Multi Media Pressure Filters

Suspended solids and certain dissolved solids can be removed by pressure filtration using the correct filter media.

Sand Filters

Moderately turbid waters can be clarified in the simplest way by being passed through a medium such as a bed of graded sand. The degree of filtration depends on the grain size of the sand used in the filter and this in turn is a function of the filtration rate used in the filter vessel. The gradual build-up of the turbidity in the filter raises the backpressure and when the resulting pressure drop from the filter inlet to the filter outlet reaches a predetermined level, the filter has to be cleaned by backwashing. Backwashing is carried out by reversing the flow through the bed, thus lifting and expanding the filter bed. The grains of sand collide with each other and, in doing so, free the accumulated turbidity, which is swept away to drain with the backwash water. Sometimes air is injected prior to backwash water to break up the bed. This reduces the flow rate of backwash water required to effectively clean the filter bed.

Selection of sand filter sizes can only be performed after careful examination of the water analysis, flow rates and required purity of filtered water.

Carbon Filters

These are similar in design to sand filters, but use a bed of activated carbon as filtration media. The activated carbon has the property of being able to remove chlorine and organic matter from water. They are often used ahead of demineralisation and reverse osmosis equipment in order to pretreat the water. For further information download our standard light industrial range carbon filters brochure.

Iron Removal Filters

These filters contain a special iron removal media. The media catalyses the oxidation of the iron in the water which is then filtered out on the media. Backwashing of the filter removes the iron and regenerates the media. Iron removal filters are used sometimes to protect ion exchange and reverse osmosis equipment, and sometimes separately, where the unpalatable taste and staining characteristics of iron is causing a problem. For further information download our standard light industrial range general turbidity filtration brochure.

Download Our Company Brochure

OTHER AWE PRODUCTS