Precoat discharge rotary vacuum drum filter

The working principle of the precoat discharge rotary vacuum drum filter is basically the same as that of a general vacuum drum filter. The main difference lies in that the GF – type filter conducts pre – coating of filter aids (such as diatomite, perlite, etc.) before filtration.

During filtration, under the action of vacuum suction, the filter aids in the tank body form a pre – coating layer of the required thickness on the outer surface of the drum. Then, the slurry to be filtered is injected. Under the action of vacuum suction, the separated filtrate penetrates through the pre – coating layer and the filter cloth, and is discharged through the suction pipe, the liquid – collecting pipe, and the gas – liquid separator.

The solid particles in the slurry are retained by the pre – coating layer and are continuously scraped off by the automatically feeding scraper along with the surface layer of the filter aid. When the residual thickness of the pre – coating layer is about 10mm, pre – coating needs to be carried out again for the next working cycle.