Established in the 1970s, Volac now has four UK and two overseas production sites producing products for the human and animal nutrition markets. Its dairy processing site at Felinfach, West Wales was acquired in 1989 and since then has benefited from significant investment. More recently this has included new process heating systems, heaters and associated pipework in a purpose built housing.
Volac already had a small Babcock Wanson thermal fluid heater in place, used to heat air to a high temperature in order to quickly dry liquid whey and turn it into powder. The company’s positive experience of both the heater type and Babcock Wanson led them to turn to the company when the decision was made to replace a large 5MW plus heater that had been in operation for many years. The heater was burning costly heavy fuel oil and was not particularly efficient.
To greatly improve energy efficiency, reduce the overall fuel bill and limit emissions, Babcock Wanson supplied Volac with two high efficiency EPC2500ES automatic coil type, multi-pass thermal fluid heaters, which offer a high efficiency solution to a very energy intensive process. The EPC ES heaters provide optimal distribution of the heat, high fluid velocity in the exchange tubes and continuous flow monitoring to ensure long fluid life and the highest level of safety. The EPC ES heaters also precisely match fuel input to plant energy requirements and include their own in-built exhaust gas to combustion air economiser for highest practicable operating efficiency. With lower energy input demand also comes lower total exhaust emissions, so there are also environmental benefits.
The EPC ES heaters have been supplied with modulating dual fuel burners. Primary fuel is Liquefied Natural Gas for the maximum turndown and high combustion efficiency with gas oil as the standby fuel. A bespoke thermal fluid combined deaeration and expansion vessel, thermal fluid pump and overflow catch tank were also supplied for the project.
“As we heat the air temperature to 210°C, thermal fluid systems are more suitable as they are more efficient and easier to operate,” Elgan Jones, chief engineer at Volac, commented. “If we used steam, the pressure would be very high. The thermal fluid system is a closed loop, plus we have swapped to running on gas with an economiser which makes for greater efficiency.”