When? KDF be applied in POE water treatment system,some oxide will be produced during electrochemica oxidation reduction.Therefor,regularl back washing of these oxide and precipitate formed by Ca2+ and Mg2+,is needed.
1 when the amount of bakc washing flow is between 3 to 25gpm,premium triple control control valve can be used.(work,back washing,cleaning) .It is best to use big flow backwashing mode.
2 when the quantity of flow is between 36gpm-325gpm, diaphragm valve is needed. It is strongly suggested that all the flow limiting device should be loosed and a proper distributor is needed. Felt tiny crack distributor is needed for the fow of 3-25gpm,while wheel hub distributor for the flow of 36gpm-325gpm.Back washing time should be set to 10 min, washing time should be 3min.The frequency should be 2-3 times every week. In a word the frequency depends on water quality. Repeated washing is a allowed if necessary, but the procedure can not be longer than 10 min. Flow speed is affected by water temprature, ?Flitering media type, the size of the pellets, density of flitering media and other factors.
The density of KDF is 2.4-2.9g/cm3,which is so high that needs flow speed two times of normal speed when washing is on, the reflux speed is 2.65cm/s.This number can be a little bit lower when temprature is lower. When the reaction bed of KDF is big enough, the flow speed can be normal.
KDF requires that its surface area should be 1261L/m per square metre. Discharge tube should be without pressure.