Sludge freezing pelletizing method and device

Abstract

The invention discloses a sludge freezing pelletizing method and device and belongs to the field of solid waste treatment. The sludge freezing pelletizing device comprises a roller press, a serrated knife molding machine and a stirring type drying machine from top to bottom in sequence, wherein sludge which is simply dried in air and disposed by precipitating is conveyed into the roller press to be frozen through a feeding machine and then is rolled into thin sludge cakes; the thin sludge cakes are then frozen and cut into bars by using the serrated knife molding machine; the sludge bars are broken into granules under the action of gravity; sludge granules are fed into the sealed stirring type drying machine and are heated and turned over for multiple times, then moisture of the sludge granules is sublimated and vaporized to an appointed range; and the sludge granules are further conveyed to an appointed position by a discharging machine, and then sludge freezing, drying and pelletizing are completed. By adopting rolling pelletizing and step-by-step treatment, the sludge freezing pelletizing method has relatively high energy utilization rate and relatively good drying effect.

Description

technical field [0001] The invention belongs to the field of solid waste treatment, and in particular relates to a method and device for freezing and granulating sludge. Background technique [0002] With the development of my country's social economy and urbanization, the generation and quantity of urban sewage are constantly increasing. According to relevant predictions, the amount of urban sewage in my country will increase significantly in the next 20 years. At present, my country's annual output of dry sludge is nearly 3×106t. With the development of domestic sewage treatment business, the total treatment water volume and treatment degree of sewage treatment plants continue to expand and improve, and the amount of sludge produced will also increase day by day. A large amount of sludge has not been treated in a timely and reasonable manner, which has become a heavy burden for sewage treatment plants. Sludge also contains a large amount of N, P, K, Ca and organic matter...

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Problems solved by technology

[0006] However, in the process of processing sludge to press sludge, because sludge with high water content and viscosity is easy to bond, this device can only treat sludge with low water content and low viscosity, and the scope of application is obvious. On the other hand, because the viscosity of the sludge is not enough to keep it in a strip shape, it is easy to break and accumulate during the turning process, which makes the drying efficiency of the device lower, which is not conducive to saving energy. way, maintain the molding effect of sludge particles, and increase the cost of drying, which is not conducive to green treatment; it can be seen that the effect of sludge granulation is very important for drying treatment

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