Situation: plant uses cold and hot water
A poultry processing plant used cold water for cooling and hot water for scalding. These processes had independent water supplies:
- Vacuum pump required constant cooling; it used 75 litres of city water per minute. Resulting warm water was drained.
- Scalding required 25 litres of hot water, which was supplied by a high-efficiency boiler.
Audit uncovered energy waste and a solution
Upon conducting direct metering of flows and temperatures auditors have found that vacuum pump received 3 times as much water as it was needed to support operation. After water flow was reduced, the resulting water became hot enough for direct use at scalding. Luckily, additional piping was only 30 ft.
Result: 30 ft of pipe saved $20,000 per year
With 16/5 operational schedule, change in settings and little piping enabled this plant to save
- 9 m3 per hour of natural gas for heating water or 37,440 m3 per year
- 75 l/min of water, 3,861 m3 pa
Additional savings were in waste water processing: reduction in drain water also reduced need for DAF chemicals and for DAF room energy use.
At Toronto rates direct savings of natural gas and water added about $20,000 to the bottom line.