Boilers are used by many manufacturers to provide steam and hot water for process use via heat exchange, directly into product, or for cleaning purposes. Boilers use large amounts of water and energy so efficient operation can provide significant savings. Often the efficient use of water in boilers leads to a reduction in energy and vice versa. This fact sheet provides a list of opportunities to assist manufacturers in the more efficient operation of boilers.

Feed water is held in the deaerator (1) tank to help remove dissolved oxygen and is then treated (2) prior to entering the boiler (4). There are two types of boilers - water tube and fire tube. Water tube boilers heat water in tubes and the hot combustion gases are contained in the space around the tubes. Fire tube boilers on the other hand have hot combustion gases contained inside tubes and the water is circulated around these. An economiser (3) pre-heats feedwater using the flue gases from the boiler’s chimney. The water is heated in the boiler (4) to produce hot water and/or steam that can be used directly in the process or sent to a heat-exchanger (5).The heat-exchanger transfers the heat from the circulating boiler water to another media such as the product, as indirect process use. Any condensate (6) (steam that has condensed) is captured and returned to the deaerator for reuse. Because the build up of contaminants in the circulating water can cause biological growth, corrosion and scale, a portion of the circulating water is blown down (7).