Flue gas heater – Applications in systems for incinerating hazardous waste, solid waste, domestic waste, medical waste, and sludge

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This post was last edited by B0SS on 2018-7-10 at 20:08. The flue gas after wet acid removal contains a large amount of water vapor; as a result, water accumulates in the exhaust fan after passing through it, and white smoke is generated upon exiting through the chimney, causing severe pollution to the surrounding environment. To address the issue of white smoke, a flue gas heater was installed after wet acid removal, using steam to raise the temperature of the flue gas, which was at around 60 °C after acid removal, to about 140 °C. This approach eliminated the corrosion caused by water vapor in the flue gas on the induced draft fan and chimney, as well as the problem of white smoke emanating from the chimney. The heat pipe-type flue gas heater consists of an outer sleeve and an inner sleeve; low-temperature flue gas flows through the outer sleeve while steam flows through the inner sleeve. The two fluids do not come into contact with each other, and heat transfer is achieved through heat pipes. Since the heat transfer coefficient of flue gas is lower than that of steam, fins are installed on the flue gas side to increase the heat exchange area there and thereby raise the heat transfer coefficient, which helps to reduce the overall size of the equipment. Product features: (1) Extremely high heat transfer performance – depending on the fluid inside the tube, the heat transfer coefficient can be 200 times that of ordinary carbon steel ； (2) High heat transfer capacity at low temperature differences ； (3) In heat exchange, both fluids flow outside the tubes, and fins can be used to enhance heat transfer efficiency ； (4) Single-tube operability: In heat exchange equipment composed of heat pipes, the damage to a single heat pipe has little impact on the equipment’s heat exchange capacity; even if some heat pipes are damaged, it does not affect the normal operation of the equipment ； (5) Heat source distribution: During design, the heat exchange length ratio between the cooling section and the steam section of the heat pipe can be adjusted as desired in order to control the wall temperature of the heat pipe. This allows the heat pipe heat exchanger to avoid the dew point, thereby preventing dew point corrosion and making it less likely for dust to accumulate ； (6) Spot welding is used between the heat pipe and the cylinder, allowing the heat pipe to expand and contract freely without being constrained, thus avoiding stress-induced damage. (7) Low fluid resistance and high heat exchange efficiency, reducing steam consumption. (8) The equipment has a compact structure, is corrosion-resistant, and has a long service life.