A dust removal process for coal-to-gas process gas

Abstract

The invention discloses a dust removal process of coal gas and process gas. The dust removal process comprises the following steps of (1) putting the process gas produced by a combustion reaction of coal water slurry in a gasification furnace into a first-stage venturi scrubber, removing most of dust particles, putting the process gas into a water knockout drum for rinsing and water knockout, and enabling the process gas to enter second-stage venturi scrubbers from the bottom; (2) respectively injecting an adsorbent into a throat pipe or a reducing pipe of the second-stage venturi scrubber, wetting the adsorbent particles with spraying water at the throat pipe, and enabling the adsorbent particles to impact and adsorb the rest of the dust particles in the process gas from bottom to top along the scrubbers; and (3) separating the adsorbent particles adsorbed with dust through a cyclone separator, then regenerating the adsorbent particles, conveying the process gas into a bag dust remover for filtering and dust removal, and enabling the process gas to enter the next process unit. By means of the process, tiny dust particles can be effectively removed from the process gas, so that the dust content of the process gas is reduced, the operating period of a device is prolonged, and the aims of saving energy and improving the efficiency are fulfilled.

Description

technical field [0001] The invention relates to a gas dust removal process, which is especially suitable for the purification and dust removal of process gas in the coal gas industry. Background technique [0002] In the coal gasification industry, the gasification process of coal water slurry is divided into two types: one is the gasification process of direct chilling method, and the other is the gasification process of total heat recovery type. Among these two processes, the former is widely used because of its simple process and easy control. Process gas dedusting after coal gasification is an important process of the gasification process, which directly affects the stable and continuous operation of subsequent devices. [0003] The gasification process of the existing direct chilling method is as follows: the process gas produced by the combustion reaction in the gasifier first enters the Venturi scrubber, fully contacts and mixes with the washing water from the atomiz...

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Problems solved by technology

[0004] At present, the common problems in this process are mainly manifested as: 1. The heat exchanger has serious dust accumulation, and the heat exchange efficiency drops rapidly. The dust is cleaned every 3-6 months. After one month, it is necessary to carry out the tower cutting operation and replace the new catalyst. The operation is cumbersome and the workload is heavy, which will increase the operating cost of the device; 2. In order to improve the dust removal effect and meet the process requirements, the washing tower should be designed with a thicker tower diameter and higher The tower is high, so the initial investment cost is relatively large, and the occupied area is also large

The reason for the poor dust removal effect of the current process: the dust particle size is small and the inertia is small. When encountering obstacles (relatively large droplets or liquid surfaces), it is easy to turn with the airflow, and it is not easy to hit obstacles (relatively large On the droplet or liquid surface), the larger particles containing the dust particles cannot be formed in the droplet, and the effective liquid-solid contact cannot be formed on the tray. Because the separation effect of the cyclone separator on small particle size particles is poor, only part of the liquid can be separated. The larger particles containing the dust are separated, so the dust removal effect of the scrubber is poor

[0005] CN202898362U discloses a coal-water slurry gasification system of a partial chilling process, which improves the energy recovery system after coal gasification, but still adopts the existing dust removal process, which cannot solve the problem of replacement caused by the high dust content of the process gas. Heater and pre-transformer dust accumulation problem

CN1944592A improved the existing process gas purification system, and added a second-level Venturi dust removal system, and the dust removal effect was improved, but the effect was not satisfactory

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