Patent GB-191319142-A (GB)
Title: Improvements in and relating to the Filtering of Water and other Liquids or the like.
Inventor: DUNBAR DAVID
IPC: B01D35/14
Filed: 1913-08-23
Granted: 1914-08-20
Abstract: 19,142. Dunbar, D. Aug. 23. Filters with vertical filtering-partitions; filters, cleansing ; strainers.- Perforated filter screens are arranged in parallel rows in housing-frames and are provided with portable devices for cleansing the screens by means of a spray or stream of water or water and air mixed. As shown in Fig. 1, a filter chamber with walls 10,11 is divided into compartments 12 by walls 9 and cortains two independent sets of filters A, B, each set having three series of filters comprising five strainers. The strainers are formed of woven wire or wire cloth arranged between rectangular sash frames 2, 3, Fig. 4, which are tightened together by means of screw blocks 6 in a rectangular channel frame 4, a rubber strip 5 and a ribbed wooden strip 7 being interposed as shown. The frames 4 slide in vertical grooves in the walls 9. The liquid to be filtered is passed to the set A or B from the supply pipe 25 through one or both of two chambers 13, 16, arranged along the side of the filter chamber and provided with vertical walls 15 having openings at top and bottom alternately. Connexions are so arranged that one of the chambers 13, 16 can be in use while the other is being inspected or cleansed. The liquid after its passage through the different series of screens is collected in a discharge pipe 26. The movable cleansing-device is shown in Fig. 3. It comprises a frame 38 arranged transversely to the filter chamber and travelling lengthways on rails 40, so that it can be moved over the various series of screens. Spray-boxes 44, one for each of the transverse compartments 12, are supported normally above the level of the filters by cords which pass around pulleys 53 and are connected to a counterweight 54. The boxes are divided by plates 49, Fig. 5, into two compartments, which are connected by separate flexible pipes to pipes 43 and thence by suitable couplings to valves 62 arranged at intervals on a longitudinal pipe 61, through which cleansing-water, preferably mixed with air from a compressor 64, is supplied by a pump 63. The valves on the flexible pipes are connected by levers to rods 57 so that they can be operated together to supply water to either side of the boxes 44 or to both sides simultaneously. When supplied with water, the boxes overcome the counterweight and fall within the compartments into a position where the spray can be delivered against the screens on either side. Pipes 67 are provided for the discharge of the waste water. When either of the sets A, B is clogged, water overflows into a chamber containing a float which actuates an audible alarm and recording-device. An overflow is also provided in the wall which separates unfiltered water in the two sets. The liquid supplied through the pipe 25 may actuate a turbine connected to a shaft 70 which drives the pump 63, the air-compressor 64, and a dynamo 69 for lighting or power purposes. A combined centrifugal turbine and pump may be used to force water from the pipe 26 to the spray-boxes. It is stated that instead of the series of screens being arranged side-by-side they may be arranged in a circular or polygonal manner.