Ethylene pyrolysis furnace

Abstract

An ethylene cracking furnace comprises a radiation segment, a convection segment, a bottom burner, sidewall burners and a quench boiler; the radiation segment is provided with a radiation room; radiation furnace tubes used for the pyrolysis of hydrocarbons and petroleum distillate are arranged inside the radiation room; each radiation furnace tube is composed of an inlet tube and an outlet tube; each inlet tube and each outlet tube are respectively provided with one channel; at least a radiation room 3 is arranged in the radiation segment of the cracking furnace; the radiation furnace tubes are arranged in two rows in the radiation room; each row of radiation furnace tubes forms a tube row plane; an inlet tube 6 and an outlet tube 7 of a radiation furnace tube are in two different tube row planes in an alternating interval way; the bottom parts of the inlet tube 6 and the outlet tube 7 are connected together through a symmetrical U-connector 8. The invention achieves a large-scale cracking furnace; the furnace tube arrangement way of the invention improves the radiation heat transfer efficiency of the radiation furnace tubes so as to prolong the operating cycle of the cracking furnace and reduce energy consumption of products.

Description

Technical field: [0001] The invention relates to a cracking furnace for producing olefins such as ethylene and propylene by pyrolyzing hydrocarbons and petroleum fractions. The utility model belongs to the field of hydrocarbon oil cracking equipment. Background technique: [0002] Since the successful development of the vertically suspended standpipe cracking furnace in the 1960s, ethylene cracking technology has made great progress. At present, the ethylene cracking furnace licensors are focusing their research on increasing the size of the cracking furnace, improving the selectivity of the cracking furnace, increasing the product yield, improving the safety of the cracking furnace operation, reducing the energy consumption of the product, and reducing the construction cost of the cracking furnace. . [0003] Patent CN1730449A describes a kind of ethylene cracking furnace structure and single-row arrangement of radiation furnace tubes. Although the cracking furnace of thi...

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Problems solved by technology

[0003] Patent CN1730449A describes a kind of ethylene cracking furnace structure and single-row arrangement of radiation furnace tubes. Although the cracking furnace of this kind of furnace tube arrangement has improved the traditional radiation furnace tube arrangement, it still has the following disadvantages: (1) in Under the premise of equivalent production capacity, the length of the furnace is longer than that of other cracking furnaces, and the volume of the cracking furnace is larger and the floor area is larger. Therefore, its manufacturing cost is higher; (2) The cracking furnace with alternately arranged inlet and outlet furnace tubes The distance between the furnace and the inlet and outlet furnace tubes is not large, which makes it very difficult to set up the hanging system of the radiation furnace; (3) The increase in the length of the cracking furnace not only has an adverse effect on the temperature distribution of the flue gas in the radiation chamber of the cracking furnace, At the same time, it is difficult to further improve the production capacity of a single cracking furnace

Its advantages are: compared with traditional pyrolysis, when it reaches the same production capacity, it has a smaller volume and a smaller footprint; its disadvantages are: (1) The inlet and outlet pipes of the radiation furnace tubes are arranged in a centralized manner, and the radiation furnace The heating of the tube will become uneven, and the use efficiency of the radiant furnace tube will be reduced; (2) The bottom of the inlet and outlet furnace tubes is connected with a straight pipe section through a 90° elbow, and the flexibility of the radiant furnace tube is limited, which is not conducive to absorbing the inlet and outlet furnace tubes. The thermal expansion of the tube is poor, which can easily lead to the bending of the radiant furnace tube, which will reduce the operational safety of the cracking furnace if the bending is serious

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