| 摘要 |
986,870. Pressure filter presses. STAHLWERKE SUDWESTFALEN A.G. Feb. 5, 1963 [Feb. 22, 1962], No. 4608/63. Heading BID. A rotary pressure filter is provided with a plurality of rotating disc filters which are arranged on a shaft parallel to one another and between which annular cyindrical filter chambers are arranged and communicate, on the inlet side, with a press chamber which is common to all filter chambers and is provided with a closable inlet for the material to be filtered and has a press piston by which the material to be filtered is compressed in the press chamber and in the filter chambers. As shown (Fig. 3), material to be filtered enters inlet 6 and passes into the press chamber 5, the piston 7 then closing the inlet. Under the action of the pistons 8, the material is forced into the annular filter chambers 13, between oposed pairs of revolving filter wheels 4, and the solid concentrate is carried along a circular path towards the discharge outlets 27, Figs. I and 2, so that there forms in front of the slide 28, a solid plug of material. Slide 28 is then opened, the plug sealing the discharge outlet, and during the withdrawal stroke of the pistons 8, fresh material is introduced via inlet 6. The filter wheels 4 each consist of two half discs 14, mounted on the shaft 3, having circumferential rubber sealing rings 15 resting against the wall of the cylindrical shell 1, and are each fitted with a perforated screen 16, Figs. 4 and 5, in close contact with a helical wire spiral spring 18 of round cross-section, Fig. 7, which acts as an edge-filter. In Fig. 6, an additional perforated screen 17 abuts the other side of the spiral. Hence liquid passes through the spiral 18 and screen 16 (or screen 17, spiral 18 and screen 16) of the filter wheel 4 and through the ducts 22 and 23 to openings 24 in the shell of the cylindrical housing 1 which communicates therewith during each revolution of the filter wheels and filtrate flows from outlet 25 into the discharge duct 26. The inlets 12 and outlets 27 are placed as close as possible so that as large a part of the circumference of the cylinder as possible is available for the removal of liquid. The narrow zone between the inlet and outlet, Fig. 1, in which no filtration takes place, may be utilized for the removal of solids, by the action of steel rods (not shown) arranged in this zone to clean the spiral spring filter linings or the surfaces of the perforated screens. In a modification (not shown) only one pair of filter wheels is used, and the covers 2 of the cylinder 1 are replaced by press pistons, moving in opposite directions along the axis of the cylinder 1, thus forming two filter chambers. In this modification the press pistons 8 and cylinders 10 are replaced by the cylinder shell. Chamber widths of 50-80 mm. and operating pressures of 470-1420 p.s.i. are specified. Such presses may be used in conjunction with pneumatic and hydraulic conveyers for concentrating the solids-liquid mixture flowing therethrough. |
