A new anti-coking vdf cracking furnace system and its application method

Abstract

The invention discloses a new anti-coking VDF cracking furnace system, which includes a cracking furnace, a waste heat recovery device and a quencher. The cracking furnace is provided with a spiral furnace tube and a partition heating device from top to bottom; the waste heat recovery device includes a first tube The shell heat exchanger and the first horizontal tank body, the first horizontal tank body is provided with a first jacket, the discharge port of the cracking furnace is connected with the first horizontal tank body, and the discharge of the first horizontal tank body The mouth is connected with the tube-side inlet of the first shell-and-tube heat exchanger, and the shell-side of the first shell-and-tube heat exchanger is fed with cold material, and its shell-side outlet is connected to the inlet of the first jacket. connected, the discharge port of the first jacket is connected with the feed port of the cracking furnace; the waste heat recovery device is connected with the feed port of the quencher, and the discharge port of the quencher is connected with the product collection process. The cracking furnace system can reduce the coking in the cracking furnace tube and the heat exchanger tube, prolong the cleaning cycle of the cracking furnace tube and the heat exchanger, and preheat the cold material through the waste heat recovery device to reduce energy consumption.

Description

technical field [0001] The invention relates to the technical field of cracking furnaces, in particular to a novel anti-coking VDF cracking furnace system and its application method. Background technique [0002] Vinylidene fluoride (CH 2 CF 2 ) or VDF, is one of the important monomers in the fluorine chemical industry, mainly used in the production of polyvinylidene fluoride and fluorine rubber. There are many ways to prepare vinylidene fluoride. At present, 1-chloro-1,1-difluoroethane (HCFC-142b or R142a) is mainly used as raw material to prepare vinylidene fluoride through pyrolysis in industry. The cracking reaction is usually carried out in a cracking furnace. The cracking reaction is sensitive to temperature. When the temperature is too low, the conversion rate is low; when the temperature is too high, coking is easy to occur. At present, in the vinylidene fluoride (VDF) production industry, most of the furnace tubes of the cracking furnace adopt a U-shaped series s...

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Problems solved by technology

The cracking reaction is usually carried out in a cracking furnace. The cracking reaction is sensitive to temperature. When the temperature is too low, the conversion rate is low; when the temperature is too high, coking is easy to occur

At present, in the vinylidene fluoride (VDF) production industry, most of the furnace tubes of the cracking furnace adopt a U-shaped series structure, which is easy to coke at the bent tube at the bottom, and the coking of the cracking furnace will reduce the yield and shorten the operation period; The coke scale reduces the heat transfer coefficient and increases the wall temperature, resulting in an increase in energy consumption; at the same time, the deposition of coke scale makes the inner diameter of the furnace tube smaller, the pressure increases, the output decreases, the operating cost increases, and the life of the furnace tube is shortened; coking In severe cases, the pipes are even blocked, and the parking lot is forced to be stopped in order to remove coking, which directly affects normal production; in addition, the temperature of the product obtained from the cracking reaction in the cracking furnace is relatively high, and it is usually necessary to perform heat exchange and cooling treatment through a heat exchanger. Carbon powder will settle and coke in the heat exchanger pipes, which not only affects the heat exchange efficiency, but also requires regular shutdown to clean the coke, affecting normal production and reducing production efficiency

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