coil to shell boilers

www.forbesmarshall.com


Energy Balance in a typical steam and condensate loop

Generation

100%

80%

Distribution losses

3-5%

Boiler House

Losses 15-18%

Trap &

Condensate 20%

Process demand

55%


Condensate

Drained and

Flash steam

vented @3bar

Losses from traps

– 75 Kgs/hr

Moisture drained..

350 Kgs/hr

Feed Water Tank

@ 30 Deg C

Process demand

500Kgs/hr dry steam

Boiler required capacity

= 1010Kgs/hr

Typical Steam & Condensate Loop Coil Type


The Issues


FWT@ 90 Deg C

Moisture Drained 2%

Condensate Recovery 20%

Process Steam Demand

Reduced to 450 Kg/hr

The Solution : Shell Type Boiler


Coil Type Boiler Shell Type Boiler

The Difference


Advantages

High dryness fraction 98.5%

Higher boiler efficiency 89%

Reduction in fuel bill by 30%

Higher plant output

Shorter heating cycle

Low maintenance

Steady steam output at fluctuating loads

Boiler life of more than 20 years


SOUNDS EXCITING !!!

A few more reasons to Change


Parameters Fuel Savings Criteria

Consumption

Coil Type Boiler 48.75 lt/hr 28% Eff = 75%

dryness fraction = 80%

Coil Type Boiler 49.85 lt/hr 30% Eff = 75%


Shell Type Boiler 35.49 lt/hr Eff = 89%


Savings due to

Flash Steam recovery Right Trapping

Dry Steam generation

Temperature & Pressure Control

Low Cost of Ownership


Actual Savings of

25 - 30%


Industry Coil Boiler Shell Boiler

Pharma Industry in Pune

Heating period for 100 ml (Autoclave) 55 mins 35 mins

Heating period for 500 ml (Autoclave) 66 mins 50 mins

Distilled water o/p from Multicolumn 200 lit 275 lit

Bottling Company

Bottles produced per Minute (BPM) 340 500

Rubber Company

Batch Time 8 Hrs 6 Hrs

Pieces per month 109,000 167,000

Increased Productivity


Coil Boiler Shell Boiler

Steam Quality Wet Dry Saturated

Constant Load Poor Steady

Fluctuating Load Water carry over as Steady due to sufficient

no steam space steam space

Instantaneous Loads Pressure Drop Steady Output

The 2 Q’s ….


Less load on

ETP

Lower

treatment

cost

Lesser blow

down

cycles.

Condensate

recovery

Savings in Water


Partial List of industries using Shell Type boilers –

1. Food 13. Personal Products

2. Garments 14. Beverages

3. Chemicals 15. Packaging Industries

4. Cattle feed 16. Plastics

5. Dairy

6. Educational Institutes

7. Rubber

8. Hotels

9. Hospitals

10. Formulations

11. Pharmaceuticals

12. Glass

More than 200 boilers in operation in the industries which

traditionally used coil type boilers

Reference List


The Old System

Feed Water Tank

@ 30 Deg C

35% Moisture

at 180 Deg C drained

Condensate Drained

and

Flash steam vented

@3bar

TD traps..!

850kg/hr 600 kg/hr

Pressure

Drop..


High Pressure Drop

Frequent Coil Failure

Increased Cycle Times

High Load on ETP

High maintenance costs

Problems


FWT@ 90 Deg C

Condensate at 95 Deg C

Condensate at 95 Deg C

recovered

Recoverable Flash

Steam @ 3 bar

1TPH boiler, dry steam load – 550Kgs/hr

Changed

to FT

traps..!

No Pressure

Drop..

The Solution !


o Fuel consumption reduced from 5 Tankers per 2 months to 4 tankers per 2 month.

(Saving of 6 tanker of 10000 Kg/Year)

o Reduced load on ETP… Practically the ETP remains idle now.

o For a Drum Heating process – The heating time has reduced from 10 hrs to 4

hours.

o Reactor heating process – 14 hrs to 8 hrs. (Endothermic Reaction)

Results Speak for themselves


• Reduced water charges and treatment charges.

• Reactor life improved. No knocking.

• No pressure drop problem.

• Reduced steam demand from 850 kgs/hr+ 600 kgs/hr=

1450 Kgs to 550Kgs/hr.

• Increase of plant production.

• Reduction in maintenance cost

Other benefits :

More improvements and Benefits

coil to shell boilers

Business

dry steam load

process steam demandreduced

reduced steam demand

shell type boilers

deg ccondensate

bar1tph boiler

boiler houselosses

deg c35