, August 20, 2017

Energy Audit at Dairy plant at Anand, Gujarat.Print


A comprehensive energy conservation study of the Dairy plant at Anand, Gujarat. was carried out by PCRA.This Dairy is engaged in the manufacture of various qualities of milk & also other milk products like cheese, ghee, and ice cream in their plant.The total milk processed yearly is 17000 Kl . Annual Production of the plant Pouch – 17067 kl, Buttermilk – 1471.8 kl ,Ghee - 378.3 MT,Cheese – 322.3 MT,Ice cream – 536.02 kl,Paneer - 22.17 MT.There are 2 nos. boilers- 3 TPH each, for generating steam for use in the plant. The boilers use furnace oil as fuel. Annual fuel consumption is 237.7 KL. The unit takes its electricity supply from the GEB .The contract demand is 450KVA. Electricity is consumed in a variety of equipment in the refrigeration plant compressors & auxiliary equipment like cooling & chilled water pumps, air compressors, water & milk pumps & lighting. Annual electricity consumption is 22.82 LakhKWH.

A comprehensive energy conservation study of the plant was carried out by PCRA, The identified total annual energy saving potential is around Rs. 10.5 Lakhs on a recurring basis. The energy audit has identified several areas for energy conservation in thermal & electrical energy. The steps identified for energy conservation are given below:

  • The excess air level in all the boilers is satisfactory. However, some fine tuning can be done such
    that the oxygen % in the flue gases is 3.0%. This will result in improvement in boiler efficiency.
  • It is also recommended that the furnace oil storage & service tanks should be drained at least once a week. Furnace oil main storage tanks should be cleaned at least once a year to remove the sludge accumulated at the bottom of the tanks.
  • Furnace oil preheating is presently done by electric heaters. The 2 nos. steam heaters should be used & electric preheating of furnace oil should be stopped. Furnace oil is preheated upto 110 – 115 deg c which is correct practice.
  • Presently, the furnace oil pressure to the burner is set at 16 kg/cm2g. It is recommended that the
    furnace oil pressure to be raised from present level of 16 kg/cm2 to 20 kg/cm2 for proper atomization.
  • It is recommended that heat from the blowdown from Vidya I boiler be recovered by installing a
    blowdown heat recovery system.
  • Boiler blowdown is manual for the boiler. Boiler water should be checked periodically for TDS level.
    Blowdown level should be optimized based on permissible TDS level of 3500 ppm.
  • Steam line insulation was in good shape in the plant in. However, some the valves & flanges on the PRV stations are not insulated in the plant. It is recommended that the bare valves & flanges be insulated.
  • Condensate is not recovered from all the powder plant. Presently, an Ogden pump has been installed for the CIP PHE. However, it is not functional. It is recommended that the condensate from the CIP PHE be recovered. Also condensate from the cheese vat can be recovered as the quantity is significant.
  • The hot ammonia gas is discharged from the KC -4 compressor at a temperature of 110 – 120 deg c. It is recommended that a desuperheater be installed to preheat boiler feed water.
  • It is recommended that the contract demand be reduced from 450 KVA to 400 KVA. This will reduce the MD charges payable.
  • There are 2 nos. IBTs in the plant. One IBT is sufficient for meeting the chilled water load of the
    entire plant. The ice thickness maintained in the IBT is 5”. It is recommended that the overall ice
    thickness maintained in the IBT be reduced to 4”.
  • Presently, the compressor cylinders are unloaded manually based on the suction pressure. It is
    recommended that the compressor cylinders be unloaded automatically & the suction pressure be
    maintained between 30 – 40 psi. This is possible if the IBT thickness required is 4” as against 5”
    maintained earlier. Similarly, the booster compressor should be maintained 5 – 10 psi.
  • It is suspected that the air supplied by the cooling tower fan is less than required. It is recommended that the cooling tower manufacturer be contacted for increasing the air flow through the cooling towers. Alternatively, the plastic fills of the cooling tower are choked & need to be replaced.
  • It is recommended that the condensers be chemically descaled. This will allow operation of only one condenser & also reduce the discharge pressure of the compressor resulting in power savings.
  • The rated head of condenser & cooling tower water pumps is quite high at 25 meters. It is
    recommended that the impellers of these pumps be trimmed by 10%.
  • It is observed that the cream storage tank chilled water collecting pot is undersized & overflows
    from periodically. It is recommended that the sump capacity to be increased to avoid overflow.
  • It is recommended that the AHU fans be shut off when the required temperature is achieved & the ammonia supply is cut off from the AHU coil. This can be implemented for milk cold store/butter cold store.
  • It is recommended that mechanical pouch packaging machines be installed for replacing the 5nos
    pneumatic machines presently in operation in the pouch packing section.
  • Present lighting single phase voltage is 250 to 260 volts. Nowadays lighting transformers are
    available, which reduce the voltage to around 220 volts. The reduction in voltage also reduces power consumption with little reduction in lumens emitted by the light source. The savings due to
    installation of lighting transformer is 30% of the power consumption.

For further information, please write to:

Director (I/C),
PCRA,
Sanrakshan Bhawan, 10,
Bhikaji Cama Place,|
New Delhi-110066
Telephone: +91-11-26198856
Fax. +91-11-26109668
Web site: www.pcra.org