Filter Aid – Diatomaceous Earth (DE)

Precoat and bodyfeed are two related applications. Both of these special applications use diatomaceous earth (commonly known as D.E.), 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 bodyfeed 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 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 press where it coats the filter cloths. The filter aid rather than the filter cloths becomes your initial filter media.

During a body 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.