Cracking furnace with double-row arranged radiant section furnace tubes

Abstract

The invention relates to an ethylene cracking furnace. The radiant furnace tube of the cracking furnace of the invention is a two-pass vertical furnace tube; the furnace tube is arranged in two rows, a first pass tube is connected with a second pass tube by a return bend pipe, and both the orthographic projection and the profile projection of the return bend pipe are U-shaped; and the first pass tube and the second pass tube of each radiant furnace tube are arranged in a plane A and a plane B. The cracking furnace of the invention has the advantages that the structure of the furnace tube is simple; as the first pass tube and the second pass tube of the radiant furnace tube are connected by the return bend pipe, the furnace tube is symmetrical and simple in structure and has better mechanical property; as a plurality of furnace tubes can be arranged in the hearth, the method is applicable to the capacity expansion reconstruction of the conventional cracking furnace, which can save investment, and finally fulfills the aim of improving the economic benefit.

Description

technical field [0001] The invention relates to an ethylene cracking furnace. Background technique [0002] In the ethylene plant, the cracking furnace is the core equipment. The design of the radiant coil is the key to determine the cracking selectivity, increase the olefin yield of cracked products and improve the adaptability to different cracking raw materials. Improving the structure and arrangement of radiant coils has become the core part of the development of tubular cracking furnace technology. For more than 20 years, there have been radiant coils with different structures such as single-row branch reducer, mixed-row branch reducer, non-branch reducer, and single-pass equal-diameter pipe. [0003] In order to greatly reduce raw material consumption, maintain an appropriate operating cycle and have better raw material adaptability, most companies currently use two-pass (18-28m) branch variable diameter or two-pass variable diameter high-selectivity furnace tubes, w...

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Problems solved by technology

[0008] The arrangement of the furnace tubes has developed from the initial single row to double rows. For a single row, the same capacity requires a larger footprint. The advantage is that the radial temperature distribution of the furnace tubes is uniform and there are fewer cases of shading; For the double row, the floor area of ​​the cracking furnace is greatly reduced, but the shading situation is more serious, which affects the radial temperature distribution of the furnace tube, and the connection between the first pass and the second pass tube is easy to cause the furnace tube the bend

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