By Khathutshelo Mutshinyalo - Senior Process Engineer, MPE, SSM
1. Did you know that a filter press mainly uses a feed pump to facilitate the filtration between the solids and liquids?
Although there are mechanisms that can be implemented in the filter press to aid with squeezing of the slurry in the filter press, the filter press itself does not press the slurry (contrary to its name).
2. Did you know that, in as much as the filter press aids in reducing moisture from slurry, it is negatively affected by the sun?
The filter cloth and filter plates that form part of a filter press are damaged by the UV-ray. This is why filter presses are generally installed in a sheltered structure.
3. Did you know that filter cloth porosity is not measured by aperture size, as is the case with screening media (such as screen panels)?
The filter cloth’s porosity is measured by air permeability, which is conducted by passing air at specific temperature and pressure through the filter cloth. This measures the differential pressure across the filter cloth.
4. Did you know that when sizing and optimising the filter press, ending the filtration cycle sooner with a higher moisture can result in an increase in the filter press size?
It is commonly thought that “quicker cycle = smaller filter press”. But this is not the case, as a larger chamber volume is required to occupy the solids, and a higher water content in the filter cake.
5. Did you know that the phrase “too much of a good thing can be bad“, is easily applied to flocculation in filtration?
Flocculant improves the filtration of slurry in the filter press. However, too much flocculant can lead to reduced filtration as it can cause blinding of the filter cloth, which reduces the filtration efficiency.