Shallow sand filter

Operating principle

Shallow sand filter adopts the principle of shallow contact flocculation+physical retention high efficiency filtration, and the whole process is divided into two automatic working conditions: filtration and backwashing. During normal filtration, the pressurized raw water uniformly penetrates the shallow quartz sand filter layer through the unique water distribution system, the suspended impurities, colloids and algae in the water are accurately intercepted and absorbed by the thin layer of filter materials, and the clean water is uniformly collected and discharged through the bottom water collection system to complete the water quality purification.

With the continuous accumulation of impurities, the pressure difference at the inlet and outlet of the equipment increases gradually. When the set threshold or timing period is reached, the system automatically enters the backwashing mode. Each filter unit is backwashed independently one by one, without shutdown of the whole machine; The water flows from bottom to top to loosen the filter layer, the sand particles rub off the attached impurities, and the sewage is discharged in a centralized manner. After backwashing, it is automatically reset and enters the filtration state. The whole-process alternate operation realizes 24h uninterrupted continuous filtration, and the water quality is stable without fluctuation.

Equipment configuration

The whole machine is of modular integrated design, with compact structure, uniform water distribution and no filtration dead angle. The whole set of industrial-grade configuration is suitable for 24h continuous circulating water working condition. The core configuration is as follows:

• Modular filter tank body: carbon steel rubber lined, carbon steel plastic lined, FRP FRP, stainless steel materials are optional. The tank body has strong bearing capacity, corrosion resistance, aging resistance and leakage resistance, and is suitable for acid and alkali, moisture, outdoor and other complex working conditions, with long service life.
• High-efficiency shallow quartz sand filter material: the high-purity wear-resistant quartz sand filter material is selected, with uniform particle size, strong adsorption and retention capacity, and repeated washing resistance. The shallow filter layer is designed with small resistance, large flux, and not easy to be hardened. The filtration efficiency is far more than that of the traditional deep sand filter.
• Special water distribution and collection system: equipped with high-precision water distributor and slot type water collector, the water flow is evenly distributed, the bias flow and short circuit filtration are eliminated, the loss of filter materials is effectively prevented, and the filtration performance of the filter layer is maximized.
• Full-automatic intelligent control valve group: independent electric pneumatic valve, single tank independent control, tank by tank time division backwashing, without shutdown, supporting differential pressure, timing dual mode automatic switch, without manual intervention.
• High-precision pressure monitoring module: real-time monitoring of inlet and outlet pressure difference and operating water pressure, accurate identification of filter plugging status, automatic triggering of backwash warning, visualization of operating status, convenient for equipment operation and maintenance management.
• PLC intelligent control system: touch control full-automatic program operation, one-key start and stop, automatic inspection, fault alarm, overload and water shortage protection, can be connected to the remote monitoring system, and adapt to unattended working conditions.
• Optional supporting system: pre-pretreatment, precision filtration, online water quality turbidity monitoring, remote data transmission and automatic dosing device can be installed, which is applicable to high impurity and high turbidity complex raw water.

Product advantages

H6>Shallow high-speed filtration, large flux and small pressure loss

The optimized design of thin filter material is adopted, with low water flow resistance, fast filtration speed, large treatment capacity per unit area, stable and controllable operating pressure loss, no load pressure on the whole water circulation system, and perfect adaptability to the working condition of large-flow circulating water side filtration.

H6>Independent time sharing backwashing without shutdown

Multi-unit modular combination, independent backwashing of single tank and normal filtration of other tanks solve the problem that the traditional filter must be shut down for backwashing, ensure the water circulation system operates continuously and stably for 24 hours without affecting the production conditions.

H6>Water and energy conservation, extremely low operation and maintenance cost

Impurities in the shallow filter layer are easy to be washed and stripped, the backwashing time is short, the water consumption is very small, and the water saving is more than 70% compared with the traditional sand filter equipment. The filter material is erosion resistant, not easy to be worn, with long replacement period, automatic operation without specially-assigned person, and the economical efficiency of long-term operation and maintenance is outstanding.

H6>Modular design, flexible installation and small footprint

Integrated skid-mounted modular structure, no complicated civil construction is required, and the pipeline can be put into production on site. The filtration unit can be increased or decreased freely according to the flow demand, and the single unit and multiple units in parallel can flexibly adapt to the working conditions, and the floor space is far less than that of the traditional filtration equipment.

H6>Wide adaptability to working conditions and strong durability

The equipment is corrosion resistant, anti-manufacturing and stable in operation. It can adapt to industrial circulating water, surface water, reclaimed water, landscape water, swimming pool water and other water qualities. It has strong pollution resistance and is not easy to failure. It can adapt to severe industrial operation environment for a long time.

Application Scenario

With the core advantages of high flux, low loss and non-stop operation, the shallow sand filter is widely applicable to various water circulation purification scenes. The core applications are as follows:

• Industrial circulating water system: plant cooling circulating water, central air conditioning circulating water and heat exchange station water circulating and side filtration purification;
• Sewage treatment and reclaimed water recycling: deep filtration at the end of sewage, interception of suspended solids for reclaimed water recycling, quality improvement and turbidity reduction;
• Municipal and landscape water body: municipal water supply pretreatment, landscape lake water, swimming pool water and artificial river water purification;
• Pretreatment of industrial process water: pure water and RO system are pre-filtered to protect the back-end membrane elements and reduce the probability of membrane pollution;
• Farmland and irrigation water: agricultural irrigation water, well water and surface water shall be filtered to remove sediment and prevent pipe nozzle blockage.

Technical parameters

• Water treatment capacity 10T/H - 500T/H (customized for modular free combination)
• The filtration precision is 20-100 μ m, which can effectively intercept suspended solids, colloids and algae
• Inflow turbidity ≤ 30NTU
• Effluent turbidity ≤ 5NTU
• Operating pressure 0.2MPa - 0.6MPa
• Control mode PLC full-automatic timing/differential pressure dual mode, no shutdown for backwashing
• Tank material Carbon steel rubber/plastic lined FRP, SS304 stainless steel optional
• Operating temperature 5 ℃ - 60 ℃
• Backwashing mode: single tank independent time-sharing backwashing, uninterrupted filtration of the whole machine
• Core advantages: low backwashing water consumption, low operating pressure loss, high flux and no shutdown

After-sales guarantee

Provide one-stop scheme customization, field installation, commissioning, operation and maintenance services for shallow sand filter, and fully guarantee long-term stable operation of water circulation system:

• Free site working condition survey and water quality inspection, and customized modular filtering scheme according to circulating water flow, turbidity and working condition;
• The whole machine is modularized and ex-factory, and can be quickly connected, installed and commissioned on site. Backwashing parameters are accurately set to guide daily operation and maintenance;
• One year warranty for the complete machine, special warranty for core parts such as control valve, control system and tank body, and lifetime technical support;
• Hour all-weather after-sales response, quick remote troubleshooting of operation faults and abnormal differential pressure, and on-site maintenance by the nearest engineer;;
• Provide lifelong value-added services such as filter material replacement, tank anti-corrosion maintenance, system parameter upgrading, module increase/decrease and transformation.