PRODUCTS > Filter presses > With membrane plates > Filtration without cake washing

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Cycle description


Graph of filtration cycle:



Description of the process stages:

  • Start of cycle
    the emptied filter press is ready to start a new filtration cycle
  • Closing of the filter press
    the whole set of filtration plates is compressed by means of a hydraulic system, filtration chambers are created between the individual plates.
     
  • Start of filling
    the suspension is conveyed from a pressure tank; however, a feeding pump is used more often.
  • Filling of the filter press
    chambers are filled up with the suspension. Solid particles are trapped by the filtration cloth, liquid phase passes through the cloth to the plate drainage system.
     
  • Formation of the filtration cake
    a layer of solid particles accomulates on the cloth, which increases the filtration resistance. The filling pressure must be increased in order for the liquid to keep passing through the cake and the cloth. The rising filtration resistance also results in reduced flow rate of the suspension through the filter press.
     
  • Achieving of the maximum filling pressure (usually 6 - 8 bars) and end of filling
    the feeding pump stops pumping the suspension into the filter press chambers
  • start of membrane compression
    the residue of unfiltered slurry is pushed out of the suspension feeding channel passing through the whole set of plates, by compressed air.
     
  • Achieving of the maximum compression value (usually 15 bar)
    the volume of discharged filtrate is at the minimum and after some time it remains almost stable. The maximum pressure is maintained for a certain period of time. The filtration is completed.
     
  • Core blow (optional)
    the residue of unfiltered slurry is pushed out of the suspension feeding channel passing through the whole set of plates by compressed air.
     
  • Releasing of pressure
    the compression medium is pumped out from behind the membrane, the pressure in the filtration chambers drops to the value before the beginning of filtration.
     
  • Opening of the filter press
    the hydraulic system releases the compression, the steel plate compressing the set of filtration plates during filtration is shifted away and the individual filtration plates are deflated, during which the filtration cake is discharged.