SUB: STEAM ENERGY CONSERVATION BY INDOANUSHKA

EXISTING EQUIPMENTS USING STEAM:-

• PLANT HAS 5 STAGE FLAKE DRYER WITH STEAM USAGE CAPACITY OF ABOUT @800KG/HR . PRESENT STEAM USAGE IS ABOUT 500KG/HR. STEAM IS USED IN COILS WITH EVERY STAGE HAVING A SEPARATE COIL. SO THERE ARE FIVE CONDENSATE OUTLETS. THE CONDENSATE FROM THE OUTLETS WAS BEING DRAINED TO ATMOSHPHERE.
• PLANT HAS THREE COOKERS TO COOK THE CORN AND TOTAL 15 BATCHES ARE BEING COOKED PER DAY. AFTER EVERY BATCH, THE EXCESS STEAM AT  2 TO 2.5 BAR PRESSURE IS VENTED DIRECTLY IN THE ATMOSPHERE FROM THE COOKER.

IT WAS THEREFORE DECIDED TO WORK ON TWO FRONTS AT A TIME. TO EFFICIENTLY DRAIN AND RETURN CONDENSATE FROM THE DRYER TO FEED WATER TANK AND TO RECOVER THE HEAT OF VENTED STEAM FROM THE COOKERS ALONG WITH ARRESTING AND REDUCING THE TREMENDOUS NOISE THAT WAS CAUSED DURING THE STEAM VENTING FROM THE COOKERS.

IMPLEMENTATION

• 5 NOS OF IA MAKE BFT CONTINUOUS DISCHARGE TYPE STEAM TRAP MODULE HAVE BEEN INSTALLED FOR PROPER CONDENSATE REMOVAL FROM DRYER OUTLETS. IA MAKE BFT STEAM TRAP MODULE HAS ONLINE CLEANABLE STRAINER BEFORE THE TRAP TO PROTECT THE TRAP FROM BEING CHOKED OR LEAKED AND DOUBLE WINDOW SIGHT GLASS AFTER THE TRAP TO MONITOR THE PERFORMANCE OF TRAP. THESE ACCESSORIES HELP IN CONTINUOUS UNINTERRUPTED FUNCTIONING OF TRAPS.
• VENT SILENCERS WERE DESIGNED AND INSTALLED ALONG WITH CYCLONE SEPERATORS FOR EACH OF THE COOKERS TO EFFECTIVELY REDUCE THE NOISE OF STEAM EXHAUST.
• A 500LTR HOT WATER TANK WAS DESIGNED AND INSTALLED AND THE VENT FROM THE SILENCERS IS INJECTED INTO THE HOT WATER TANK TO GENERATE HOT WATER. THIS HOT WATER IS THEN PUMPED BACK TO THE BOILER FEED WATER TANK USING A STEAM OPERATED CONDENSATE RETURN PUMP.
• ONE NOS. COMMON IA MAKE 50NB STEAM OPERATED CONDENSATE RETURN SYSTEM HAS BEEN INSTALLED TO RECOVER THE 400 KG CONDENSATE PER HOUR FROM DRYER AND HOT WATER FROM COOKERS AT THE RATE OF 500 KG/ EXHAUST OF COOKER, AT THE MAXIMUM AVAILABLE TEMPERATURE.

SAVINGS ACHIEVED FROM IMPLEMENTING OF RECOMMENDATIONS.

TRAP MODULES

• TOTAL INVESTMENT FOR TRAP MODULES : 1,00,000 (20000X5)………(1)
• EFFICIENT STEAM TRAPPING AND CONDENSATE REMOVAL – NO NEED TO OPEN BYPASSES FOR CONDENSATE REMOVAL THEREFORE NO DIRECT STEAM LOSS

             CONDENSATE RETURN

 INVESTMENT OF CONDENSATE RETURN SYSTEM ( COMMON FOR DRYER AND HOT WATER GENERATED FROM COOKER) –  1,35,000/-……………..(2) 

SAVINGS FROM 500 KG/HR CONDENSATE OF DRYER:

CONDENSATE IS RECOVERED AT 95° C INSTEAD OF 35° C (FRESH WATER)

THEREFORE THE SAVING IS            = (95-35) x 500 KG x 16 HRS/DAY

= 4,80,000 Kcal per Day

THEREFORE MONETARY SAVING = (480000/540) X 1.5

TOTAL SAVINGS                               = RS.1,334 PER DAY

( 540 K.CAL/KG. IS THE LATENT HEAT OF STEAM AT ATM PRESSURE, 1.5 IS THE COST OF STEAM PER KG.)

               RUNNING COST

(3 KG. STEAM IS REQUIRED TO TRANSFER 1000 KG. CONDENSATE)

THE COST OF OPERATING A STEAM OPERATED PUMP    = 3 X 16 X 1.5

= RS.72 PER DAY

(TOTAL SAVING (ANS.A) MINUS OPERATING COST)

THEREFORE SAVINGS                                    = 1334 – 72

                                                                     = Rs. 1262…….(A)

SAVINGS FROM RETURN OF HOT WATER GENERATED FROM COOKER   VENT :

THE 500 KG WATER BEING HEATED FROM 30° C TO 80° C FROM EVERY VENT OF BATCH.

THEREFORE THE SAVING IS            = (80-30) x 500 KG x 15 BATCH

= 3,75,000 Kcal per Day

THEREFORE MONETARY SAVING = (375000/540) X 1.5

TOTAL SAVINGS                               = RS.1041 PER DAY…………………….. (B)

(WHERE 30°C IS THE ATM TEMPERATURE OF WATER, 540 K.CAL/KG. IS THE LATENT HEAT OF STEAM AT ATM PRESSURE, 1.5 IS THE COST OF STEAM PER KG.)

Therefore total savings achieved from Recommended Implementations

= 1262 + 1041 = 2303 PER DAY.……………..from  A & B

 THEREFORE SAVINGS IN A YEAR WOULD AMMOUNT TO 2303 X 300 =  Rs 6,90,900

The total investment from (1) & (2) above = 100000 + 135000 = Rs 235000

Cost of three silencers , piping, cyclone separators and tank fabrication as additional  Rs 70,000

Therefore total investment = Rs. 3,05,000

The total investment has paid it self back in 305000/ 2303 = 132 days.

Therefore return of investment was only 4 months and ten days.

 NOTE: WE HAVE CONSIDERED ONLY THE SAVING BY CONDENSATE RECOVERY. THE SAVING OF THE STEAM, WHICH WAS WASTED FROM LEAKED TRAPS AND OPEN BYPASSES, IS NOT CONSIDERED AS QUANTIFYING THE STEAM LOSS WAS NOT POSSIBLE PRACTICALLY IN ABSENCE OF FLOW METERS. IF THIS STEAM LOSS IS CONSIDERED THEN THE SAVINGS WOULD BE MUCH HIGHER.