Filtration principle of filter bag
The basic concept of filtration is the separation of a suspension using a porous medium. When the filter bag works, under the action of external force, the liquid in the suspension flows out through the orifice of the medium, and the solid particles are trapped, thus achieving separation. The suspension to be filtered is generally referred to as the filter slurry. The porous medium used is called filter medium. The liquid passing through the channel of the medium is called filtrate. The solids that are trapped are called filter cakes or dregs.
The driving force of the filtration operation is the pressure difference between the upstream and downstream of the filtration medium. The pressure difference can be generated in the following ways:
(1) use the pressure head of the filter pulp itself;
(2) pressure on the filter surface;
Vacuum in the downstream side of the filter medium;
(4) the use of inertia centrifugal force.