Filtering installation

Claim 1

In a filtration apparatus comprising a substantially cylindrical vessel centered on a vertical axis, a central vertical shaft rotatably journaled in said vessel, a set of vanes each having a flat hollow body disposed in an axial plane of said vessel and provided with a filter screen on at least one major vertical surface, said vanes being mounted on said shaft with freedom of vertical displacement between a normal position above said lower part, a plurality of radial partitions in said vessel dividing said lower part into several compartments concurrently receiving respective groups of said vanes, a fluid collector supported on said shaft, flexible conduits extending from said collector to said vanes and terminating at the interior thereof for communication with the surrounding compartments through the respective filter screens, a distributor head fixedly disposed in said vessel adjacent said fluid collector and provided with channels communicating with said conduits in different rotary positions of said shaft, drive means for progressively rotating said shaft in said vessel, and hoist means synchronized with said drive means for lifting each of said vanes into said elevated position upon the approach of any of said partitions and returning said vanes to said normal position upon transition to an adjoining compartment across the intervening partition, the improvement wherein said distributor head is provided with a plurality of outlet tubes communicating intermittently with respective compartments of said vessel by way of said channels and conduits leading to the vanes temporarily immersed in liquids contained in said compartments, said vessel having an upper part connected to a source of gas under substantially constant pressure for driving said liquids into the respective outlet tubes, said compartments having inlet connections to respective supplies of said liquids, one of said inlet connections being provided with sensing means for measuring the supply pressure of the corresponding liquid, the associated outlet tube being provided with regulator means coupled to said sensing means for varying the discharge rate of said corresponding liquid in response to variations in said supply pressure.