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Activities
• Cold Forging,
• Heat Treatment,
• CNC machining
Bengaluru, Karnataka
No of plants : 5
All certified for :
• IATF 16949 : 2016
• EMS ISO 14001 : 2015
1
“Surface Treatment using 100% waste heat
recovered from Furnaces & Compressors “
- An eco friendly approach
2
Need for the Project :• To meet customer demand, need to add heating capacity for
Phosphating line to augment from 23 tons/day to ~55 tons/day.
Trigger for the project :• High environmental issues from existing wood briquette boiler viz.,
smoke, ash, heat, noise, oil and ‘no go’ for addition of the same.• Space constraint for both phosphating baths as well as for heater is
an issue other than investment.• Capacity issue addressed by successive optimization of process
parameters, barrel size and automation.• SQF safety flames glaringly visible and heat going away – was the
trigger point.• Calculations show heat availability from SQF flame, but cannot meet
the demand completely. Idea extension to use waste heat from aircompressors that can eliminate the existing wood heated boiler.
3
Uniqueness of the project :• For the first time, heat recovery from SQF safety flame is done in
India & abroad to the best of information.• First ever conceived by us and referred to OEM for concurrence
before implementation. Risk involved in decision making to recover heat from safety flame and necessary mitigation applied.
Major milestones of project accomplishment :• Project concept, design, commercials : Jan’2018• Receipt of material, installation &
transition management : Apr’2018• Tryout, parameter optimization & validation : Nov’2018,
Initial target plan : Aug’18
4
Phosphating line capacity augmentation
5
Layout evolution Area Configuration2017 -
Befo
re
1,940
SFT
Barrel capacity : 250 kg
Fillings : 90 per day
Wagon : 1
Mode : Manual
22.5
tons/
day
Phase
1 -
2017
1,940
SFT
Barrel capacity : 250 kg
Fillings : 175 per day
Wagon : 2
Mode : Manual
43.7
ton/day
2018 -
Aft
er
1,610
SFT
Barrel capacity : 300 kg(Barrel size change)
Fillings : 185 per day
Wagon : 3
Mode : Auto – PLC 55 t
ons
/ d
ay
Parameters for optimization : Temp, pH & concentration, soaking time – trials and validation.
Gangway
Wall
Wood briquette fired heater
Wagon
Wagons
Gangway
Wall
Wood briquette fired heater
Gangway
Wall
Wood briquette fired heater
Wagons
6
Waste
heatCold Cold
Waste
heat
Waste
heat
Waste
heat
Waste
heatCold Cold
Waste
heat
Waste
heatCold Cold
Waste
heat
Waste
heatHeating mode
Neu
tral
izat
ion
Co
ld w
ater
rin
sin
g 6
Co
ld w
ater
rin
sin
g 5
Ph
osp
hat
ing
4
Ph
osp
hat
ing
3
Ph
osp
hat
ing
2
Ph
osp
hat
ing
1
Co
ld w
ater
rin
sin
g 4
Co
ld w
ater
rin
sin
g 3
Pic
klin
g 2
Pic
klin
g 1
Co
ld w
ater
rin
sin
g 2
Co
ld w
ater
rin
sin
g 1
Deg
reas
ing
2 (
30
kW
)
Deg
reas
ing
1 (
30
kW
) Running Running Running Standby Standby Running Running Running Running Standby Running Running Running Standby Running Running/Standby
Productivity Evolution
Wood Cold Cold Wood Wood Wood Wood Cold Cold Wood Wood Cold Cold Elec Elec Heating mode
Neu
tral
izat
ion
Co
ld w
ater
rin
sin
g 6
Co
ld w
ater
rin
sin
g 5
Ph
osp
hat
ing
4
Ph
osp
hat
ing
3
Ph
osp
hat
ing
2
Ph
osp
hat
ing
1
Co
ld w
ater
rin
sin
g 4
Co
ld w
ater
rin
sin
g 3
Pic
klin
g 2
Pic
klin
g 1
Co
ld w
ater
rin
sin
g 2
Co
ld w
ater
rin
sin
g 1
Deg
reas
ing
2 (
24
kW
)
Deg
reas
ing
1 (
24
kW
)
Running Running Running Running Running Standby Running Running Running Running Running Running Standby Running Running Running/Standby
Capacity : 45 tons/day
250 kg/barrel
170 barrel fillings/day
2 Wagons, Manual cycle
Capacity : 23 tons/day
250 kg/barrel
90 barrel fillings/day
1 Wagon, Manual cycle
Befo
re
Phase
1
Capacity : 55 tons/day
300 kg/barrel
185 barrel fillings/day
3 Wagons, Auto cycle-PLC
Fin
al
Wood Cold Wood Wood Wood Cold Wood Wood Cold Elec Elec Heating mode
Neu
tral
izat
ion
Co
ld w
ater
rin
sin
g 3
Ph
osp
hat
ing
3
Ph
osp
hat
ing
2
Ph
osp
hat
ing
1
Co
ld w
ater
rin
sin
g 2
Pic
klin
g 2
Pic
klin
g 1
Co
ld w
ater
rin
sin
g 1
Deg
reas
ing
2 (
18
kW
)
Deg
reas
ing
1 (
18
kW
)
Running Running Standby Running Running Running Standby Running Running Standby Running Running/Standby
7
Waste Heat recovery and its use
8
Safety flame or pilot burner in an SQF is provided to ensure that all
combustible gases are 100 % burnt to prevent furnace blast chances. This
flame is for safety and no work is done by the input energy.
SQFS
4 S
eale
d Q
uench F
urn
aces.
LPG input 50 kg /day for 4 SQFs
Methanol input 400 liters /day
Electrical 320 kW & 4,200 kWh/day
Safety flame to ensure 100%
burning of gases & prevent
furnace from blast chances
Waste heat quantity : 1,768 kWh/day
In an air compressor, 96% of energy inputs goes out in
the form of heat, heating up atmosphere around & loss of
energy . ~70% is recovered here.
Waste heat quantity : 2,400 kWh/day @ 70%
Compressors
4 C
om
pre
ssors
-225 k
W.
Heat recovery concept from SQFs and from Compressors
7
Process along value stream, recovery & usage points
Product family
Pulley, Pinion,
Hub, Driver & sleeve,
Switch Housings &
SP Housings etc.,
Location Processes Tonnage processed per month 1,350
RM inward
Slug Cutting
Annealing
Phosphating : Baths 550C to 800CHeat Input : 800 kg Wood briquette/day
+ Electrical Heating : 48 kW, Total : 3,504 kWh /day
Forging
2 Unit I,IV,VI & Savin CNC MachiningU1,U4,
U6 & S
3 External Surface Treatment
4 Unit III
Heat Treatment Washing m/c 600C - 800C
Heat Input : : Electrical : 4,200 kWh/d, LPG-50 kg/d,
Methanol : 400 l/day. Total : 5,918 kWh/day.
Waste heat : 1,768 kWh/d at 950C
5 Unit IV Grinding
6 U1,UII,UIV & Savin Inspn, pkg & disp U1,U3,U4
7 Unit III Compressed Air system Load : 225 kW, Consumption : 3,590 kWh/day.
Waste heat ~ 2,400 kW/d at 750C
1 Unit III
10
Sealed
quench
furnaces
Heat
Recovery
units
Air
Compressors
Degreasing Bath
70-80 deg.cDegreasing
Bath
70-80 deg.c
Phosphating (3)
Bath 70-75 deg.cPickling Bath
55-65 deg.c
Washing Machine
65-70 deg.c
Pickling Bath
55-65 deg.cNeutralization
Bath 65-70 deg.c
Heat Source Heat utilization
Excess Heat
Rejection Radiator
950C
750C
Stratified Storage tank
HRU
Schematic of Heat Recovery from SQF & Compressors
11
Heat recovery side Heat consumption side
Up stream and down stream piping scheme
12
Present recovered heat : 4,168 kWh/day , Total savings : 3,899 kWh/day.
Energy Balance – Recovery & consumptions
Description Units Value
No of Compressors No's 4
Compressor 1 to 4 kW 224
Present running 3,
1 standbykW 187.5
Heat Recovery from 3
running CompressorskW/h 2,400
No of Furnaces Nos 4
Gases Used - LPG/Methanol
LPG/Methanol Flow
RateKg/hr 2.05/13.22
Heat Recovery from
FurnaceskWh/day 1,768
Total energy recovered :
4,168 kWh/d & 173 kW
Ener
gy R
eco
vere
dAir Compressors
Sealed Quench Furnaces
13
Description Units Value
No of baths No's 16
Heating Method -Electric/
Thermic Fluid
Electric heater
capacitykW 2× 24
Degreasing Bath
EnergykWh/day 1,152
Briquette
Consumption/dayKg/day 800
Briquette energy
consmn/daykWh/day 2,507
Tank Capacity Liters 5,000
Heaters No× kW 9× 3kW
Total Energy
Consumed by heaterskWh/day 240
Total Consumption :
3,899 kWh/d @ 162 kW
Rec
ove
red
En
ergy
- c
on
sum
ed
Phosphating Process
Washing Machine
Tangible benefits UnitsPer
dayPer year
1 Wood briquette burning stopped tons 0.8 281.6
2 Energy Savings from wood briquettes kWh 2,507 882,464
3 Electrical Energy savings from 2 baths + W M kWh 1,392 489,984
4 Total energy savings kWh 3,899 1,372,448
5 Cost savings per day INR 14,016 4,933,632
6 Manpower savings : No briquette feeding Nos 3 3
7 Savings from manpower INR 2,833 1,020,000
8 Payback period Years 1.05
9 Cycle time reduction from57.5 min/ ton to 26.2
min/ton
10 CO2 reduction from saving of Elec energy 1,097 MT per annum
14
Intangible benefits
1 Zero smoke, ash within premises & to neighborhood.
2 No heat and flame from wood briquette fired boiler
3 No use of thermic fluid oil – Storage of 200 liters and weekly top up of 40 liters
4 Less chemical consumption due to low fluid circulating temp from 1400C to 950C
5 Heat around SQF and compressor area reduced, better comfort for operators
6 Employee morale high due to no noise, heat & dust.
7 There is shift towards positive attitude for working in this area
15
Challenges facedD
esi
gn a
nd r
isk iss
ues
• Placement of heat exchanger
coil above safety blame is
risky & may lead to explosion .
• 2 grades of heats – one from
SQFs of energy 1,176 kWh/d @
950C & 2nd from compressors
with 2,400 kWh/d @ 750C .
Both required to stop boiler
Usage range from 550C to 800C
• SS coils with bottom safety
tray to prevent any fall
reaching the flame.
• Deployed low water pressure.
• Use of ‘stratified heat storage
tank’ and graded flow control
to meet bath temperature
ranges.
• The biggest challenge faced was “scale deposition & fall of heat
transfer efficiency”
16
Main
tenance
• High deposition of scale on HE
coils in Phosphating and Pickling
baths.
• Fall of transfer efficiency in ~ 3
days.
• Intense cleaning efforts – not
practical. Scale hard in cool
condition.
• Heat exchanger design changed from coil type to ‘cassette’ type with fins on either surfaces for surface area.
• Special ‘shovel’ edge cleaning tool developed for on line cleaning when the scale is still soft.
• Cleaning efforts minimized and easier than before with wood boiler
Opera
tional
• Rotating barrel fouling with the
heat exchanger
• Increase in production rate
within project execution period
and demand for higher supplies.
• Provide guide slot on both sides
of barrels and protection sheet
on HE.
• Re-adjustment of system & heat
exchangers parameters to meet
higher capacity needs.
Challenges faced…
17
Implementation:
• Concept generation for phosphating line capacity augmentation & heat recovery system.
• Time plan considering lead times for design, commercials, analysis, approvals, PO, receipt of
equipment & controls, installation and transit during working.
• Concept tryouts & installation.
• Resolution of technical issues in the functional & operational issues faced.
• Line & process validation.
Realization of
equipment &
installation
Concept & design
for phosphating
line capacity
augment
Commercials,
analysis,
approvals
and PO Concept & design
for heat recovery
system.
Lin
e in
tegr
atio
n, t
ran
siti
on
m
anag
emen
t, r
eso
lve
tech
nic
al
issu
es &
try
ou
t. L
ine
& p
roce
ss
valid
atio
ns.
P
roce
ss a
nd
lin
e va
lidat
ion
18
Replication potential within SAAB group & progress
Project extension in Unit
(use up available heat)Units Values
Project extension at Shoolagiri
plant (horizontal deployment)Units Values
Molylube baths X 2 nos kW 48 Heat recovery from 2 nos SQF & use it for liquid
heating in washing m/c
Tray cleaning machine liquid
heaterkW 10
Washing m/c electrical
heating loadkW 60
Savings potential kWh/d 835 Savings potential kWh/d 821
Cost savings potential* INR/d 7,517 Cost savings potential # INR/d 7,387
• Payback : 7 months* & 10 month# Proposals ready & due for completion by Sept'19
19
# Phosphating line parameters Before Planned/impleme
nted (After)Highlights
1 No of baths 11 11
2 No of Wagons / cycle 01 03
3 Loading weight per wagon 250 kg 300 kg
4 No of fillings per barrel per day 90 times 185 times
5 Mode Manual Auto PLC used.
6Energy used/required for heating
per day3,504 kWh 3,899 kWh
7Quantity of wood briquette used
in kg/day
800 kg or 2,112
kWhZero
8 Electrical Energy used48kW 1,152
kWh/dayZero
9 Recovered heat used Zero 3,889 kWh/day100% recovered
heat used.
10 Floor area of the phosphating line 1,560 SFT 1,560 SFTNo change in line
area.
11Floor area of the wood heating
system380 SFT
50 SFT for Recovery
equipmentSaving of 330 SFT
12 Phosphating line capacity per day 25 tons/day 55 tons/dayCapacity increase
is 120 %20
Energy Saved 3,889 kWh/day or 1.32 mio. units / year : 100 % Green Energy
Environmental
benefits
- Smoke and ash totally avoided.
- Noise from blower motor is zero which was ~ 80 dB.
- No red hot surfaces & radiation heat from burner – increased
safety.
- Oil usage avoidance of 200 liters in the tank and consumption of
25 liters / week.
- Ambient temperature in SQF area is lower by ~ 4 0 C and also in
the compressor room due to heat recovery.
- Due to above plant is ‘Greener’
Carbon Foot
Print CO2 reduction of : 3,227 kg/day or 1,097 ton/ year
Environmental Benefits
21
# Savings parameter Before After Remarks
1 Phosphating line capacity25 tons per
day
55 tons
per day
2 Wood briquette consumption800 kg or
2,112 kWh/dZero
3 Electrical Energy consumption48kW 1,152
kWh/dayZero
4 Recovered heat used Zero3,889
kWh/day
100% recovered heat &
no other energy used.
5 Floor area of phosphating line 1,560 SFT 1,560 SFT No change in line area.
6 Floor area of the wood heating
system380 SFT
50 SFT for
HR Eqpt.
Wood burner stopped.
Saving of 330 SFT.
7No of operators for the whole
line24 24
No change despite
increase in line capacity.
8No of operators for feeding of
wood briquette round the clock.3 Zero
No wood briquette
feeding required.
9Phosphating line capacity per
day25 tons/day
55
tons/day
Capacity increase is
120 %
Results:
22
Replication in the sector is free for sharing
1. Project presented to all plants and groups with MDs participation.
2. Concept shared with OE for SQF & other HT operators.
3. Customer groups have evinced interest and details are shared.
4. Being shared at productivity summit 2019 by IMMTA.
Sharing in the internal forum on
07.03.19
• This heat recovery concept is applicable in all Heat Treatment processing
using SQFs even without a phosphating line.
• Recovered heat is usable for its own pre & post washing machines for liquid
heating.
• Potential in the sector is huge & our company invites & welcomes all
interested entities for open transfer of the project info & support them.23
Achieving bench marks / standards
• Input resource for Heat treatment using SQF is a function of :
- metallurgical parameters viz., surface & core hardness, case depth.
- part geometry,
- fixturing,
- pre-heating & tempering temperatures,
- batch size etc.,
Individual operators use the parameters to suit the product, hence only
internal bench marking is done
24
Internal Bench marking & improvements
Year
Heat Treatment :
Specific Energy
Consumption in kWh/kg
Measures
Phosphating : Specific
Energy Consumption in
kWh/kg
Measures
2017 0.677 Thermal mass
reduction &
fixturing material
change
0.171 Productivity,
process &
thermal
insulation
improvements
2018 0.491 0.110
2019 0.353 Heat Recovery 0.085
0.677
0.491
0.353
0.1710.11 0.085
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
2017 2018 2019
Heat Treatment SPEC in kWh/kg
Phosphating SPEC in kWh/kg
25
26
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