The Impact of Filter Cloth Pore Size on Dewatering Efficiency

Filter cloth pore size is one of the core parameters affecting dewatering efficiency. Its influence is not a simple matter of “the larger, the better” or “the smaller, the better,” but rather a balancing process that must be optimized based on the characteristics of the material being processed.

Below is Bolian Filtration’s analysis of how filter cloth pore size affects different aspects of dewatering efficiency.

1. Effect on Filtration Rate

Larger pore size: More open flow channels result in lower filtration resistance and a higher initial filtration rate.

Smaller pore size: Higher initial resistance leads to a slower filtration rate.

2. Effect on Filter Cake Moisture Content

Larger pore size: Water passes through more easily, and the initial filter cake tends to be more porous. This approach creates lower resistance during subsequent squeezing or vacuum dewatering stages and helps reduce the final moisture content, provided that solid particles are effectively retained to form a stable filter cake.

Smaller pore size: A dense initial filter cake forms quickly, but fine particles may accumulate on the surface and create a “mud layer,” which severely restricts water drainage from inside the cake and may result in higher final moisture content.

3. Effect on Filtrate Clarity and Solid Recovery

Larger pore size: Fine particles smaller than the pore size may pass through the cloth, causing turbid filtrate and higher solid loss, thus reducing recovery rates.

Smaller pore size: Better particle retention leads to clearer filtrate and higher solid recovery.

4. Effect on Filter Cloth Clogging and Service Life

Excessively large pore size: Fine particles may penetrate into the internal structure of the cloth and become trapped, causing deep clogging that is difficult to clean and gradually reducing permeability.

If the pore size is too small or poorly matched to particle size, particles easily form a dense surface layer. This causes surface clogging and significantly increases filtration resistance. Consequently, cleaning frequency increases, operations are interrupted, and filter cloth service life is reduced.

Conclusion

Only by combining particle size distribution, solids concentration, dewatering method, and requirements for filtrate clarity and solid recovery can we scientifically select the appropriate filter cloth pore size. This balanced approach ensures optimal filtration rate, lower cake moisture, and longer filter cloth service life.
BOLIAN is committed to application-oriented solutions, delivering more efficient, stable, and durable filter cloth products for industrial dewatering processes.