During the continuous filtration process, if the processing speed of the belt filter is too fast, it will cause accumulation. At this point, it is necessary to add an appropriate amount of filter aid, which can accumulate together with solid particles in the filtrate on the surface of the original pre coating or filter layer to form a new filter layer, thereby maintaining a relatively stable filtration speed. From this, it can be seen that the filtration effect and filtration speed of a belt filter are closely related.

In liquid, the resistance to filtration rate slowly increases with the thickening of the filter residue layer.

The reasons for this situation include: filter area, resistance of filter residue layer and filter material, viscosity of filtrate, pressure difference on both sides of the filter, etc.

In addition, the filtration speed of a belt filter is related to the properties, structure, and thickness of the filter residue, which can usually be divided into incompressible and compressible types. Incompressible filter materials are generally composed of non deformable particles, which are amorphous particles. When uncompressed filter residue is deposited on the filter material, the arrangement of particles and the diameter of the pores between particles do not change with the increase of pressure.

On the contrary, when filtering compressible filter residue, the pore size between particles decreases with increasing pressure, thus increasing the obstruction effect on the flow of filtrate. Therefore, in the actual production process, increasing the pressure difference on both sides of the filter cake of the belt filter, that is, using pressure or pressure reduction filtration methods; Raise the temperature of the filter slurry to reduce its viscosity.