Organic solid waste incineration high-temperature flue gas pretreatment quenching and tempering device and method

Abstract

The invention discloses an organic solid waste incineration high-temperature flue gas pretreatment quenching and tempering device and method which are used for pre-removing HCl, NOx, SOx, dust and heavy metals in flue gas at a high temperature (greater than or equal to 850 DEG C) to realize pretreatment quenching and tempering of the flue gas. The flue gas pretreatment quenching and tempering device comprises an adiabatic cyclone settling flue, an absorbent storage unit, an absorbent delivering unit and a nozzle; the adiabatic cyclone settling flue comprises an inlet flue, a cyclone separationchamber, a flow guide body, an exhaust pipe, a dust outlet and an ash collecting hopper; and the absorbent storage unit comprises a limestone powder storage bin, a kaolin powder storage bin and a urea solution storage tank. The invention aims to improve the defects of high and low temperature corrosion, dioxin synthesis promotion, heavy metal volatilization and the like in a traditional medium and low temperature flue gas purification mode, the treatment effect of removing various pollutants (HCl, SO2, NO, fly ash and heavy metals) cooperatively at high temperature is achieved by adopting anintegrated design, and the waste heat utilization efficiency is improved.

Description

technical field [0001] The invention belongs to the field of environmental protection, and in particular relates to a device and method for pretreatment and conditioning of high-temperature flue gas from organic solid waste incineration. Background technique [0002] As a treatment technology with the most complete harmlessness, the most significant volume reduction, and the highest degree of resource utilization, incineration has become an important technology for domestic waste treatment in today's international society. The secondary pollutants of waste incineration to the environment mainly come from the flue gas generated during the incineration process, which contains acid gases (HCl, SO x , NO x ), particulate matter, organic matter dioxins and heavy metals, etc., are all harmful to human health. Dioxin is a highly toxic substance, easily soluble in fat, and long-term ingestion can cause cancer, deformity, etc.; heavy metal components and content in fly ash are rela...

AI Technical Summary

Problems solved by technology

Dioxin is a highly toxic substance, easily soluble in fat, and long-term intake can cause cancer, deformity, etc.; heavy metal components and content in fly ash are relatively large, which is hazardous waste and has a huge impact on the environment

Therefore, if the secondary pollution generated by domestic waste incineration flue gas is not effectively controlled and treated, it will cause great harm to the environment and human health.

[0003] my country's large-scale domestic waste incineration flue gas purification system basically adopts the combined flue gas treatment process of "SNCR denitrification in the furnace + flue gas quenching + semi-dry deacidification + activated carbon injection adsorption of dioxins + bag filter dust removal". process, the flue gas is purified after passing through the heating surface of the waste heat boiler, and the temperature drops to the medium and low temperature zone (≤350°C). This medium and low temperature purification has the following problems: (1) High and low temperature corrosion of the heating surface of the waste heat boiler

[0004] In recent years, more and more researchers have paid more and more attention to the efficient and deep removal of pollutants in the flue gas of organic solid waste incineration. For the deep removal of the acid gas produced in the process of garbage or coal combustion, different adsorbents are added to the multi-stage cross-flow moving bed reactor, and the high-temperature flue gas is sequentially contacted with the adsorbent in the wrong direction. The gas is removed in a multi-stage depth; however, the inventors of the present application have analyzed and found that this method cannot carry out synergistic removal of fly ash and heavy metals, and does not remove the purification products

Chinese patent CN1426830A discloses an integrated method and device for flue gas and dust removal. A mixing granulator is used to mix and granulate the catalyst, desulfurizer and water-holding agent to form composite granules, which are humidified and activated by high-temperature steam together with the flue gas. into the baghouse, reaching the fly ash and SO 2 The purpose of removing simultaneously; But, the inventor of the present application analyzes and finds that this method can't work under the high temperature environment

Chinese patent CN107297142A discloses a flue gas purification method, which removes nitrogen oxides, sulfur-containing pollutants, dust and heavy metals in the flue gas through a series of means such as catalytic treatment, plasma treatment, chemical reaction treatment, and electric field adsorption treatment. However, the inventors of the present application have analyzed and found that the method requires more steps, the process is more complicated, and the cost is higher simultaneously, so it is not suitable for industrial application.

Chinese patent CN104147915A discloses a flue gas treatment method, which is mainly used for the flue gas treatment of waste incinerators. It adopts the method of injecting reducing agent into the incinerator for denitrification, and then performing desulfurization and dust removal in the low temperature section; however, the invention of the present application Human analysis found that the way of injecting reducing agent in the furnace has poor mixing effect and low efficiency. At the same time, desulfurization in the low temperature section may cause sulfuric acid to condense and corrode the heating surface

[0005] Due to the complex composition of waste, the composition of secondary pollutants produced by its incineration is also complex and changeable. The coordinated removal of various pollutants such as acid gas, dust, and heavy metals is a key issue in the incineration of organic solid waste. Most of the existing processes It is to process various pollutants step by step, with many steps and complicated process; at the same time, the traditional medium and low temperature purification can no longer meet the requirements, and the pretreatment and tempering of the incineration flue gas in the high temperature section can not only prevent the waste heat boiler from being heated surface corrosion, control the emission of dioxins and heavy metals, and improve the efficiency of the waste heat boiler; however, spraying calcium agent deacidification in the high temperature section will easily lead to the increase of sticky particles in the flue gas, such as the formation of calcium absorbent absorbing HCl The melting point of the CaCl product is 782°C, while the flue gas temperature at the outlet of the incinerator is around 900°C

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