Device and method for indirect thermal desorption disposal of persistent organic pollutant contaminated soil

Abstract

The invention discloses a device and a method for indirect thermal desorption disposal of persistent organic pollutant contaminated soil. The device comprises a contaminated soil pretreatment system, a feeding system, a thermal desorption system, a discharging system, a tail gas purification system and an automatic control system, wherein the contaminated soil pretreatment system is connected with a feed opening of the thermal desorption system through the feeding system, a solid discharge opening of the thermal desorption system is connected with the discharging system, and a gas discharge opening of the thermal desorption system is connected with an inlet of the tail gas purification system. According to the method, after pretreatment, contaminated soil is conveyed to the thermal desorption system for desorption for 10-40 min at the temperature of 400-600 DEG C, and desorption exhaust gas adopts a technology including procedures of cyclone dust removal, two stages of spraying, drying and activated carbon adsorption / gliding arc degradation. The device and the method adopt indirect heating, so that risks of generation of poisonous materials such as dioxine and the like are avoided effectively; and a double-layer cylinder rotary kiln type furnace body, the furnace body axis and the ground form a 0-degree angle, and accordingly, the operation and maintenance costs are reduced.

Description

technical field [0001] The invention belongs to the technical field of physical and chemical treatment of polluted soil, and in particular relates to an indirect thermal desorption treatment device and method for persistent organic matter polluted soil. Background technique [0002] Persistent organic pollutants (POPs) refer to long-distance migration through various environmental media (atmosphere, water, organisms, etc.) Natural or synthetic organic pollutants that pose serious hazards to human health and the environment, mainly including organochlorine pesticides, polychlorinated biphenyls, and dioxins. In recent years, with the adjustment of my country's industrial structure and the acceleration of urbanization, as well as the signing and implementation of the "Stockholm Convention on Persistent Organic Pollutants (POPs)", a large number of pesticides, chemicals, coking, and steel that were originally located in the main urban area of ​​the city Such high-polluting enter...

AI Technical Summary

Problems solved by technology

The thermal desorption temperature of this invention is relatively low, at 50-300°C, only organic pollutants with low boiling points can be treated, and persistent organic pollutants with high boiling points cannot be effectively treated.

At the same time, its disposal efficiency is low, and the benzene series is generally only about 70-80%; the tail gas treatment device composed of a dust collector and a lye absorption tower in this invention cannot effectively treat trace organic substances in the tail gas; The design of the 5-10 degree angle between the axis and the ground increases the cost and difficulty of system operation and maintenance; the invention does not provide clear equipment operation control parameters

[0005] The invention with the patent number CN 102218446 A discloses a thermal desorption method for polluted soil. In this invention, the polluted soil is thermally desorbed at 400-650°C, and the flue gas generated by the desorption is incinerated at 750-1200°C. , the invention does not provide a complete thermal desorption device for realizing the above thermal desorption treatment

[0006] The patent No. CN 102357521 A discloses a method for continuous direct thermal desorption of persistent organic polluted soil, and the patent No. CN 102513346 A discloses a method for thermal desorption of organic polluted soil based on cement technology and The above two patents use incineration to dispose of the desorption tail gas, which increases energy consumption and disposal costs, and also has the risk of dioxin pollution

[0007] The invention with the patent number CN 102029287 B discloses a drum-type reverse thermal desorption system for organic-contaminated soil. The invention uses direct heating, that is, the heat source directly acts on the soil to separate organic pollutants from soil particles, and the disposal process will occur Incomplete combustion phenomenon, which has the environmental risk of producing toxic substances such as dioxin

[0008] All the inventions disclosed in the above-mentioned patents do not carry out a mobile and modular integrated design for the thermal desorption device system, and cannot realize the functional requirements of quick disassembly and assembly of the device and convenient movement

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