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Q What is the best feed pump for a filter press?
A Many pump types are used with good results, depending upon the characteristics of the material being processed. Air diaphragm pumps do not shear flocculated slurries and are the most common type of pump used. An added advantage to this type of pump is that the air drive stalls when filtration is complete.
Positive displacement pumps are used on high pressure filter press.
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Q What is open filtrate discharge?
A Open Discharge is where the filtrate is discharged externally to the filter plate with no drain eyes in the corners of the filter plate.
The filtrate will drain into an open trough (launder) running the length of the Filter Press.
The big advantage is the easy visual identification of a failed filter cloth – that plate will run dirty when compared with the others.
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Q What is closed filtrate discharge?
A Closed Discharge is where the filtrate is discharged internally to corner drain eyes. In this design, all of the filtrate goes to the feed end of the filter press, ideal in instances where the filtrate needs to be contained due to pH or odor. This configuration is required in instances where the filter cake needs to be washed or air-blowing dried.
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Q Can I reduce the filtration cycle time?
A Normally the slurry characteristics determine cycle time. Conditioning of the slurry can improve the cycle time. Thinner cakes will also reduce cycle times and are more easily washed.
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Q Why the filter plates leaking during the feed process
A If do not made any recent changes to the plate stack (which is the number one reason this might occur), there are several possibilities.
Build-up of solids on the sealing surfaces which will then need to be cleaned.
Check to see if the hydraulic pressure is set to the recommended specifications. If not, make the appropriate adjustment.
Another possibility is that there could be a wrinkle or hole in the filter cloth or the gaskets may be loose.
If you continue to have problems, Touch on JWK.
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Q How do I precoat the filter press
A Precoat and slurry feed are two related applications.
Both of these special applications use diatomaceous earth, cellulose, perlite or fly ash, as a filtering aid when the solids in a slurry are extremely fine and free-filtering.
The filter aid helps to trap the fine solids that otherwise might flow through the filter cloths.
The processes of precoat and slurry feed increase the clarity of the filtrate, provide for higher flow rates, more consistent runs, shorter cycles, dryer cakes, better cake release, and also help to protect and increase the life of the filter cloths.
The precoat process is performed before the slurry is pumped into the filter press. A precoat system consists of a tank, mixer and pump.
The filter aid is mixed with water in the precoat tank.
It is then pumped into the filter press where it coats the filter cloths.
The filter aid rather than the filter cloths becomes your initial filter media.
During a slurry feed the filter aid mixes with the slurry in the holding tank prior to being fed into the filter press.
The filter aid becomes part of the slurry thereby providing a better filter cake.
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Q What can I do to ensure the driest possible filter cake
A Add feed pressure, or membrane squeezing pressure, and Be sure cloths are cleaned as needed and the air blowing system is run for a full cycle.
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Q How long is the filtration cycle time
A Filtration cycle time is dependent on solids loading and can take anywhere
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Q How do I know when the filter press is full
A Firslty, check the liquid discharge completed on outlet port, then the feed pump will get max. feed pressure quickly, indicating that feed pressure has increased due to solids building up inside the filter press chamber. This is signal that the filter press is full.
