Thermal cracking simulation experiment device and method

Abstract

The invention discloses a thermal cracking simulation experiment device and method. The thermal cracking simulation experiment device comprises a raw material feeding device, a cracking furnace and aproduct quenching recovery device which are sequentially connected; the product quenching recovery device comprises a direct quenching system and a circulating quenching recovery system; the circulating quenching recovery system comprises a cracked gas circulating quenching loop composed of a mixing quencher, an indirect quencher, a cyclone separator, a gas circulating pump and a cooler; the mixing quencher is connected to a cracking furnace pipe discharging hole in a sealing way; the direct quenching system is used for horizontally arranging a quenching water injection pipe in an upper regioninside the mixing quencher; and a water injection hole is formed in the end of the water injection pipe. The thermal cracking simulation experiment device has the advantages that a high-temperature cracking product is directly quenched in the mixing quencher by sequentially using quenching water and a circulating gas product, so that the cooling efficiency is high, the injection quantity of the quenching water is small, the phenomenon that coking happens near the water injection hole of the quenching water injection pipe can be effectively avoided, and the accuracy of a simulation effect of the cracking furnace is improved.

Description

technical field [0001] The invention relates to a pyrolysis simulation experiment device and method, in particular to a thermal cracking simulation experiment device with a novel product quenching recovery device and a method 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 ensure the opti...

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Problems solved by technology

[0004] At present, the product quenching recovery device of the thermal cracking simulation experiment device is generally refrigerated in series by multi-stage indirect quenchers. Patent CN 204111681U discloses a thermal cracking simulation experiment device. The quencher of the thermal cracking simulation experiment device includes sequentially connected first cooling The first and second coolers respectively include a shell and a cracked gas pipeline installed in the shell. There is a cooling water flow space between the shell and the cracked gas pipeline, and the high-temperature cracking gas coming out of the cracking furnace tube After the gas passes through the quencher, the temperature drops to 200-300°C, and then it can be cooled to 3-5°C after passing through the two-stage water cooler and semiconductor refrigerator. The angle can make the decoking operation faster and more convenient, but its cooling efficiency is not high and the subsequent product separation and recovery needs to add multi-stage coolers, resulting in a large volume of the entire simulation experimental device, and it is inconvenient to disassemble and overhaul

However, if the quenching water is injected into the cracking furnace tube for direct quenching, the cooling efficiency is improved and the space is saved. However, when the high-temperature cracking gas passes through the quenching water injection hole area, the resistance increases, the residence time increases, and the high-temperature cracking gas is easy to flow at the end. Secondary reaction or even coking occurs in the vicinity; and it is necessary to inject quenching water about 2-3 times the amount of feedstock oil into the cracking furnace tube to instantly reduce the temperature of the cracked gas from 800-900°C to 40-55°C, introducing a large amount of Quenching water will cause pressure and temperature fluctuations in the furnace tube, and increase the load of subsequent indirect quenching and separation devices, which is not conducive to the separation of oil and water for the collected cracked liquid phase products; at the same time, a large amount of quenched water will be cooled and recycled to the cracked liquid phase when doing long-term tests Product storage tank, intermittent emptying of the cracked liquid phase product storage tank will cause pressure fluctuations in the entire simulation device system, affecting the normal experimental operation of the simulation device

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