Water purification equipment generally refers to ultrafiltration equipment or reverse osmosis equipment.
Ultra-filtration equipment and reverse osmosis equipment with high filtration precision, there are strict requirements for the incoming water, the need to use specialized filtration devices for pre-treatment to ensure that the incoming water quality meets the requirements.
Multi-media filter is commonly used pretreatment equipment
Multi-media filter working principle
Multi-media filter working principle is that when the filtration, the raw water in the external pressure, the water through the shallow multi-media filter on the upper part of the water filter, in a state of close to the advection to reach the filter media layer. Raw water is subjected to the continuous pressure of the filter media, from top to bottom layers through the filter media layer, impurities are retained in the packing layer.
The raw water after single filtration reaches the bottom of the filter, and the collector at the bottom collects the filtered water evenly and discharges it through the water production outlet.
The multi-media filter adopts advection filtration to ensure that the filter can still maintain stable filtration effect under higher flow rate.
With the increasing impurities in the filter media layer, the pressure head loss (i.e., differential pressure) inside the filter is increasing. When the differential pressure exceeds the set limit the system will start the backwash state to remove the impurities.
When the multi-media filter into the start of backwashing, through the PLC control to change the three-way valve on and off position, the filter tank through the filtered water partially into the filter tank to be backwashed. The packing layer is washed up under the impact of water flow, and the impurities are discharged through the discharge port of the three-way valve.
Water Sky Blue designed the multi-media filter collector so that the packing layer in the backwash state to form an internal loop flow, the packing rubbing each other, maximize the backwash efficiency, reduce the required backwash water, while backwashing does not run out of material. After the end of the backwash, the valve returns to the filtration state. Shallow multi-media filter to restart water production operation.
Multi-media filter operating parameters
Filtration speed: 7~15m/h
Inlet turbidity <15mg/L
Outlet turbidity <5mg/L
Inlet SS<50mg/L
Producing water SS<5mg/L< /p>
PH value of influent water:6~9
Operating temperature:0-50℃
Operating pressure< 0.4 MPa
Height of filter media layer:800~1200mm
Amount of compressed air for backwashing:18~25L/m2.s
Pressure of compressed air:l~2Kg/cm2
Single filter area:1-5m2
Backwashing intensity:8-12 L/(s-m?)
Single tank backwashing duration s:90sec
Backwashing differential pressure:0.08MPa
Interval time between backwash:4-8h