In the industrial/manufacturing sector dealing with heat is one of the single most expensive cost. Whether it is from generating heat for drying, curing, baking or through disposing of heat through exhaust, ventilation, air conditioning, or other cooling means such as cooling towers.
In today’s world, heat needs to be treated as a commodity. Harnessing heat and reusing it is essential to lowering energy cost. Whether the heat is in the form of air or water there are many options for capturing and utilizing this heat in a positive way.
Hot air is usually sent up a stack never to be heard from again. In some cases the hot air leaving a process can range from 350 degrees to well over 750 degrees. This heat is too valuable to let escape.
Stack economizers are a specially designed heat exchanger made for specific applications. There are air to water economizers made to transfer the heat from the exhaust air to water. This water can then be used as “free” hot boiler makeup water, or other uses where hot water is needed. There are also air to air heat exchangers. These are commonly used to pre-heat combustion air going into a boiler. In both cases, the air to water or air to air heat exchangers can improve boiler efficiency substantially.
Just as hot air is sent to the winds, often hot water is sent down the drain. This hot water can come from various cooling processes, boiler blow down or just hot water dumped at the end of a washing or rinsing cycle. This hot water can be filtered if need be and sent through a water to water heat exchanger. This hot water can be used to pre-heat boiler makeup, fill water for a washing cycle, etc. Tranter is an excellent source for plate heat exchangers which efficiently transfer heat from waste water to fresh water.
Heat can no longer be ignored as a waste product. It must be treated as a commodity and special attention must be paid to re-using it.