Sand filter :
Inside filled medium: quartz sand (made from crushing natural quartz)
1.Principle: the filter purifying water with granular or ungranular material of certain thickness.
2.When there are too many impurities in filtering layer, the hole shall be blocked and then stream resistance shall increase, filtering speed shall reduce.
3.So as to keep original filtering speed, it must be washed repeatedly to get rid of all impurities leaving in filtered material.

Active carbon filter :
It is compose with active carbon layer and supporting layer. Active carbon has good holes. The holes have high adsorbed ability. Because of this, it is used in many industries. After working for a long time, active adsorb many material to tend to a saturation state. So, it we should change active carbon or make it regenerates.
The supporting layer is used in preventing the loss of active carbon from the equipment; it is also helpful to make water equality.

Sodiun ion exchanger :
The ion exchange soften machine is used for cutting down hardness of water.( Drinking water treatment equipment for filling line). Drinking water treatment equipment for filling line )Raw water goes through the exchanger from top to bottom, to be soften by the sodium ion-exchanger inside the divice. The positive ions of magnesium and calcium are exchanged with that of sodium. Then the raw water become soft water containing very few magnesium and calcium ion

The hardness of water is mainly composed of the cation: calcium (Ca2+), magnesium (Mg2+) ion. When the hardness of raw water containing the exchanger resin layer, the water calcium, magnesium ion is absorbed by resin and release of sodium ions at the same time, this exchanger outflow of water is to remove the hardness ions in softened water, when the resin absorption of calcium and magnesium ions reached a certain saturation, increase the hardness of the water. At this time water softener will according to a predetermined program automatic failure of the regeneration of the resin, by the resin,the resin failure to restore to a sodium type resin with high concentrations of sodium chloride solution (saline).