Beanz meanz 6% energy saving
14 Apr 2011
Wigan, UK – Heinz is saving 6% of its average steam load per year at its baked bean factory in Wigan – the largest food plant in Europe – by recovering energy from effluent using a system designed and built by Spirax Sarco.
The Heinz process begins by blanching the raw haricot beans in hot water. Starches and sugars leach from the beans into the water and agricultural residues are washed off. The blanching water must be purged regularly to maintain the necessary quality.
Before the new system was installed, the purged hot water was disposed of to drain. The Spirax Sarco system now intercepts it and uses it to help heat the blanching process, recovering around 1,500kW.
Filtered effluent is passed to one of two heat exchangers, which use its energy to pre-heat the blanching make-up water, cooling the effluent in the process.
The make-up water then passes through another exchanger, which uses steam to raise its temperature before entering the blanching vessel. The vessel itself is maintained at an optimum temperature by injecting live steam.
“It’s been in place for 18 months now and we are seeing excellent results from the heat recovery,” says Barry Aspey, environmental compliance manager at Heinz.
The 55-acre site in Wigan, north west England, produces canned soups, baked beans, pasta and puddings. It employs an on-site energy centre that generates up to 140 tonnes of steam per hour to keep the canning lines running.
