One Batch Time of Filter Press

 Product Knowledge    |      2019-05-21
The Total batch time is the Full Cycle time plus a constant. For machine capacity of 125 cubic meters and under this constant is usually around 45 minutes. This is the time required to close-open the filter press, and discharge the filter cake. If the particular application requires operations such as Core Blow or Cake Wash, for example, this constant is longer.
The one batch time depends on many parameters. The most important parameter is the nature of material to be dewatered. For example, a sand slurry releases its water readily and dewaters quickly. On the other hand, an Aluminum Hydroxide waste slurry from beverage can manufacture does not readily release its water and dewaters slowly.
The next most important parameter is the concentration of the solids by weight in the slurry. The full batch for a 5% solids slurry is about twice as long as a 10% solids slurry (with all other parameters being equal). This is because the press has to process half of the water to fill with solids.
Other parameters include the thickness of the filter cake, the maximum feed pressure which the slurry is fed to the press, and the filter cloth selection. These parameters are typically fixed during the proposal process.
With 32mm (1.25”) cake chamber thickness, 0.6 Mpa max feed to the press and a 3-5 SCFM filter cloth, a 5% sand slurry would be expected to dewater in 20-30 minutes and a 10% sand slurry in 10-15 minutes.
Conversely, the 5% Aluminum Hydroxide slurry may take 4-6 hours to dewater, while the 10% slurry would dewater in 2-3 hours.
We have an in-house laboratory where we can test a sample of different slurry to determine the one batch time as well as the other outputs from pressure filtration testing. 
The one batch times for a 1 cubic meter, 10 cubic meter and 100 cubic meter are approximately the same. Press volume is the ability to remove solids. Associated with this volume is the square feet of surface area in the press.
Square footage is the ability to process fluid. As volume is added, square feet of surface area is proportionally added and the cubic foot to square foot ratio remains (roughly) constant. Therefore, the one batch time is basically the same.