Waste burning smoke purification process and purification system

Abstract

The invention discloses a waste burning smoke purification process. The process comprises a denitration step and an acid removal step. The denitration step comprises a combination step of a smoke recycling process and a selective non-catalytic reduction (SNCR) denitration process; the acid removal step comprises a primary acid removal step and a secondary acid removal step; and a spray drying method is used for removing acid in the primary acid removal step, and a suspension boiling method is used for removing acid in the secondary acid removal step. The generation of NOx is inhibited by the smoke recycling process, acidic gases in the smoke are removed by the secondary acid removal process, and the burned smoke is efficiently purified with relatively low operating cost. The deep purification effect of the smoke is achieved by organically combining several processes.

Description

technical field [0001] The present invention relates to a purification technology of flue gas produced by grate furnace incineration of waste such as general domestic waste, medical waste, hazardous waste and industrial waste, in particular to a waste incineration flue gas purification process and its purification system . Background technique [0002] With the process of urbanization and the development of industry and medical and health services, the treatment and disposal of various wastes has attracted more and more attention. As one of the most effective means of disposing of waste, waste incineration has been widely used. [0003] Since garbage is a mixture of complex components, taking domestic garbage as an example, it contains some organic compounds, chlorides, sulfides, fluorides, etc., and also contains a large amount of heavy metals. According to relevant data, the content of chromium is generally 100~ 450 g / t, nickel 50-200 g / t, copper 450-2500 g / t, zinc 900-3...

AI Technical Summary

Problems solved by technology

When the calcium-acid ratio is 1.2, the HCl removal rate of the semi-dry method can reach more than 95%, and the SOx removal rate can reach about 80%. When the calcium-acid ratio is 2:1, the HCL removal rate can reach nearly 97%. The removal rate of SOx can reach 95%, that is, the concentration of HCl in the exhaust gas can be controlled between 6 and 48 mg / Nm3, and the concentration of SOx can be controlled between 10 and 40 mg / Nm3, the continuous emission concentration still cannot meet the EU 2000 standard

Moreover, as the deacidification efficiency requirements increase, the amount of absorbent is becoming less and less economical

The spray drying semi-dry method has the following disadvantages: 1) In order to obtain a better deacidification efficiency, the lime slurry spray system is required to maintain a good atomization effect, which leads to increased power consumption of the system, serious wear of the spray system equipment, and high operation and maintenance costs. 2) When the concentration of acid gas in the original flue gas is high, the injection amount of lime slurry is limited by the outlet temperature of the reaction tower, and the adjustable range is small, so it is necessary to increase the concentration of lime slurry, and increasing the concentration of lime slurry will cause Cause blockage of the slurry pipeline, increase nozzle wear, reduce atomization effect, etc., affecting the continuous and stable operation of the deacidification system; 3) Some lime in the injected lime slurry fails to fully react with the acid gas in the flue gas In the ash, it is collected and discharged together with the fly ash, resulting in a large waste

[0017] In order to meet the ever-increasing emission standards of waste incineration flue gas, especially to solve the problem of low efficiency and high cost of the deacidification system, it is necessary to adopt more advanced and more economical , New more efficient flue gas treatment process

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