Self-cleaning filter for filtering greasy effluents, has movable shutter to scrape each different sized mesh to push retained waste to outlet

摘要

A mesh (12a, 12b, 12c) has at least one opening (13a, 13b, 13c) which is closed in a first, filtering position by a movable shutter (18a, 18b, 18c) displaced by the action of a motor (11) to open the opening. The filter (1) has at least one filter mesh (12a, 12b, 12c) placed in a vessel (2) between an inlet (5) for the effluents and an outlet (7) for the filtered effluents. The movable shutter scrapes the mesh as it is displaced and the retained residues are pushed towards the opening. The mesh(es) are circular and the vessel is cylindrical. The shutters and openings are in the form of solid sectors of an axle (9) placed at the axis of the vessel. Each mesh describes, with the preceding mesh or with the cover for the vessel, a chamber (19a, 19b, 19c) for receiving effluents. The shutter of the mesh being considered has a height equal to that of the chamber. The filter has a pipe (15) for waste recovery which is placed below the openings in the meshes. There are means of heating the vessel, such as pipes (4) for a heat-bearing fluid around one wall of the vessel, to ensure the filter is at a temperature of between 80 and 95 deg C. The filter contains at least two meshes with different mesh dimensions decreasing from top to bottom of the filter. An Independent claim is included for an effluent filter installation containing at least one filter as above, supplied with preheated effluents which are pressurized by a pump. The installation contains at least two filters fed with effluent by a three-way valve which allows one filter to be outside the circulation while the other is working. A device injecting water or steam under pressure is connected to the vessel and operated during filter cleaning.