Efficient waste heat using organic contaminated soil displacement thermal desorption repairing system and method

Abstract

The invention relates to an efficient waste heat using organic contaminated soil displacement thermal desorption repairing system and method. A burner is communicated with a high temperature oxidizingchamber, a high temperature smoke pipe of the high temperature oxidizing chamber is communicated with a rotary kiln heating processing system and an air heat exchanger, a high temperature air outletof the air heat exchanger is communicated with the burner, a smoke pipe of the air preheater is communicated with an inlet of a quench tower, an outlet of the quench tower is communicated with an inlet of a bag-type dust collector, an outlet of the bag-type dust collector is communicated with an inlet of a deacidification tower, an outlet of the deacidification tower is communicated with an air inlet of a second induced draft fan, and an outlet of the second induced draft fan is communicated with a chimney. A part of high temperature flue gas generated by the burner enters a rotary kiln thermal desorption reactor to achieve desorption of organic pollutant and soil drying pretreatment, organic matter enters the high temperature oxidizing chamber through a backflow pipe for burning treatment, and thorough oxidative degradation removal is achieved; and the other part of high temperature flue gas is used for increasing the temperature of combustion air through the air heat exchanger.

Description

technical field [0001] The invention relates to an ex-situ heat desorption restoration system and method for organic polluted soil with high efficiency utilization of waste heat, and belongs to the technical field of ex-situ heat desorption restoration system for organic polluted soil. Background technique [0002] At present, with the implementation of "retreat from the second to the third, and retreat from the city to the garden", many domestic polluted sites, especially chemical polluted sites, have found serious organic pollution in the soil. If timely and effective control measures are not taken, it will pose a health threat to the surrounding atmosphere and organisms, and may seep into groundwater with rainwater deposition, seriously threatening human health. The problem of soil organic matter pollution has aroused widespread concern, and soil restoration is imperative. [0003] The current organic site pollution in my country is mainly non-chlorinated organic polluta...

AI Technical Summary

Problems solved by technology

[0005] Chinese patent (CN 204247684 U) discloses a thermal desorption system for polluted soil with highly efficient reuse of waste heat. Part of the high-temperature flue gas produced by the combustion chamber is directly cooled, resulting in a large amount of heat loss; while another part of the high-temperature flue gas from the combustion chamber The air mixed with fresh air enters the rotary kiln, which increases the oxygen content in the thermal desorption area, and also increases the risk of toxic substances such as dioxins in the thermal desorption process to a certain extent.

Chinese patent (CN 102218446 A) discloses a system for utilizing waste heat in the process of thermal desorption of polluted soil. The device adopts two-stage combustion, the energy consumption of the system is high, and the disposal cost is bound to increase; waste heat power generation needs to be equipped with steam turbine power generation Unit, complex system, high cost

[0006] Chinese patent (CN 105080957 A) discloses a thermal desorption repair system for contaminated soil that reuses waste heat. It uses a surface heat exchange device to preheat the high-temperature exhaust gas generated during the repair process to the combustion-supporting air at normal temperature. The tail gas treatment process adopts activated carbon adsorption, which does not realize the complete degradation of pollutants, but only realizes the transfer process of pollutants from the gas phase to the solid phase. After the activated carbon is saturated with adsorption, it becomes hazardous waste, which requires secondary treatment, and the disposal cost is high.

Chinese patent (CN 104741372 A) discloses a new thermal desorption repair system and method that uses charcoal instead of activated carbon as an exhaust gas adsorbent and uses charcoal mixed with polluted soil as a combustion heat source for thermal desorption heat supply. This invention does not provide Complete thermal desorption unit for the above thermal desorption process

Moreover, the adsorption effect of charcoal on dioxins needs to be further verified.

[0007] Chinese patent (CN 101530858A) discloses a direct thermal desorption device for polluted soil, in which the hot air contacts the polluted soil in the same direction, which cannot fully mix the hot air and the polluted soil, and the thermal desorption efficiency is low

Chinese patent (CN 101780467A) discloses an indirect thermal desorption equipment for contaminated soil. The core device of the patent is a heating rotary kiln composed of an inner structure and an outer structure. The heating and combustion system heats between the inner structure and the outer structure. Contaminated soil and heat source cannot fully contact and exchange heat, resulting in low thermal desorption efficiency

[0008] The above ex-situ thermal desorption systems or devices have disadvantages such as low heat utilization efficiency and unreasonable tail gas treatment design.

Images