Apparatus for filtering liquids

A filtering apparatus for filtering liquids comprising

• a container having an inlet for the liquid to be filtered and an outlet for the filtered liquid;
• a first chamber, inside the container, which communicates with said inlet and is intended to receive liquid to be filtered from said inlet;
• a second chamber, inside the container, which communicates with said outlet and is intended to receive filtered liquid and discharge it towards said outlet;
• a first porous wall and a second porous wall which are positioned inside the container and delimit a filtration chamber between them, wherein the first porous wall divides the first chamber from the filtration chamber and wherein the second porous wall divides the second chamber from the filtration chamber, the filtration chamber being interposed between the first chamber and the second chamber;
• a granular filter material which is housed in the filtration chamber, the granular filter material being enclosed between the first porous wall and the second porous wall;
• wherein the first chamber has a receiving region of liquid to be filtered which is at a first height and wherein the second chamber has a discharge region of filtered liquid which is at a second height, the first height being at a higher altitude than the second height;
• a washing system to wash the granular filter material, the washing system being configured to force a washing liquid flow which travels through the filtration chamber with a substantially vertical path;
• a pump connected to the outlet for the filtered liquid and to the washing system, the filtration apparatus comprising ducts and shut-off valves configured in such a way that, during the filtration step, the pump can be used to discharge the filtered liquid from the outlet and, during washing, the pump can be used to force the washing liquid flow in the filtration chamber and in the first chamber;
• wherein the first chamber, the filtration chamber and the second chamber are flanked to each other and, in a section between the first height and the second height, are all intersected by a plurality of horizontal planes parallel to each other, and
• whereby in use the liquid to be filtered passes from the first chamber to the second chamber substantially by gravity and through the filtration chamber with a flow path having a horizontal component.