Steam thermal cracking simulating experiment apparatus and technology

Abstract

The invention provides steam thermal cracking simulating experiment apparatus and a technology. The apparatus comprises a raw material inlet device, a cracking furnace, a product quick cooling deviceand a product separation and recovery device, wherein the raw material inlet device, the cracking furnace, the product quick cooling device and the product separation and recovery device are connectedsequentially, the product quick cooling device comprises a direct cooling system and an indirect quick cooling device, an operation method of the direct cooling system comprises the following steps:a quick-cooling water injecting pipe is inserted vertically into a material outlet of a cracking furnace pipe, the end part of an inserted end is in the shape of a circular cone, water injecting holesare uniformly arranged in the bottom surface circumference of the end part of the circular cone shape, quick cooling water is directly sprayed into the cracking furnace pipe through the water injecting holes, and high-temperature pyrolysis gases subjected to quick cooling through the quick cooling water enter the indirect quick cooling device. The apparatus has the advantages that the novel product quick cooling device is adopted, thus quick cooling of the high-temperature pyrolysis gases is facilitated, pressure loss of the pyrolysis gases in the furnace pipe is reduced, coking near the quick-cooling water injecting holes is effectively prevented, smooth operation of the simulating apparatus is guaranteed, and at the same time simulation effect accuracy of the cracking furnace is improved.

Description

technical field [0001] The invention relates to a steam thermal cracking simulation experiment device and process, in particular to a steam thermal cracking simulation experiment device with a novel product quenching device and a process for performing cracking simulation experiments using the device. Background technique [0002] The trienes (ethylene, propylene, butadiene) and triphenyls (benzene, toluene, xylene) produced by the ethylene plant are the basic raw materials of the petrochemical industry and play a pivotal role in the petrochemical industry. At the same time, the level of ethylene production is It is an important symbol to measure the development level of a country's petrochemical industry. According to statistics, about 95% of ethylene and more than 50% of propylene in the world are produced by steam pyrolysis. At present, it has become one of the development trends of ethylene production to continuously improve the operation level of ethylene plants and ens...

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Problems solved by technology

[0004] At present, the product quenching device of the steam thermal cracking simulation experimental device is generally refrigerated in series by a multi-stage indirect quencher. Patent CN 204111681U discloses a steam thermal cracking simulation experimental device. The quenching device of the steam thermal cracking simulation experimental device includes a The first cooler and the second cooler connected sequentially by the feed port, the first and second coolers respectively include a shell and a cracking gas pipeline installed in the shell, and there is a cooling water flow space between the shell and the cracking gas pipeline, The high-temperature cracked gas from the cracking furnace is rapidly cooled by the quencher, and the temperature is reduced to 200-300°C, and then cooled to 3-5°C through two-stage water coolers and semiconductor refrigerators, although the first and second coolers Setting the axis of the pyrolysis gas pipeline with an included angle can make the decoking operation faster and more convenient, but the cooling efficiency is not high and the subsequent product separation and recovery device is equipped with multi-stage coolers. inconvenient

However, if the quenching water is injected into the discharge port of the cracking furnace tube for direct quenching, since the quenching water is in direct contact with the high-temperature cracked gas, the slight fluctuation of the injection amount of the quenching water will cause the temperature fluctuation in the quenching water injection port area, and the internal state of the cracking furnace tube will not be stable. Stable, at the same time, the insertion of the quenching water injection pipe into the cracking furnace tube will cause the cracking gas to increase resistance and residence time when passing through the quenching water injection hole area, and the high-temperature cracking gas is prone to secondary reactions and even coking near its end

Therefore, the structural design of the quench water injection pipe and the stable injection of quench water are important factors affecting the coking in the area near the quench water injection hole. The coking of the furnace tube will affect the heat transfer and mass transfer efficiency of the furnace tube, and thus affect the accuracy of the pyrolysis simulation effect. When the coking is serious, the pipeline will be blocked and the furnace must be shut down for coking, which will affect the normal experimental operation of the simulation device.

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