During the operation of the plate and frame filter press, it is common for the sludge to stick to the filter cloth and for the sludge to have a high moisture content. This not only affects the working efficiency of the equipment but also increases the subsequent treatment costs. The following will conduct an in-depth analysis of the causes of these problems and recommend an effective agent - sludge enhancer.

The reason why the sludge sticks to the filter cloth

Factors of sludge properties

When the particles in the sludge are too fine, during the filtration process, these fine particles are prone to clogging the pores of the filter cloth, making it difficult for water to pass through the filter cloth smoothly and be discharged. At the same time, the sludge particles will also adhere to the surface of the filter cloth, causing adhesion. For instance, the sludge produced from some industrial wastewater that has undergone advanced treatment often has relatively small particle diameters, which makes this situation more likely to occur.

Youdaoplaceholder0 high organic matter content in sludge ‌ : Sludge with a high organic matter content usually has strong viscosity. During the filtration process, these organic substances will bond the sludge particles together like glue and tend to adhere to the filter cloth, causing clogging and sticking of the filter cloth. Sludge produced in the food processing industry, which is rich in a large amount of organic matter such as protein and starch, is prone to the problem of sludge sticking to the filter cloth during pressing.

Operational factors

Youdaoplaceholder0 Insufficient filtration pressure ‌ : If the pressure applied during the filtration process is not sufficient, the water in the sludge cannot be fully squeezed out, and the sludge cannot form a tight filter cake, thus it is prone to stick to the filter cloth. For instance, this situation occurs when the hydraulic system of the filter press malfunctions, causing the pressure to fail to reach the set value.

Youdaoplaceholder0 Too short filtration time ‌ : If the filtration time is insufficient, the water in the sludge will not have enough time to be discharged, which will also cause the sludge to have a high moisture content and be sticky to the filter cloth. For instance, if the filtration operation is stopped too early in pursuit of production efficiency, it may lead to poor filtration results.

Filter cloth factor

Youdaoplaceholder0 Improper selection of filter cloth ‌ : Different types of sludge require the choice of filter cloth with appropriate pore size and material. If the pore size of the filter cloth is too large, sludge particles are prone to pass through the filter cloth, resulting in turbid filtrate. However, if the pore size is too small, it is prone to being clogged by sludge particles, resulting in sticky sludge pressing. In addition, the selection of filter cloth material is also very important. For some corrosive sludge, if a filter cloth that is not corrosion-resistant is chosen, it will shorten the service life of the filter cloth and may also affect the filtration effect.

Youdaoplaceholder0 The filter cloth is not cleaned in time ‌ : During the filtration process, sludge particles and impurities will continuously accumulate on the filter cloth. If not cleaned in time, these dirt will gradually clog the pores of the filter cloth, reducing its filtration performance and thus causing the sludge to stick.

The reasons for the high moisture content of sludge

In addition to some of the reasons mentioned above that cause the sludge to have a high moisture content due to the sticky filter cloth during sludge pressing, there are also some other factors.

Improper sludge conditioning

Before filtration, it is usually necessary to condition the sludge to improve its dewatering performance. If the selection of the conditioner is inappropriate or the addition amount is insufficient, it will be impossible to effectively change the structure and properties of the sludge, making it difficult to separate the water in the sludge and resulting in a persistently high moisture content. For instance, for some high-viscosity sludge, if the conditioning agent used cannot effectively destroy its colloid structure, a good dewatering effect cannot be achieved.

The amount of sludge intake is too large

When the sludge intake of the plate and frame filter press exceeds its processing capacity, the sludge cannot be fully compressed and dehydrated in the filter press chamber, which leads to an increase in the moisture content of the sludge. This is just like a container. If it holds too much, it cannot be compacted and the moisture will be difficult to drain out.

Chemical Recommendation - Sludge enhancer

To address the issues of sticky filter cloth and high moisture content in the sludge pressed by plate and frame filter presses, it is recommended to use sludge enhancers. It has the following significant advantages:

Improve the dewatering performance of sludge

Sludge enhancers can disrupt the colloidal structure of sludge, weakening the binding force between sludge particles and making it easier for water to separate from the sludge. By adding sludge efficiency enhancers, the moisture content of sludge can be significantly reduced and the filtration efficiency can be improved. For instance, in practical applications, after adding sludge efficiency enhancers, the moisture content of sludge can be reduced from over 80% to around 60%.

 

Reduce the stickiness phenomenon

Sludge enhancers can form a protective film on the surface of sludge particles, reducing the adhesion between sludge particles and also lowering the stickiness between sludge and filter cloth. In this way, during the filtration process, sludge is more likely to fall off the filter cloth, reducing the frequency of clogging and cleaning of the filter cloth and extending its service life.

In conclusion, the sticking of the filter cloth and the high moisture content in the sludge pressed by the plate and frame filter press are caused by the combined effect of multiple factors. By analyzing these reasons and taking corresponding measures, such as rationally selecting filter cloth and optimizing operating parameters, while using sludge enhancers, these problems can be effectively solved, improving the operational efficiency of the plate and frame filter press and the sludge treatment effect.