Abstract: An assembly for removing wash water for washing filters containing granular filter material, which are washed simultaneously with water and air, such as those employed especially in water treatment, and recovering the particles of granular filter material entrained by the water during the washing which includes a collecting member having calibrated holes for collecting and removing dirty water, internal and external partitions placed on each side of the collecting member, defining a water recovering zone inside the internal partitions and between the internal and external partitions, tranquil flow zones promoting the separation, by downward concurrent settling of the particles of granular material and of the dirty water to be removed, and a baffle intended to avoid disturbing the preceding zones by the water/air/granular material three-phase mixture formed during the washing, placed under said zones and directing the three phase mixture towards an external degassing zone where the air is removed before the re

Abstract: Apparatus for setting in position and securing, on the floor of a filter, members providing for fluid to flow through the floor. The apparatus consists of a support arranged so as to receive the member, such as a nozzle or equivalent, introduced inside a housing created in shuttering used for making the filter floor. The housing and the support are configured to removably secure mechanically, for example by a snap-in action, the support in its housing.

Abstract: A method for making floors for filters, particularly for filters including a granular filtrating material, wherein the method includes forming two stages. The first stage is made by casting in concrete or the equivalent, at least one carrier self-supporting element or pre-slab, formed with openings in which are housed elements, such as nozzles, for the introduction of fluids used for washing the filter. Then the second stage is formed, during which, once the carrier self-supporting elements have been put in position on the supports of the filter, concrete is cast in a single operation on this element or elements, in a quantity sufficient for reaching the required total thickness of the floor and thereby providing a slab which will receive the filter granular material.