高温高气密性陶土换热器的研究

STUDY OF A CERAMIC HEAT-EXCHANGER WITH HIGH TEMPERATURE RESISTANCE AND HIGH AIR SEAL

陶土换热器具有耐高温和造价低的优点,广泛用于回收高温工业炉的烟气余热,预热空气回炉助燃,但其接缝多、漏气率高是影响使用的老大难技术问题。本文介绍1种新型密封方法,其特征在于将换热管和接头制成1个整体,并在接头上采用“(?)”型槽插入式密封结构,能有效地防止压力较高的空气漏入压力较低的烟气。经钢铁工业均热炉上使用表明,换热器漏气率为13％,在烟气温度1200℃时,空气预热温度达800℃,烟气余热回收率为60％,温度效率为66％,与传统陶土换热器相比,其使用寿命可延长1倍,取得节能15％和增产18％的综合经济效益。

Owing to its higher temperature resistance and lower cost, ceramic heat-exchanger has been extensively used for recovering residual heat from flue gases of high temperature industrial furnaces, to preheat air for furnace operation. However, such heat-exchanger has a main technical problem to be solved-it has many joints and higher leakage coefficient. Now a new sealing method is introduced in this article. This method makes the heat-exchanger tube and its joint together as a single body. The sealing structure on the joint is inserted in form of 'U' trough. Therefore, it can efficiently prevent the higher pressure air from soaking into the flue gas of lower pressure. Practice of a soaking pit at an Iron and Steel Company has proved that when the temperature of flue gas is 1200℃, the leakage coefficient of the new type heat-exchanger is 13%; the preheating temperature of air for operation reaches 800℃, recovery ratio of residual heat from flue gas is 60%, temperature efficiency is 66%. The service life of the new heat-exchanger is twice as long as the conventional one. Consumption of heat energy for soaking pit is 15% less than the old one, and the output of steel of the soaking pit is increased by 18%.