Novel anti-coking VDF cracking furnace system and using method thereof

Abstract

The invention discloses a novel anti-coking VDF cracking furnace system which comprises a cracking furnace, a waste heat recoverer and a quench cooler, wherein the cracking furnace is internally provided with a spiral furnace tube and partition heating devices from top to bottom; the waste heat recoverer comprises a first shell-and-tube heat exchanger and a first horizontal tank body, a first jacket is arranged outside the first horizontal tank body, a discharge port of the cracking furnace is communicated with the first horizontal tank body, a discharge port of the first horizontal tank body is communicated with a tube pass feed port of the first shell-and-tube heat exchanger, a cold material is introduced into a shell pass of the first shell-and-tube heat exchanger, a shell pass discharge port of the first shell-and-tube heat exchanger is communicated with a feed port of the first jacket, and a discharge port of the first jacket is communicated with a feed port of the cracking furnace; and the waste heat recoverer is connected with a feed port of the quench cooler, and a discharge port of the quench cooler is connected to a product collection process. The cracking furnace system can reduce coking in the cracking furnace tube and the heat exchanger pipeline, prolongs the cleaning period of the cracking furnace tube and the heat exchanger, preheats cold materials through the waste heat recoverer, and reduces 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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