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钢铁工业的轧钢加热炉、锻造炉、热处理炉及其它有色金属、化工、耐火材料、玻璃等工业炉窑,排出的废气温度都很高,带走了大量的热量,造成燃料的浪费。为了充分利用这些废热,通常要在烟道安置换热器,利用这些高温废气的热量把空气和煤气预热到适当的温度,以达到节约燃料和提高理论燃烧温度的目的。钢管换热器具有制造简单、气密性好、体积小等优点,它是目前应用最广泛的一种。钢管换热器一般采用壁厚3～5mm,直径15～100mm的无缝钢管制做。因为无缝钢管管壁较簿,所以它的抗氧化能力就决定它的使用寿命。一般来说,普通低碳钢管的换热器可以在低于600℃以下长期使用,高于600℃以上时,则钢管换热器的材质应选用不锈或耐热钢管。由于铬不锈、镍铬不锈管材的价格是普通低碳
Iron and steel industry, steel rolling furnace, forging furnace, heat treatment furnace and other non-ferrous metals, chemical, refractory, glass and other industrial furnaces, the exhaust gas temperature is high, take away a lot of heat, resulting in the waste of fuel. In order to make full use of these waste heat, heat exchangers are usually placed in the flue to utilize the heat of these high-temperature exhaust gases to preheat the air and gas to an appropriate temperature so as to save fuel and increase the theoretical combustion temperature. Steel tube heat exchanger has the advantages of simple manufacture, good air tightness, small volume, etc., which is currently the most widely used one. Steel pipe heat exchanger generally used wall thickness 3 ~ 5mm, diameter 15 ~ 100mm seamless steel pipe system to do. Because seamless steel pipe wall than books, so its antioxidant capacity to determine its service life. In general, the ordinary low-carbon steel heat exchanger can be below 600 ℃ the following long-term use, above 600 ℃ above, the steel heat exchanger material should be used stainless steel or heat-resistant steel. Due to the chrome stainless steel, the price of nickel chrome stainless pipe is average low carbon