The Open Country Cheese Company (OCC) in Waharoa, near Hamilton NZ operates a 10MW John Thompson coal fired water tube boiler.
The boiler supplies 10 bar saturated steam to the Cheese and Whey plant. Originally supplied in 1986 to National Textiles, Rutherford, NSW Australia, the boiler was dismantled and brought over in 2005.
The original fin tube feedwater economiser did not make it across the ditch. When OCC needed more steam and improved efficiency RCR Energy Systems was approach to design, manufacture and install a feedwater economiser.
The economiser heats feedwater on its way to the boiler by utilising the flue gas heat. Fitting the plain tube economiser adds nearly 15% to the boiler steam output.
When firing at its original rated output the economiser has the benefit of reducing the flue gas stack temperature to below 200°C.
Incidentally Dairy Trust, a new player in the NZ dairy industry, has recently taken a majority shareholding in OCC.
RCR Energy Systems, a business segment of RCR Tomlinson, was awarded the contract to supply two new 40 bar coal fired boilers for Dairy Trust - one for the OCC site and one for the new Invercargill dairy factory to feed the new milk powder plants being built at those sites.