cast radiant coils for cracking heater by Qingdao Hexin Machinery Co., Ltd.

 cast radiant coils for cracking heater by Qingdao Hexin Machinery Co., Ltd.

The petrochemical cracking tube is suitable for cracking furnace (cracking furnace), which refers to the equipment used to carry out the cracking reaction of hydrocarbons. The requirement to the cracking furnace is: (1) the reactant can be quickly heated to 700～90CTC to ensure the equilibrium yield of ethylene, and heat supply and heat transfer need to be guaranteed; (2) the medium residence time is short, reducing the coke in the cracking process (3) suitable high temperature resistant materials. Due to the differences in the raw materials used for cracking and the method of providing the heat required for cracking, different types of cracking furnaces are used, such as regenerative cracking furnaces, sand furnaces and tubular cracking furnaces. The most widely used and the most mature technology is the tubular cracking furnace.

In the past, the cracking tube generally used HK-40 alloy steel containing 20% ​​nickel and 25% chromium as the material of the cracking reaction tube, which can withstand high temperature of 1050 °C. Due to the technical requirements to further improve the thermal strength of the furnace tube surface, after the 1970s, HP-40 alloy steel containing 35% nickel and 25% chromium was used, which can withstand high temperatures of 1100 °C. The diameter of the reaction tube is 2-7in (1in is equal to 2.54cm), it is made by centrifugal casting, and the interior is machined flat to reduce coking during the reaction.