When heating the furnace, when should the air preheater be put into use?
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This post was last edited by zgj2405 on 2011-3-4 08:22. When heating a furnace, at what point should the air preheater be put into use? What are the consequences of using it too early or too late?
The type of air preheater used depends on its design – there are those with heat pipes and those using water as the heating medium. In fact, both types can be put into use when starting up the furnace; it’s not harmful to use them at low temperatures. However, at high temperatures, the heat pipe type may experience tube rupture, while the water-based heating medium can create vapor barriers that affect normal operation.
I agree with the view above; however, from the perspective of energy saving and consumption reduction, air preheaters generally use air and exhaust gas for preheating. There is no negative effect when they are used at low temperatures – it’s just that the preheating effect is not achieved due to the low temperatures. However, when it is put into use at high temperatures, on the one hand, an excessive temperature difference between the shell and tube sides of the preheater occurs, which can damage the preheater ； On the other hand, it cannot absorb the heat from the flue gas, reducing the efficiency of the heating furnace and leading to energy waste.