Sludge desanding device, pretreatment device and method for municipal sewage plant

Abstract

The invention discloses a sludge desanding device for a municipal sewage plant, and the sludge desanding device comprises a pretreatment device and a main separating device, the pretreatment device is a prescreening sieve whose top is provided with multiple rows of rod devices obliquely arranged along the sludge flowing direction, in the rod device, ends of multiple rods are fixedly installed on a substrate while their other ends are regarded as free ends arranged along the sludge flowing direction. A sludge desanding method for the municipal sewage plant comprises the following steps of: firstly, preprocessing; removing soft fibers from primary sludge through the prescreening sieve and guiding underflow under the prescreening sieve into a slurry-storing tank; secondly, performing solid-liquid separation with hydraulic cyclone; thirdly, screening with a dewatering screen; desanding sludge from the municipal sewage plant through the mentioned steps. Through utilization of the device and the method, hairs and other soft fibers from the sludge can be effectively removed, thereby reducing gravels in the sludge, improving the content of the organic matter from the treated sludge, reducing the sludge concentration and preventing sediment from deposition.

Description

technical field [0001] The invention relates to the field of primary sludge treatment in urban sewage treatment plants, in particular to a sludge desanding device, pretreatment device and method for urban sewage treatment plants. Background technique [0002] In recent years, with the rapid development of society, the amount of urban sewage is also increasing day by day, and due to the society's high attention to environmental protection, the number of sewage plants is also increasing rapidly, and sludge as a by-product of sewage plants is also inevitable. Substantial growth. How to economically, effectively and safely treat and dispose of the large amount of sludge produced by these sewage plants has become an urgent problem to be solved in the field of sewage treatment in our country. In the process of sewage treatment, the accumulation of inert inorganic substances (silt) in the sewage treatment system not only affects the sewage treatment effect, but also the accumulati...

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Problems solved by technology

[0005] 1. Sewage treatment system equipment flow-through parts (pump casing, pipes and elbows) are severely worn, and equipment operation and maintenance costs are high; especially soft fiber substances such as hair in sewage can easily cause equipment damage

[0006] 2. The sludge quality is poor and the cement plant is unwilling to accept it, so the sewage plant has to pay a higher sludge disposal fee to the cement plant

[0007] 3. According to the general sewage treatment process, the primary sludge and the remaining sludge should enter the digester together for digestion. Due to its high sand content, the biogas produced by it is impure and cannot be used as a resource.

[0008] Various sewage treatment plants have carried out transformation on the original basis, or built advection grit chambers, or transformed the original gas type into a bottom stagnation type for sand-water separation, but none of them have achieved satisfactory results

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