Fully immersed filter cloth turntable filter

1. Working principle

The outside-in and inside-out type turntable filter consists of a series of horizontally installed rotating filter discs. Each filter turntable is composed of an even number of fan-shaped filter plates. The turntable is equipped with an easily removable filter cloth. The filter cloth is made of fiber and the filter pore size of the filter cloth is 10um.

The operating status of the fiber turntable filter includes: filtration, backwashing, and mud discharge status.

(1)Filtering

The sewage gravity flows into the filter tank, which is equipped with a water distribution weir. The filter cloth adopts a fully submerged type. The sewage enters through the outside of the filter cloth, the filtrate is collected through the hollow tube, and the gravity flow  is discharged from the filter tank through the outlet weir. The whole process is continuous.

(2)Cleaning

During filtration, part of the sludge is adsorbed on the outside of the filter cloth, gradually forming a sludge layer. As sludge accumulates on the filter cloth, the filtration resistance of the filter cloth increases, and the water level in the filter gradually rises. Monitor the liquid level changes in the pool through a pressure sensor. When the liquid level in the pool reaches the cleaning set value (high water level), the PLC can start the anti-suction pump and start the cleaning process. During cleaning, the filter tank can be continuously filtered.

During filtration, the filter turntable is in a static state, which is conducive to the sedimentation of sludge at the bottom of the tank. During cleaning, the filter disc rotates at a speed of 1 rpm/2 minutes. The suction pump uses negative pressure to suck  the surface of the filter cloth , sucking out the sludge particles accumulated on the filter cloth. The water in the filter turntable is sucked from the inside out at the same time, and has a back-cleaning effect on the filter cloth. The instantaneous flushing area only accounts for  about 1% of the total filter turntable area. The backwash process is intermittent.

During cleaning, 2 filter discs form a group and are controlled by the electric valve on the suction pump pipeline that automatically switches. During a complete cleaning process of the fiber turntable filter, the cleaning of each group is performed alternately,  during which the suction pump works continuously. When the incoming water quality suddenly deteriorates, the liquid level in the pool quickly rises to the backwash level. During cleaning, all backwash pumps are started at the same time, and several sets of  filter turntables can be backwashed at the same time until the backwash cycle returns to normal.

(3) Mud discharge system

The fiber turntable filter has a bucket-shaped bottom under the filter turntable to facilitate the collection of sludge at the bottom. The sedimentation at the bottom of the sludge pool reduces the amount of sludge on the filter cloth, which can extend the filtration time and reduce the  amount of backwash water. After a set period of time, the PLC starts the sludge pump and returns the sludge to the factory drainage system through the perforated sludge pipe at the bottom of the tank. Among them, the mud discharge interval and mud discharge duration  can be adjusted.

2. Overall dimensions