4 replies to this topic

[Processmen]

Dear Members,

I have an inquiry regarding the filter press operation. My understanding is that the slurry is fed to the chambers and the liquid is withdrawn form bottom until the cake is build up in them (no compression yet). As the cake forms the flow rate of the feeder pump decreases ( or the flow stays constant if we use a VFD pump, which is signaled by a PIT on the filter inlet). When the chamber is filled then the flow is stopped and the cake is compressed by filter hydraulic devices.The feeder pump should stop when the cake is being pressed. Is that right?

Thanks

[ankur2061]

Uottawa,

Refer the attachment. This may provide the answer you are looking for.

Regards,
Ankur.

Attached Files

•  Filter_Press.pdf   1.06MB   81 downloads

[fallah]

Dear Members,

I have an inquiry regarding the filter press operation. My understanding is that the slurry is fed to the chambers and the liquid is withdrawn form bottom until the cake is build up in them (no compression yet). As the cake forms the flow rate of the feeder pump decreases ( or the flow stays constant if we use a VFD pump, which is signaled by a PIT on the filter inlet). When the chamber is filled then the flow is stopped and the cake is compressed by filter hydraulic devices.The feeder pump should stop when the cake is being pressed. Is that right?

Thanks

Uottawa,

Based on your explanations and at a glance seems to be right, but even a simple sketch can help to be able to submit stronger judgment on the matter.

Fallah

[Dave Bowers]

Uottawa,

The cake is never compressed by hydraulic devices. Once the press is closed (via hydraulic devices usually) the cake is then formed by the incoming slurry pressure. As the solids build in the recessed chamber the pressure increases and thus dewatering begins. Once the max feed pressure is reached, anywhere from 50 - 100 psi depending on whats being filtered, the press is then ready for opening and cake discharge, or additional filter cake drying or washing.

Please let us know if we can help with any additional questions on filter press operations or parts, etc.

Dave
ErtelAlsop

[kkala]

My understanding of polishing filtration (http://bauxite2alumi...in-alumina.html) in alumina plants complies with the previous post by Dave Bowers. Stages are same, realized according to his description in rotary vertical (leaf) filters. These may be a development over filter press (an old book by Reynolds spoke of filter press).
An additional stage, not necessary for all liquors to be filtrated, is precoating. Filtration is realized by the cake rather than the filter cloth, so there may be "escape" of fine solids at the beginning (when there is no cake on the cloth). So the cloth is precoated by passing another slurry (of coarse particles), prior to introducing the liquor. Apparently precoating is convenient, if the cake is rejected (having no commercial value).