Shallow sand filter

1. Filter characteristics

 The backwashing system of shallow sand filtration system has manual, semi-automatic and fully automatic three modes, which can be started by manual button, internal clock, PLC, pressure difference or management system respectively. Backwashing time adjustable, factory set to 3 minutes. There is a timer inside the system, which can be used to set the appropriate backwash time for specific process conditions. By designing special controllers, highly demanding control can be achieved centrally or remotely.

Shallow sand filtration systems can be installed in different ways. The shallow sand filter can be used as a stand-alone filtration system, using the existing process water supply pump, of course, if it is used as a bypass filter, it can also be equipped with its own pump. Shallow sand filterscan also be installed in multiple processing units on a common pipeline, which can achieve unlimited filtration capacity of the system.

UNIGRAN series filter media are used for shallow sand. All filter media are carefully selected, washed and dried. The small filtration accuracy can reach 0.45 micron. Homogeneous high-performance filter media with specially designed filter water distribution up and down to ensure that shallow sand can achieve very good filtration effect at high flow rates.

Shallow sand filter overallsystem, factory before all the internal pipes, control chain lines are complete, installation system only need to connect the peripheral pipes and power supply, easy to install.

Second, the filter operation mode

When the system is in the filtering state, pressurized water flows into the water distribution system from the inlet of the filter tank and evenly reaches the filter layer. When water flows through the filter media layer, suspended matter is retained by the filter media. The bottom of the filter has a water collector with precision slits, and the filtered water is evenly collected and flows out of the filter. The precise gap on the collector can effectively prevent the loss of filter media. Mechanically linked castellations (pneumatic or electric) control the direction of water flow.

When the system is in automatic backwash mode, the backwash cycle is controlled by increasing pressure differential. As impurities accumulate in the filter layer, the pressure loss increases continuously. When the pressure difference increases to a certain set value, the system will automatically switch to the backwash state. Pressurized water enters the filter media layer through the fluidization device (i.e., the water collection device), washes it, and the trapped pollutants fall off and are discharged from the filter system. After backwashing for at least 2 minutes, the valve automatically switches the system to filtration.