Today, when water resources are scarce and the demand for water pollution control is becoming increasingly urgent, fully immersed fiber turntable filters, as an efficient and energy-saving deep water treatment equipment, are being widely used in municipal sewage standard improvement, industrial wastewater reuse, landscape water purification and other fields. With its unique structural design and operation mode, it solves the pain points of traditional filtration equipment such as large footprint, high backwash energy consumption, and complex maintenance, and has become the "new favorite" in the water treatment industry.
1. What is a fully immersed fiber turntable filter?
The fully immersed fiber turntable filter (hereinafter referred to as the "fiber turntable filter") is a continuously operating filtration equipment that uses fiber filter material as the core filter medium. Its core component is the fiber turntable, which is composed of multiple fan-shaped filter discs. Each filter disc has a layer of high specific surface area polyester fiber filter material attached to its surface. The entire equipment is installed in the pool, and the filter disc is completely immersed in the water to be treated. The turntable is slowly rotated to achieve continuous filtration and backwashing without shutting down the machine.
2. Core structure and working principle
1. Core structure
- Fiber filter disc: woven from polyester fiber, with a porosity of more than 80% and a large specific surface area (approximately 1000㎡/m³), which can efficiently intercept suspended solids (SS), colloidal particles and some organic matter.
- Drive system: The motor drives the turntable to rotate slowly at a speed of 0.5-1 rpm to ensure that each filter disk passes through the backwash area in turn.
- Backwash system: including vacuum suction pump, suction pipe and mud discharge tank. When the filter disc rotates to the backwash area, the sludge suction pump generates negative pressure to suck away the sludge trapped on the surface of the filter material and discharge it into the sludge treatment system.
- Water outlet system: The filtered clean water is discharged through the water collection pipe inside the filter plate to ensure stable outlet water quality.
2. Workflow
(1) Filtration stage
After the water to be treated enters the filter tank, it passes through the fiber filter material layer under the action of gravity. Suspended particles and colloids in the water are intercepted by the filter material, and the clean water passes through the filter material and enters the water collection system. Since the filter disc is completely submerged, the filtration process continues without additional pressure and energy consumption is low.
(2) Backwash stage
As the filtration time increases, the sludge trapped on the surface of the filter material gradually increases, and the resistance of the filter layer increases. When the head loss reaches the preset value (usually 0.5-1.0m) or the time reaches the backwash cycle (30-60 minutes), the backwash system starts:
- The turntable rotates to the backwash area, and the mud suction pipe is close to the surface of the filter plate;
- The vacuum sludge pump starts to generate negative pressure to suck away the sludge on the surface of the filter material;
- The backwashing time only takes 10-30 seconds per filter plate, and the water consumption only accounts for 0.5%-1% of the treated water volume, which is much lower than traditional sand filter (5%-10%).
The backwash process does not affect the overall filtration operation, achieving continuous operation of "filtering and backwashing at the same time".
3. Core advantages
Compared with traditional sand filtration, membrane filtration and other equipment, fiber turntable filters have the following significant advantages:
1. Small footprint: The filter plate is arranged vertically, and the processing capacity per unit area reaches 20-50m³/(m²·h), which is 3-5 times that of sand filter. It is suitable for projects with tight land use.
2. High efficiency and energy saving: less backwash water and low energy consumption (driving power only 0.5-2kW), the operating cost is more than 30% lower than that of sand filter.
3. High filtration precision: it can remove particles with a particle size of ≥10 μm, and the effluent SS is ≤5 mg/L, meeting Class A emission standards or reclaimed water reuse requirements.
4. Simple maintenance: the filter material has a service life of 5-8 years and does not need to be replaced frequently; the equipment is highly automated and can achieve remote monitoring and unattended operation.
5. Strong adaptability: It can handle high turbidity water (SS≤300mg/L), and can also be used to purify low-temperature and low-turbidity water, with a wide range of applications.
4. Typical application scenarios
1. Advanced treatment of municipal sewage
In the municipal sewage treatment plant tail water standard improvement transformation, the fiber turntable filter is used as an in-depth treatment unit, which can effectively remove SS and TP (by adding flocculant), so that the effluent can reach the "Urban Wastewater Treatment Plant Pollutant Discharge Standard" (GB18918-2002) Class A standard, and even the surface level Class IV standard. For example, after using this equipment in a city's sewage treatment plant, the effluent SS was stabilized below 3 mg/L and TP ≤ 0.3 mg/L.
2. Industrial wastewater reuse
In industries such as electronics, printing and dyeing, and food processing, fiber turntable filters are used for wastewater reuse treatment to remove suspended particles and colloids in the water, provide pretreatment for subsequent reverse osmosis (RO) or ultrafiltration (UF) systems, and extend membrane life. For example, in the reuse system of an electronics factory, the fiber turntable filter reduces the wastewater SS from 50mg/L to 5mg/L, and the RO membrane cleaning cycle is extended by 2 times.
3. Landscape water and river management
For water bodies such as landscape lakes and artificial rivers, the fiber turntable filter can circulate and purify the water quality, remove algae and suspended matter, and maintain the transparency of the water body. After using this equipment in a park landscape lake, the water transparency increased from 0.5m to 1.5m, and the water quality reached the surface water level III standard.
5. Future development trends
With the improvement of environmental protection requirements, fiber turntable filters are developing in the direction of intelligence and modularization:
- Intelligent: Real-time monitoring of water head loss and outlet water quality through sensors, automatically adjusting the backwash cycle and optimizing operating parameters;
- Modularization: Using standardized module design, it can be flexibly combined according to the amount of water treated, shortening the construction period;
- Function expansion: Combined with biomembrane technology, it can achieve simultaneous filtration and biodegradation, further reducing COD, NH3-N and other pollutants.
The fully immersed fiber rotating disk filter has become a key equipment in the field of water treatment due to its high efficiency, energy saving and compactness. In the context of the "double carbon" goal and water resource recycling, it will play a greater role in sewage standard improvement, wastewater reuse and other fields, providing strong support for building a green and low-carbon water treatment system.
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