A two-pass radiation section furnace tube for ethylene cracking furnace

Abstract

The invention discloses a two-range radiant section furnace tube used for an ethylene cracking furnace. Every two first-range furnace tubes are connected by an arced first-stage collection tube. The upper two tube orifices of the first-stage collection tube are connected to two first-range furnace tubes respectively. Two first-stage collection tubes are connected to an arced second-stage collection tube, the upper two tube orifices of which are connected to the lower tube orifices of the first-stage collection tubes respectively. The lower tube orifice of the second-stage collection tube is connected to a bent tube, the other end of which is connected to a second-range furnace tube. The two-range radiant section furnace tube provided by the invention can eliminate the additional force generated by deformation of a furnace tube bottom connecting piece to a radiation furnace tube, thus avoiding bending deformation of the radiation furnace tube, prolonging the operation cycle of a cracking furnace, and extending the service life of furnace tubes. At the same time, the flow rate fluctuation of reaction materials in the tube is small, no flow retention area appears, and the residence time of materials in the tube is reduced. The two-range radiant section furnace tube provided by the invention is in favor of hydrocarbon cracking reaction, and improves the yield of objective products.

Description

technical field [0001] The invention relates to the field of ethylene cracking furnaces, in particular to a two-pass radiation section furnace tube for ethylene cracking furnaces. Background technique [0002] The ethylene tubular cracking furnace is the core device in the current ethylene production. In recent years, my country's ethylene production has continued to increase. As of 2011, the total annual production of ethylene in my country has exceeded 15 million tons. During the "Twelfth Five-Year Plan" period, 800,000 tons of ethylene per year in Chengdu, Sichuan, 800,000 tons of ethylene per year in Wuhan, 1 million tons of ethylene per year in Fushun, and 1.2 million tons of ethylene per year in Daqing will all be put into operation one after another. Technological progress in this field will bring huge economic efficiency and social benefits. [0003] The world's patentees who develop ethylene tube cracking furnace technology include ABB Lummus Global, Technip, Stone...

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Problems solved by technology

[0006] In order to solve the existing 4-1 type, 5-1 type, 6-1 type and 8-1 type furnace tube connection structure and arrangement method, some furnace tubes such as collecting tube, bent tube and straight tube Uneven heating, bending deformation, shortened service life of the furnace tube, and shortened cracking furnace operating cycle. The tube form connects the first-pass furnace tube and the second-pass furnace tube, eliminating the additional force of the deformation of the bottom connection part of the furnace tube on the radiation furnace tube, avoiding the bending and deformation of the radiation furnace tube, prolonging the operating cycle of the cracking furnace and prolonging the service life of the furnace tube. At the same time, due to the use of arc-shaped collecting pipes and curved pipes, the flow rate fluctuation of the reaction materials in the pipes is small, and there is no flow stagnation area, which reduces the residence time of the materials in the pipes, is beneficial to the cracking reaction of hydrocarbons, and improves the yield of the target product.

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