Factors affecting the washing are types of fiber raw materials, pulp hardness, washing water temperature, slurry thickness and dryness, vacuum degree, etc., the specific analysis is as follows:
The most important influence factor is the pulp species. General long fiber has good drainability performance, easy for dry washing, straw pulp has poor drainability, more difficult to wash. According to the difficulty of raw materials washing, the sequence is as follows:
Straw pulp – wheat straw pulp – bagasse pulp – silvergrass reed pulp – bamboo pulp – wood pulp – cotton pulp
After cooking, the same raw material will have different hardness, and the drainability performance is also different. If hardness of the pulp is high, the viscosity is small, the performance of drainability is good at the beginning, but the final washing degree is relatively poor. This is because a part of the waste liquid exists inside the fiber, if the slurry has high hardness, fiber damage is small, the waste liquor inside the fiber gradually diffuses outward from the cells mainly through the pits, nearly in static state, the washing speed Is very slow. If you require cleaning, you need a long soaking time.
The higher the hardness of the pulp, the less fiber surface loss is, if it is very hard and not soft, diffusion resistance of waste liquor within the fiber will be greater, and washing will be more difficult.
The washing water temperature has a great influence on the washing. If water temperature is high, viscosity is low, filtration resistance is small, diffusion will be fast, promoting washing and replacement.
When the slurry is thick, the filter resistance will be great, filtration speed will be low, which is not conducive to the diffusion of pulp, and the residual alkali in the slurry will be relatively high.
Vacuum degree is one of the important factors affecting the washing. If vacuum degree is large, filtration speed will be fast, and pulp dryness will be large, too large vacuum degree will make pulp dryness large, and the slurry paste the mesh,which will affect the filtration. Therefore, it generally does not exceed 300 ~ 350mm Hg.
Leizhan can offer high-performance Screw Press Washer suitable for washing and thickening all kinds of paper pulp which is used in paper pulp processing line, feel free to contact with us if you have any needs,email: leizhanchina@gmail.com