Gasifying grey water hardness-removing turbidity-lowering device and process method

Abstract

The invention belongs to a gasifying grey water hardness-removing turbidity-lowering device and a process method. The device comprises a three-stage flashing system which is connected with a clarifying tank through a grey water pipeline, a slurry outlet at the bottom of the clarifying tank is connected with a vacuum press filter through a discharging pump, a supernate outlet on the upper portion of the clarifying tank is connected with an inlet of a grey water tank through a T joint, an outlet of the grey water tank is connected with a to-be-used work section through a grey water pump, and thethird end of the T joint is connected with the inlet of the grey water tank through a grey water hardness-removing self-cleaning unit; the grey water hardness-removing self-cleaning unit comprises agrey water hardness-removing self-cleaning shell, an acidic gas exhaust port and a grey water inlet connected with the third end of the T joint are arranged at the top of the grey water hardness-removing self-cleaning shell, and a bottom outlet of the grey water hardness-removing self-cleaning shell is connected with a rotary screen portion. The device has the advantages of being simple in structure, reasonable in design, energy-saving, environment-friendly, low in running cost and capable of removing about 80% of hardness in grey water and effectively increasing stable running time of a gasifying grey water system.

Description

technical field [0001] The invention belongs to the technical field of coal chemical gasification gray water pretreatment, and in particular relates to a gasification gray water hardening and turbidity removal device and a process method. Background technique [0002] Coal-water slurry gasification, as the most effective clean coal technology to improve coal utilization, is the most coal gasification process device built in my country in recent years; the gray water of coal-water slurry gasification mainly comes from chilled water and washing water. The quenching water at the bottom of the quenching chamber of the gasifier and the gas washing water at the bottom of the carbon scrubber enter the flash system through the black water pipeline, and pass through the high-pressure flash tank, low-pressure flash tank, and vacuum flash tank step by step. After the high-temperature black water is cooled by flash evaporation, the ash and dust in the black water are concentrated, and t...

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Problems solved by technology

[0004] There is a large amount of Ca in gasification ash water 2+ , Mg 2+ , Si 2+ , Fe 2+ etc. When they reach a certain concentration, they will react with the HCO in the water 3 - and CO 3 2- Combined with the formation of carbonic acid precipitates and then scaling occurs, and in the production of CaCO 3 Scaling is the most common, CaCO at high temperature 3 Dissolved in water, when the water temperature drops, CaCO 3 It resolves into crystal nuclei and grows continuously, and adheres to the inner wall of pipes and equipment to form scales. At the same time, the scales will wrap a large amount of ash, making the formation of scales faster and harder, causing more damage to the cleaning work. It is very difficult, and what is more serious is that the pipeline will be blocked after the scale flakes fall off, which will seriously affect the normal operation of the system.

[0005] The existing gray water dehardening technology in the industry is divided into two categories, one is the electrocoagulation three-method integrated device, and the other is the combination of sodium hydroxide / sodium carbonate dosing method. The above two methods require additional water Adding chemical agents not only increases the operating cost, but also increases the presence of ions in the water, which increases the difficulty of sewage terminal treatment

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