The filter-cloth rotary disc filter is mainly used for the treatment of cooling circulating water and the reuse of wastewater after deep treatment. Reuse after filtration as cooling water and circulating water: inflow water quality SS≤80mg/L, outflow water quality SS≤20mg/L, to be used for advanced treatment of wastewater, after being set in conventional activated sludge process, extended aeration process, SBR system, oxidation ditch system, trickling filter system, oxidation pond system, it can be used in the following fields: ① removal of total suspended solids ② removal of phosphorus in combination with the addition of chemicals ③ removal of heavy metals, etc. The filter- cloth rotary disc filter is used to filter the activated sludge and outflow the water from the final sedimentation tank of . The designed water quality: inflow water SS: 30mg/L ( withstand up to 80-100mg/L), outflow water SS≤5mg/L, turbidity ≤2NTU. In actual operation, the outflow water quality is better, generally the outflow water turbidity is around 1.

The operation of the filter-cloth rotary-disc filter is divided into two relatively independent but concurrent processes: raw water filtration and backwashing sludge discharge. The two processes are carried out at different locations within the same filter.

a. Raw water filtration: The wastewater to be filtered enters into the inner side of the rotating central cylinder of the filter through the gravity drop, there are square water distribution holes in the rotating central cylinder. The wastewater flows into the rotating drum and enters the inner liner of each filter disc through the water distribution port, and then passes through the filter cloth so that the suspended solids in the wastewater are retained on the inner side of the filter disc, and the filtered water is discharged through the overflow collection. The equipment is in a static state during filtration.

b. Backwashing: The sludge in the sewage is collected on the inner side 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, monitoring the changes in the liquid level in the tank by the level gauge. When the liquid level in the tank reaches thewashing (high water level), the PLC controls the startup of the backwashing process: Under the rotation of the central cylinder, the filter disc drives the reducer to rotate at a speed of 1-3 revolutions per minute while the backwash pump starts. The backwashing pump draws the filtered water and then flushes the filter cloth at the top position from the outside to the inside through a high-pressure umbrella-shaped jet system located at the top of the filter disc, thereby removing the dirt accumulated on the inner surface of the filter cloth to discharge out through the drain pipe. Thewashing nozzles move up and down to clean the filter cloth thoroughly without any dead spots and save water consumption forwashing. The frequency and duration of backwashing can be adjusted. During backwashing, the filter can filter continuously.

1. Continuous operation: Work continuously for 24 hours without the need to shut down for backwashing. Continuous filtration can be carried out while backwashing;

2. Good treatment effect: The pore size of the filter cloth is 10 microns, which can retain particles smaller than 10 microns, thus ensuring the effluent quality and effluent stability;

3. Low backwashing water consumption: The backwashing water consumption is 1% to 2% of the total inflow, which is much less than the water required for filtration by other filtration equipment;

4. Small head loss, generally 0.05 to 0.25m;

5. Low operating cost: (excluding the removal cost of phosphorus addition chemicals) less than 0.01 Yuan per ton of water;

6. Low installed power;

7. The operation is fully automated, and the filtration, backwashing, etc. are all programmed, with multiple protections, and the dedicated personnel is required to operate and manage on a daily basis;

8. Small footprint: The disc of the rotary filter is designed vertically, thus having a large filtration area with a small footprint;

9. Short design and construction period: The rotary disc filter is modularized as a whole, making its design and construction convenient and fast, and it is easy to expand.