Heat recovery method of washing tower process water

Abstract

The invention discloses a heat recovery method of washing tower process water, which comprises the following steps: a liquid level of a heat-removed water buffer tank is established through desalted water F, the desalted water F is used as a source of heat-removed water, and heat-removed water G flows out of the bottom of the heat-removed water buffer tank to a heat-removed water circulating pump;and an inlet of the heat-removed water circulating pump receives heat-removed water G from the heat-removed water buffer tank, heat-removed water H is obtained after pressurization, and the heat-removed water H is sent to a shell pass inlet of a washing water cooler to serve as a cold source of the washing water cooler. On the premise of not increasing the consumption of circulating water and steam, the heat balance problem of the system is solved, the operating temperature of the washing tower is stabilized, scaling is avoided, the heat exchange efficiency of a heat exchanger is guaranteed,the overhaul frequency of the heat exchanger is reduced, and the yield of the device is increased.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for recovering heat from washing tower process water. Background technique [0002] The fluidized bed methanol to olefins process is mainly composed of a reaction regeneration device and a compression separation device. The main function of the reaction regeneration device is to contact the raw material methanol with the catalyst to generate process gas mainly composed of ethylene and propylene. The process gas is removed by gas-solid separation equipment. After a large amount of catalyst enters the quenching and washing system at the rear to further cool down and remove dust, the process gas with the temperature and dust content up to the standard is sent to the compression separation device for further processing. The reaction temperature is relatively high, generally about 380-400°C, and the process gas contains a large Water vapor, so the process gas will h...

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Problems solved by technology

[0002] The fluidized bed methanol to olefins process is mainly composed of a reaction regeneration device and a compression separation device. The main function of the reaction regeneration device is to contact the raw material methanol with the catalyst to generate process gas mainly composed of ethylene and propylene. The process gas is removed by gas-solid separation equipment. After a large amount of catalyst enters the quenching and washing system at the rear to further cool down and remove dust, the process gas with the temperature and dust content up to the standard is sent to the compression separation device for further processing. The reaction temperature is relatively high, generally about 380-400°C, and the process gas contains a large Water vapor, so the process gas will have a large amount of water vapor condensed during the washing and cooling process, which will greatly increase the temperature of the washing water. If the temperature of the washing water is not removed in time, the tower top and bottom will be damaged during the washing water cycle. Over-temperature will affect the washing effect of process gas. If circulating water is used to directly cool the washing water, it will inevitably increase the amount and scale of circulating water in the reaction regeneration device, and will also waste the heat of washing water. At the same time, the part of the separation device will be compressed The reboiler at the bottom of the tower needs part of the heat to heat and vaporize the material, and if it is directly heated by steam, it will cause unnecessary waste

[0003] There is a heat balance problem in the washing tower system in the existing process, and the temperature of the washing water cannot be removed in time, which is not enough for energy saving

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