Fiber Disc Filter

Fiber Disc Filter

Overview

The Fiber Filter Disc Filter offers excellent processing performance, high water quality output, stable water quality, reliable equipment operation, and high automation level.

Fiber felt disc filters are primarily used for cooling circulating water treatment and the reuse of wastewater after deep treatment. As for cooling and circulating water filtration and reuse: the incoming water quality SS ≤ 80mg/L, the outgoing water quality SS ≤ 10mg/L. For the deep treatment of wastewater, they are set after conventional activated sludge process,延时曝气法, SBR systems, oxidation ditch systems, trickling filter systems, and oxidation pond systems, and can be applied in the following fields: ① Removal of total suspended solids; ② Combined with chemical dosing, phosphorus can be removed; ③ Heavy metals and others can also be removed.

Fiber Disc Filter Design Parameters

Filter Type: Membrane Microfiltration

Filter Disc Diameter: DN2000mm (additional settings available)

Mesh diameter of filter cloth: ≤10 micrometers

Filter Fabric Material: Fiber Filter Fabric

Effective Filtration Area: 5.2 m² (per disk)

Pre-filtration Water Quality Conditions: Effluent from Secondary Sewage Treatment

Inflow Water Quality: SS ≤ 30 mg/l (Instantaneous Peak 80 mg/l)

Water Quality Outflow: SS ≤ 5mg/l, Turbidity ≤ 2NTU. Note: The suspended solids filtration efficiency is 70% when the incoming water SS ≥ 50mg/l.

Medium Temperature: Room Temperature

pH：6～9

Operation Costs: 0.01 Yuan/ton of water (excluding depreciation costs)

Fiber Disc Filter Tank Specifications and Models

Fiber disc filter tank structure

The Fiber Disc Filter Tank is primarily composed of: (1) the tank, (2) filter discs, (3) backwashing mechanism, (4) sludge discharge mechanism, (5) central tube, (6) driving unit, (7) electrical control, (8) pump, and valve assembly.

(1) Box: Carbon steel welded, internally coated with imported anti-corrosion paint, externally treated with Baota Mountain epoxy zinc-rich anti-corrosion paint. The box structure is compact, lightweight, and has a small footprint. The auxiliary box can adjust the water level difference.

(2) Filter Disc: Each filter disc is composed of 6 independent segments, covered with filter fabric and a backing. The depth of the filter hair stores captured particles, reducing head loss during normal operation. Each filter fabric disc has at least a 5.2m² (53.8 sq ft) effective immersed filtration area and is easily removable from the unit.

(3) Backwashing System: Comprised of backwashing inlets, pipes, and backwashing inlet bracket components. Used for filtering cloth backwashing.

(4) Sludge Discharge Mechanism: Composed of sludge suction ports, pipes, and support components for sludge suction ports. Used for cleaning sludge at the bottom of the filter pond.

(5) Central Tube: Treated middle water flows into the auxiliary box through the hollow tube, which can both convey the middle water and rotate the filter disk.

(6) Drive Mechanism: Comprising a reducer, sprocket, chain, etc., it is used to drive the center tube and filter disc rotation.

(7) Electrical System: Composed of components such as the control cabinet, PLC, touch screen, and level monitoring, it is used to control backwashing and sludge removal processes, enabling automation and allowing adjustment of backwashing and sludge removal intervals.

(8) Pump and Valve Assembly: Comprises centrifugal pumps, pipelines, and electric ball valves, used for backwashing and sludge removal.

Fiber Disc Filter Bed Process Operation Method

The operational states of the fiber disc filter include: static filtration process, negative pressure backwashing process, and sludge discharge process.

(1) Static filtration process: Wastewater flows into the filter tank by gravity, where energy-dissipating baffles are installed. The wastewater is filtered through the filter cloth, the filtrate is collected through hollow pipes, and the gravity flow is discharged from the filter tank via overflow channels. The entire process is continuous.

(2) Negative pressure reversal gradually increases. The water level height in the pool is monitored by a pressure measurement device. Once the water level reaches the backwash setpoint (high water level), the PLC can start the reverse suction pump to initiate the backwashing process. During backwashing, the filter pool can continue to filter continuously.

During the filtration period, the filter disk remains stationary, facilitating sedimentation at the bottom of the sludge pond. During the backwashing period, the filter disk rotates at a speed of 1 revolution per minute. The suction pump draws a vacuum to remove sludge particles accumulated on the filter cloth surface, simultaneously aspirating water within the filter disk, which cleans the filter cloth from the inside out and discharges the backwashed water. The backwashing area occupies only 1% of the total filter disk area. The backwashing process is intermittent.

(3) Sludge Removal Process: The under-bottom of the fiber disc filter pool is equipped with a trapezoidal pool bottom, which is conducive to the collection of sludge at the pool bottom. Reducing the sludge on the filter cloth by sedimentation at the pool bottom can extend the filtration time and reduce the backwashing water volume. After a set time period, the PLC starts the sludge pump, returning the sludge to the wastewater pretreatment structure through the sludge removal pipeline at the pool bottom.

Fiber Disk Filter Electric Control System

1. The electrical control system utilizes a modern programmable logic controller (PLC) as the core of the program control system, enabling automated control of filter cloth backwashing and sludge discharge. It boasts reliable quality, excellent performance, strong adaptability to various environments, and good anti-interference capability.

2. The system features both manual and automatic modes: in the automatic mode, the operator adjusts the backwashing interval as needed, and the equipment operates according to the pre-set PLC program (based on time and liquid level control). The manual mode is used only for equipment debugging or maintenance, enabling manual control of valves, pumps, and filter disk motors. It also allows the operator to use a single button to activate the pre-shutdown backwashing function, pool cleaning function, or shutdown anti-freezing function.

3. The S7200 can be optionally equipped with an Ethernet interface or DP interface communication module to facilitate data transmission with the factory master station.

4. Selection of manual and automatic modes, parameter settings, status indication, and key operations are all completed on the touch screen; navigate to the desired interface from the initial screen and click the corresponding buttons to execute the respective functions.

5. The touch screen system features a fault alarm prompt function; it detects if the valve is not fully opened or closed, as well as overcurrent and overload conditions in the pump and filter disk motor. When a fault occurs, the touch screen displays the fault information and triggers an audio-visual alarm.

What are the differences between fiber disc filters and conventional filters?

(1) The effluent water quality is excellent and consistent. The fiber disk filter is designed to replace the traditional sand filter medium in the filter basin with filter fabric wrapped around the filter disk. The fabric has very small pore sizes, capable of retaining particles as small as a few micrometers (μm). Consequently, both the effluent water quality and stability are superior to granular material filter basins. Additionally, conventional filters often have poor water quality before flushing due to penetration issues, and the effluent quality can be affected after flushing due to the residual cleaning water in the filter layer. Moreover, the amount of filtered water varies with the change in resistance.

(2) Innovative design with resistance to shock loads. The fiber disc filter is a combination of a filter and a sedimentation tank, featuring污泥 removal capabilities. Large sludge particles settle directly to the funnel-shaped tank bottom, preventing clogging of the filter cloth, unlike standard filters where all suspended solids (SS) must pass through the filter media. This results in a longer filtration cycle and longer cleaning intervals. Moreover, it can withstand significantly higher hydraulic and sludge loads compared to conventional sand filters, with suspended solids (SS) load equivalent to 1.5 times that of a standard sand filter and a filtration rate 50% higher. Therefore, the fiber disc filter is more resilient against high concentrations of suspended solids and large particles.

(3) Equipment is simple and compact with minimal auxiliary equipment, resulting in low investment for the entire filtration system. The fiber disk filter pond can continuously filter during cleaning. However, the sand filter pond cannot continuously filter during backwashing, and to ensure continuity, an intermediate storage pond before the sand filter pond or alternating operation of multiple filter ponds is required. The fiber disk filter pond uses a small pump for vacuum extraction of filtered water for automatic cleaning, eliminating the need for backwashing ponds, water towers, and other traditional filter pond requirements. Traditional filters, due to high backwashing intensity, require not only high-power pumps and blowers but also a large-diameter pipe valve system for both air and water. The entire system is extensive and complex, with high investment. The automatic control system is also large and complicated.

(4) Low equipment idleness and low total installed power. Due to the thinness of the filter cloth, it is easy to clean thoroughly. During cleaning, the area cleaned of the filter plate is only 1% of the total filter plate area. The cleaning feature is frequent but with short duration (1 time/60-120 minutes, 1 minute per time). The overall water used for cleaning is also minimal. In contrast, traditional filter basins have more equipment like air-water backwashing pumps and blowers, numerous large automatic valves, high power, and high idleness rates.

(5) Operation is automated, making it simple and convenient for operation and maintenance. The filtration process is controlled by a computer, allowing for adjustable intervals and durations of the negative pressure suction cleaning and sludge discharge processes. Minimal need for dedicated maintenance and management.

The maintenance volume for fiber disk filter pools is low. These filter pools have fewer mechanical components, with pumps and motors operating intermittently, resulting in minimal wear on the filter fabric, which is also easy to replace. In case the filter fabric gets clogged due to certain reasons, it can be easily replaced. For sand filter pools, if the filter medium gets clogged, a significant amount of cleaning work is required. Moreover, it is difficult to replace the filter medium in sand filters.

(6) The head loss is much smaller than that of a sand filter. The head loss of a fiber disc filter is generally 0.2m, whereas the head loss of a sand filter is typically over 2m. The head loss of a sand filter tank is even higher than 5m, resulting in significant energy loss and increased operating costs.

(7) The land area is much smaller than that of other filter basins. Due to the vertical hollow tube design of the filter plate, the small land area ensures a large filtering area, thereby reducing the pool volume, material quantity, and earthwork volume, significantly lowering the construction cost. A filter basin with a daily processing capacity of 10,000 tons requires no more than 20 square meters of land area and is 3.3 meters in height. For technical renovations, it can address the issue of insufficient space.

(8) Fiberglass disc filter beds are easier to install than granular filter beds. Once the on-site pipe fittings and electrical equipment are connected, they can be put into use. Granular filter beds typically require filter media installation.

(9) Short design and construction periods. The fiber disk filter system is fully integrated, allowing for easy overall shipment. Design and construction are convenient and quick; additionally, expansion is simple.

(10) Low ground resistance requirements, with minimal investment in equipment foundations.