A direct sludge drying and incineration system and its drying and incineration method

Abstract

The invention relates to a direct sludge drying and incineration system and its drying and incineration method, comprising: a power unit for sending gas into a preheating unit, and the preheating unit heats the gas; the preheating unit, It includes an air preheater A installed in the high-temperature dust collector and an air preheater B installed in the inlet flue of the dryer. One end of the air preheater A communicates with the power unit, and the other end communicates with the air preheater. The heater B is connected, the air preheater B is connected with the air chamber of the incinerator, and the air preheater A is arranged in the lower ash section of the high temperature dust collector. It has the advantages of more reasonable process design, reduced energy consumption, energy saving and emission reduction, avoiding coking, and smoother system operation.

Description

Technical field: [0001] The invention relates to the technical field of sludge treatment, in particular to a direct sludge drying and incineration system and a drying and incineration method thereof. Background technique: [0002] Sludge is a solid sediment produced in the process of sewage treatment. It mainly contains a large amount of organic debris, bacteria, inorganic particles and colloids. If it is discharged randomly, it will pollute the environment. The sludge treatment method with dry incineration as the core is currently a relatively reasonable and effective treatment method. The use of dry incineration treatment method is more conducive to carbonization of organic matter, killing pathogens, reducing sludge volume, and is conducive to reducing sludge treatment. Quantification, harmlessness, stabilization and resource utilization. This method has been gradually promoted. [0003] At present, according to whether the high-temperature flue gas produced by sludge in...

AI Technical Summary

Problems solved by technology

However, the existing direct sludge drying and incineration system still has some shortcomings in actual use. First, due to the high water content of the sludge, the water content of the dried sludge is still between 30% and 40%. Therefore, the sludge cannot be fully incinerated by itself. The existing technology is to solve the problem by continuously adding auxiliary fuel (generally using biomass or natural gas as auxiliary fuel) to the incinerator. The existing solutions have high cost and energy High energy consumption and potential safety hazards; Second, the problem of secondary combustion and coking of ash and slag often occurs in high-temperature dust collectors during sludge treatment, which seriously affects production efficiency. The main reason is that the sludge in the incinerator is fine powder and unburned And / or incompletely burned sludge fine powder is easy to float up through the outlet flue of the incinerator and enter the high-temperature dust collector, where it is secondary burned in the high-temperature dust collector, which in turn causes secondary combustion and coking of the ash in the lower ash section of the high-temperature dust collector. Finally, the feeding leg is blocked. The existing technology mainly solves it by using air supply, that is, blowing air to the middle of the incinerator to supplement oxygen, hoping to fully burn the sludge, but because the sludge is in the form of fine powder, the rising speed is very fast , so the existing air distribution method can only be effective for the edge of the sludge, and it is beyond the reach of the central area of ​​the sludge. There will still be a large amount of sludge that is not fully burned and enters the high-temperature dust collector for secondary combustion. The existing technical means The technical effect is limited, and the problem of coking of the high-temperature dust collector has not been completely solved; there is another way to achieve it by raising the height of the incinerator. Although this solution can also solve the problem, it has the problems of difficult construction and significantly increased costs, and the incinerator After heightening, there will be a problem of increased heat loss, which is not worth the loss compared with the problem of coking, so this scheme has basically been eliminated

The above two technical problems are the main factors restricting the development of the direct sludge drying and incineration system at present

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