Due to void spaces as small as 3 microns, Filter-Ag Plus creates a surface area over 100 times greater than silica sand. The angularity of the granules and the tapered internal pore spaces allow for reduction of dirt, silt, and organic matter suspended in water by bridging, straining, and adhesion.
Filter-Ag Plus can be applied to systems designed for either pressure or gravity flow. Because of its unique physical characteristics, Filter-Ag Plus can be used to replace multimedia (graded density) filter designs. |
AIR SCOUR
Air scour is possible and helpful when there is heavy loading in the bed. It has to be done minimally in order to prevent too much bed lift and/or advanced attrition.
An air scour of 1 to 2 cfm/sq.ft. at backwash rates of 15 to 20 gpm/sq.ft. would be sufficient. The pressure required would be static head pressure plus the psi necessary to deliver 1 to 2 cfm/sq.ft. Bed expansion should be observed to ensure that media is not being discharged in the backwash water. A one minute air scour at the beginning of the backwash cycle should be sufficient. Prolonged air scour may cause stratification of the smaller media to the top of the bed which could affect future head loss. |