#in, and aste-mana,ement (on(ept sho"#d a#so @e (onsidered. 't is ad8anta,eo"s to in(reasin,#

8e for (#osed-#oop ((#es4 @e(a"se reso"r(es and #and?## areas are #imited. A sstemati( approa(h is

ered @ the internationa# standard '+O 10014 hi(h pro8ides a frameork for esta@#ishin, an

8ironmenta# mana,ement sstem that (an @e (erti?ed.



& "uggestions for eco'eciencye @est time to make #on,-term and e(o-e(ient in8estments is hen a M& p#ant is @ein, ne# @"i#t or

n, "p,raded.

nsider for e>amp#e:

e8ie ,eo,raphi( #o(ations 2PG4 +G4 +%A4 &O* #a3

+t"d ener, so"r(es 2espe(ia## therma# ener,3 2EnG4 En%3

Minimie interna# tra8e# distan(es 2+G4 &O* #a3

+imp#if (on8ein, pro(esses 2or shorten them3

se ater-(onser8in, pro(esses 2re((#in,4 ashin, stations3

Emp#o asteater treatment sstems and "se re((#ed ater 2Gs(hG4 Gs(h%3 ;herma## ins"#ate a,,re,ates si#os 2EnG4 En%3

Ens"re hea#th and safe orkp#a(es 2ArG4 %G4 %%3

&are for the appearan(e of the @"i#din,s and ,ro"nds 2@"i#din, re,"#ations4 NG3

se re((#ed materia#s 2+AEF1 ,"ide#ines3

App# a (on(ept for aste mana,ement and re((#in, 2;%A4 %%+ re((#in, of resid"a# (on(rete3

( Material sourcing

(%$ )ater

(%$%$ GeneralM& p#ant re"ires ater for (on(rete prod"(tion and for (#eanin, of mi>ers and tr"(ks. Potentia# so"r(es

e man: ,ro"ndater4 e## ater4 p"@#i( ater s"pp#4 (o##e(ted rainater4 and ater from (#eanin, of

>ers and tr"(ks. ;he re#e8ant (on(essions and permits m"st @e in hand and 8a#id.

(%$%& "uggestions for eco'eciencyd"(e the (ons"mption of fresh ater to a minim"m 2see ater mana,ement4 ater re((#in,4 and

steater disposa#3. &o##e(t rainater in a separate @asin o8er5o of @asin sho"#d seep into the"ndater. ;he "se of a (ertain per(ent @ 8o#"me of re((#ed ater for the prod"(tion of desi,ned

n(rete is permissi@#e if (on?rmed @ the appropriate pre-tests.

(%& Cement

(%&%$ Generalment is a hdra"#i( @inder made of (ement (#inker4 minera# additions4 and ,ps"m to re,"#ate the settin,

e. &ertain minera# additions (arr hi,her hea8 meta# (ontent than does (#inker. ;he hea8 meta#s in these

nera# additions are not e>pe(ted to pose an en8iron-menta# risk for e>amp#e hen (on(rete is #ea(hed o"t.

(%&%& "uggestions for eco'eciencytimie transport dispat(hin,. Optimie the n"m@er and sie of #ar,er (ement si#os. Optimie de#i8er

tan(es4 transportation modes and (apa(ities. se s"ita@#e means to pre8ent the inad8ertent "se of the

on, si#o feed pipes. D"st (an @e re#eased hen a si#o is ?##ed4 as air is disp#a(ed and e>pe##ed4 #oaded ith

ment d"st. +i#o ?#ters ith po#ester-mesh ?#ter e#ements sho"#d @e insta##ed. Air (ompressors for (ement

nd#in, sho"#d @e a(o"sti(a## ins"#ated if the are too #o"d. 'n ,enera#4 ener, and ra materia# reso"r(es

n @e sa8ed in (ement prod"(tion if the M& p#ant red"(es the (ontent of Port#and (ement 2@ "sin, more

mposite (ements3 or @ "sin, minera# additions s"(h as 5 ash dire(t# in (on(rete.

note on safety:

ment is a hdra"#i( @inder. 'n the presen(e of moist"re or ater it "nder,oes an a#ka#ine rea(tion. A8oid

n (onta(t as m"(h as possi@#e. se persona# prote(ti8e e"ipment. 'f (ement ,ets in the ees it m"st @e

mediate# and thoro",h# rinsed o"t ith ater and a do(-tor sho"#d @e (ons"#ted itho"t de#a.



(%( Aggregates

(%(%$ Generalere are no spe(i?( #e,a# re"irements for a,,re,ates. 'n +iter#and4 sand and ,ra8e# are so"r(ed

(ordin, to (riteria s"(h as "a#it4 ,radin,4 and other properties. ;he (omponents and per(enta,es are a

(tion of the tpe of (on(rete @ein, prod"(ed.

,re,ates are (#assi?ed a((ordin, to their so"r(e:

er and #ake deposits

(ia# deposits

teria# from shot ro(k "arries

e(ia# a,,re,ates are "sed for spe(ia# app#i(ations. e"irements for a,,re,ates are de-?ned @ the

e8ant standards.

important (riterion for sand is "niformit. e"irements for a,,re,ates are de?ned in +'A +tandard 16*-1

d more re(ent# in the E"ropean &on(rete +tandards EN *06-14 &on(rete - Part 1: +pe(i?(ation4

rforman(e4 prod"(tion and (onformit4 and EN 1*6*04 A,,re,ates for (on(rete. ;he hand#in, and stora,e of

,re,ates (an re"ire spe(ia# meas"res re,ardin, (#ean#iness4 se,re,ation4 d"st4 and noise. D"st (an @e a

san(e espe(ia## in the s"mmer and near residentia# areas. Noise emissions (an @e parti("#ar# a("te hen8e# is d"mped into meta# si#os or @ins.

(%(%& "uggestions for eco'eciencye so"r(in, of a,,re,ates (an @e optimied to red"(e en8ironmenta# impa(t. ;ransport distan(es and modes

transport (an @e impro8ed @oth @eteen the a,,re,ates so"r(e and M& p#ant and ithin the M& p#ant

e itse#f. ;he a8oidan(e of intermediate sto(kpi#in, "s"a## ("ts (osts 2see &hapter 94 ;ransport4 and 9.)4

,,estions for e(o-e(ien(3 and oBers en8ironmenta# ad8anta,es 2red"(in, ener, (ons"mption and

issions3. ;h"s ne M& p#ants sho"#d in(#"de s"(ient# #ar,e si#os. 'ns"#atin, a,,re,ates si#os marked#

s ener, (ons"mption for heatin, in the inter. D"st de8e#opment on the p#ant site (an @e red"(ed @

ink#in, ater and @ other a((epted pra(ti(es. Feed @ins (an @e #ined ith an e#astomeri( or po#meri(

m@rane to dampen the noise of #oadin,.

(%* Recycled construction materials +secondary construction materialspreser8e reso"r(es e stri8e for (#osed-#oop ((#es. ;his means that H(onstr"(tion asteH or demo#ition

teria# sho"#d @e (o##e(ted4 sorted4 and re"sed to prod"(e ne (onstr"(tion materia#s. ;his pra(ti(e i##

ntin"e to ,ro in importan(e for en8ironmenta# and e(onomi( reasons and @e(a"se reso"r(es and #and?##

as are #imited. For more information see the G"ide#ines for re((#in, minera# demo#ition materia#s4 +AEF

973 and the A%* I"a#it (erti?(ation for re((#ed (onstr"(tion materia#s.

(%- Mineral additions, including .y ash, added directly to concrete

(%-%$ Generalash4 (#assi?ed as a minera# addition4 is a @-prod"(t of f"rna(es in (oa#-?red poer p#ants. F# ash ma @e

ded to (on(rete to in(rease the ?nes (ontent or to a(hie8e spe(ia# (hara(teristi(s. efer to appendi> 6 of

hand@ook He(ommendations for the import and "se of 5 ash and @#ast-f"rna(e s#a, in the prod"(tion of

#din, materia#s4H +AEF4 J"# 1997.

(%-%& "uggestions for eco'eciencyme 5 ash has a hi,her hea8 meta# (ontent than does (ement. ;he hea8 meta#s in 5 ash are not

pe(ted to pose an en8ironmenta# risk for e>amp#e @ #ea(hin, o"t of the (on(rete. ;he (riti(a# iss"e here is

amo"nt of hea8 meta#s that (an #ea(h o"t d"rin, the ser-8i(e #ife of a str"(t"re and afterards 2see +'A

164 En8ironmenta# Aspe(ts of &on(rete3. For additiona# s",,estions see +e(tion *.*.) 2&ement3.



(%/ Energy

(%/%$ Generalst M& p#ants re"ire e#e(tri(it to poer (on8eors and mi>er2s34 heatin, oi# for heatin, @"i#din,s and the

,re,ates4 and diese# f"e# for the tr"(ks and mo@i#e e"ipment. ;he (ons"mption of e#e(tri(a# poer

(t"ates thro",ho"t the da dependin, on prod"(tion intensit. eatin, oi# is @"rned on# for a fe months

inter.

(%/%& "uggestions for eco'eciencyE#e(tri(a# poer

e#e(tro-ma,neti( (ons"mers s"(h as e#e(tri( motors re"ire not on# orkin, ener, @"t a#so rea(ti8e

er,. ea(ti8e ("rrent prod"(es no armth and performs no me(hani(a# ork it ser8es mere# to esta@#ish

,neti( ?e#ds. 't is not (ons"med4 @"t 5os @a(k to the poer p#ant. ;h"s it tra8e#s @a(k and forth @eteen

od"(er and (ons"mer. Poer prod"(ers donKt #ike rea(ti8e ("rrent @e(a"se it @"rdens the poer #ines4

nsformers4 and ,enerators. ;h"s poer (ompanies (har,e hi,h rates for rea(ti8e ("rrent hen the de,ree

effi(ien( 2(osine L3 fa##s @e#o a (ertain rate 2appro>. $3. ea(ti8e ("rrent (an @e (ompensated for @

ans of the proper e"ipment on site. /ith s"(h sstems4 the rea(ti8e ("rrent os(i##ates on# @eteen the

er and the (ompensation e"ipment. ;his e"ipment sho"#d th"s e#iminate e>tra fees for rea(ti8e ("rrent.

ether this a(t"a## orks m"st @e 8eri?ed ith ea(h in8oi(e. 'f (har,es appear for rea(ti8e ("rrent4 the

(ti8e ("rrent (ompensation sstem m"st @e (he(ked.

er rates are stron,# re#ated to peak #oads4 @e(a"se the poer #ines m"st @e desi,ned to hand#e the

aks. Poer (ompanies prefer "niform ener, (ons"mption. &ons"mption d"rin, peaks (an "i(k# r"n "p

sts si,ni?(ant#4 so one ,oa# m"st @e to a8oid peak "se. ;his (an @e a(hie8ed @ t"rnin, oB non-mandator

"ipment d"rin, peak times. E8en sh"tdons for min"tes (an @e eBe(ti8e. &onsider the fo##oin,:

"rn oB heatin,

"rn oB #oadin, p"mps

8oid ?##in, si#os d"rin, (on(rete prod"(tion

e optimiation potentia# is ,reat on an M& prod"(tion site ith a ,ra8e# p#ant @e(a"se prod"(tion (an

i(a## @e interr"pted for a fe min"tes ith no dra@a(k. ;he opport"nities in(#"de:

;"rn oB (r"shers 2mere# stoppin, materia# feed is often s"(ient3 d"rin, (on(rete prod"(tion or si#o?##in,

;"rn oB s#"d,e p"mps and s#"d,e pressin, e"ipment

ta@#e (omp"ter-(ontro##ed optimiation sstems are a8ai#a@#e. ;hese often pa @a(k their (ost ithin a fenths.

th the dere,"#ation of the poer ind"str4 #on,-term @a#an(ed (ons"mption is @e(omin, (riti(a# tohie8in, #oer rates for poer. &ons"mption (an @e moderated @ formin, poo#s of "sers ith diBerentns"mption times. Or @ a (#a"se in the s"pp# a,reement that a##os the poer (ompan to interr"pt thepp# if ne(essar d"rin, times s"(h as midda4 ear# e8enin,4 and (o#d inter das. +"(h poer sa8in,sas @ene?t the en8ironment too @e(a"se distri@"tion #osses are #oer and #ess infrastr"(t"re is re"ireder poer p#ants and distri@"tion stations3.

eatin, ener,

(a"se the @"#k of the heatin, ener, is needed on# on a fe (o#d das4 options for optimiation are

ited. ;he in8estment (ost for a#ternati8e ener, sstems is often prohi@iti8e# hi,h. ;he @i,,est sa8in,s

n @e rea#ied @ armin, a,,re,ates no more than ne(essar.



* 0istory

ad mi> (on(rete as ?rst patented in German in 190) its (ommer(ia# de#i8er as not possi@#e d"ea(k of transportation needs. ;he ?rst (ommer(ia# de#i8er as made in Ca#timore +A in 191).;he ?rst re8o#8in, dr"m tpe

transit mi>er as de8e#oped in 19*6. In 19)14 a M& p#ant as set "p for the (onstr"(tion ofeathro airport4 ondon.

'n the mid 90Ks there ere a@o"t 1100 M& p#ants in ! (ons"min, a@o"t of (ement

prod"(ed in that (o"ntr. 'n E"rope in 1997 there ere $0 (ompanies prod"(in, a tota# of )0mi##ion ("se(s of M&. In +A @ 19904 aro"nd 7* 2more than *<)rd3 of (ement prod"(ed as@ein, "sed @ 8ario"s M& p#ants.

'n Japan ?rst M& p#ant as set "p in 199. C 199* Japan as the then #ar,est prod"(er of M&4prod"(in, 1$196 mi##ion tons of (on(rete. 'n man other (o"ntries of the or#d in(#"din, some ofthe de8e#opin, (o"ntries #ike ;aian4 Ma#asia et(4 M& ind"str is e## de8e#oped.

- 1e2elo3ment in India

'n 'ndia M& as ?rst initia## as "sed in 190 d"rin, the (onstr"(tion sites of Dams #ike

ChakraNan,a#4 !ona. At the (onstr"(tion the transportation of (on(rete is done @ either man"a##or me(hani(a## "sin, ropeas =@"(kets or (on8eor sstems. M& at P"ne in the ear 1991.oe8er4 d"e to 8ario"s pit fa##s and pro@#ems this p#ant did not s"r8i8e for #on, and as (#osed./ithin a (o"p#e of months in the ear 199)4 to M& p#ants ere set "p in M"m@ai to(ommer(ia## se## M& to the proje(ts here the ere insta##ed. nite(h &onstr"(tion set "p onep#ant at iranandani &omp#e> and Asso(iated &ement &ompanies set "p another p#ant at CharatDiamond Co"rse &ommer(ia# &omp#e>.

The first concrete mixed off site and delivered to a construction site was effectively done in Baltimore, United States in 1913

just before the First orld ar!

The increasin" availability of s#ecial trans#ort vehicles, su##lied by the new and fast "rowin" automobile industry, #layed a

#ositive role in the develo#ment of $%& industry!

hapter *: iterat"re e8ie

$ 4arious ty3es of RMC 3lants

F"## a"tomati( (on(rete @at(hin, and ;in-+haft Mi>in, P#ant 2EA-+eries3.

F"## a"tomati( (on(rete @at(hin, and ;in-+haft Mi>in, P#ant 2A;+-+eries3.



F"## a"tomati( (on(rete @at(hin, and ;in-+haft Mi>in, P#ant 2;+-+eries3.

AP +eries Cat(hin, and Mi>in, P#ant.

'n#ine +eries Cat(hin, and Mi>in, P#ant.

F"## a"tomati( (on(rete @at(hin, and Mi>in, P#ant 2A-+eries3.

D +eries Cat(hin, and Mi>in, P#ant.

D-'n#ine +eries Cat(hin, and Mi>in, P#ant.

& Parts of Ty3ical RMC Plant

Cat(hin, p#ant

+i#os

Ce#t &on8eor

;ransit mi>er

( Merits and 1emerits of RMC

Merits of Ready'Mi5 Concrete

centrali(ed concrete batchin" #lant can serve a wide area! Site %ix truc)s can serve a

"er area includin" remote locations that standard truc)s cannot!

he #lants are located in areas (oned for industrial use, and yet the delivery truc)s can

vice residential districts or inner cities! Site %ix truc)s have the same ca#abilities!etter *uality concrete is #roduced! Site %ix can #roduce hi"her com#ression stren"th

h less water than standard batchin" methods!

imination of stora"e s#ace for basic materials at site! Standard Batch #lant need more

m for their o#eration than Site %ix truc)s!imination of #rocurement hirin" of #lant and machinery

asta"e of basic materials is avoided! ith a Site %ix truc), there is less waste and wash

This is better for the environment!

abour associated with #roduction of concrete is eliminated! .t ta)es more #eo#le to

rate a standard batch #lant than a %obile %ix truc)!

me re*uired is "reatly reduced! /ne %obile mix truc) can #roduce 0 yards of concreteminutes! .t can also o#erate continuously without needin" to be moved away from

#um# truc)! /ne %obile mix truc) can #roduce 2 yards of concrete in an 0 hour ft! here standard truc)s must sto# and move off the #um# to brin" in the next truc)!

to deliver the same amount of concrete it will ta)e nearly 3 more hours with andard truc)! This will increase labour cost!

1emerits of Ready'Mi5 Concrete

he materials are batched at a central #lant, and the mixin" be"ins at that #lant, so the

vellin" time from the #lant to the site is critical over lon"er distances! Some sites are

too far away, thou"h this is usually a commercial rather than technical issue!eneration of additional road traffic6 furthermore, access roads, and site access has to be

e to carry the wei"ht of the truc) and load! &oncrete is a##rox! 7!8tonne #er m!his #roblem can be overcome by utili(in" so:called ;minimix; com#anies, usin" smaller

ca#acity mixers able to access more restricted sites!oncrete;s limited time s#an between mixin" and "oin":off means that ready:mix should

#laced within 1 minutes of batchin" at the #lant!odern additives modify #recisely that time s#an however, the amount of additive added

he mix is very im#ortant!



* Manufactures in India

APOO 'NFA;E& P%;. ;D. ...Mehsana

N'!AN; ENG'NEE'NG /O!+.......... Ahmeda@ad

N'%E+A &ON+;&;'ON MA&'NE = EI'PMEN; ....P"ne

MA&ON+ Ahmeda@ad

A!ONA ENG'NEE'NG P%;. ;D. ......ardar

hapter ): ;heor<Methodo#o,

hapter : Ana#sis

hapter : &ase +t"d

hapter 6: &on(#"sion = emarks



Concrete Q a,,re,ates R @indin, a,ent 2Port#and (ement4 ater3

@e (onsidered ener,-e(ient in the nited +tates4 a motor m"st meet NEMA performan(e

teria. ;he &onsorti"m for Ener, E(ien( 2&EE3 has des(ri@ed the e8o#"tion of standards

ener,-e(ient motors in the nited +tates4 hi(h is he#pf"# for "nderstandin, the

(ientT motor nomen(#at"re 2&EE4 *0073:



MA ener,-e(ient motor standard 2NEMA EE3 as de8e#oped in the mid-19$0s

EMA4 *00*34 and in 199* the Ener, Po#i( A(t 2EPA&;3 re"ired that man motors

mp# ith NEMA Sener,-e(ientT ratin,s if so#d in the nited +tates.

&EE Premi"m E(ien( &riteria spe(i?(ation as desi,ned in 1996 to promote

tors ith hi,her e(ien( #e8e#s than EPA&; re"ired.

*0014 the NEMA Premi"m E(ien( E#e(tri( Motor spe(i?(ation as de8e#oped to

dress (onf"sion ith respe(t to hat (onstit"ted the most e(ient motors a8ai#a@#e in

market. ;his spe(i?(ation as de8e#oped @ NEMA4 &EE4 and other stakeho#ders4

d as adapted from the &EE 1996 (riteria. 't ("rrent# ser8es as the @en(hmark for

mi"m ener,-e(ient motors. NEMA Premi"mU a#so denotes a @rand name for

tors hi(h meet this spe(i?(ation. +pe(i?(a##4 this spe(i?(ation (o8ers motors ith

fo##oin, attri@"tes:

peed: *-4 -4 and 6-po#e

ie: 1 to 00 horsepoer 2hp3

Desi,n: NEMA A and C

n(#os"re tpe: open and (#osed

%o#ta,e: #o and medi"m 8o#ta,e

#ass: ,enera#4 de?nite4 and spe(ia#-p"rpose

e (hoi(e of hether or not to insta## a premi"m e(ien( motor stron,# depends on 213 motor

eratin, (onditions4 and 2*3 the #ife ((#e (osts asso(iated ith the in8estment. 'n ,enera#4

emi"m e(ien( motors are most e(onomi(a## attra(ti8e hen rep#a(in, motors ith an ann"a#

eration e>(eedin, *4000 ho"rs<ear. +oftare too#s s"(h as MotorMasterR 2see ;oo#s for +e#f-

sessment in Appendi> &3 (an he#p identif attra(ti8e app#i(ations of premi"m e(ien( motors

sed on spe(i?( p#ant (onditions. Gi8en the "i(k pa@a(k time4 it "s"a## makes sense to @" the

st e(ient motor a8ai#a@#e.

metimes4 rep#a(in, an operatin, motor ith a premi"m e(ien( mode# ma ha8e a short

@a(k period. A((ordin, to data from the &opper De8e#opment Asso(iation4 the "p,rade to

h-e(ien( motors4 as (ompared to motors that a(hie8e the minim"m e(ien( as spe(i?ed

EPA&;4 (an ha8e pa@a(ks of #ess than 1 months for 0 hp motors. Pa@a(k times i## 8ar

sed on sie4 #oad fa(tor4 r"nnin, time4 #o(a# ener, (osts4 and a8ai#a@#e re@ates and<or in(enti8es.

wind versus replace. 'n some (ases4 it ma @e (ost-



e(ti8e to reind an e>istin, ener,-e(ient motor

tead of p"r(hasin, a ne one. As a r"#e of th"m@4

en reindin, (osts e>(eed 60 of the (osts of a

motor4 p"r(hasin, the ne motor is a @etter

oi(e 2MDM4 *0073. 'f o" do de(ide to reind4

oose a motor ser8i(e (enter that fo##os @est-

(ti(e motor reindin, standards in order to

nimie potentia# e(ien( #osses. An AN+'-appro8ed re(ommended @est-pra(ti(e standard has

en oBered @ the E#e(tri( Apparat"s +er8i(e Asso(iation 2EA+A3 for the repair and reindin, of

tors 2EA+A4 *0063. /hen @est reindin, pra(ti(es are imp#emented4 e(ien( #osses are

i(a## #ess than 0. to 1 2EA+A4 *00)3. oe8er4 poor "a#it reinds ma res"#t in #ar,er

(ien( #osses4 so it is important to ask hether the motor ser8i(e (enter fo##os EA+A @est

(ti(e standards 2EA+A4 *0063.

a rule of thum#, 8hen re8inding

sts e5ceed /9: of the costs of a

8 motor, 3urchasing the ne8 motor

a #etter choice%

Com3ressed Air

mpressed air is the most e>pensi8e form of ener, "sed in an ind"stria# p#ant @e(a"se of its

or e(ien(4 tpi(a## a@o"t 10 from start to end "se. 'f (ompressed air is "sed4 it sho"#d @e

the minim"m "antit for the shortest possi@#e time4 and it sho"#d @e (onstant# monitored and

ei,hed a,ainst a#ternati8es. Man ener,-red"(tion opport"nities in (ompressed air sstems

not prohi@iti8e# e>pensi8e4 and pa@a(k periods for some are e>treme# short4 often #ess

n one ear.

m3ressor ;acts



re(ei8ers (an @e emp#oed near hi,h-demand areas to pro8ide a s"pp# @"Ber to meet

ort-term demand spikes that (an e>(eed norma# (ompressor (apa(it. 'n this a4 re"ired

ine (ompressors ma @e red"(ed.

#tip#e-sta,e (ompressors theoreti(a## operate more e(ient# than sin,#e-sta,e

mpressors. ep#a(in, sin,#e sta,e (ompressors ith to-sta,e (ompressors tpi(a##

8ides a pa@a(k period of * ears or #ess.

n m"#ti-sta,e (ompressors sa8e ener, @ (oo#in, the air @eteen sta,es4 red"(in, the

"me and ork re"ired to (ompress the air.

n, m"#tip#e sma##er (ompressors instead of one #ar,e (ompressor (an sa8e ener, as e##.

,e (ompressors (ons"me more e#e(tri(it hen the are "n#oaded than do m"#tip#e sma##er

mpressors ith simi#ar o8era## (apa(it.

ana#sis of (ase st"dies aro"nd the (o"ntr shos an a8era,e pa@a(k period of a@o"t 1.*

ars.

e fo##oin, @"##ets s"mmarie (ompressed air pro@#ems and maintenan(e so#"tions:

cked pipeline flters increase pressure drop. !eep the (ompressor and inter(oo#in,

fa(es (#ean and fo"#-free @ inspe(tin, and periodi(a## (#eanin, ?#ters. +eek ?#ters

h j"st a 1 po"nd per s"are in(h 2psi3 press"re drop. ;he pa@a(k period for ?#ter

anin, is "s"a## "nder to ears. Fi>in, improper# operatin, ?#ters i## a#so pre8ent

ntaminants from enterin, into too#s4 hi(h (a"ses them to ear o"t premat"re#.

nera##4 hen press"re drop e>(eeds * to ) psi,4 rep#a(e the parti("#ate and #"@ri(ant

mo8a# e#ements. 'nspe(t a## e#ements at #east ann"a##. A#so4 (onsider addin, ?#ters in

ra##e# to de(rease press"re drop. E>pe(t a * red"(tion of ann"a# ener, (ons"mption

(ompressed air sstems hen ?#ters are (han,ed fre"ent#.

or motor cooling (an in(rease motor temperat"re and indin, resistan(e4 shortenin,

tor #ife and in(reasin, ener, (ons"mption. !eep motors and (ompressors proper#

ri(ated and (#eaned. +amp#e and ana#e (ompressor #"@ri(ant e8er 1000 ho"rs and

s"re that it is at the proper #e8e#. 'n addition to ener, sa8in,s4 this maintenan(e (an

p a8oid sstem (orrosion and de,radation.

pect ans and water pumps re,"#ar# to ens"re proper performan(e.

pect drain traps periodi(a## to ens"re the are not st"(k in either the open or (#osed



sition and are (#ean. +ome "sers #ea8e a"tomati( (ondensate traps partia## open at a##

es to a##o for (onstant drainin, hoe8er4 this pra(ti(e astes s"@stantia# amo"nts of

er, and sho"#d ne8er @e imp#emented. 'nstead4 insta## simp#e press"re-dri8en 8a#8es.

an and repair ma#f"n(tionin, traps instead of #ea8in, them open. +ome a"tomati(

ins or 8a#8es do not aste air4 s"(h as those that open hen (ondensate is present.

(ordin, to 8endors4 inspe(tin, and maintainin, drains tpi(a## has a pa@a(k period

ess than to ears.

intain the coolers on the (ompressor and the after(oo#er to ens"re that the drer ,ets

#oest possi@#e in#et temperat"re.

sin, (ompressors ith @e#ts4 check the belts for ear and adj"st them. A ,ood r"#e of

m@ is to adj"st them e8er 00 ho"rs of operation.

eck water cooling systems for ater "a#it 2p and tota# disso#8ed so#ids34 5o4 and

mperat"re. &#ean and rep#a(e ?#ters and heat e>(han,ers as s",,ested @ the

n"fa(t"rer.

nimie leaks 2see a#so eaks se(tion4 @e#o3.

eciy pressure regulators that (#ose hen fai#in,.

p#i(ations re"irin, (ompressed air sho"#d @e checked or e"cessive pressure4

ration4 or 8o#"me. ;he sho"#d @e re,"#ated4 either @ prod"(tion #ine se(tionin, or @

ss"re re,"#ators on the e"ipment itse#f. ;oo#s not re"ired to operate at ma>im"m

tem press"re sho"#d "se a "a#it press"re re,"#ator4 sin(e poor "a#it re,"#ators tend

drift and #ose more air. Otherise4 the "nre,"#ated too#s operate at ma>im"m sstem

ss"re at a## times and aste e>(ess ener,. +stem press"res operatin, too hi,h a#so

"#t in shorter too# #ife and hi,her maintenan(e (osts.

nitor (ompressed air "se. As ith maintenan(e4 proper monitorin, of (ompressed air sstems

n sa8e ener, and mone. Proper monitorin, in(#"des the fo##oin,:

ss"re ,a",es on ea(h re(ei8er or main @ran(h #ine4 and diBerentia# ,a",es a(ross

ers and ?#ters. ;emperat"re ,a",es a(ross the (ompressor and its (oo#in, sstem to

e(t fo"#in, and @#o(ka,es.

meters to meas"re the "antit of air "sed.

point temperat"re ,a",es to monitor air drer eBe(ti8eness.

oatt-ho"r meters and ho"rs-r"n meters on the (ompressor dri8e.







other simp#e a to identif #eaks is @

rformin, a @#eed don test 2Cane4 *0113. 'n order

(ond"(t the test4 the p#ant air sstem is @ro",ht to

press"re and then sh"t don. C re(ordin, the

tem press"re hi#e (ompressed air is not "sed

here in the p#ant4 an press"re #osses (an @e

ri@"ted to e>istin, #eaks.

e @est a to dete(t #eaks is to "se an "#trasoni( a(o"sti( dete(tor4 hi(h (an re(o,nie the

h-fre"en( hissin, so"nds asso(iated ith air #eaks. After identifin, them4 #eaks sho"#d @e

(ked4 repaired4 and 8eri?ed. eak dete(tion and (orre(tion pro,rams sho"#d @e on,oin,

orts.



ntrols% ;he tota# air re"irement is the s"m of the a8era,e air (ons"mption for ea(h too# on

sstem4 so a (ontro# strate, sho"#d fo("s on sh"ttin, oB "nneeded too#s. ;his (an mean

"ttin, oB (ompressors or not t"rnin, on additiona# (ompressors "nti# needed. A## (ompressors

t are on sho"#d @e r"nnin, at f"## #oad4 e>(ept for one4 hi(h sho"#d hand#e trim d"t.

determine proper (ontro# sstems4 assess (ompressed air re"irements o8er time4 esta@#ishin,

oad pro?#e. /hen demand is #ess than peak4 the most e(ient strate, is to "se m"#tip#e

a##er (ompressors ith se"en(in, (ontro#s. Fa(i#ities ith a 5at #oad pro?#e (an "se simp#er

ntro# strate,ies.

ntro# #oop positionin, is a#so important red"(in, and (ontro##in, the sstem press"re

nstream of the primar re(ei8er (an red"(e ener, (ons"mption "p to 10 to 1*. %ario"s

ntro# tpes e>ist:

rt#stop 2on<oB3 is the simp#est (ontro# strate, and (an @e app#ied to sma##

ipro(atin, or rotar s(re (ompressors. +tart<stop (ontro#s t"rn the motor dri8in, the

mpressor on or oB in response to the ma(hineKs dis(har,e press"re. ;hese (ontro#s are

ed for app#i(ations ith 8er #o d"t ((#es. App#i(ations ith fre"ent ((#in, i##

"se the motor to o8erheat. ;pi(a# pa@a(k period for start<stop (ontro#s is one to to

ars.

ad#unload control4 or constant speed control% a##os the motor to r"n (ontin"o"s# @"t

oads the (ompressor hen the dis(har,e press"re is ade"ate. 'n most (ases4 "n#oaded

ar s(re (ompressors sti## (ons"me 1 to ) of f"##-#oad poer hen f"##

oaded4 hi#e de#i8erin, no "sef"# ork. ;herefore4 #oad<"n#oad (ontro#s (an @e

(ient and re"ire amp#e primar re(ei8er 8o#"me.

dulating or throttling controls a##o the o"tp"t of a (ompressor to @e 8aried to meet

re"irements @ (#osin, don the in#et 8a#8e and restri(tin, in#et air to the

mpressor. ;hrott#in, (ontro#s are app#ied to (entrif",a# and rotar s(re (ompressors.

an,in, the (ompressor (ontro# to a 8aria@#e speed (ontro# (an sa8e "p to $ of

(tri(it and e#e(tri(it (ost per ear.

lti&step or part&load controls (an operate in to or more partia## #oaded (onditions.



tp"t press"res (an @e (#ose# (ontro##ed itho"t re"irin, the (ompressor to start<stop

oad<"n#oad.

stem controls ork on m"#tip#e (ompressors. +in,#e master se"en(in, sstem (ontro#s

e indi8id"a# (ompressor (apa(ities on and oVine in response to monitored sstem

ss"re demand and sh"t don an (ompressors r"nnin, "nne(essari#. +stem (ontro#s

m"#tip#e (ompressors tpi(a## oBer a hi,her e(ien( than indi8id"a# (ompressor

ntro#s.

o3erly si<e regulators% e,"#ators (an pro8ide the #ar,est ener, sa8in,s in (ompressed air

tems. C proper# siin, re,"#ators4 (ompressed air that is otherise asted as e>(ess air i##

sa8ed. +pe(if press"re re,"#ators that (#ose hen fai#in,.

e 3i3e diameter correctly% 'nade"ate pipe siin, (an (a"se press"re #osses4 in(rease #eaks4

d in(rease ,eneratin, (osts. Pipes m"st @e sied (orre(t# for optima# performan(e or resied

?t the ("rrent (ompressor sstem. 'n(reasin, pipe diameter tpi(a## red"(es ann"a# ener,

ns"mption @ ).

3lement system im3ro2ements% Addin, additiona# (ompressors sho"#d @e (onsidered on#

er a (omp#ete sstem e8a#"ation. 'mp#ementin, some of the meas"res dis("ssed in this se(tion

n red"(e air demand (onsidera@#4 ne,atin, the need to p"r(hase additiona# (ompressors. ;he

mpressed Air &ha##en,e U oBers free e@-@ased ,"idan(e for se#e(tin, the ri,ht inte,rated

8i(e pro8ider4 as e## as ,"ide#ines de?nin, a#k-thro",h e8a#"ations4 sstem assessments4

d f"## instr"mented sstem a"dits.

co2er heat for 8ater 3reheating% As m"(h as $0 to 9) of the e#e(tri(a# ener, "sed @ an

"stria# air (ompressor is (on8erted into heat. 'n man (ases4 a heat re(o8er "nit (an re(o8er

to 90 of the a8ai#a@#e therma# ener, for the fo##oin, app#i(ations:

a(e heatin,

"stria# pro(ess heatin,

ter heatin,

ke"p air heatin,

http://www.compressedairchallenge.org/







#er make"p ater preheatin,

"stria# drin,

@a(k periods are tpi(a## #ess than one ear. 't is estimated that appro>imate# 0 kCt"<ho"r

ener, is a8ai#a@#e for ea(h 100 ("@i( foot per min"te of (apa(it 2at f"## #oad3. Note that heat

o8er for spa(e heatin, is not as (ommon ith ater-(oo#ed (ompressors @e(a"se an e>tra

,e of heat e>(han,e is re"ired and the temperat"re of the a8ai#a@#e heat is #oer.

ot )ater and "team "ystems

t ater and steam is "sed for man ind"stria# app#i(ations. 'n the (on(rete ind"str4 @oi#ers are

ed to heat @at(hin, ater d"rin, (o#d eather4 and heat the a,,re,ates hen needed. 'n the

(ast<prestressed ind"str si,ni?(ant amo"nts of steam are "sed to a((e#erate the ("rin,

o(ess. ;he sie and "se of modern sstems 8ar ,reat# hoe8er4 steam sstems do fo##o a

i(a# pattern4 as i##"strated in Fi,"re 7. ;reated (o#d feed ater is fed to the @oi#er4 here it is

ated to form steam. &hemi(a# treatment of the feed ater remo8es man imp"rities that o"#d

erise (o##e(t on @oi#er a##s4 @"t some remain4 so the ater is periodi(a## p"r,ed from the

#er in a pro(ess knon as blowdown. ;he ,enerated steam tra8e#s a#on, distri@"tion pipes to

pro(ess here the heat i## @e "sed. 'f the pro(ess re"ires #oer press"re steam4 the steam

m the @oi#er ma @e passed thro",h a press"re red"(tion 8a#8e @efore ?na# "se. As the steam

"sed to heat pro(esses4 and e8en as it tra8e#s thro",h the distri@"tion sstem to ,et there4 the

am (oo#s and some is (ondensed. ;his (ondensate is remo8ed @ a steam trap4 hi(h passes

(ondensate thro",h @"t @#o(ks passa,e of the steam. ;he (ondensate (an @e re(ir("#ated to

@oi#er4 th"s re(o8erin, some heat and red"(in, the need for fresh treated feed ater. ;he

o8er of (ondensate and @#odon a#so red"(es the (osts of @oi#er feed ater treatment.



;he most important

"stria# app#i(ations for steam are:

(ess heatin,4

in,4

n(entratin,4

am (ra(kin,4

ti##ation4 and

8in, ma(hiner s"(h as (ompressors.

ate8er the "se or the so"r(e of the hot ater or steam4 e(ien( impro8ements in steam

neration4 distri@"tion4 and end "se are possi@#e. A((ordin, to the .+. DOE4 a tpi(a#

"stria# steam sstem assessment (an identif potentia# ener, "se and (ost sa8in,s of 10 to

per ear 2.+. DOE4 *006@3.

ke a sstem approa(h in e8a#"atin, steam sstems. First4 identif here and ho hot ater

d steam is "sed and then identif the e(ien(ies ith hi(h it is "sed4 @e(a"se often this (an

"#t in the #ar,est sa8in,s.

(a"se steam4 #ike an other se(ondar ener, (arrier4 is e>pensi8e to prod"(e and s"pp#4 its

e sho"#d @e (aref"## (onsidered and e8a#"ated a,ainst other options. Often steam is ,enerated

hi,her press"res than needed or in #ar,er 8o#"mes than needed at a parti("#ar time. ;hese



(ien(ies ma #ead steam sstems to #et don steam to a #oer press"re or to 8ent it to the

mosphere. +o e8a#"ate the steam sstem on the "se of appropriate press"re #e8e#s and

d"(tion s(hed"#es.

is not possi@#e to red"(e the steam ,eneration press"re4 it ma sti## @e possi@#e to re(o8er the

er, thro",h a t"r@o e>pander or @a(k-press"re steam t"r@ine. Man sstems ma prod"(e

am at hi,her press"res4 to a##o for the e(ient (o,eneration of poer and heat thro",h the

e of @a(k-press"re t"r@ines. E>(ess steam ,eneration (an @e red"(ed thro",h impro8ed pro(ess

e,ration and impro8ed mana,ement of steam 5os in the ind"str.

e norma# rep#a(ement in8estment ((#e mi,ht oBer opport"nities to (han,e to more ener,-

(ient steam sstems.

/%$ oiler energy eciency measures

e @oi#er ener, e(ien( meas"res presented @e#o fo("s primari# on impro8ed pro(ess

ntro#4 red"(ed heat #oss4 and impro8ed heat re(o8er. /hen ne @oi#er sstems are needed4

sho"#d @e desi,ned and insta##ed in a ("stom (on?,"ration that meets a parti("#ar p#antKs

eds. Pre-desi,ned @oi#ers often (annot @e ?ne-t"ned to meet the "ni"e steam ,eneration and

tri@"tion sstem re"irements of a spe(i?( p#ant in the most e(ient manner.

ntrol #oiler 3rocesses% F#"e ,as monitors maintain optim"m 5ame temperat"re and monitor

@on mono>ide 2&O34 o>,en4 and smoke. ;he o>,en (ontent of the e>ha"st ,as is a

m@ination of e>(ess air 2hi(h is de#i@erate# introd"(ed to impro8e safet or red"(e

issions3 and air in?#tration. C (om@inin, an o>,en monitor ith an intake air5o monitor4

s possi@#e to dete(t e8en sma## #e8e#s of air in?#tration.

ma## 1 air in?#tration i## res"#t in *0 hi,her o>,en readin,s. A hi,her &O or smoke

ntent in the e>ha"st ,as is a si,n that there is ins"(ient air to (omp#ete f"e# @"rnin,. sin, a

m@ination of &O and o>,en readin,s4 it is possi@#e to optimie the f"e#<air mi>t"re for hi,h

me temperat"re 2and th"s the @est ener, e(ien(3 and #oer air po##"tant emissions.

pi(a##4 this meas"re is ?nan(ia## attra(ti8e on# for #ar,e @oi#ers4 @e(a"se sma##er @oi#ers



en i## not make "p the initia# (apita# (ost as easi#. &ase st"dies indi(ate that the a8era,e

@a(k period for this meas"re is a@o"t 1.7 ears.

duce .ue gas =uantities using 2isual ins3ection% E>(essi8e 5"e ,as (an @e re#eased from

ks in the @oi#er and<or in the 5"e. ;hese #eaks (an red"(e the heat transferred to the steam and

rease p"mpin, re"irements. oe8er4 s"(h #eaks are easi# repaired4 sa8in, * to of the

er, former# "sed @ the @oi#er.

s meas"re diBers from 5"e ,as monitorin, in that it (onsists of a periodi( repair @ased on

"a# inspe(tion. ;he sa8in,s from this meas"re and from 5"e ,as monitorin, are not

m"#ati8e4 as the @oth address the same #osses.

duce e5cess air% /hen too m"(h e>(ess air is "sed to @"rn f"e#4 ener, is asted4 @e(a"se

(essi8e heat is transferred to the air rather than to the steam. Air s#i,ht# in e>(ess of the idea#

i(hiometri( f"e#-to-air ratio 2that is4 the amo"nt of in#et air per "nit of f"e# (om@"sted3 is

"ired for safet and to red"(e nitro,en o>ide 2NO>3 emissions4 @"t appro>imate# 1 e>(ess

is ,enera## ade"ate. Most ind"stria# @oi#ers a#read operate at 1 e>(ess air or #oer4 and

s this meas"re ma not @e ide# app#i(a@#e 2Weit4 19973. oe8er4 if a @oi#er is "sin, too

(h e>(ess air4 n"mero"s ind"stria# (ase st"dies indi(ate that the pa@a(k period for this

as"re is #ess than 1 ear.



o3erly si<e #oiler systems% Desi,nin, the @oi#er

tem to operate at the proper steam press"re (an

8e ener, @ red"(in, sta(k temperat"re4 pipin,

iation #osses4 and #eaks in steam traps. 'n a

nadian st"d of )0 @oi#er p#ants4 sa8in,s from this

as"re ran,ed from ) to $ of tota# @oi#er f"e#

ns"mption 2Grin4 *0003. &osts and sa8in,s i##

pend hea8i# on the ("rrent @oi#er sstem

iation at indi8id"a# p#ants.

3ro2e #oiler insulation% 't is possi@#e to "se ne ins"#ation materia#s4 s"(h as (erami( ?@ers4

t @oth ins"#ate @etter and ha8e a #oer heat (apa(it 2th"s a##oin, for more rapid heatin,3.

8in,s of 6 to *6 (an @e a(hie8ed if impro8ed ins"#ation is (om@ined ith impro8ed heater

("it (ontro#s. D"e to the #oer heat (apa(it of ne ins"#atin, materia#s4 the steam o"tp"t

mperat"re i## 8ar more "i(k# ith 8ariations in the heatin, e#ement temperat"re. 'mpro8ed

#er pro(ess (ontro# is therefore often re"ired in tandem ith ne ins"#ation to maintain the

sired o"tp"t temperat"re ran,e.

3lement a #oiler maintenance 3rogram% A simp#e maintenan(e pro,ram ens"res that a##

#er (omponents are operatin, at peak performan(e and (an res"#t in s"@stantia# sa8in,s. 'n the

sen(e of a ,ood maintenan(e sstem4 @"rners and (ondensate ret"rn sstems (an ear or ,et

t of adj"stment. ;hese fa(tors (an end "p (ostin, a steam sstem "p to )0 of its initia#

(ien( o8er to to three ears.

ntro# fo"#in, on the ?re side of @oi#er t"@es and s(a#in, on the ater side of @oi#ers. Fo"#in,

d s(a#in, are more of a pro@#em ith (oa#-fed @oi#ers than nat"ra# ,as or oi#-fed @oi#ers.

#ers that @"rn so#id f"e#s #ike (oa# sho"#d @e (he(ked more often @e(a"se the ha8e a hi,her

#in, tenden( than #i"id f"e# @oi#ers do. ;ests of 8ario"s &anadian @oi#ers sho that a ?re

e soot #aer of 0.0) in(hes 20.$ mm3 red"(es heat transfer @ 9.4 hi#e a 0.1$ in(h

mm3 soot #aer red"(es heat transfer @ 69 2&'PE&4 *001@3. For ater side s(a#in,4 0.0



hes 21 mm3 of @"i#d"p (an in(rease f"e# (ons"mption @ * 2&'PE&4 *001@3.

co2er .ue gas heat% eat re(o8er from 5"e ,as is often the @est opport"nit for heat

o8er in steam sstems4 as it (an @e "sed to preheat @oi#er feed ater in an e(onomier. /hi#e

s meas"re is fair# (ommon in #ar,e @oi#ers4 there is sti## room for more heat re(o8er. ;he

itin, fa(tor is that the e(onomier a## temperat"re m"st not drop @e#o the de point of

ds (ontained in the 5"e ,as 2s"(h as s"#f"ri( a(id deri8ed from s"#f"r-(ontainin, fossi# f"e#s3.

ditiona##4 this has @een a((omp#ished @ keepin, the 5"e ,ases e>itin, the e(onomier at a

mperat"re si,ni?(ant# a@o8e the a(id de point. 'n fa(t4 the e(onomier a## temperat"re is

(h more dependent on feed ater temperat"re

n on 5"e ,as temperat"re @e(a"se of the hi,h heat

nsfer (oe(ient of ater. As a res"#t4 it makes

re sense to preheat feed ater to (#ose to the a(id

point @efore it enters the e(onomier. ;his

proa(h a##os the e(onomier to @e desi,ned so

t e>itin, 5"e ,as is j"st a@o8e the a(id de point.

pi(a##4 1 of f"e# "se is sa8ed for e8er F

&3 red"(tion in e>ha"st ,as temperat"re.

turn condensate to the #oiler% e"sin, hot

ndensate in @oi#ers sa8es ener,4 red"(es the need

treated @oi#er feed ater4 and re(#aims ater at "p

100 & 2*1* F3 of sensi@#e heat.

pi(a##4 fresh feed ater m"st @e treated to remo8e

ids that mi,ht a(("m"#ate in the @oi#er th"s4

"rnin, (ondensate 2hi(h has a#read @een

ated3 to a @oi#er (an s"@stantia## red"(e the

o"nt of p"r(hased (hemi(a# re"ired to

(omp#ish this treatment. ;his meas"re (an sa8e

@stantia# ener, (osts and4 p"r(hased (hemi(a#s

sts often makes @"i#din, a ret"rn pipin, sstem



ra(ti8e. Pa@a(k period i## depend on the p#ant

o"t4 @"t (an 8ar @eteen to and three ears.

co2er #lo8do8n steam% /hen ater is @#on from a hi,h-press"re @oi#er tank4 the press"re

"(tion often prod"(es s"@stantia# amo"nts of steam. ;his steam is tpi(a## #o ,rade4 @"t (an

"sed for spa(e heatin, and feed ater preheatin,. ;he re(o8er of @#odon steam (an sa8e

o"t 1 of @oi#er f"e# "se in sma## @oi#ers. 'n addition to ener, sa8in,s4 @#odon steam

o8er ma red"(e the potentia# for (orrosion dama,e in steam sstem pipin,.

3lace old #oilers% +"@stantia# e(ien( ,ains (an often @e a(hie8ed @ rep#a(in, o#d @oi#ers

h ne4 hi,her-e(ien( mode#s. 'n parti("#ar4 rep#a(in, ine(ient (oa#-?red @oi#ers ith

"ra# ,as-?red @oi#ers is a so"nd strate, for red"(in, @oth @oi#er f"e# (osts and air po##"tant

issions.

/%& "team distri#ution system energy eciency measures

am and hot ater distri@"tion sstems are often "ite e>tensi8e and (an @e major so"r(es of

er, #osses. Ener, e(ien( impro8ements to steam distri@"tion sstems primari# fo("s on

"(in, heat #osses thro",ho"t the sstem and re(o8erin, "sef"# heat from the sstem here8er

si@#e. ;he fo##oin, meas"res are some of the most si,ni?(ant opport"nities for sa8in,

er, in ind"stria# steam distri@"tion sstems.

3ro2e distri#ution system insulation% sin, more ins"#atin, materia# or "sin, the @est tpe



ns"#ation materia# for the app#i(ation (an sa8e

er, in steam sstems. &r"(ia# fa(tors in (hoosin,

"#atin, materia# in(#"de #o therma# (ond"(ti8it4

mensiona# sta@i#it "nder temperat"re (han,e4

istan(e to ater a@sorption4 and resistan(e to

m@"stion. Other (hara(teristi(s of ins"#atin,

teria# a#so ma @e important4 dependin, on the

p#i(ation4 s"(h as to#eran(e of #ar,e temperat"re

riations4 to#eran(e of sstem 8i@rations4 and

e"ate (ompressi8e stren,th here the ins"#ation is

d @earin,. 'nd"stria# (ase st"dies indi(ate that the

@a(k period for impro8ed ins"#ation is tpi(a##

o"t one ear.

aintain distri#ution system insulation% 't is often fo"nd that after heat distri@"tion sstems

8e "nder,one some form of repair4 the ins"#ation is not rep#a(ed. 'n addition4 some tpes of

"#ation (an @e(ome @ritt#e or rot o8er time. A re,"#ar inspe(tion and maintenan(e sstem for

"#ation (an sa8e ener,.

3ro2e steam tra3s% Modern thermostati( e#ement steam traps (an red"(e ener, "se hi#e

pro8in, re#ia@i#it. ;he main e(ien( ad8anta,es are that these traps:

en hen the temperat"re is 8er (#ose to that of sat"rated steam 2ithin F or * &34

r,e non-(ondensa@#e ,ases after ea(h openin,4 and

open on start"p to a##o a fast steam sstem arm-"p.

ese traps a#so ha8e the ad8anta,e of @ein, hi,h# re#ia@#e and "sea@#e for a ran,e of steam

ss"res.

s (ommon to ?nd 1 to *0 of steam traps ma#f"n(tionin,.

aintain steam tra3s% A simp#e pro,ram of (he(kin, steam traps to ens"re that the are

eratin, proper# (an sa8e si,ni?(ant amo"nts of ener, for 8er #itt#e mone. 'n the a@sen(e



s"(h a pro,ram4 it is (ommon to ?nd 1 to *0 of steam traps in a distri@"tion sstem

#f"n(tionin,. Ener, sa8in,s from (he(kin, steam traps and fo##o-"p maintenan(e is

nser8ati8e# estimated at 10. One ind"stria# (ase st"d indi(ates a pa@a(k period of #ess

n fo"r months. A#tho",h this meas"re oBers "i(k pa@a(k4 it is often not imp#emented

(a"se maintenan(e and ener, (osts are ,enera## separate# @"d,eted. 'n addition to ener,

d (ost sa8in,s4 proper# f"n(tionin, steam traps red"(e the risk of (orrosion in the steam

tri@"tion sstem.

onitor steam tra3s% Atta(hin, a"tomated monitors to steam traps in (onj"n(tion ith a

intenan(e pro,ram (an sa8e e8en more ener, itho"t si,ni?(ant# addin, (osts. ;his

as"re is an impro8ement o8er steam trap maintenan(e a#one4 @e(a"se it ,i8es "i(ker noti(e

steam trap fai#"re and (an dete(t hen a steam trap is not performin, at peak e(ien(. ;his

ate, (an pro8ide an additiona# in ener, sa8in,s (ompared to steam trap maintenan(e

ne4 at a pa@a(k period of a@o"t one ear. +stems that (an imp#ement steam trap

intenan(e are a#so #ike# to @e a@#e to imp#ement a"tomati( monitorin,.

3air lea>s% As ith steam traps4 steam distri@"tion pipin, netorks often ha8e #eaks that (an

"ndete(ted itho"t a re,"#ar inspe(tion and maintenan(e pro,ram. ;he .+. DOE estimates

t repairin, #eaks in an ind"stria# steam distri@"tion sstem i## #ead to ener, sa8in,s of a@o"t

to 10.

co2er .ash steam% /hen a steam trap p"r,es (ondensate from a press"ried steam

tri@"tion sstem to am@ient press"re4 5ash steam is prod"(ed. ;his 5ash steam (an @e

o8ered and "sed for #o-,rade app#i(ations4 s"(h as spa(e heatin, or feed ater preheatin,.

e potentia# for this meas"re is site dependent4 as its (ost eBe(ti8eness depends on hether or

areas here #o-,rade heat is "sef"# are #o(ated (#ose to steam traps. /here feasi@#e4 this

as"re (an @e eas to imp#ement and (an sa8e (onsidera@#e amo"nts of ener,.

hillers

n(retin, at e#e8ated temperat"res (an aBe(t the properties of (on(rete. /hen the am@ient



mperat"re is hi,h4 man (on(rete fa(i#ities prod"(e (hi##ed ater to (oo# ra materia# and "se

s @at(h ater. Other methods of (on(rete pre-(oo#in, in(#"de (oo#in, mi>in, ater ith

"id nitro,en4 (oo#in, (on(rete ith i(e4 and (oo#in, (on(rete ith #i"id nitro,en 2A&'4 19913.

s se(tion fo("ses on ener, e(ien( impro8ements in (hi##ers. 'nformation on other

thods of (on(rete pre-(oo#in, (an @e fo"nd in +e(tion 6.9.6.

ere are to tpes of (hi##ers me(hani(a# (ompression and a@sorption (hi##ers. Me(hani(a#

mpression (hi##ers are (omposed of a3 an e8aporator4 @3 a (ompressor4 (3 a (ondenser4 and d3

e>pansion 8a#8e. ;he (hi##er ((#e initiates in the e8aporator4 here the #i"id refri,erant

sor@s heat from the (hi##ed ater and e8aporates. ;he refri,erant 8apor is then dran o"t of

e8aporator @ the (ompressor hi(h in(reases the 8aporsK press"re and temperat"re4 and

mpsT it into the (ondenser. 'n the (ondenser4 the refri,erant 8apor ,i8es "p heat to the (oo#ed

ter and (ondenses. ;he hi,h press"re refri,erant #i"id e>pands in the e>pansion 8a#8e and the

o#e refri,eration ((#e starts a,ain. Me(hani(a# (ompression (hi##ers are (#assi?ed @ased on

tpe of (ompressor "sed: re(ipro(atin,4 (entrif",a#4 and s(re 2.+. DOE4 *0103.

sorption (hi##ers and me(hani(a# (ompression (hi##ers (onsist of the same e8aporation and

ndensation ((#es. ;he main diBeren(e is in the a the refri,erantKs temperat"re is in(reased

the (ondensation pro(ess me(hani(a# (ompression (hi##ers emp#o a (ompressor hi#e

sorption (hi##ers "se heat 2"s"a## steam3 2.+. DOE4 *0103. A@sorption (hi##ers "se to

rkin, 5"ids a refri,erant and an a@sor@ent.

e &hi##ed /ater +stem Ana#sis ;oo# 2&/+A;3 is a softare too# pro8ided @ .+. DOE to

p ener, and p#ant mana,ers identifin, e(ien( impro8ements in (hi##er ater sstems.

e "ser is a@#e to make (han,es on e"ipment s"(h as (hi##er4 p"mps4 and toers and determine

ener, and (ost sa8in,s @ imp#ementin, these (han,es.

ere are se8era# as to impro8e the (hi##ersK e(ien( and red"(e operationa# (osts 2.+.

E4 *0103:



se chilled water temperature. ;he ener, "se in

th tpes of #i"id (hi##ers 2me(hani(a# (ompression

a@sorption (hi##ers3 in(reases as the temperat"re

Beren(e @eteen the e8aporator and the (ondenser

reases. C raisin, the (hi##ed ater temperat"re4

e8aporator temperat"re i## in(rease th"s4

(reasin, the re"ired temperat"re #ift.

duce condenser water temperature. +imi#ar#4 de(reasin, the ater temperat"re in the

ndenser i## #imit the temperat"re diBeren(e @eteen the (ondenser and the e8aporator4 th"s

(reasin, the re"ired temperat"re #ift.

ep heat transer suraces clean. eat transfer e(ien( in the (hi##er sstem (an de(rease d"e

minera# or s#"d,e @"i#t-"p on the heat transfer s"rfa(es. e,"#ar (#eanin, i## impro8e the

temKs e(ien(.



Remove trapped air rom the condenser. ;rapped air

in the (ondenser #imits the (o#d s"rfa(e e>posed to

the refri,erant. ;his (an @e o8er(ome on# ith

hi,her press"re 2and temperat"re3.

Maintain the water (ow in the condenser. C#o(ka,e of the ?#ter in the (ondenser

ater #ine 2"sed in the

majorit of (hi##ers3 i## res"#t in an in(rease in (ondenser refri,erant

temperat"re d"e to #ess

e(ient heat transfer.

)se naturally occurring cooling water. /hen o"tside temperat"re is not 8er

hi,h4 nat"ra##

o(("rrin, (oo# ater (o"#d @e "sed instead of (hi##ed ater hen a8ai#a@#e. +ee

a#so +e(tion

6.9.6.

Manage the load. P#ants ith more than to (hi##ers (an red"(e their ener, "se

@ mana,in,

the #oad (aref"## in order to o@tain (om@ined peak e(ien(. ;he "se of a

re(ipro(atin, (hi##er

in (om@ination ith a (entrif",a# (hi##er is an e>amp#e.

?n a centrifugal chiller increasing the

tem3erature of the condenser 8ater

#y &o; to (o; can im3ro2e the

systems@ eciency #y &: to (:%

*eat recovery. eat re(o8er sstems (an e>tra(t heat from the (hi##ed #i"id

that (an @e "sed

a#on, ith ener, of (ompression to arm the (ir("it ater for reheat and

(oo#in,.



)se absorption chillers. A@sorption (hi##ers (o"#d rep#a(e me(hani(a# (hi##ers to

#imit the

fa(i#itiesK e#e(tri(it "se.

Replace absorption chillers with electric drive centriugal chillers. 'n a tpi(a#

a@sorption (hi##er

1.6 Ct" of therma# ener, are re"ired to remo8e 1 Ct" of ener, from the

therma# ater.

oe8er4 on# 0.* Ct" of e#e(tri( ener, is re"ired in modern e#e(tri( dri8e

(entrif",a# (hi##ers

to remo8e 1 Ct" of ener, from the therma# ater.

+ptimie the perormance o au"iliary e,uipment. Opport"nities to impro8e the

e(ien( of the

a">i#iar e"ipment "sed in the (hi##er sstems4 s"(h as (ompressors4 p"mps4

motors4 and fans

(an @e fo"nd in the pre8io"s se(tions of the Ener, G"ide.

A more detai#ed des(ription of ener, e(ien( opport"nities in (hi##er sstems

is pro8ided @

.+. DOE 2*0103.

23Pum3s

P"mps are parti("#ar# important pie(es of motor-

dri8en e"ipment in man sma##- and medi"m-sied

p#ants. ;he are "sed e>tensi8e# to press"rie and

transport ater in (#eanin,4 ater 5"min,4 and

asteater hand#in, operations for transportin,



#i"id streams @eteen pro(esses and for (ir("#atin,

#i"ids ithin pro(esses. ;he @asi( (omponents in a

p"mp sstem are p"mps4 dri8e motors4 pipin,

netorks4 8a#8es4 and sstem (ontro#s. +ome of the

most si,ni?(ant ener, e(ien( meas"res app#i(a@#e to these (omponents and

to p"mp

sstems as a ho#e are des(ri@ed @e#o.

;ake a sstems approa(h hen assessin, p"mp ener, e(ien( impro8ement

opport"nities

ithin a fa(i#it. E8en if an indi8id"a# p"mp is operatin, e(ient#4 if it is

,eneratin, more 5o

than the sstem re"ires for a ,i8en app#i(ation4 it is astin, ener, and mone.

Assess @oth

indi8id"a# p"mp e(ien(ies and ho e## the 8ario"s p"mp sstem end "ses are

@ein, ser8ed

@ its p"mps.

A p"mpKs initia# (apita# (ost is tpi(a## on# a sma## fra(tion of its tota# #ife ((#e(osts. 'n

,enera#4 maintenan(e and ener, (osts represent @ far the most si,ni?(ant

fra(tion of a p"mpKs

tota# #ife ((#e (osts. 'n some (ases4 ener, (osts (an a((o"nt for "p to 90 of

the tota# (ost of

onin, a p"mp. +o4 hen (hoosin, p"mpin, e"ipment4 @ase o"r de(ision on

proje(ted ener,

and maintenan(e (osts rather than on initia# (apita# (osts a#one.

;he P"mp +stems MatterY pro,ram 2.p"mpsstemsmatter.or,<34 (on(ei8ed

@ the

dra"#i( 'nstit"te4 pro8ides detai#ed information on impro8in, the performan(e

of p"mp

sstems. ;he most important opport"nities for in(reasin, e(ien( are

dis("ssed @e#o.



P#a(e orn impe##ers4 espe(ia## in (a"sti( or semi-so#id app#i(ations.

'nspe(t and repair @earin,s.

ep#a(e @earin, #"@ri(ation ann"a## or semiann"a##.

'nspe(t and rep#a(e pa(kin, sea#s. A##oa@#e #eaka,e from pa(kin, sea#s is

"s"a##

@eteen * to 60 drops per min"te.

'nspe(t and rep#a(e me(hani(a# sea#s. A##oa@#e #eaka,e is tpi(a## 1 to drops

per

min"te.

ep#a(e ear rin, and impe##er. P"mp e(ien( de,rades @ 1 to 6 for

impe##ers

#ess than the ma>im"m diameter and ith in(reased ear rin, (#earan(es.

&he(k p"mp<motor a#i,nment.

'nspe(t motor (ondition4 in(#"din, the motor indin, ins"#ation.

Monitorin, of diBerentia# head and temperat"re rise a(ross p"mps 2a#so knonas

thermodnami( monitorin,3.

Distri@"tion sstem inspe(tion for s(a#in, or (ontaminant @"i#d-"p. Monitor

3um3 systems% Monitorin,4 (om@ined ith a proper maintenan(e pro,ram4 i##

he#p

dete(t p"mp sstem pro@#ems @efore the es(a#ate into major performan(e

iss"es or e"ipment

repairs. Monitorin, (an @e done man"a## on a periodi( @asis 2for e>amp#e4

performin, re,"#ar

@earin, oi# ana#ses to dete(t @earin, ear4 or "sin, infrared s(annin, to dete(t

e>(essi8e p"mp

heat34 or it (an @e performed (ontin"o"s# "sin, sensor netorks and data

ana#sis softare

2s"(h as "sin, a((e#erometers to dete(t a@norma# sstem 8i@rations3 2.+. DOE4

*006a3.



Monitorin, (an he#p keep p"mp sstems r"nnin, e(ient# @ dete(tin, sstem

@#o(ka,es4

impe##er dama,e4 inade"ate s"(tion4 (#o,,ed or ,as-?##ed p"mps or pipes4

p"mp ear4 and if

p"mp (#earan(es need to @e adj"sted.

'n ,enera#4 a ,ood p"mp monitorin, pro,ram sho"#d in(#"de the fo##oin,

aspe(ts:

/ear monitorin,.

%i@ration ana#sis.

Press"re and 5o monitorin,.

&"rrent or poer monitorin,.

Install controls% &ontro# sstems (an in(rease the ener, e(ien( of a p"mpsstem @

sh"ttin, oB p"mps a"tomati(a## hen demand is red"(ed or @ p"ttin, p"mps

on stand@ at

red"(ed #oads "nti# demand in(reases.

Pro3erly si<e 3um3s% P"mps that are o8ersied for an app#i(ation (ons"memore ener, than

ne(essar. ep#a(in, o8ersied p"mps ith proper# sied ones (an red"(e

p"mpin, sstem

e#e(tri(it "se @ 1 to *. /here peak #oads (an @e red"(ed thro",h

impro8ements to p"mp

sstem desi,n or operation 2for e>amp#e4 thro",h the "se of ho#din, tanks34

p"mp sie (an a#so



@e red"(ed. 'f a p"mp is dramati(a## o8ersied4 often its speed (an @e red"(ed

ith ,ear or @e#t

dri8es4 or ith a s#oer-speed motor. ;he tpi(a# pa@a(k period for these

strate,ies (an @e #ess

than one ear.

se multi3le 3um3s for 2aria#le loads% ;he "se of m"#tip#e p"mps insta##ed

in para##e# (an @e a

(ost-eBe(ti8e and ener,-e(ient so#"tion for p"mp sstems ith 8aria@#e #oads.

Para##e# p"mps

oBer red"ndan( and in(reased re#ia@i#it4 and (an often red"(e p"mp sstem

e#e(tri(it "se @

10 to 0 for hi,h# 8aria@#e #oads. Para##e# p"mp arran,ements often (onsist

of a #ar,e p"mp4

hi(h operates d"rin, periods of peak demand4 and a sma## 2or SponT3 p"mp4

hi(h operates

"nder norma#4 more stead-state (onditions 2.+. DOE4 *006a3. Ce(a"se the

pon p"mp is sied

for norma# sstem operation4 this (on?,"ration operates more e(ient# than a

sstem that re#ies

on a #ar,e p"mp to hand#e #oads far @e#o its optim"m (apa(it.

Consider trimming im3ellers% Impeller trimming is ma(hinin, to red"(e an

impe##erKs

diameter. ;his red"(es the ener, added @ the p"mp to the sstem 5"id.

A((ordin, to the .+.

DOE 2*006a34 one sho"#d (onsider trimmin, an impe##er hen an of these

(onditions o(("r:

Man sstem @pass 8a#8es are open4 indi(atin, that e>(ess 5o is a8ai#a@#e to

sstem

e"ipment.



E>(essi8e thrott#in, is needed to (ontro# 5o thro",h the sstem or pro(ess.

i,h #e8e#s of noise or 8i@ration indi(ate e>(essi8e 5o.

A p"mp is operatin, far from its desi,n point.

;rimmin, an impe##er is s#i,ht# #ess eBe(ti8e than @"in, a sma##er impe##er from

the p"mp

man"fa(t"rer4 @"t it (an @e "sef"# hen an impe##er at the ne>t a8ai#a@#e sma##er

sie o"#d @e

too sma## for the ,i8en p"mp #oad. ;he ener, sa8in,s asso(iated ith impe##er

trimmin, are

dependent "pon p"mp poer4 sstem 5o4 and sstem head4 @"t are ro",h#proportiona# to the

("@e of the diameter red"(tion 2.+. DOE4 *006a3. An additiona# @ene?t of

impe##er trimmin, is

a de(rease in p"mp operatin, and maintenan(e (osts.

A2oid throttling 2al2es% ;hrott#in, 8a#8es and @pass #oops are indi(ations of

o8ersied p"mps.

;he a#so indi(ate the ina@i#it of the p"mp sstem desi,n to a((ommodate #oad

8ariations

e(ient#4 so the sho"#d a#as @e a8oided. P"mp demand red"(tion4 (ontro#s4

impe##er

trimmin,4 and m"#tip#e p"mp strate,ies 2a## pre8io"s# dis("ssed3 are preferred

o8er thrott#in,

8a#8es.

Re3lace dri2e #elts% A((ordin, to ind"stria# p"mp in8entor data4 "p to of

p"mps are

e"ipped ith %-@e#t dri8es. Man of these %-@e#t dri8es (an @e rep#a(ed ith

dire(t (o"p#in,s4

hi(h are estimated to #ead to ener, sa8in,s of a@o"t 1.



Pro3erly si<e 3i3es% Pipes that are too sma## for the re"ired 5o 8e#o(it (an

si,ni?(ant#

in(rease the amo"nt of ener, re"ired for p"mpin,4 in m"(h the same a that

drinkin, a

@e8era,e thro",h a sma## stra re"ires a ,reater amo"nt of s"(tion. /here

possi@#e4 pipe

diameters (an @e in(reased to red"(e p"mpin, ener, re"irements4 @"t the

ener, sa8in,s d"e

to in(reased pipe diameters m"st @e @a#an(ed ith in(reased (osts for pipin,

sstem (omponents.

'n(reasin, pipe diameters i## #ike# on# @e (ost eBe(ti8e d"rin, ,reater p"mp

sstem retro?t

proje(ts. ;pi(a# ener, sa8in,s are estimated at to *0.

Consider adBusta#le's3eed dri2es +A"1s% P"mps that e>perien(e hi,h#

8aria@#e demand

(onditions are often ,ood (andidates for A+Ds. As p"mp sstem demand

(han,es4 A+Ds adj"st

the p"mp speed to meet this demand4 there@ sa8in, ener, that o"#dotherise @e #ost to

thrott#in, or @passin,. ;he res"#tin, ener, and maintenan(e (ost sa8in,s (an

often j"stif the

in8estment (osts for the A+D. oe8er4 A+Ds are not pra(ti(a# for a## p"mp

sstem

app#i(ationsZfor e>amp#e4 those that operate at hi,h stati( head and those that

operate for

e>tended periods "nder #o-5o (onditions 2.+. DOE4 *006a3.

+1ust Collectors

Fa@ri( @a,s or (artrid,e (o##e(tors are "s"a## insta##ed on the top of (ement and

5 ash si#os to

(apt"re d"st ,enerated hen the si#os are ?##ed or dran don. D"st ,eneratedd"rin, tr"(k



#oadin, or at the ei,h hoppers is dri8en 8ia a 8a(""m 5o to the d"st

(o##e(tors. ;o ens"re

proper operation of d"st (o##e(tors4 p"#se air jets4 me(hani(a# shakers4 @a,s and

(artrid,es need

to @e inspe(ted re,"#ar#4 fa@ri( @a,s need to @e sied (orre(t# and ?tted

proper#4 and a## the

orn fa@ri(s sho"#d @e rep#a(ed 2MEM+4 *0103.

;itan Ameri(a has re,"#ar# o@ser8ed d"rin, p#ant assessments that d"st

(o##e(tors ma operate

a## da thro",h4 a#tho",h it is on# re"ired d"rin, tr"(k #oadin, 2Cane4 *0113.

+i,ni?(ant

ener, sa8in,s are e>pe(ted hen the motors "sed to dri8e the d"st (o##e(tors

sh"t don hen

not needed see a#so the A"tomated Motors in +e(tion .). Cased on p#ant

assessments @ ;itan

Ameri(a 2Cane4 *01134 a n"m@er of @est pra(ti(es ha8e @een identi?ed that (an

ens"re e(ient

operation of @a,ho"se ?#ters at minim"m ener, re"irements:

!eal areas% as the e>isten(e of #eaks i## in(rease draft re"irements.

Emp#o the minimum e-ective drat . E>tra draft emp#oment i## a(("m"#ate

more d"st

on the ?#ters res"#tin, in in(reased ear of d"(ts and @a,s. se dampers and<or

8aria@#e

speed fans to (ontro# the draft.

utomate dust collectors so that the donKt operate hen not needed.

esiin, and s#oin, don fans that are too @i, i## res"#t in ener, sa8in,s.

'nsta##in,

an adj"sta@#e speed dri8er 2A+D3 i## re"ire hi,her (apita# in8estment @"t i##

res"#t in

in(reased ener, sa8in,s.

Maintain a di-erential pressure a(ross the d"st (o##e(tor 2press"re diBeren(e

@eteen the

dirt and (#ean side of the @a,s3 @eteen to in(hes of ater. For the e(ient



operation of d"st (o##e(tors ?#ters sho"#d @e re#ati8e# dirt or ha8e a d"st (ake.

se a di-erential pressure control system on o"r (#eanin, sstem. DiBerentia#

press"re

sho"#d ran,e @eteen and in(hes of ater hen a fan dri8en d"st (o##e(tor is

"sed.

/hen a (ompressed air jet p"#se (#eanin, sstem is "sed emp#o the minimum

e-ective

pressure hi(h "s"a## ran,es @eteen 60 and 70 psi4 and not more than the

man"fa(t"rerKs re(ommended press"re hen a pne"mati( shaker is "sed.

Emp#o a rather short pulse to shake the e>tra d"st oB in the (ase of (ompressed

air @#o

don sstems.

.

Maintain #ins and storage silos% eaks (an de8e#op in the a,,re,ate @ins and

stora,e si#os.

Dete(t #eaks and ?> them4 otherise o8era## heatin, e(ien( i## @e red"(ed2A&' &ommittee4

*00*3.

Choose an a33ro3riate method for heating aggregates% A((ordin, to the

A&' &ommittee

2*00*34 the most appropriate a of heatin, a,,re,ates is @ (ir("#atin, steam

in pipes. eatin,



a,,re,ates ith hot air or steam jets dire(t# into the a,,re,ate @in is more

therma## e(ient

20 #ess ener,34 @"t (a"ses h"midit 8ariations. oe8er4 their "se is the on#

8ia@#e option

hen #ar,e 8o#"mes of froen a,,re,ates need to @e heated.

23

Turn a “dry'#atch 3lant into a “8et'#atch% Man (on(rete p#ants "se

moist"re meters to

determine the moist"re (ontent of a,,re,ates. oe8er4 their (a#i@ration (an @eakard4

#eadin, to errors in the estimation of ater (ontent. 'n a Sdr-@at(hT p#ant4 a##

in,redients are

mi>ed in the tr"(k4 and an errors in the (a#("#ation of the ater (ontent in

a,,re,ates i## @e

dire(t# (on8erted into errors in the amo"nt of added ater 2&aa(#i" and

%ent"ra4 *0103.

&aa(#i" and %ent"ra 2*0103 ha8e shon that the addition of a (entra# mi>er in a

read mi>ed

(on(rete fa(i#it (an impro8e ater (ontro#4 and hen a(("rate# "sed a(hie8e

si,ni?(ant

sa8in,s in (ement (ons"mption4 estimated at a@o"t ) #@<d) 2*0 k,<m)3. 'n a

Set-@at(hT p#ant

a## ra materia#s are mi>ed in the (entra# mi>er. Ea(h time a @at(h is mi>ed4 theproportions of

ea(h materia# are adj"sted a((ordin, to prod"(t spe(i?(ations. 'n a n"m@er of

(on(rete p#ants the

ater (ontent of a mi>ed @at(h is a#so estimated i.e. from the (han,e in poer

(ons"mption

d"rin, mi>in,. ;he p#ant operator (an "se this information to adj"st the amo"nt

of ater to @e



added in the ne>t @at(hes 2hen more than one @at(hes are needed to ?## the

tr"(k34 (orre(tin,

an errors in the ater (ontent in the mi>in, tr"(k 2&aa(#i" and %ent"ra4 *0103.

;he (ost sa8in,s of red"(in, (ement "se4 for a Sdr-@at(hT p#ant ith an ann"a#

prod"(tion of

604000 d)4 ass"min, a (ement pri(e of [90<short ton (ement4 amo"nt to

[904000<ear. Ann"a#

e#e(tri(it (osts are estimated to in(rease @ [174000<ear. ;he additiona#

maintenan(e (ost is

estimated at [1*4000 2&aa(#i" and %ent"ra4 *0103. &apita# (osts for a *.6 d) 2*

m)3 mi>er

ran,e from [704000 to [*104000 2&aa(#i" and %ent"ra4 *0103. A tpi(a# pa@a(k

period is

estimated to ran,e @eteen 1 and ) ears.

More @ene?ts (an o(("r @ mi>in, the @at(h for the minim"m re"ired time4

res"#tin, in

e#e(tri(it sa8in,s and hi,h prod"(t homo,eneit. For more information read

+e(tion 6.

Mi>in,.

'n (o##a@oration ith the tr"(k dri8ers4 ;itan Ameri(a identi?ed a n"m@er of @est

pra(ti(es

2Dons4 *00934 in(#"din,:

sh"ttin,-oB the en,ine hen ashin, the tr"(k @eteen #oads4

trainin, 5eet (oordinators to impro8e tr"(k dispat(hin,4

dis(o8erin, dri8er mis(on(eptions a@o"t 8ehi(#es4

identifin, te(hno#o,ies a@#e to red"(e id#in, time4 s"(h as a spra no#e or a

ash ra(k4

irin, radios to the @atter to a8oid ha8in, the en,ine on to poer the radio.



Route o3timi<ation% A ro"te p#annin, sstem s"(h as GP+ 2G#o@a# Positionin,

+stem3 (an

sa8e f"e# as a shorter distan(e to the (onstr"(tion site is identi?ed. &are sho"#d

@e taken to

(onsider other fa(tors in5"en(in, f"e# (ons"mption s"(h as road ,radation and

id#in, time.

'n the NM&A *010 I"a#it Cen(hmarkin, +"r8e it as reported that one of the

major reasons

(on(rete is ret"rned to the p#ant 21 of ret"rned (on(rete3 is @e(a"se of

de#i8er time or

prod"(t o8er-mi>in, 2NM&A4 *011a3. Optimiin, the tr"(k ro"te and identifin,the reasons

for de#as in de#i8er (o"#d de(rease this per(enta,e.

1ri2er training% ;r"(k dri8ers p#a an important ro#e

in the tr"(kKs e(ient operation and f"e#

(ons"mption. ;r"(k dri8ers sho"#d @e trained in

pro,rams #ike the &on(rete De#i8er Professiona#

2&DP3 oBered @ the NM&A. /orkers are trained

in orker safet4 tr"(k operation and maintenan(e4

and en8ironmenta# iss"es.

Increase load si<e coecient% C di8idin, the

a8era,e #oad sie @ the nomina# f"## #oad sie of the

tr"(k4 and m"#tip#in, @ 1004 the #oad sie

(oe(ient is determined. ;he hi,her the #oad sie

(oe(ient 2@etter tr"(k "ti#iation34 the #oer the

transportation (ost is. A((ordin, to the *010 I"a#it

Cen(hmarkin, eport 2NM&A4 *011a34 the a8era,e

#oad-sie (oe(ient as $)4 ith (ompanies

reportin, as hi,h as 9$ and as #o as 60.



Pre2enti2e maintenance% A e## str"(t"red pre8enti8e maintenan(e pro,ram

(an impro8e f"e#

e(ien(4 ens"re 2to (ertain e>tent3 (orre(t tr"(k operation4 and a8oid

"ndesira@#e @reakdons

that re"ire si,ni?(ant repair (osts. ;he tr"(k sho"#d @e proper# maintained in a

,ood (ondition4

@ (ond"(tin, re,"#ar inspe(tions and ser8i(e. Pre8enti8e Maintenan(e drain

inter8a#s are

re(ommended for e8er )00 ho"rs of tr"(k operation4 a#tho",h in re(ent ears4

the re(ommended

operatin, ho"rs @eteen inspe(tions ha8e in(reased to * d"e to the "se of

hi,her "a#it motor

oi#s 2&are et a#.4 *0073.

23Curing

&"rin, is the pro(ess d"rin, hi(h (ement rea(ts ith ater 2hdration pro(ess3

to form a ,e#

2(a#(i"m si#i(ate hdrate3 that @inds a## (onstit"ent materia#s to,ether to (reate a

stron, and

d"ra@#e (on(rete prod"(t.

A main ad8anta,e of pre(ast (on(rete is that "nder proper (onditions4 it ,ains

(ompressi8e

stren,th rapid#. +ome pre(ast fa(i#ities hen hi,h (ompressi8e stren,ths are not

re"ired hen

strippin, the prod"(ts4 norma# ("rin, (an @e eno",h to fa(i#itate the re"ired

stren,th. oe8er4

in most pre(ast<prestressed fa(i#ities4 the hi,h (ompressi8e stren,th

re"irements (annot @e

attained itho"t a((e#erated ("rin, 2P&'4 19973.

A((e#erated ("rin, enhan(es the nat"ra# ("rin, ith the addition of heat and

moist"re. 'ts main

p"rpose is to speed "p stren,th ,ain. +team ("rin, at atmospheri( press"re isthe most ide#



"sed tpe of a((e#erated ("rin, 2A&'4 199*3. +team ("rin, 8aries @eteen

diBerent prod"(ts.

For e>amp#e4 hen masonr "nits are ("red4 the heat transfer and e8aporation

i## @e rapid as the

mass to air ratio is hi,h. On the other hand4 hen @i, pre(ast prod"(ts 2e.,.

pipes3 are ("red the

hdration rate is #o hi#e the are p#a(ed in mo#ds4 and heat transfer is s#o

d"e to the hi,h

mass.

Other methods of a((e#erated ("rin,4 not ide# "sed4 are the infrared4 e#e(tri(a#

and oi# ("rin,4

and ("rin, ith steam at e#e8ated temperat"res 2a"to(#a8in,3. ;here are a#so

spe(ia# treatments

s"(h as (ar@onation and a((e#erated drin, and heatin, prior to formin, 2A&'4

199*3.

;he ener, "sed for ("rin, in pre(ast fa(i#ities a((o"nts for 0-60 of the o8era##

ener,

(ons"mption 2Mar(ea" et a#.4 *0073. An ener, e(ien( impro8ements i##

therefore res"#t in

si,ni?(ant ener, and (ost-sa8in,s.

Im3ro2e insulation% Man pre(ast fa(i#ities "se ("rin, (ham@ers made of

(on(rete masonr

"nits4 "s"a## ith no or orn ins"#ation4 hi(h res"#ts in si,ni?(ant heat #ossesand ater

(ondensation iss"es. &ondensed ater (a"ses a n"m@er of "ndesira@#e

pro@#ems4 s"(h as prod"(t

"a#it deterioration4 hen ater drop#ets drop on (on(rete prod"(ts4 and

in(reased ener,

(ons"mption as steam is transformed into ater4 th"s

#osin, ener, that needs to @e maintained @

pro8idin, more ener,.



C proper# ins"#atin, the ("rin, (ham@er4 heat

#osses thro",h irradiation and steam (ondensation (an

@e red"(ed. ;he a8era,e pa@a(k period of ins"#atin,

@are (ham@ers is a@o"t 0.9 ears 2'A&4 8ario"s

ears3.

't has @een o@ser8ed that in se8era# pre(ast (on(rete

fa(i#ities4 the ins"#ation is p#a(ed on the o"tside of the

(ham@er a##s 2Atkinson4 *0103. ;his (on?,"ration

is hi,h# ine(ient4 as e>(ept for heatin, the

(on(rete prod"(ts that need to @e ("red4 the @ri(ks

(omposin, the (ham@er are a#so heated. 'ns"#ation

needs to @e p#a(ed on the inside of the (ham@er.

1etect lea>s% ndete(ted and "ntreated #eaks in ("rin, (ham@ers (an res"#t in

in(reased heat

#osses. epairin, #eaks and ?rm# (#osin, doors (an #ead to si,ni?(ant ener,

sa8in,s.

Process control% Man pre(ast fa(i#ities s"pp# heat to a((e#erate the ("rin, of

(on(rete itho"t

(ontro##in, the temperat"re (han,e and itho"t monitorin, the diBerent sta,es

of the ("rin,

((#e. eat re"irements for diBerent tpes of (on(rete prod"(ts and prod"(t

ei,hts (an 8ar

si,ni?(ant#. 't is essentia# to (ontro# (on(rete ("rin, to "se heat more eBe(ti8e#

and ens"re

prod"(t "a#it.

+e8era# aspe(ts of ("rin, need to @e monitored s"(h as h"midit rates and rate

of heat in(rease.



;he fo##oin, are those that (an ha8e a si,ni?(ant (ontri@"tion in the ener,

sa8in,s.

Preset period. ;he preset period is determined as the period after (on(rete

@at(hin, and "nti# the

initia# set of (on(rete. D"rin, the preset period4 heat is not "s"a## app#ied "n#ess

otherise

re"ired. Ener, sa8in,s and an in(rease in (ompressi8e stren,th (an o(("r

hen steam ("rin, is

(ond"(ted as soon as settin, starts 2A&'4 199*3.

't is (r"(ia# to identif in ea(h (ase the preset time as e>posin, (on(rete

prod"(ts to heat @efore

the end of a preset period i## res"#t in de(rease of (ompressi8e stren,th and

(ra(kin,4 as not

eno",h stren,th is attained to resist the interna# stresses (a"sed @ therma#

e>pansion 2A&'4

199*3.

)tilie hydration heat. C p#a(in, a temperat"re pro@e in the (on(rete prod"(t4

the interna#

(on(rete temperat"re (an @e meas"red instead of the air temperat"re inside the

(ham@er. 'n this

a4 the rea# heat re"irements (an @e identi?ed4 as the heat of hdration a#so

(ontri@"tes to the

("rin, of (on(rete. C determinin, the rea# heat re"irements f"e# is @"rned on#as needed.

D"rin, arm eather the hdration heat (an @e eno",h for the de8e#opment of

hi,h ear#

(on(rete stren,th. +"pp#in, the same amo"nt of heat thro",ho"t the ear is

therefore not

e(ient.



Period o ma"imum temperature. ;he period that the

ma>im"m temperat"re sho"#d @e maintained inside

the (ham@er does not ha8e to @e e"a# to the period

that heat is app#ied. A((ordin, to the A&' 2199*34 in

n"mero"s p#ant st"dies it has @een shon that if the

heat is t"rned oB after the ma>im"m temperat"re is

rea(hed4 and the (ham@ers are e## ins"#ated4 the

de(rease in the 1*-hr (ompressi8e stren,th is not

si,ni?(ant.

Cement ty3e% /hen a((e#erated ("rin, is needed4

tpe ''' Port#and (ement is often "sed. ;he main

diBeren(e from tpe ' Port#and (ement is that the

parti(#es of tpe ''' Port#and (ement are ?ner. Fine

parti(#es are of preferen(e as the (onta(t @eteen

(ement and ater is more intimate4 res"#tin, in a

more e(ient (on(rete hdration 2eje@4 1993. %er

?ne (ement i## therefore ,enerate #ar,er amo"nts of

hdration heat that (an @e "ti#ied. Great (are sho"#d

@e taken tho",h4 as (ra(ks (an de8e#op 2eje@4 1993.

se admi5tures% +"pp#ementar (ementitio"s materia#s 2+&Ms3 2or e#se (a##edminera#

admi>t"res3 or (hemi(a# admi>t"res4 in addition to impro8in, a n"m@er of

en,ineerin, properties

of (on(rete prod"(ts4 (an a#so @e "sed for a((e#eratin, (on(rete ("rin,.

+"pp#ementar

(ementitio"s 2+&Ms3 materia#s are a#so (a##ed minera# admi>t"res. ;he addition

of admi>t"res



a((e#erates the attainment of (ompressi8e stren,th and red"(es si,ni?(ant# the

d"ration of the

("rin, ((#e. Man pre(ast fa(i#ities "se admi>t"res a#on, ith in(reased

temperat"res for

a((e#eratin, ("rin, d"rin, inter4 and d"rin, the s"mmer period the emp#o

on# in(reased

temperat"res itho"t the addition of admi>t"res 2A&'4 199*3.

!upplementary cementitious materials. Mi(rosi#i(a 2si#i(a f"me3 is one of the

most (ommon

s"pp#ementar (ementitio"s materia#s "sed in the a((e#eration of the ("rin,

pro(ess. 'n

(om@ination ith heat and moist"re4 the (an in(rease the short- and #on,-term

(ompressi8e

stren,th of (on(rete 2Fren(h et a#.4 199$3.

;he "se of ,ran"#ated @#ast f"rna(e s#a, 2CF+34 "nder in(reased temperat"res

(an (onsidera@#

in(rease the short-term (ompressi8e stren,th of (on(rete 2Mak4 199$3. A((ordin,

to A&' 2199*34

("rin, temperat"res emp#oed sho"#d @e a@o8e 10oF 260o&3. 't has @een shon

that the therma#

a(ti8it of mi>es (ontainin, CF+ in(reases as the CF+ (ontent in(reases. ;he

,reatest de,ree of

stren,th enhan(ement as a(hie8ed hen 70 of the (ement as rep#a(ed ith

CF+ 2Mak4

199$3.

F# ash has @een "sed as a rep#a(ement of (ement in (on(rete and its

(ontri@"tion to the

a((e#eration of ("rin, a((ordin, to the A&' 2199*3 has @een satisfa(tor.

oe8er4 in order to

tri,,er ear# stren,th ,ains4 hi,h temperat"res of "p to 190oF 2$$o&3 need to @e"ti#ied.



A((ordin, to Fren(h et a#. 2199*3 tho",h4 5 ash sho"#d not @e "sed as a ("rin,

a((e#erator4 as it

de(reases the #on,-term stren,th.

Chemical admi"tures. &a#(i"m (h#oride (an eBe(ti8e# a((e#erate ("rin,.

oe8er4 its "se

sho"#d @e a8oided4 hen stee# @ars are "sed for prod"(t reinfor(ement4 as

(orrosion (an o(("r.

i,h an,e /ater ed"(in, 2/3 admi>t"res 2s"perp#asti(iers3 are "sed in

the

pre(ast<prestressed ind"str to prod"(e hi,h stren,th prod"(ts4 red"(e the

mi>in, ater

re"irements 2"p to *0-*34 red"(e the (ement (ontent4 optimie the 8i@ration

ener,4 and

red"(e heat re"irements in a((e#erated ("rin, 2ama(handran4 1996 ester4

197$3. /ith the

"se of s"perp#asti(iers si,ni?(ant ener, sa8in,s (an o(("r as hi,h stren,th (an

@e ,ained at

#oer heatin, temperat"res and<or thro",h shorter ("rin, ((#es

2ama(handran4 19963.

Cefore the "se of an admi>t"re4 tria# @at(hes sho"#d @e (ond"(ted @efore

pro(eedin, to a f"##

prod"(tion "se4 as their "se (an de#a the de8e#opment of medi"m- and #on,-

term stren,th4 and

possi@# (a"se stren,th red"(tion 2Mak4 199$3. A#so4 the ri,ht admi>t"re

proportion sho"#d @e

identi?ed for an e(onomi(a## optim"m ("rin, ((#e.

Autocla2e re3lacement% A"to(#a8es are press"re 8esse#s s"pp#in, the 8esse#

area ith hi,h-

press"re steam4 and are "sed for a((e#eratin, (on(rete ("rin,. 'n the .+. theare s"((essf"##



"sed main# in ("rin, sma## sie (on(rete prod"(ts4 #ike masonr "nits.

A"to(#a8in, is more ener, intensi8e than #o-press"re steam ("rin,. Ener,

intensit in ("rin,

ith hi,h-press"re steam is aro"nd 0.16 MCt"<d) 20.71* GJ<m)3 hi#e ener,

intensit ith

steam at #o-press"res is aro"nd 0.)0 MCt"<d) 20.9) GJ<m)3 2!aai et a#.4

*003. ;herefore

adoptin, a #ess ener, intensi8e sstem4 hen possi@#e4 res"#ts in si,ni?(ant

ener, sa8in,s.

Automated +Continuous curing systems% A"tomated ("rin, sstems are

main# emp#oed in

(on(rete masonr "nit prod"(tion fa(i#ities. ;hese sstems are said to oBer a

n"m@er of

ad8anta,es hen (ompared to (on8entiona# ("rin, and hand#in, te(hni"es

emp#oed @ the

pre(ast ind"str4 s"(h as #oer operation (osts4 sma##er spa(e re"irement4 and

#ess initia#

in8estment 2A&'4 199*3. ;he "se of fork#ift 8ehi(#es is e#iminated as materia#s are

hand#ed

a"tomati(a##4 th"s red"(in, fossi# f"e# (ons"mption and d"ration of the ("rin,

((#e.

23Returned Concrete

Ann"a## in the .+. it is estimated that * to 10 2a8era,e 3 of the readmi>ed (on(rete

prod"(ed is ret"rned to the @at(hin, p#ant a#tho",h ret"rn rates of 1 ha8e

a#so @een reported

2O@#a et a#.4 *007 Ar,e#es et a#.4 *0103. ;he main reasons in(#"de s#"mp #oss

d"rin,

transportation and o8er orderin, of (on(rete 2Pao#ini and !h"rana4 199$3.

A((ordin, to ("rrent



pra(ti(e4 fresh (on(rete is d"mped at the p#ant site ti## it hardens. /hen

hardened4 front end

#oaders @reak it4 #oad it into tr"(ks4 and it is disposed of in #and?##s. /hi#e sti##

fresh4 the dri8er

(an add ater4 sand or air entrained admi>t"res in order to make @reakin, easier

2Pao#ini and

!h"rana4 199$3.

et"rned (on(rete instead of @ein, disposed to #and?##s4 (an @e re"sed in 8ario"s

as. ;he

ad8anta,es of rep"rposin, the 8ia@#e (on(rete are o@8io"s: red"(tion in disposa#4

transportation4

and ater (osts 2hen ater is a#so re((#ed34 red"(ed e>p#oitation of nat"ra#

reso"r(es4 and

red"(tion of #and?## aste.

E5cess concrete reduction% ed"(e the orderin, safet fa(tor and impro8e

estimations of the

amo"nt of (on(rete needed at the jo@ site. ;he red"(tion of e>(ess (on(rete

prod"(tion to the

minim"m4 res"#ts in #ess (on(rete ret"rned to the p#ant.

Another a to a8oid hi,h rates of ret"rned (on(rete is @ the "se of GP+

sstems in a,itatin,

tr"(ks4 (oordinated ith a (entra# (ontro# station. As a res"#t4 de#as are a8oided

hen possi@#e4

and (han,es in prod"(t de#i8er are hand#ed more eBe(ti8e#.

Reuse on the 3lant site% et"rned (on(rete (an @e re"sed on the p#ant site4 @

pa8in, for

e>amp#e p#ant areas. 'n this a #and?##in, (osts are a8oided and d"st emissions

from tr"(ks

dri8in, on "npa8ed areas (an @e red"(ed. A#so4 as mentioned in +e(tion 6.*4

ret"rned (on(rete is



8a#"a@#e in pro8idin, a pa8ed area to keep ra materia# (#ean and dr. Another

a to "se

ret"rned (on(rete is @ indroin, 2disposin, fresh (on(rete and @reakin, it

hen hardened3

fresh (on(rete and "sin, it here needed4 as a ?##4 road @ase or rip rap 2Ar,e#es

et a#.4 *0103.

e"se of ret"rned (on(rete on the p#ant site is restrained as there (an @e #imited

needs for pa8in,

or ?##in,.

Create 3recast 3roducts% C p#a(in, ret"rned (on(rete into mo#ds4 (on(rete

@#o(ks (an @e

man"fa(t"red and then so#d. /indroin, fresh (on(rete and (r"shin, it (an a#so

(reate sa#ea@#e

prod"(ts. A#tho",h this re((#in, option (an @e (ost eBe(ti8e4 it is hi,h#

dependent on #o(a#

market (onditions and market opport"nities 2O@#a et a#.4 *0073.

atch on to3% +ma## "antities of fresh ret"rned (on(rete 2#ess than 3 (an @e

"sed ith the

ne>t @at(h itho"t aBe(tin, its properties 2Ar,e#es at a#.4 *0103. dration

sta@i#iin,

admi>t"res 2+As3 (an a#so @e "sed to sta@i#ie the hdration of (ement.

dration sta@i#iers

ith ater are spraed on the mi>erKs a##s at the end of the da. ;he fo##oin,da4 the ne

(on(rete @at(h is p#a(ed into the tr"(k4 itho"t re(#aimin, the pre8io"s dasK

ret"rned (on(rete.

A#tho",h sta@i#iin, admi>t"res are e>pensi8e4 their "se (an @e (ost-eBe(ti8e

hen ret"rned

(on(rete is re"sed4 disposa# (osts a8oided and ater "se for tr"(k asho"tred"(ed )00 #iters



instead of )4000 #iters 2Cor,er et a#.4 199 +ea#e4 *0013.

;his meas"re is "s"a## adopted in sma## s(a#e @at(hin, p#ants4 and a#tho",h it

(an @e (ost-

eBe(ti8e4 it is not (onsidered a#as pra(ti(a@#e as prod"(t spe(i?(ations (an

#imit its "se.

"toning out% An e(ient a of (#eanin, the tr"(kKs

dr"m mi>er is @ Sstonin, o"tT the ret"rned (on(rete

at the end of the da. ;he mi>er is #oaded ith to

tons of a,,re,ate and *00 #iters of ater and is then

@ro",ht to the point of dis(har,e a@o"t to times.

;he mi>t"re (an either remain in the tr"(k o8erni,ht

and then "sed the ne>t da - after makin, some

adj"stments - as part of the ?rst @at(h4 or p#a(ed on

the top of the a,,re,ates sto(kpi#e for f"t"re "se

2+ea#e et a#.4 *0013.

+tonin, o"t is an e(ient a of retrie8in, and

re"sin, ret"rned (on(rete as a,,re,ates sin(e it

re"ires no in8estment4 maintenan(e and admi>t"re

(osts.

Mechanical concrete reclaimer% &on(rete ret"rned to the p#ant (an @e

pro(essed thro",h a

me(hani(a# re(#aimer4 a@#e to separate a,,re,ates and ,re ater 2s#"rr

(omposed of (ement

and ater3. ;he re(#aimed a,,re,ates and ,re ater (an then @e "sed in the

(on(rete mi>er.

Main ad8anta,es are re"se of ret"rned (on(rete and e#imination of ash o"t

ater.



;he (apita# in8estment for o@tainin, a (on(rete re(#aimer is si,ni?(ant and

a((ordin, to

#iterat"re4 (an ran,e from [904000 and [)04000 2;am and ;am4 *007 C'C!O4

*0113. ;he

e"ipment is hi,h# (omp#e> and re"ires (aref"# operation and maintenan(e

2+ea#e4 *0013. ;he

red"(tion in disposa# (osts 8aries from appro>imate# 0 to $04 dependin, on

hether @oth

(oarse and ?ne a,,re,ates are re((#ed or not. ;he net (ost sa8in,s are hi,h#

in5"en(ed @

disposa# (osts and the pri(e of 8ir,in (oarse and ?ne a,,re,ates. 'n an a8era,e

read mi>ed

(on(rete fa(i#it 2604000 d) ann"a# prod"(tion34 the net (ost sa8in,s for a

[16<ton disposa# (ost4

(an ran,e @eteen [0. and [*.<d) of (on(rete prod"(ed. ;he pa@a(k time is

estimated to

ran,e @eteen *. and ) ears.

e((#in, is #imited in #ar,e read mi>ed @at(hin, fa(i#ities as it re"ires hi,hinitia# in8estment

and (aref"# operation 2O@#a et a#.4 *0073. ;he pa@a(k time for #ar,er fa(i#ities

2more than

1004000 d) per ear3 is #ess than * ears.

Mechanical reclaimer 3lus 0"As +$99: 8aste recycling system%

et"rned (on(rete is fed

thro",h a p#"me to a me(hani(a# re(#aimer. &oarse a,,re,ates are separated

and #ed to the (oarse

a,,re,ate sto(kpi#es. &ement and (ementitio"s materia#s4 a#on, ith ?ne sand

and ater are

transferred to a primar tank hi#e +As are added. C addin, +As4 hdration

of (ement is

s"spended and a part of its (ementitio"s 8a#"e is a8ai#a@#e for f"t"re "se. ;he

primar tankKs



(ontent is then transferred to the se(ond tank for "se as @at(h s#"rr4 hi#e

d"rin, tranfer it is

@ein, mi>ed ith fresh or pro(ess ater in order to meet the ("stomerKs prod"(t

spe(i?(ations

2o@o and M"##in,s4 *00) Ce(kham4 n.d.3.

;his re((#in, sstem re"ses 100 of ,enerated aste in a read mi>ed

(on(rete fa(i#it.

/itho"t the "se of +As4 the "se of re((#ed (on(rete in @at(hin, o"#d not @e

possi@#e. ;here

are a n"m@er of (on(rete fa(i#ities in the .+.4 E"rope and Japan s"((essf"##

"sin, this 100

aste re((#in, s(heme 2o@o and M"##in,s4 *00)3. ;he e(onomi( feasi@i#it i##

depend on the

disposa# (ost of ret"rned (on(rete and pro(ess ater4 on the (ost of 8ir,in

a,,re,ates and ater

and the rate of aste "ti#iation a(hie8ed.

Crushing and recycling concrete% Fresh (on(rete4 hen ret"rned to the p#ant

site (an @e #eft to

harden and "sed afterards in a (r"sher for f"rther pro(essin,. &r"shed (on(rete

a,,re,ates

2&&A3 (an then @e "sed in (on(rete prod"(tion or at the p#ant site4 as road @ase

or ?##.

A((ordin, to O@#a et a#. 2*0073 this re((#in, option has a si,ni?(ant potentia# inthe .+. and

(o"#d @e "sed to re((#e 60 of ret"rned (on(rete. ;he in8estment (ost for an

a8era,e (r"sher is

estimated at [704000 2Joint +er8i(e Po##"tion Pre8ention *00)3.

Potentia# (ost sa8in,s depend on hether ret"rned (on(rete is separated into

diBerent stren,th



(#asses4 and into (oarse and ?ne parti(#es 2O@#a et a#.4 *0073. /hen it is not

separated into

stren,th (#asses4 the &&A (ontent of a,,re,ates "sed in (on(rete mi>in, sho"#d

not e>(eed 10

2ass"min, &&A is deri8ed from #oer stren,th ret"rned (on(rete34 as more

(ement and

admi>t"res are re"ired to (ompensate for stren,th #osses. /hen separated @

stren,th (#asses

the share of &&A (an in(rease to )04 impro8in, the (ost @ene?ts. /hen &&A is

separated

a((ordin, to stren,th (#asses and parti(#e ?neness4 the sa8in,s a(hie8ed are

ma>imied.

;he net (ost sa8in,s 8ar a((ordin, to the &&A separation s(heme adopted and

ran,e @eteen

[0.) and [.0<d) of (on(rete prod"(ed 2O@#a et a#. *0073. For hi,her disposa#

(osts4 the net (ost

sa8in,s in(rease drasti(a## and (an ran,e @eteen [) and [1*<d). ;he

pa@a(k period ran,es

from a fe months to ma>im"m of ears.

For prod"(t spe(i?(ations and ,"idan(e (on(ernin, the "se of &&A in @at(hin,4

see S+tandard

and +pe(i?(ations for e(#aimed &on(rete A,,re,ate for se as &oarse

A,,re,ate in Port#and

&ement &on(reteT.

23Process )ater

Fresh ater is a 8a#"a@#e4 s(ar(e and "s"a## e>pensi8e reso"r(e. 't sho"#d @e

"sed ith ,reat

(are. /ater in read mi>ed (on(rete p#ants is "sed in (on(rete @at(hin, 21-1$

of fresh

(on(rete is ater34 a,,re,ate heatin, or (hi##in,4 tr"(k and (entra# mi>er asho"t4 and in d"st



emission s"ppression operations here 8ario"s fa(i#it areas are spraed ith

ater. 'n pre(ast

p#ants4 ater is main# "sed for @at(hin, and ("rin,.

/ater (ons"mption shos ,reat 8ariations for diBerent fa(i#it tpes. ead

mi>ed (on(rete

p#ants itho"t a (entra# mi>er tend to (ons"me more ater for tr"(k ashin,

hen (ompared to

(entra# mi> p#ants4 sin(e the dr"m is #oaded ith dr materia#s instead of fresh

(on(rete. P#ants in

r"ra# areas here #on,er tra8e# distan(es e>ist for prod"(t de#i8er4 are #ike# to

ha8e hi,her

ater (ons"mption as the main# "se transit mi>ers4 and #ar,e p#ants in "r@an

sites are more

#ike# to ha8e adopted a ater re((#in, s(heme 2Ar,e#es et a#.4 *0103.

A((ordin, to Mar(ea" et a#. 2*0073 2@ased on *7 read mi>ed (on(rete p#ant

responses34 the

a8era,e ater (ons"mption in a read mi>ed (on(rete p#ant is 1) ,a##ons<d)

26 #iters<m)3

itho"t in(#"din, the ater "sed in (on(rete @at(hin,4 and 7 ,a##ons<d) 2)

#iters<m)3 of ater is

tpi(a## disposed. /ater that is not disposed is re"sed. 'n pre(ast fa(i#ities there

is no tr"(k

ash o"t<oB4 and ater is "sed for prod"(t ("rin, as steam or 8apor. Aro"nd 170

,a##ons of

ater per d) are "sed for ("rin, hi#e 100 ,a##ons<d) are dis(arded the rest is

#ost as steam4

and on# a sma## amo"nt of ater is re((#ed.

+tri(t re,"#ations on the disposa# of pro(ess ater prod"(ed in (on(rete fa(i#ities

for(e p#ant

mana,ers to adopt ater re((#in, s(hemes4 fo##oin, a trend toard ero-dis(har,in, fa(i#ities.



;here are to main as to red"(e fresh ater (ons"mption and #imit the

,eneration of pro(ess

ater a3 "se #ess o8era## ater4 and @3 rep#a(e fresh ater ith re((#ed pro(ess

ater and

(apt"red stormater. ed"(in, ater "sa,e and (apt"rin, pro(ess ater (an @e

(ost eBe(ti8e as

the "se of m"ni(ipa# and e## fresh ater poses si,ni?(ant operationa# (osts to

(on(rete

prod"(ers. ;pi(a# ater (osts ran,e @eteen [0.0* and [0.*<d). /e## ater

p#ants spend

aro"nd [0.07<d)4 hi#e p#ants "sin, fresh ater from m"ni(ipa# so"r(es ha8ethe hi,hest ater

(osts ran,in, @eteen [0.* and [0.*<d) 2er@ert4 *0063. e((#in, pro(ess

ater a#so #imits

the ater dis(har,e (osts.

+tandards prepared @ the NM&A4 the A+;M & 160* +tandard +pe(i?(ation for

Mi>in, /ater

sed in the Prod"(tion of dra"#i( &ement &on(rete4 and the A+;M & 160)4

+tandard ;est

Method for the Meas"rement of +o#ids in /ater e>p#ain ho to re((#e pro(ess

ater and "se it

in @at(hin, itho"t deterioratin, the prod"(tKs "a#it.

/%D%$ 1ecrease ;resh )ater sage

;here are a n"m@er of meas"res that (o"#d @e adopted to #imit ater

(ons"mption. ;he most

ater intensi8e operation is ashin, tr"(k dr"ms 20-*00 ,a##ons of ater per

tr"(k3. /ater

sa8in, meas"res in this operation i## ha8e the ,reatest (ost sa8in,s.

Multi3le lo8 2olume drum 8ashouts% sin, m"#tip#e #o 8o#"me rinses in

dr"m asho"t4



red"(es ater (ons"mption @ 0 2Ar,e#es et a#.4 *0103. One rinse of *0

,a##ons 290 #iters3

i## (#ean a tr"(kKs dr"m as e(ient# as a do"@#e rinse of 100 ,a##ons 2)$0

#iters3 ti(e4 or a

trip#e rinse of 0 ,a##ons 2190 #iters3 "sed three times 2Ar,e#es et a#.4 *010

Athena +"staina@#e

Materia#s 'nstit"te4 199)3. ;he ann"a# sa8in,s in fresh ater for an a8era,e read

mi>ed (on(rete

fa(i#it (an rea(h [14000.

se chemical admi5tures% /ith the introd"(tion of (hemi(a# admi>t"res

2ater red"(in, and

p#asti(iin,3 in @at(hin,4 the fresh ater demand (an @e red"(ed @ 1*-*

itho"t ha8in, an

ne,ati8e eBe(t on orka@i#it 2.+. Department of ;ransportation4 *0113.

0eating aggregates% 'n (o#d eather (on(retin,4 it is (ommon pra(ti(e to heat

the ater and not

the a,,re,ates. /ater (an @e (onser8ed4 @ heatin, a sma## amo"nt to (reate

steam for a,,re,ate

heatin,. A#so4 a portion of the @at(h ater (an @e heated instead of heatin, a## of

it 2Ar,e#es et

a#.4 *0103.

Restrain fresh 8ater .o8% +i,ni?(ant amo"nts of fresh ater (an @e sa8ed

hen 5o-(ontro#

no#es or sma## diameter hoses are "sed.

"hut'o 2al2es% Fresh ater (an @e asted hen d"rin, ater tank #oadin, if

the tank is

o8er?##ed. 'nsta##in, a sh"t-oB 8a#8e (an pre8ent o8er?##in,.



Create cur#ings and gutters% Generation of e>tra pro(ess ater (an @e

a8oided @ pre8entin,

stormater from mi>in, ith pro(ess ater. +tormater that @e(omes

(ontaminated re"ires

treatment. ;he (reation of ("r@in,s and ater ,"tters in the p#ant area i##

fa(i#itate this meas"re.

)ater har2esting% A,,re,ates d"rin, arm periods are spraed ith ater to

keep them (oo#.

/hen the sto(kpi#es are p#a(ed on pa8ed and in(#ined areas4 the r"noB ater at

the @ase of the

sto(kpi#e (an @e (o##e(ted and re"sed in (on(rete @at(hin, or tr"(k ash o"t<oB.+torm ater (an

a#so @e (apt"red and dire(ted to sett#ement @asins a#on, ith pro(ess ater and

re"sed in some

p#ant operations.

)ater recycling

For e8er ("@i( ard of (on(rete prod"(ed4 aro"nd 7

,a##ons 2) #iters<m)3 of pro(ess ater re"ire

disposa# 2Mar(ea" et a#.4 *0073. C #imitin, pro(ess

ater ,eneration4 pro(ess ater a#on, ith

stormater (an @e (o##e(ted4 treated4 and re"sed in

(on(rete @at(hin,4 @"t a#so in other operations 2i.e.

tr"(k ash o"t<oB34 red"(in, the "se of fresh ater.

+e8era# of the most promisin, methods of ater

re((#in, in(#"de the stonin, o"t of ret"rned

(on(rete4 the @at(h on top operation4 the "se of a

me(hani(a# re(#aimer4 and the "se of a me(hani(a#

re(#aimer ith +As. ead more in +e(tion 6.7

2et"rned &on(rete3.



Create settlement #asins% +ett#ement @asins are the

most pre8a#ent a of treatin, pro(ess ater for

f"t"re re"se 2Ar,e#es et a#.4 *0103. Pro(ess ater is

(o##e(ted from tr"(k #oadin, and (#eanin, areas4 and is dri8en to a ater @asin

sstem (omposed of a n"m@er of ,ro"nd @asins "s"a## p#a(ed side @

side. Pro(ess ater enters the ?rst @asin and as the ater 8o#"me in(reases4 it

o8er5os to the

ne>t one ti## it ends "p free of so#ids 2so#ids are hea8ier and sett#e to the @ottom

of the ear#

@asins3. ;he @asins sho"#d @e proper# maintained and so#id astes (o##e(tedre,"#ar#. After

sedimentation4 ater is p"mped into a ater tank ith a minor impa(t on p#ant

ener,

(ons"mption.

'f the so#id (on(entration is not dropped to desira@#e #e8e#s4 (#oth ?#ters (an @e

dep#oed.

Maintenan(e and (#eanin, of (#oths (an maintain #o so#id (on(entration.

At the #ast @asin4 ater is treated to red"(e the p #e8e#s a((ordin, to

re,"#ations 2#oer than 9

re#ati8e "nits3. p treatment is done @ mi>in, pro(ess ater ith an a(id

so#"tion or @

inje(tin, (ar@on dio>ide 2Mi##enni"m EM+ +o#"tion td.4 *0103.

\]Miscellaneous

23"treamline ra8 material handling

Aro"nd 16 of the ener, "sed in read mi>ed (on(rete fa(i#ities is "sed for the

operation of



#i,ht tr"(ks 2fork #ifts4 front end #oaders et(.3 2Mar(ea" et a#.4 *0073. i,ht tr"(ks

(ons"me as

m"(h as -10 ,a##ons of diese# per ho"r 219-)$ #iters<ho"r3 2Ar,e#es et. a#4 *0103.

+i,ni?(ant sa8in,s in diese# f"e# (an o(("r hen (on8eor @e#ts in (om@ination

ith a,,re,ate

feed hoppers are "sed to fa(i#itate the transfer of a,,re,ates to the mi>er. 'n

addition4 hen

"nder,ro"nd a,,re,ate stora,e fa(i#ities are insta##ed4 in (om@ination ith a

(on8eor @e#t

2horionta# p#ant (on?,"ration3 the "se of front-end #oaders (an @e e#iminated4

#eadin, to

s"@stantia# f"e# and #a@or sa8in,s. ;he (apita# (osts for an a8era,e read mi>ed

(on(rete fa(i#it

are estimated aro"nd [04000 for a,,re,ate stora,e4 and [4000 for a 6 ft 2*0

m3 tro",hed

(on8eor @e#t 2'&F4 *00* &arter and ;roano-&"t"ri4 *011 /a#as4 19903.

;he pa@a(k period is estimated to @e appro>imate# 1.) ears. oe8er4 this

?,"re is e>pe(ted

to @e a @it hi,her hen the additiona# #a@or (osts for operatin, the (on8eor @e#t

and the

"nder,ro"nd stora,e area are in(#"ded. No information as a8ai#a@#e (on(ernin,

the (han,e in

maintenan(e (osts.

/%F%& Automation in Precast ;acilities%

;he "se of a"tomation in pre(ast fa(i#ities si,ni?(ant# de(reases the need for

ski##ed #a@or4 and

the o8era## n"m@er of orkers. Additiona# ad8anta,e is the ease in pro@#em

identi?(ation as ea(h

part of pre(ast man"fa(t"re is monitored separate#. A#so4 feer mistakes are

made hen ro@ots



are ,i8en (orre(t orders4 and the prod"(t "a#it4 and orker safet in(reases

2;oda^s &on(rete

;e(hno#o,4 *0103. n#ike North Ameri(a4 a"tomation in pre(ast fa(i#ities has

@een "sed for

se8era# ears in E"rope.

'n an a"tomated p#ant4 ro@ots are "sed to prepare the mo#ds4 p#a(e the

reinfor(ement4 inserts and

the (on(rete into the mo#ds4 transfer the pa##ets to the ("rin, area and the ("red

prod"(ts to the

de-mo#din, area4 demo#d4 and ?na## (#ean the mo#ds. ;he ro@ots are (ontro##ed

@ a (entra#

(omp"ter sstem re(ei8in, instr"(tions from &AD 2(omp"ter-aided drain,3 data

?#es.

A"tomation is appropriate for @oth standard and ("stom prod"(ts. ;he time

re"ired to prod"(e a

(ertain n"m@er of prod"(ts in a f"## a"tomated fa(i#it is the one third of the

time re"ired in a

(on8entiona# pre(ast fa(i#it to prod"(e the same "antit of prod"(ts. 'n E"rope4

#a@or (osts

ha8e de(reased @ 0 to 70. Ener, (osts (an a#so de(rease from the more

e(ient "ti#iation

of the ma(hiner 2;oda^s &on(rete ;e(hno#o,4 *0103.

&osts depend on a 8ariet of fa(tors the de,ree of a"tomation adopted2a"tomation (an @e

adopted in steps34 hether it is a retro?t meas"re or a ne# @"i#t p#ant4 the

tpe4 sie and

"antit of prod"(ts4 and the desired prod"(t o"tp"t per shift. E"ipment (osts

for f"##

a"tomated pre(ast fa(i#ities in E"rope ha8e ran,ed @eteen [) to [ mi##ion4

hi#e partia##



a"tomated p#ants ran,e @eteen [1. and [) mi##ion 2;oda^s &on(rete

;e(hno#o,4 *0103. ;he

pa@a(k time as estimated to ears.

/%F%( Co'generation

For ind"stries ith re"irements in @oth heat and e#e(tri(it4 the insta##ation of a

(om@ined heat

and poer "nit (an si,ni?(ant# red"(e ener, (ons"mption4 and as a res"#t the

asso(iated

,reenho"se ,as emissions. 'n the pre(ast ind"str4 heat is "sed in se8era#

operations heatin,

@at(h ater4 preheatin, the a,,re,ates4 heatin, the @"i#din,4 and (on(rete

hardenin,. E#e(tri(it

is "sed to poer e#e(tri( (on8eors4 the mi>er4 (ompressors4 fans4 p"mps4 et(.

;his e(ien( impro8in, meas"re (annot @e imp#emented in a## (on(rete

fa(i#ities. 'ts^ adoption

depends on a 8ariet of fa(tors i.e. on-site heat and e#e(tri(it re"irements4

#o(a# f"e# and

e#e(tri(it pri(es4 and initia# in8estment.

&P p#ants4 are (omposed of a t"r@ine<en,ine4 an e#e(tri( ,enerator4 and a heat

re(o8er "nit

hi(h "ti#ie the ,enerated heat from (oo#in, the en,ine. 'n this a4 fossi# f"e#s

are transformed

into heat and e#e(tri(it. &P "nits are more e(ient than (on8entiona# poer

p#ants as their

main ad8anta,e is the "ti#iation of e>ha"st heat

d"rin, e#e(tri(it prod"(tion. O8era## sstem

e(ien( (an e>(eed $0.

;he pa@a(k period for a &P (on?,"ration (an 8ar



ide#. Ass"min, the imp#ementation of a (o-

,eneration p#ant simi#ar to the one in the (ase st"d

@"t instead in the nited +tates4 the pa@a(k time

o"#d ran,e @eteen * to 7 ears4 dependin, on

e#e(tri(it pri(es. 'n *009 e#e(tri(it pri(es in 8ario"s

+tates ran,ed @eteen 6.$ to 1_<k/h 2.+.DOE-

E'A4 *0113. Cased on a #imited n"m@er of a(t"a# p#ant

assessments in the .+.4 the pa@a(k times for &P

insta##ation ran,e @eteen * and 10 ears 2'A&4 *0103.

/%F%* ?3timi<e concrete mi5ture

A((ordin, to the e>perimenta# (ase st"dies appearin,

in O@#a et a#. 2*0034 (on(ernin, the prod"(tion of

(on(rete 5oors and i,h Performan(e &on(rete 2P&3

@#o(ks4 the (on(rete mi> optimiation (an ie#d

si,ni?(ant sa8in,s in materia# (osts. Materia# (osts in

the read mi>ed (on(rete ind"str are responsi@#e for

more than 0 of the o8era## prod"(tion (osts `

(ement on# a((o"nts for a@o"t * 2O#i8arri4 *0113.

C a#terin, the (onsisten( of the initia# mi>t"re 2the initia# mi>t"re as desi,ned

a((ordin, to

the pres(ripti8e spe(i?(ations i.e. spe(i?( ater to (ement ratio 2<(3 and

spe(i?( (ementitio"s

(ontent3 hi#e at the same time meetin, the performan(e (riteria4 the materia#

(osts in the ?rst

(ase st"d de(reased @ 9-1 hi#e in the se(ond

(ase st"d @ 16-19. ;he red"(tion in materia# (osts

as main# a(hie8ed ith the s"@stit"tion of (ement



ith (ementitio"s materia#s4 5 ash and ,ran"#ated

@#ast f"rna(e s#a,. ;he s"@stit"tion of (ement ith 5

ash and<or @#ast f"rna(e s#a, ran,ed from *0 to

0. 'n addition4 (ertain mi>t"res appeared to

perform si,ni?(ant# @etter than the prin(ip#e

mi>t"res.

Port#and (ement is responsi@#e for the 90 of the

em@odied ener, in (on(rete 2Mar(ea" et a#. *0073.

An red"(tion in the (ement (ontent of (on(rete mi>

i## therefore res"#t in a s"@stantia# red"(tion in the

em@odied ,reenho"se ,as emissions.

/%F%- "elf consolidating concrete +"CC

+e#f-(onso#idatin, (on(rete4 a#so (a##ed se#f (ompa(tin, (on(rete 2+&&34 is "sed

to s"@stit"te

(on8entiona# (on(rete in some app#i(ations in Japan4 E"rope and the nited

+tates 2O"(hi et a#.4

*00)3. 'n the .+.4 the pre(ast<prestressed (on(rete ind"str has shon an

in(reasin, interest in

+&& d"rin, re(ent ears. A n"m@er of pre(ast (on(rete fa(i#ities reported "sin,

+&& instead of

(on8entiona# (on(rete in near# 100 of their prod"(tion 2P&'4 *00)3.

+&& (an (onso#idate "nder its on ei,ht4 itho"t

the need of 8i@ration. ;he main @ene?ts are #oer

prod"(tion

(osts and in(reased prod"(ti8it

Other @ene?ts are the 13

hi,h "a#it4 as it (an ?## ,aps ith ease itho"t

(reatin, ho#es4 *3 ad8an(ed aestheti(4 it has a smooth



?nish and #i,hter (o#ors4 )3 desi,n 5e>i@i#it4 it (an @e

"sed in the prod"(tion of (omp#e> desi,ns4 3

in(reased d"ra@i#it4 as it (an form prod"(ts ith

hi,her (ompression stren,ths than (on8entiona#

(on(rete and ith #oer permea@i#it4 and 3 a safer

orkin, en8ironment4 as the noise of 8i@ration is

e#iminated and d"st emissions are red"(ed 2+h"tt4

*00* Grnea#d et a#.4 *0103. ;he e#imination of

8i@ration4 res"#ts in e#e(tri(it sa8in,s 2 kCt"<ho"r

for a 5e>i@#e shaft 8i@rator4 0. kCt"<ho"r for a form

8i@rator3 2!aai et a#.4 *003.

;he main @arriers for adoption of +&& are hi,h materia# (osts4 as hi,h "a#it

prod"(ts and more

;he Ne(rete Prod"(ts Di8ision of

Ne Enterprise +tine = ime &o. 'n(. in

oarin, +prin,4 Pa.4 "ses +&& in the

man"fa(t"re of a 8ariet of (on(rete

prod"(ts. /hen +&& is "sed in the tee

/hen +&& is eBe(ti8e# prod"(ed4 it (an res"#t in s"@stantia# (ost ,ains main#

from red"(ed

of (on(rete are estimated to ). 2+h"tt4

*00*3. ;hese (osts (an @e oBset hen

takin, into a((o"nt the 6 de(rease in

tota# manpoer per se(tion and

de(rease in pat(hin, #a@or per se(tion.

"sed to ens"re s"((ess in +&& prod"(t man"fa(t"re.

/%F%/ Concrete 3re'cooling method

http://www.pci.org/view_file.cfm?file=TR-6-03_PCI_SCC_GUIDELINES.PDF













i,h am@ient temperat"res aBe(t mi>in,4 ("rin, and p#a(ement of (on(rete4

ne,ati8e# aBe(tin,

(on(rete properties. Potentia# pro@#ems are the de(reased #on,-term stren,th

2a#tho",h "nder

hi,h temperat"res the ear#-stren,th de8e#opment in(reases34 in(reased

(ra(kin,4 de(reased

d"ra@i#it4 in(reased risk of reinfor(ement (orrosion4 in(reased permea@i#it and

deteriorated

prod"(t appearan(e. Most of theses pro@#ems are asso(iated ith the in(reased

rate of (ement

hdration and in(reased moist"re e8aporation "nder hi,h temperat"res 2A&'419913.

;here are se8era# as to (ontro# (on(retin, at

e#e8ated temperat"res. A,,re,ates (an @e stored in

#ar,e (apa(it sto(kpi#es4 as temperat"re (an remain

#o in the (enter4 and in (o8ered and shaded areas.

Paintin, the mi>in, and ha"#in, e"ipment in #i,ht

(o#ors (an a#so @e 8er he#pf"# 2A&'4 199)3. 'n

addition4 ra materia#s (an @e pre-(oo#ed. Methods

for (on(rete pre-(oo#in, are 13 (oo#in, ith (hi##ed

mi>in, ater4 *3 (oo#in, mi>in, ater ith #i"id

nitro,en4 )3 (oo#in, (on(rete ith i(e4 3 (oo#in,

(oarse a,,re,ates and 3 (oo#in, (on(rete ith #i"id

nitro,en. A des(ription of the 8ario"s methods and

their temperat"re red"(tion potentia#s (an @e fo"nd in

ot /eather &on(retin, and &oo#in, and 'ns"#atin,

+stems for Mass &on(rete reports @ the A&'

&ommittee 2A&'4 1991 A&'4 199)3.

A((ordin, to the A&' )0 report4 one of the major



means of red"(in, (on(rete temperat"re is @ addin,

i(e as a part of the @at(hin, ater 2A&'4 19913. ;he

in8estment needed to insta## an i(e-p#ant is hi,h4 th"s

the majorit of (on(rete p#ants @" i(e 2Cea8er4

*003. ;his method (an @e (ost-eBe(ti8e for sma##

@at(hes4 @"t other (on(rete pre-(oo#in, methods (o"#d in some (ases (ost #ess.

;h"s4 it is ise to

?rst st"d and then se#e(t the most s"ita@#e pre-(oo#in, option for o"r (on(rete

fa(i#it.

/vaporative cooling o aggregates. /ettin, a,,re,ate sto(kpi#es ith ater (an

in some (ases

de(rease the temperat"re of (on(rete @ a fe de,rees. For e>amp#e if the et-

@"#@ temperat"re

is $0oF 2*7o&3 and the initia# a,,re,ate temperat"re is 90oF 2)*o&34 e8aporation

(an de(rease the

a,,re,ate temperat"re to $oF 2*9o&3 2ee4 19$93. oe8er4 hen #oer

temperat"re

spe(i?(ations are re"ired4 e8aporati8e (oo#in, a#one i## not @e eno",h.

Cool aggregates with naturally chilled water. /hen a8ai#a@#e4 nat"ra## o(("rrin,

(o#d ater

2i.e. from a e##3 (o"#d @e "sed for @at(h ater. ;he (apita# (ost for a ater

p"mp4 a pipe sstem

to de#i8er (hi##ed ater to the sto(kpi#es4 and a ater draina,e sstem asestimated at [1$4000

2ee4 19$93.

Chillers. /hen nat"ra## o(("rrin, (oo# ater is not a8ai#a@#e4 ater (hi##ers (an

@e emp#oed

for (oo#in, the a,,re,ates and the @at(hin, ater. ;his re"ires a #ar,e (apa(it

ater tank4



sprink#ers4 ater p"mps4 a ater distri@"tion and draina,e sstem4 and (hi##ers.

Despite the

si,ni?(ant (apita# (ost4 this method (osts #ess hen si,ni?(ant amo"nts of

(on(rete are (oo#ed

2ee4 19$93. &hi##in, (an de(rease the (on(rete temperat"re to 6oF 21$o&3. 'n

some (ases4 the

in(reased operationa# (osts d"e to ater draina,e and e>(ess ater hand#in,

(an make the

insta##ation of an i(e p#ant a more (ost-eBe(ti8e option 2ee4 19$93.

*eat Pump. A heat p"mp (an @e "sed for the prod"(tion of arm ater d"rin,

the (o#d months

and (hi##ed ater d"rin, the arm months. Despite its si,ni?(ant (apita# (ost4 it

is (onsidered to

@e the most (ost-eBe(ti8e a of (oo#in, @at(h ater 2A&'4 19913.

Cooling towers. &oo#in, toers re"ire #oer in8estment and are (hara(teried

@ #oer

operationa# (osts hen (ompared to (hi##ers 2ee4 19$93. /ater deri8ed from

(oo#in, toers (an

@e "sed for e8aporati8e (oo#in, of a,,re,ates and (an oBer hi,her temperat"re

red"(tions than

e8aporati8e (oo#in, ith nat"ra# ater4 as ater from the (oo#in, toer is (o#der.

;emperat"re

spe(i?(ations of $oF 2*9o&3 or 90oF 2)*o&3 (an "s"a## @e met @ insta##in, a

(oo#in, toer or

@ "sin, nat"ra# ater. Cased on a sin,#e a"dit4 the pa@a(k period to rep#a(e a

refri,eration

sstem ith a (oo#in, toer is estimated at appro>imate# 1 ear 2'A&4 *0103.

$i,uid 0itrogen. nder spe(i?( (onditions4 the "se of #i"id nitro,en (an @e #ess

(ost# than

"sin, i(e or (hi##ed ater 2Cea8er4 *003. /hen sma## @at(hes need to @e (oo#edto rea(h 60oF



216o&34 dire(t# sprain, #i"id nitro,en 2N3 on fresh (on(rete ma @e more

(ost-eBe(ti8e than

(oo#in, ater ith i(e 2ee4 19$93. Pre-(oo#in, (on(rete from 9oF 2)o&3 to

7oF 2*o&3 ith

N4 (osts a@o"t [7.<d)4 hi#e pre-(oo#in, it from 9oF 2)o&3 to $oF 2*9o&3

i## (ost a@o"t

[<d) 2e>(#"din, (apita# (osts or renta# of #i"id nitro,en stora,e 8esse#s3. ;he

(apita# (ost of a

permanent fa(i#it is aro"nd [740004 hi#e a dri8e-thro",h fa(i#it it is estimated

at [)64000

2Cea8er4 *003. A((ordin, to J"en,er et a#. 2*0073 e>(ept for a fe e>(eptions4

#i"id nitro,en

does not aBe(t most of the (on(rete properties that ere tested. Great (are is

(r"(ia# hen s#"mp

is (a#("#ated as the initia# hi,h temperat"re in(reases s#"mp #oss4 and hen the

#i"id nitro,en

inje(tion #an(es are not proper# a#i,ned as the (an dama,e the tr"(kKs dr"m

2J"en,er et a#.4

*0073.

"ummary

C in(reasin, ener, e(ien(4 (ompanies (an red"(e (osts and in(rease

predi(ta@#e earnin,s in

the fa(e of on,oin, ener, pri(e 8o#ati#it. &onsiderin, ener, pri(e 8o#ati#it and

re(ent sharp

in(reases in nat"ra# ,as pri(es a(ross the nation4 ener, e(ien(

impro8ements are needed

toda more than e8er. Man (ompanies ha8e a#read a((epted the (ha##en,e to

impro8e their

ener, e(ien( in the fa(e of hi,h ener, (osts and ha8e @e,"n to reap the

reards of ener,

e(ien( in8estments. 'n addition4 (ompanies are t"rnin, to ener,-e(ient

pro(esses and

te(hno#o,ies to red"(e their (riteria po##"tant and (ar@on emissions4 to meet(orporate



en8ironmenta# ,oa#s.

;his Ener, G"ide has s"mmaried man ener,-e(ient te(hno#o,ies and

pra(ti(es that are

pro8en4 (ost-eBe(ti8e4 and a8ai#a@#e for imp#ementation toda. ;hese

opport"nities are

app#i(a@#e at the (omponent4 pro(ess4 fa(i#it4 and or,aniationa# #e8e#s.

Pre#iminar estimates of

sa8in,s in ener, and ener,-re#ated (osts ha8e @een pro8ided for man of the

meas"res4 @ased

on (ase st"d data from rea#-or#d ind"stria# app#i(ations. ;pi(a# in8estment

pa@a(k periods

and referen(es to f"rther information ha8e @een pro8ided4 here a8ai#a@#e.

;o @e s"((essf"#4 esta@#ish a fo("sed and strate,i( ener, mana,ement pro,ram

that he#ps o"

identif and imp#ement ener, e(ien( meas"res and pra(ti(es a(ross o"r

or,aniation and

ens"re (ontin"o"s impro8ement. ;hen assess o"r (ompanKs ener,-"sin,

sstems and identif

areas for impro8ement. ;a@#es $ and 9 s"mmarie the ener, e(ien(

meas"res presented in

this ,"ide. !eep in mind that a#tho",h the e>pe(ted sa8in,s asso(iated ith

some of the

indi8id"a# meas"res ma @e re#ati8e# sma##4 their ("m"#ati8e eBe(t a(ross an

entire fa(i#it ma

@e "ite #ar,e. Man meas"res ha8e re#ati8e# short pa@a(k periods and are

therefore attra(ti8e

e(onomi( in8estments on their on. ;he de,ree to hi(h these meas"res are

imp#emented i##

8ar amon, p#ants and end "ses4 @"t (ontin"o"s e8a#"ation of o"r fa(i#itKs

ener, pro?#e i##

he#p to identif f"rther (ost sa8in,s o8er time. For a## of the ener, e(ien(

meas"res



presented in this ,"ide4 resear(h their e(onomi(s and app#i(a@i#it to o"r

fa(i#itKs on "ni"e

prod"(tion pra(ti(es to assess the feasi@i#it and potentia# @ene?ts of ea(h

meas"reKs

imp#ementation.

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