SE310310B - - Google Patents

Abstract

1,004,864. Centrifugal pumps. G. NEIDL. Sept. 5, 1961 [Sept. 6, 1960; Oct. 21, 1960; Aug. 3, 1961], No. 31818/61. Heading F1C: [Also in Divisions B2 and B3] In a rotary pump comprising an impeller mounted in an inclined position on a shaft as claimed in Specification 848,757, a screw conveyer is used to feed material to the pump. Fig. 1 shows a pump in which the material is fed to the inclined-disc impeller 150 by way of a conveyer belt 209, a hopper 155 and a screw conveyer 153. The material is discharged through a tangential duct 160. The impeller 150 and the screw 154 are independently driven through infinitely variable gears 151 and 158 respectively. The conveyer belt may be replaced by a bucket conveyer or a further screw conveyer. Instead of being cylindrical as shown, the screw and its casing may be of conical form, tapering in the direction of feed. The casing of the inclineddisc pump may be of spherical or elliptical form. Fig. 6 shows three pumps connected in series, the first pump being fed through a hopper 189. The screws 190 are independently driven but the inclined-disc impellers are driven together through chain or toothed gearing 200, impeller 193 being 180 degrees out of phase with impellers 191, 192. When this phase relationship is not required, the impellers can be non- positively driven through belts. The axes of the pumps may be vertical, as shown, or horizontal. The pumps may be used for the treatment of cellulose, cellulose pulp, waste paper, rags or the like. A filter may be provided at the outlet of one or more of the pumps to prevent the passage of lumps. For the purpose of comminuting the material, the inclined-disc impeller may be provided with peripheral teeth cooperating with grooves on the inner periphery of the casing, as described in Specification 879,546. The teeth may be cut in a lathe by means of a tool 258, Fig. 15, the impeller disc 248 being mounted between centres 256, 257 by means of hubs 249, 252. After a set of cuts has been made the impeller disc 248 is turned through 90 degrees relative to the hubs 249, 252 and a further set of cuts is made with the tool 258. These cuts cross the original cuts, whereby the pyramidal tooth form shown in Fig. 14 is generated. The teeth alternate in two rows, each tooth having a triangular face 243 lying in the plane of one or the other of the two faces of the impeller disc. The two other triangular faces of each tooth have a common edge 247 running from the apex of the pyramid to the opposite face of the impeller disc. Further sets of cuts may be made, using hubs giving different angles of inclination from the angle a shown in Fig. 15. In an alternative set-up, the impeller disc is mounted on a single hub carried by a chuck.