| 摘要 |
1,091,390. Liquid filtering apparatus. M.E.L. EQUIPMENT CO. Ltd. Oct. 21, 1966 [Oct. 21, 1965], No. 47175/66. Heading B1D. In a liquid filter in which a moving band of filter medium 15, such as paper, felted viscose fibres or synthetic tissue, is entrained round an inward flow drum 1 in a tank 3 of liquid to be filtered, the band 15 is washed by water sprays 19 after leaving the tank and then wound on to a spool 23. In Fig. 3 the filter band extends between spools 14, 23 round drum 1, and its direction of travel is periodically reversed by transferring the drive from one spool to the other and reversing the drum rotation. Only the water spray 19, 19' on the take-up side of the drum are operative, their valve (24), and the spool drive clutch being controlled by a common mechanism. A signal may be given when the fabric on the supply roll nears its end and the motors automatically stopped. The drive speeds may be controlled by floatoperated means responding to the level in tank 3. Sprays 19 may be placed above the band rather than below, to wash it by reverse flow. In Figs. 1, 2 (not shown), the drum and filter band travel only in one direction, and when the supply spool 14 is exhausted it is replaced by a second spool, the ends of filter bands being temporarily joined until the leading end of the second band reaches the take-up spool. Since the filter bands are washed clean as they come off the drum 1, the apparatus can be operated with only two bands which are used alternately. The supply spool has a brake, and a pump delivers the washing water to the sprays. The drum 1 comprises coaxial perforate and imperforate walls 1b, 1a with the intervening space divided by axial partitions into chambers (5), each connected by a pipe 6 to a rotary distribution valve comprising two perforate plates (7, 9) which connect appropriate chambers to vacuum. |
