Ethylene cracking furnace structure of ethylene cracking furnace

The ethylene cracking furnace is divided into convection section and radiation section. Generally speaking, the function of convection section is to recover flue gas waste heat, which is used to preheat vaporized feed oil, superheated feed oil and dilution steam to the temperature of materials, and the waste heat is used to overheat ultra-high pressure steam and preheat boiler feed water. In the process of preheating and vaporizing raw materials, dilute steam is injected to reduce the vaporization temperature of raw oil and prevent coking of raw oil during vaporization. Each group of coils in the convection section of the cracking furnace is mainly composed of heat exchange tubes (smooth tubes or finned tubes) welded with return elbows. The end tube plate and the middle tube plate support the starting tube, and the inlets and outlets of some coils are gathered together through the header. The periphery of each group of coils is combined with the furnace wall to form a module.

The ethylene cracking furnace should be customized according to the process characteristics. At present, most of our domestic ethylene plant process packages are purchased from foreign advanced technology patents, and the cracking furnace is produced by bidding from several manufacturers designated by the designer according to the process design.

Cracking furnace is a big energy consumer in ethylene plant, and its energy consumption accounts for 50%-60% of the total energy consumption of the plant. Reducing energy consumption of cracking furnace is one of the important ways to reduce ethylene production cost. With the rising energy price, relevant departments at home and abroad have strengthened the research on energy-saving measures for cracking furnaces. The energy consumption of the cracking furnace largely depends on the design and operation level of the cracking furnace system itself. In recent years, cracking furnace technology is developing towards high temperature, short residence time, large scale and long operation cycle. By improving the cracking selectivity, improving the thermal efficiency of the cracking furnace, improving the heat recovery of high-temperature cracking gas, prolonging the operation cycle and implementing new energy-saving technologies, the energy consumption of the cracking furnace can be significantly reduced.