High-dryness squeezing method for sludge

Abstract

The object of the invention is to provide a high-dryness squeezing method for sludge. The method has the advantages that the moisture content of sludge cakes is effectively lowered, and the squeezing time is short. According to the method, mud, which is obtained through carrying out modification treatment on sludge, is subjected to high-dryness dehydration by adopting a press filter, wherein a pressure value P applied by the press filter is firstly subjected to linear increase, then, undulatory changes and then linear increase along with time t. According to the method, the pressure value P of the press filter is firstly subjected to the linear increase, so that part of water in the sludge is squeezed out rapidly; then, the pressure value P is subjected to the undulatory changes, so that the sludge is in a periodic compressed and loosened state, the separation of the sludge from capillary water and pore water and the squeezing-out of the capillary water and the pore water are facilitated, and thus, the moisture content of the interior of the sludge cakes and the moisture content of the outside surfaces of the sludge cakes tend to be consistent; finally, the pressure value P is subjected to the linear changes again, so that water in the sludge cakes is squeezed out. According to the method, the squeezing time is short, the entire process needs 18 minutes only, and the moisture content of the finally obtained sludge cakes is 56% to 60%, so that the dehydration effect is good.

Description

technical field [0001] The invention relates to the field of sludge treatment, in particular to a sludge high-dry pressing method. Background technique [0002] During the sewage treatment process of the sewage treatment plant, a large amount of sludge will be produced. After the sludge is concentrated, the moisture content is usually 94% to 96%. After conditioning and modification, the sludge needs to be dehydrated to dry the wet material Separation for subsequent landfill or recycling. At present, the high-dry dehydration of sludge is usually carried out by a filter press. During the dehydration process, hydraulic cylinders or other hydraulic methods generate squeezing pressure, which acts on the filter plate device for filtering sludge. Due to the effect of pressure, the filter The volume of the inner cavity of the plate device is reduced, forcing the sludge to be separated from free water, capillary water, and interstitial water, and finally a dehydrated and solidified ...

AI Technical Summary

Problems solved by technology

[0003] The filter press equipment in the prior art generally adopts the following two pressurization methods during the pressurization process. One is that the pressure acting on the filter plate device is an uninterrupted and continuous increase mode. In this method, after the pressing pressure reaches a certain value, , which is not conducive to the separation of sludge, capillary water, and interstitial water. The final mud cake has a high moisture content, and at the same time, it is easy to cause temperature rise and damage hydraulic components; This method is beneficial to reduce the moisture content of the mud cake, but it increases the dehydration time, reduces the output, and is not conducive to saving electric energy

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