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Operation and filtration process of press filter

  • Release Date:02-08-2017
  • Abst:

    Filtration operation
    (1), open the filtrate outlet valve, start the feed pump, and gradually increase the inlet valve as the filtration velocity and filtration time, filtration pressure can increase gradually, generally not more than 0.6Mpa (frame type is not greater than 0.4MPa) may just start filtering the filtrate turbidity, it is because the material has not formed by pre coating in the cloth, can continue to use, will naturally become clear later. If there is a big leakage between the filter plates, the pressing force can be increased properly. Because the filter cloth has capillary phenomenon, a small amount of filtrate exudation is normal.
    (2), found that monitoring the filtrate, shut down the muddy water turbid liquid flow type, undercurrent type can stop filtering, check cloth and sewing or replacement.
    (3) if pneumatic diaphragm pump is adopted, the pressure reducing valve can be adjusted, and the filtering pressure can be adjusted at one time, and no operation is needed during the filtration process. If the use of screw pump and other feed pump, not only to install reflux system, but also according to changes in filtration pressure, at any time to adjust the size of the return valve to control filtration pressure, need someone to operate, otherwise it will damage the equipment.
    (4) when the filtration pressure is large, the water is smaller, it can be regarded as the end of the filter and return to the compression plate. If the moisture content of the filter cake is found to be large, it can be closed to the pressure plate and continue to filter.
    (5), the filtering time is too long or the cake can not be formed, should be considered to reduce the moisture content of the material, such as increasing the deposition time, adding clarifier or adding flocculant and filter aid (lime, diatomite, perlite) to replace the filter media and other solutions.
    (6), such as cake wash, wash off the outlet flow type plate, close feed valve, open the washing water valve, water flushing, flushing water pressure is less than rated pressure filtration equipment, washing time should be according to the flushing effect and decide, such as a flushing effect is not ideal, can in the process of filtration, washed several times.
    (7) in order to reduce the moisture content of the filter cake, the compressed air purge method can be adopted. The method is the same as that of the washing method, or the inlet air inlet method or the diaphragm press filter press is adopted.


    A filter of different materials and the same material due to moisture, temperature and even different filtering effect (speed, moisture) may vary, some even before filtration material in filtration additive such as Cao, flocculant, carbide slag, to filter characteristics of the conditioning materials. So the filter cake is not necessarily the same.
    Before filtration, check the filter cloth and filter board. If you need to wash or blow, check the washing board, non washing board and washing hole, whether the air vent is unblocked. Is the pressing force adequate.