Biscuit factory in hot water

The factory decided to upgrade its system because the existing system of two, 1,000-litre calorifiers couldn't keep up with demand from the site's cleaning operations, especially at weekends. "Although we are often producing at the weekend, we don't usually have every line running, so that's when we wash absolutely everything," said central services charge hand Graham Walker. "The problem with calorifiers is that if you take out 500 litres you have to put 500 litres of cold water in and start heating that up again. It wasn't very efficient and we couldn't meet demand, causing delays in cleaning, and increasing our operating costs." The new Spirax Sarco EasiHeat engineered system (pictured) uses a steam-to-hot water plate heat exchanger to provide domestic hot water on demand. The compact system was supplied skid-mounted and ready to connect to the site's utilities. This approach is typically more energy efficient than systems relying on stored hot water because it eliminates a significant proportion of heat losses. "Cost savings are definitely there, although I'm not in a position to say exactly how much we've saved," Walker said. At the Fox's factory - part of Northern Foods - the site's operating schedule means that the two calorifiers can still be used as buffers. "We might have people cleaning until five or six o'clock on a Saturday, but having the buffer vessels means we can turn off the boilers at three o'clock if we've finished producing, which further improves energy efficiency." The new hot water system feeds the factory's taps directly on demand and can also maintain the temperature in the buffer vessels when it would otherwise be idle.