High-efficiency and energy-saving thermal desorption treatment system for organic contaminated soil

Abstract

The invention discloses a high-efficiency and energy-saving thermal desorption treatment system for organic contaminated soil. The thermal desorption treatment system comprises a combustion system, a heat exchange system and a thermal desorption system, wherein the combustion system generates heat-carrying gas, and the heat-carrying gas flows through the heat exchange system and is partly or completely introduced into the thermal desorption system; in the thermal desorption system, the contaminated soil is heated by the heat-carrying gas to generate waste gas, the waste gas flows through the heat exchange system and is introduced into the combustion system to be combusted to generate heat-carrying gas, and the heat-carrying gas is recycled to be introduced into the heat exchange system and the thermal desorption system; and in the heat exchange system, the heat-carrying gas exchanges heat with the waste gas. The thermal desorption treatment system provided by the invention is simple in structure and low in energy consumption, and has an excellent effect in contaminated soil remediation.

Description

technical field [0001] The invention belongs to the field of soil remediation, and in particular relates to a high-efficiency and energy-saving thermal desorption treatment system and method for organic polluted soil. Background technique [0002] Thermal desorption remediation technology is a process in which organically polluted soil is heated to a certain temperature by direct or indirect heating, so that the organic pollutants contained in it can be volatilized or separated. Thermal desorption is a physical separation process that converts pollutants from one phase to another. By controlling the temperature of the thermal desorption system and the residence time of contaminated soil, the target pollutants are selectively volatilized. [0003] At present, the main scope of application of thermal desorption technology is semi-volatile and volatile organic pollutants, including polycyclic aromatic hydrocarbons, organic pesticides and insecticides, polychlorinated biphenyls,...

AI Technical Summary

Problems solved by technology

Although thermal desorption technology has the advantages of high treatment efficiency, wide range of pollutant treatment, and reusable soil after remediation, it also has problems such as high energy consumption and high treatment costs.

[0004] A drum-type reverse direct heating thermal desorption equipment (ZL201010598161.7), which adopts the method of countercurrent flow of hot gas and soil, which improves the heat utilization rate, but the clean heat source gas is mixed with the volatilized polluted gas, which increases the subsequent exhaust gas treatment. cost

Indirect thermal analysis equipment (CN101780467A) uses a rotary kiln with a double-layer structure to indirectly heat the soil, reducing the amount of tail gas treatment, but the heat source of the system is only used to heat the rotary kiln, and the heat utilization rate is low

The invention patent application document with the application publication number CN105537258A discloses a thermal desorption furnace. The volatile gas in the furnace enters the radiation burner for combustion treatment, and no other tail gas treatment equipment is added. On the one hand, the tail gas cannot be discharged up to the standard, and on the other On the one hand, the soil heating temperature is inconsistent with the tail gas combustion treatment temperature, and the respective system temperatures cannot be precisely controlled. Moreover, when continuous feeding is used, the concentration of volatile gases is low, and the energy consumption that can be saved through combustion is limited.

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