Cleaning process of the filter medium of a sand filter by gravity and filtering system

摘要

A filtration system comprising a vessel sand filter (3) with a separator (8) permeable to water, a filter medium (7) located on the separator (8), an outlet pipe (6) leading from space of filtered water (9) under the separator (8) to a reservoir of filtered water (12), a pump filtered water (13) and a compressed air inlet (15) leading under the separator (8), characterized that - the compressed air inlet (15) is located immediately below the separator (8), - the outlet tube (6) has a flow inlet (11) near the bottom (10) of the vessel of the sand filter (3) and an outflow (5) to the reservoir of filtered water (12) to a height which determines the minimum level (4) water, having flow outlet (5) of the outlet tube (6) a profile selected or calibrated opening (24) to limit the flow of water from the filtered water space (9), such that the flow through the outlet tube (6) to less than the flow through the compressed air inlet (15), - the volume of filtered water space (9) is at least of the same magnitude as the volume of filtered water tank (12). - a flow inlet of turbid water (19) to a reservoir of turbid water (20) is located on the surface of the filter medium (7) and below the minimum level (4) water in the vessel of the sand filter ( 3).