Ultra-clean treatment method for incinerated tail gas

Abstract

The invention discloses an ultra-clean treatment method for incinerated tail gas. The ultra-clean treatment method is characterized by sequentially comprising the steps that the tail gas continues to be combusted through a secondary combustion chamber; heat recovery is conducted on the tail gas through a waste heat boiler; the tail gas is cooled through a quench tower; baking soda powder and active carbon powder are sprayed into the tail gas exhausted out of the quench tower, and the tail gas, the baking soda powder and the active carbon powder are mixed and fed into a dust remover provided with a catalytic filtering bag to remove heavy metal and dioxin in the tail gas; and the qualified tail gas with the acid gas being removed is exhausted into the atmosphere through an induced draft fan and a chimney. The ultra-clean processing method is simple in technique. By treating and incinerating the tail gas through the method, spraying, washing and smoke reheating are not needed, the effect for removing the dioxin in the tail gas is good, fire disasters can be avoided, and the operation cost is reduced; and in addition, secondary pollution such as sewage is avoided. The ultra-clean processing method is suitable for treating the tail gas exhausted from household refuse and hazardous waste combustion furnaces.

Description

technical field [0001] The invention relates to a flue gas treatment method. Specifically, it is an ultra-clean treatment method used to treat exhaust gas discharged from domestic garbage and hazardous waste combustion furnaces. Background technique [0002] As we all know in the waste treatment industry, the commonly used processes for tail gas treatment of domestic waste incineration and hazardous waste incineration are: secondary combustion chamber + waste heat boiler + quench tower (also called semi-dry reaction device) + activated carbon and raw injection (also called Dry reaction device) + ordinary dust collector + heat exchange cooling + spray washing + flue gas reheating + chimney. After combustion, the flue gas enters the secondary combustion chamber for further heating and combustion. The combustion temperature is greater than 1100°C, and the flue gas residence time: >2s, allowing harmful substances to be completely burned. The flue gas from the secondary comb...

AI Technical Summary

Problems solved by technology

However, in actual operation, if the turbulent flow cannot be completely formed in the secondary combustion chamber, the incomplete combustion of the exhaust gas cannot completely decompose the dioxin

At the same time, it is impossible to quench the flue gas from 500°C to 200°C within 1 second in the quench tower, so it is difficult to avoid the regeneration of dioxin

Although there are activated carbon injection and bag filter behind the quench tower, the removal efficiency of activated carbon injection and bag filter for dioxin is limited, so it is difficult to discharge dioxin according to this process, especially to meet the latest national emission standard of 0.1 ngI-TEQ / m 3 even more difficult

[0004] The second is that dioxins are only adsorbed on the surface of activated carbon and are not really decomposed, which will cause secondary pollution and troublesome follow-up treatment

[0005] Third, in order to ensure a better adsorption effect, a large amount of activated carbon needs to be injected, not only the operating cost is high

And improper operation has caused a fire

[0006] Fourth, when the amount of flue gas changes greatly, it is difficult to control the amount of activated carbon injection, which not only easily causes waste, but also has poor dioxin removal effect

The process and equipment are relatively complicated, the energy loss is large, the system pressure loss is large, the power of the induced draft fan is large, a large amount of alkaline water is required for spray washing, the operation cost is high, and gypsum rain is easy to form

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