Classification of rotary filter

(1) Vertical disc filter: Vertical disc filter is also called butterfly filter (Figs. 1 and 2). The structure of its filter surface is different from that of barrel filter, but the operation principle is basically the same. The filter surface is composed of several separate fan-shaped discs (usually 10-12). Each fan-shaped piece is a separate filter unit, and a bag made of filter cloth is used to form a filter chamber on the fan-shaped piece. When working, the filter tray rotates clockwise, and the solid particles in the slurry attach to the filter tray to form a filter cake. The agitator swings back and forth to prevent solid precipitation.

The filtrate passes through the filter cloth, enters the filter tray, passes through the filter tube, and discharges from the distribution head. The filter cake is discharged from the inside to the outside through the filter disc in the discharging area. The fan-shaped sheet is fixed on the main shaft (hollow shaft) by screw inspection. It is convenient to disassemble and replace the filter cloth. It can even be carried out during the operation of the filter, which brings convenience to the production and maintenance. (2) Horizontal disc filter: This machine is also called flat disc or horizontal table filter. The filter surface is round and table-shaped. There are concentric inner and outer retaining rings with a certain height on the disk. Under the filter surface, a number of radial vertical partitions are divided into separate fan-shaped filters, which are connected with the automatic valve under the disc. The slurry is evenly distributed from the weir-shaped distributor at the top to the fan-shaped filter blades. The filter residue is scraped onto the screw conveyor or belt conveyor with a scraper. The filtrate is discharged into the filter tank through the outlet under the filter blade, the filter tube and the central distribution head. The filter cake can be washed many times. Wash and filtrate can be collected separately. In order to eliminate the obstruction of the residual filter cake to the next filtration, compressed air is introduced into the feeding position and the residual filter cake is blown back into the new feeding slurry. Horizontal disc air-passing filter covers a large area, and the filter cloth is easily blocked and damaged. Generally, it is used to filter the slurry which requires good washing effect and contains coarse solid with large density. It can also filter the slurry which contains suspended particles with small density.

(3) Horizontal rotary turntable filter: The annular filter surface is arranged by several independent fan-shaped filters, and the filter outlet of the filter plate is connected with the central distribution pipe head. Each fan-shaped filter plate is mounted on the rotary table. The pulp is fed to the filter plate through a distributor and filtered under attraction. The filtrate is discharged through central suction tube, branch tube and central distribution head. The filter cake is left on the filter cloth. After three-stage washing, it enters the discharging area. The filter disc is reversed 180 degrees and discharged under the action of gravity or compressed air back-blowing. Thereafter, the filter disc is reset, cleaned and dried, and then transferred to the feeding position to start a new filtering cycle.