Multi-stage thermal desorption technology and device for waste salt refining

Abstract

The invention discloses a multi-stage thermal desorption device for waste salt refining. The multi-stage thermal desorption device comprises a first-stage hot air heating furnace, a first-stage rotary kiln, a second-stage hot air heating furnace, a second-stage rotary kiln, feeders and an induced draft fan, wherein a feeding hole and one of the feeders are arranged at the top of the first-stage rotary kiln; the bottom of the first-stage rotary kiln is connected on the feeder of the second-stage rotary kiln through a pipeline; a discharge hole is formed in the bottom of the second-stage rotary kiln; an air outlet of the second-stage hot air heating furnace is connected with the bottom of the second-stage rotary kiln; a pipeline connected with the top of the first-stage rotary kiln is arranged on an air inlet of the second-stage hot air heating furnace; an air outlet of the first-stage hot air heating furnace is connected with the bottom of the first-stage rotary kiln; and a pipeline and the induced draft fan which are connected with the top of the second-stage rotary kiln are arranged on an air inlet of the first-stage hot air heating furnace. The device and a technology provided by the invention are mainly used for refining of waste salt, the structure is simple, the thermal desorption efficiency of organic matters is high, gases generated by thermal desorption are circularly utilized, no tail gas is generated, atmospheric pollution is avoided, and economic benefits and environmental benefits are achieved.

Description

technical field [0001] The invention relates to the technical field of hazardous waste salt treatment produced in pesticide, medicine, printing and dyeing industries, and in particular to a multi-stage thermal desorption process and equipment for refining waste salt. Background technique [0002] At present, my country's coal chemical industry, pesticides, dyes and other industries produce a large amount of polluted salt, with an annual output of millions of tons, and there is a lack of suitable treatment methods. These waste salts contain a large amount of toxic and harmful organic substances, and have a pungent smell, and are generally identified as hazardous waste by the local environmental protection department. At present, the relevant national departments have included the hazardous waste salt produced by the pesticide industry in the list of hazardous waste, and it does not need to be identified as hazardous solid waste. Because there is no clear standard or guidance...

AI Technical Summary

Problems solved by technology

[0005] 1) Hazardous waste salt sticks to the inner wall of the equipment, making the equipment unusable

Hazardous waste salt itself has a certain moisture content. When it enters the incinerator, rotary kiln and other equipment, it is easy to stick to the inner wall of the equipment under the action of high temperature, and the composition of the organic matter is complex during the decomposition process. Viscous organic matter will be produced, which will make the hazardous waste salt more firmly bonded to the inner wall of the equipment, making manual cleaning impossible, resulting in insufficient space for the equipment, and the equipment cannot be reused, resulting in the final waste of the equipment;

[0006] 2) Uneven heating and low processing efficiency

Such a heating method will make the heating temperature of the hazardous waste salt uneven, resulting in excessive local temperature or low local temperature, which will eventually lead to incomplete decomposition of the organic matter in the hazardous waste salt, and the inability to completely oxidize and decompose the organic matter, resulting in a treatment effect. bad

[0007] Patent CN201510063379.5 discloses a multi-stage thermal desorption repair system for organic polluted soil, which mainly uses two-stage thermal desorption treatment to perform thermal desorption treatment on organic polluted soil, but combined with its technical solution, Its thermal desorption produces a large amount of organic waste gas, which requires tail gas treatment and waste heat application, which requires the addition of tail gas treatment devices and waste heat reuse devices, which greatly increases production costs, and due to the technological conditions of soil thermal desorption and waste salt particles There is a certain difference in the process conditions of thermal desorption. In the process of thermal desorption, if the organic waste gas is recycled and heated, the generated organic waste gas is likely to be re-adsorbed in the soil, causing secondary pollution and causing the final product soil The purification effect becomes worse

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