| 摘要 |
<p>971,476. Filters for liquids. J. A. RICHARDS. April 16, 1962 [April 18, 1961], No. 14536/62. Heading BID. A filter system comprises a filter tank 29 incorporating a plurality of filter elements 74, a reversible pump having a tubular casing 10, a conduit 37 leading to the side of the pump which normally operates as the suction side from a source of liquid, a waste conduit 30 leading from this conduit, a conduit 36 leading from the side of the pump which normally operates as the pressure side to the tank, a conduit 38 leading from the tank to the source of liquid, and an isolating ball valve mechanism in a casing 21 adapted to close the waste conduit when the pump is drawing liquid from the source and for opening the waste conduit when the pump is reversed for drawing liquid from the tank. Normally, liquid passes through conduit 37, casing 21 containing a strainer basket, pump 10, filter tank 29, and conduit 38. When back-washing is required, the pump is reversed, flow being through conduit 38, tank 29, pump 10, casing 21, and waste conduit 30. A suitable automaticallyoperated valve for opening conduit 30 within casing 21 is described, Fig. 7 (not shown). To replace filtering material deposited on the filter members 74, a tank 57 containing a slurry of, for example, diatomaceous earth, is agitated by liquid injected through a jet tube 60 on opening of a valve 54 when normal flow is resumed. This raises an arm 82 and rod 63a to open a valve 63 and allow the pump to pass slurry to the filter until the level of slurry drops and valve 63 closes again. During this operation, a magnet 65 on rod 63a draws down an armature 66 releasing a catch 70 from drum 71, until the connection between magnet and armature is broken as rod 63a falls further. Drum 71 rotates under gravity to drop one load of pellets 72 of filter material. Valve 61 controlled by rod 82 restores the slurry level. This cycle of operations may be governed by cams driven by an electric motor, Fig. 8 (not shown), and initiated by hand, at a given time, or in response to pressure within the system. The pump 10 may be a multi-stage turbine.</p> |
