When the filter cloth is used for a long time, the problems caused by the filter cloth will be encountered from time to time, which seriously affects the filtering function of the filter cloth. So, what are the problems? Let's take a look at some common problems
1. The growth of bacteria
Mold, bacteria and algae can cause medium blockage. In places with low velocity, this kind of breeding is especially serious.
2. Solid particle load of yarn
If the size of the solid particles is equal to the pore size of the filter cloth, the particles enter the yarn gap of the multi fiber cloth and stay there. These solid particles are difficult to remove by back washing.
3. Precipitation from solution
he effect of this kind of precipitation phenomenon is similar to the growth of organic matter in the medium, which causes the plugging of medium pores.
4. Critical concentration
In the process of pressurized filtration, the particle bridging effect does not appear on the media because the concentration of the particles added at the beginning is relatively thin. If the medium is not bridged, it will cause particles to settle in the pores of the filter cloth, which will cause blockage.
5. Insufficient drainage
If the filter media is not well supported, or the filter plate adopts an incorrect drainage channel, it will cause difficulties in filtration. If the diameter of the drainage pipe from the pressure filter to the outside is too small, it will also cause filtering difficulties.
6. Critical pressure
Each filtration system has its own critical pressure. When the pressure value is exceeded, the particle bridge on the medium will collapse and the particles will settle directly in the filter cloth. In the laboratory, the critical pressure can be obtained by gradually increasing the pressure for filtration.
7. Effect of bubbles
When the suspension contains air or bubbles, the particles will be graded and the colloid tends to concentrate on the surface of the bubbles.
8. Grading of particles
In filtration, suspension with a wide range of particle size distribution is always involved. Under the action of gravity and fluid drag towards the medium, particles always divide into fine and coarse components before settling on the filter cloth. In the central feed box filter plate, fine particles are washed to the edge of the filter plate, resulting in poor particle distribution on the filter cloth.
9. Influence of filter fabric structure
In the process of fluid flowing through the multi fiber cloth, the flow through the yarn and the flow around the yarn will depend on the degree of twist of the yarn and the size of the small hole between the yarns, and the size of the small hole also depends on the weaving pattern of the cloth (plain, twill, etc.).
(Addtime：2020-6-10)
