OBJECTIVES Determine the phenomena related to flows in solid-liquid system. Determine the minimum speeds of Fluidization Determine the loss of head in a bed of particle Determining the expansion of the bed INTRODUCTION It is called Fluidization process of contact that occurs between a solid and a fluid in which the bed formed by finely divided solid particles rises and is stirred by means of a current fluid upward. The flow of fluids through beds of solid particles (Fluidizat ion) is a process of wide use inindustrial operations such as: filtration, ion exchange and solvent extraction, absorption and Catalytic reactors. The team is composed by: a) Column of Fluidization: consists of a tube which travele d the fluid that will suspend the particles. b) Section uniformity: it is a diffuser cone that exists i n order to obtain a profile of desired speed. c) Distributor: consists of a plate with some holes, its de sign impact on the quality of Fluidization. d) Fluid supply system: consists of systems flow regulating valves,
OBJECTIVES Determine the phenomena related to flows in
solid-liquid system. Determine the minimum speeds of luidi!ation
Determine the loss of head in a "ed of parti#le Determinin$ the
e%pansion of the "edI&T'OD(CTIO&It is #alled luidi!ation
pro#ess of #onta#t that o##urs "etween a solid and a fluid inwhi#h
the "ed formed "y finely di)ided solid parti#les rises and is
stirred "ymeans of a #urrent fluid upward.The flow of fluids
throu$h "eds of solid parti#les *luidi!ation+ is a pro#ess of wide
use inindustrial operations su#h as, filtration- ion e%#han$e and
sol)ent e%tra#tion-a"sorption and Catalyti# rea#tors.The team is
#omposed "y,a+ Column of luidi!ation, #onsists of a tu"e whi#h
tra)eled the fluid that willsuspend the parti#les."+Se#tion
uniformity, it is a diffuser #one that e%ists in orderto o"tain a
profile of desired speed.#+ Distri"utor, #onsists of a plate with
some holes- its desi$n impa#t on the quality of luidi!ation.d+ luid
supply system, #onsists of systems flow re$ulatin$
)al)es-instruments- flow meters- heaters- and other de)i#es to
pro)ide thefluid in the thermodynami# #onditions.e+ .ressure
measurement system, it is important to measure the pressure drop in
a fluidi!ed "ed.f+ Temperature measurement system.In a "ed of
parti#les with upward flow- the flow of a $as or a liquid at low
speed notprodu#es the parti#les mo)ement. The fluid #ir#ulates
throu$h the holes of the "edlosin$ pressure. This pressure drop in
a stationary "ed of solids is $i)en "y theequation of Er$un. The
Er$un equation allows predi#tin$ losses "y fri#tion sufferin$
asin$le phase fluid as it passes throu$h a "ed pa#/a$ed.Otherwise-
if the fluid )elo#ity is in#reased pro$ressi)ely- in#reases the
pressure dropand the fri#tion on the indi)idual parti#les. It
rea#hes a point where parti#les donotremain stationary lon$er- "ut
"e$in to mo)e and are suspended in fluid- i.e.-0fluidi!in$0 "y the
a#tion of liquid or $as.The behavior of a bed fill is primarily
characterized by the following quantities:Beddin$ or fra#tion of
)oids- porosity 1, is the relationship "etween the )olume of)oids
of the "ed and the total )olume of the same *more solid
holes+Apparent mass of the pellets bed: ap is the relationship
between volume and massof pearls or beads occupied by
them.Fluidization mechanism:2e is a short- )erti#al tu"e partially
filled with a material to $ranular.If the speed of the fluid upward
is lar$e enou$h- on solids thrust for#e is equal to thenet wei$ht
of the parti#les- a moment in whi#h they "e$in to mo)e freely and
mi%withothers. The speed of the fluid for whi#h these #onditions
are rea#hed is #alledluidi!ation *(mf+ minimum speed and the "ed of
parti#les /nown as fluidi!ed "ed.3s it #an "e seen in i$ure4- in a
fi%ed "ed of parti#les from se#tion 3 and whosewei$ht is5- when it
rea#hes the minimum luidi!ation speed loss of load a#quires
itsma%imum )alue *w6a+ and stays on until the parti#les dra$-
de#reasin$ sharply in thattime. 3 pro$ressi)e e%pansion of the "ed-
whi#h is ha)in$ one porosity*1+- from thepoint of minimum speed
in#reasin$ of luidi!ation*1mf+ is also o"ser)ed durin$
thispro#ess.The useful for luidi!ation speed ran$e is "etween (mf
and the speed- *ua+for whi#h the solid parti#les are dra$$ed out of
"ed- the porosity is approa#hin$ theunit and elle#ho #eased to
e%ist as su#h.The team of Fluidization7. it wasdetermined whi#h was
the flow whi#h "e$an to ad)anta$e one of the "edswith the 8 )al)es
open and the pressure in ea#h of the "eds.TABLESTABLE1:
LECHOWITHTHESAME FLOWLEC! "#$TA%C#A CA&"AL '(E$#)% *cm+!,- 9:
7;:: 44.9+ 9:.; 7;:: 47.- 9: 79:: 7.; 9::: 9;.7888(E$<$rom
pre)ious data were requested, The #ur)e of the loss of load for the
three fluidi!ed "eds. The #ur)e of luidi!ation of "alls for ea#h of
the fluidi!ed "eds. minimum luidi!ation rate. The #ur)e of the
)ariation of the hei$ht of the "edTABLE5: DATAGENERAL'
SCOLUMNSC!L&3% #%TE(%"#A3ETE( *mm,E#2T *mm,T(A%$4E($AL$ECT#!%
A(EA*mm+,- ?: 7::: 4=4
