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