System and method for low-temperature thermal desorption of volatile organic contaminated soil

Abstract

The invention discloses a volatile organic contaminated soil low-temperature thermal desorption system which comprises a thermal desorption unit, the thermal desorption unit comprises a baking device,a cyclone dust collector, an indirect heat exchanger and an induced draft fan, the baking device comprises a baking oven, a conveyor is arranged in the baking oven, the conveyor is enable to enter from an inlet of the baking oven, and stretch out through an outlet of the baking over; a hot air inlet of the baking oven is formed in the lower portion of a box body of the baking oven, a hot air outlet of the baking oven is formed in the top of the box body, the hot air outlet is connected with the cyclone dust collector, the cyclone dust collector is connected with the indirect heat exchanger, and the indirect heat exchanger is connected with the induced draft fan. Preheated air is used for baking the contaminated soil to remove target pollutants in the volatile organic contaminated soil, the water content of the contaminated soil is rapidly reduced, the pretreatment time of the contaminated soil is shortened, and the occupied space for contaminated soil pretreatment is saved.

Description

technical field [0001] The invention discloses a system and method for low-temperature thermal desorption of volatile organic polluted soil and rapidly reducing the water content of the polluted soil, belonging to the field of polluted soil remediation. Background technique [0002] Due to historical reasons, there are generally many types of pollutants, high pollution concentrations, and deep pollution depths in domestic organic matter-contaminated plots. In the process of remediation and treatment of organic-contaminated land, there is also the phenomenon of "separation of soil and water", that is, with the increase of excavation depth of contaminated soil, the coexistence of contaminated soil and groundwater is very common. It is only possible to excavate the contaminated soil after establishing a water-stop curtain around the repaired plot and pumping the groundwater through the precipitation well. [0003] The water in the soil is divided into free water and bound wate...

AI Technical Summary

Problems solved by technology

[0004] (1) The moisture content of the polluted soil is too high, which will cause a substantial increase in operating costs during the thermal desorption of the polluted soil;

[0005] (2) The thermal desorption process cannot be carried out smoothly due to poor feeding of contaminated soil during the feeding and transportation process;

[0006] (3) For cohesive large-grained soil, it will lead to incomplete thermal desorption;

[0007] (4) Polluted soil with a high moisture content will adhere to the gaps of stones, concrete blocks, bricks, etc., or be entangled in plastic products, which will impede the incomplete treatment of these impurities mixed in the polluted soil, or with these substances The transportation of the transport causes secondary pollution

These engineering methods require a large pretreatment space; operators work in a closed greenhouse with high concentrations of target pollutants, which will cause great harm to the operators; at the same time, for organic matter with a higher boiling point polluted soil, These engineering methods may cause the soil after remediation to fail to reach the remediation target value

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