© MANTRA Innovative Systems 2013

Tomorrow's Energy Solutions.
MUSHROOM FARM INVESTS IN GAS-TO-WATER EXCHANGER TO PREHEAT STEAM BOILER WATER
Boilers are used to supply the steam during the mushroom production process on an industrial level. The correct combination of humidity and temperature is critical when heat sterilization is applied during the pasteurization phase of production.




SELECTION CRITERIA
CHALLENGES
To contend with the rising cost of energy, this mushroom manufacturing facility sought a means by which energy lost through steam production could be reused, thereby reducing the process energy demand. The goal was to recover waste exhaust heat and use it to preheat three boilers’ return feed circuits. Due to the nature of the industry, a system manufactured to food-grade applications negating cross-contamination was essential. Each of the three boilers presented their own challenges in terms of flue alignments for the installation of the exchanger units.
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TECHNICAL DATA
Exhaust temp in: 446° F
Exhaust temp post recuperator: 212° F
Water temp in: 59° F
Water temp out: 208° F
Exhaust mass flow: 2,459 lb/h
Water mass flow: 978 lb/h
Energy recovered: 42.85 kW
Payback period: <10 months
SOLUTION
RESULTS
After an extensive feasibility study, three custom-built gas-to-water energy recovery units were selected to recover waste exhaust heat and preheat the boiler return feed circuits. The robust and self-contained nature of the energy recovery units facilitated an easy installation with only a simple insertion to the flue being required and a minor rerouting of the return circuits. Unlike the classical exchanger designs, the superior thermal transfer of the heat pipe units allowed for smaller exchanger volume, making operation in the restricted space feasible.
The net effect was a 25% reduction in overall boiler running costs and a 10 month return on investment for the production facility.