Slag water treatment device and method in pulverized coal gasification process

Abstract

The invention relates to a slag slurry treatment apparatus in a fine coal gasification process, and a method thereof. The apparatus comprises an inclined plate inclined tube sedimentation pool and a rotational flow grit pool, the inlet of the inclined plate inclined tube sedimentation pool is connected with a water inlet tube, the outlet of the inclined plate inclined tube sedimentation pool is connected with a water outlet weir, the water outlet weir is connected with a water outlet channel of the rotational flow grit pool, and the water outlet channel of the rotational flow grit pool is communicated with a water outlet tube; an impeller is arranged at the bottom of the rotational flow grit pool; and a sand collecting bucket is arranged below the center of the bottom of the rotational flow grit pool, the rotational flow grit pool is connected with a sand-water separator, and the impeller rotates under the action of a driving motor. The method comprises the following steps: carrying out high pressure flash evaporation and vacuum flash evaporation of a slag slurry; sending the obtained slag slurry to the inclined plate inclined tube sedimentation pool for gritting treatment; sending to the rotational flow grit pool for gritting treatment; and allowing an obtained clear liquid to flow through the water outlet tube to a water tank. The apparatus and the method greatly improve the pollutant removal rate and reduce the water retention time.

Description

technical field [0001] The invention relates to the technical field of slag water treatment, in particular to a slag water treatment device and method in a pulverized coal gasification process. Background technique [0002] At present, the domestic coal gasification process is mainly divided into two types: coal water slurry gasification and dry pulverized coal gasification, represented by Texaco furnace and hydrogenation furnace respectively. The existing technologies in the slag water treatment of the two processes are basically the same, so the slag water treatment technology in the Texaco technology is used as the background technology introduction. Texaco gasification slag water system includes black water treatment and gray water circulation. Black water is the water from the gasifier, washing tower or water washing tower, hot water tower to the flashing device. Gray water is clear water after black water clarification treatment. Whether the slag water system operat...

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Problems solved by technology

[0005] The existing technology mainly uses the clarifier to carry out simple gravity sedimentation to realize solid-liquid separation after flash evaporation. The main defect is that this gravity sedimentation method is greatly affected by the physical properties of the slag water and the properties of the solid particles in the slag water, especially small particles. Substances are easy to form a suspension layer in water, resulting in low removal rate and unsatisfactory solid-liquid separation effect, which affects the subsequent reuse of gray water

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