Centrifuge 1.35M* 100m PE Filter Press Cloth , Double Layer Filter Press Fabric

1.35M* 100m PE Double Layer Cloth For Centrifuge Filter

The principles and methods of selection. The following aspects should be considered comprehensively in the selection of filter cloths

1 The physical and chemical stability of the filter cloth material. The appropriate filter cloth material should be selected according to the physical and chemical properties of the slurry. The physical and chemical properties to be considered when selecting the filter cloth include the use temperature, tensile and deformation properties, chemical stability, solubility or swelling properties, and acid and alkali resistance.
2 mechanical properties. Filter cloths should be selected according to the type of filter tensile properties, wear resistance, elongation, elasticity and other mechanical properties. Such as belt type vacuum filter, filter cloth walking box type filter press, folding belt discharge drum vacuum filter and other filtering equipment require that the filter cloth has good tensile properties. Table 10-31 lists the domestic commonly used filter cloth tensile properties, Table 10-32 lists the domestic commonly used filter cloth breaking force ranking table, Table 10-33 lists the domestic commonly used filter cloth elongation at break sequence table . Box type filter presses and plate and frame type filter presses require that the filter cloth have a certain degree of elasticity and a certain degree of deformation, and the elongation and elongation at break reflect its deformability. Squeegee filter cake filter, frame filter press, van press filter require a good abrasion resistance of the filter cloth. Table 10-34 lists the wear resistance of domestic commonly used filter cloths.
3 filtration accuracy. The selected filter cloth must meet the filtration accuracy specified by the production process. The indicators reflecting the filtration accuracy include bubbling pore size, maximum transmission particle size, and initial filtrate turbidity (filtrate allowable solid content). There are two indicators for the bubbling pore size, namely the maximum bubbling pore size and the boiling bubbling pore size. In general, the maximum bubbling pore size is about 2 to 4 times the maximum transmission particle. Filtration of high-concentration materials with less stringent filtration requirements. The maximum permeation particle size of the selected filter cloth should not be too different from the particle size of the particles to be retained in the material to avoid short circuits. However, for filtration with high filtration accuracy or filtration of thin slurry without cake formation, the maximum permeation particle size of the selected filter cloth should not be larger than the particle size of the particles to be retained in the material to ensure the filtration accuracy. In addition, the uniformity of the pores of the filter cloth is also very important. It can be described by the ratio of the boiling bubbling pore diameter and the maximum bubbling pore diameter. When the ratio approaches 1, the uniformity of the pores of the filter cloth is good. Table 10-35 lists the maximum bubbling pore size, boiling bubbling pore size, and their ratio of commonly used filter cloths made in China. Table 10-36 lists the maximum permeation particle diameter of domestically used filter cloths. Table 10-37 lists them. When several representative materials are pressure filtered, the initial filtrate turbidity of domestic commonly used filter cloths.
4 initial filtration rate. The air permeability resistance, permeability resistance and pressure of the filter cloth, and the initial filtration rate of vacuum filtration all indirectly or directly indicate the initial filtration rate of the filter cloth. The corresponding relationship between the above three indicators, in general, the filter cloth with large ventilation resistance, the permeability resistance is also large, the initial filtration rate of the filter cloth with large resistance is small, and vice versa. For liquid-solid separation filtration equipment, filter cloth should be selected based on water permeability or initial filtration rate. In general, the filter cloth with a good retention performance has a large resistance, and the filter cloth with a poor retention performance has a low resistance. Separation of fine particles and low-concentration materials generally select filter cloths with good retention performance to meet the separation precision specified in the production; for the separation of large particles and high-concentration materials, filter cloths with slightly lower retention performance and low resistance are generally selected. To increase the productivity of the equipment. Table 10-38 lists the air permeability resistance of commonly used domestic filter cloths, Table 10-39 lists the domestic water resistance of commonly used filter cloths, and Table 10-40 to Table 10-43 respectively list several representative materials. The filtration rates for pressure filtration, Table 10-37 lists their initial filtrate turbidities, and Table 10-44 lists the typical vacuum filter initial filtration rates and filtrate clearing times for several representative materials.
5 Cake peel performance. There is adhesion between the filter cake and the filter cloth, and the smaller the adhesive force, the easier it is to unload the cake. The adhesion between the filter cloth and the filter cake is related to the material of the filter cloth, the length of the fiber, and the weave. In general, the monofilament fiber filter cloth has better performance than the long multifilament fiber and the short fiber filter cloth unloading cake. The plain woven filter cloth has the worst unloading performance, and the satin-like filter cloth has the best unloading performance. Table 10-28 shows the relationship between filter cake peeling performance and yarn composition and weaving method. Table 10-45 lists the adhesive stress between domestic commonly used filter cloth and light calcium carbonate filter cake.
6 regeneration efficiency. With the prolongation of the use time of the filter cloth, some of the pores are blocked by the solid particles, so that the filtration resistance increases and the filtration rate decreases. Therefore, regeneration is required. The regeneration performance of the filter cloth is related to the material of the filter cloth, the length of the fiber, and the weave. In general, monofilament filter cloths have the best regeneration performance, filament filter cloths second, and short fiber filter cloths the worst. Dense structure of plain weave and canvas filter cloths have poor reproducibility, and twill and satin-like filter cloths have good reproducibility. In fact, the regenerated filter cloth has a period of "recovery performance stable period", so the filtration rate normally exhibited in the production equipment is the transition rate when the filter cloth enters the "recovery performance stable period". Therefore, under the premise of satisfying the filtration accuracy specified in the production when the filter cloth is selected, the filter cloth with good regeneration performance should also be considered.
7 sample test. The filter cloths tentatively determined by the above methods often have many varieties. The best filter cloth can be selected through the sample test. The sample test can determine the filtration rate of the filter cloth, the strength of the filtrate, the moisture content of the filter cake, the unloading cake performance and other data. Through the comparison and analysis of the data, the best filter cloth can be selected. Sample tests generally use vacuum filter funnel device or pressure filter device.
8 simulation test. After the filter cloth is selected, a simulation test can be performed in order to verify its reliability. It is optional to conduct a simulation test using the same small filter or testing machine with a similar filtration process to verify the measurement data obtained from the sample test. The filter cloth used in the simulation test is generally applied to the production of good performance.