GB176495A - Improvements in and relating to rotary disc filters - Google Patents

Abstract

176,495. Jung, H. Dec. 7, 1920. Rotary filters. - An apparatus for filtering sugar, dyes, &c. comprises a series of discs F, B, the hubs of which have apertures forming, when the discs are placed together on a shaft 20, continuous passages 6 through some of which filtered liquid is discharged from discs F, and through others fluid is supplied to the alternate discs B for treatment of the separated solid matter. The discs may be of clay, fire-brick, or kieselguhr, or covered with filter cloth; they are provided with inner channels or passages and divided into sectors communicating with separate passages 6. The material to be treated is supplied to the casing U through a passage 1 and enters the spaces betwen the discs. The solid matter collects on the discs F and is carried round thereon and subjected in the sectors f, g, h, i to treatment by fluids passed across from the discs B to the discs F. In each of the spaces between adjacent discs there is a plate 3 supporting the hubs and separating the inlet 1 from a rake 4, which aids the discharge of the solid matter. The rakes 4 have hooked ends 12 and are connected to a common frame 24 oscillated by hydraulic or pneumatic pressure in cylinders C. The solid is pushed over a guide-plate 23 to a conveyer band T. The solid matter may be forced out by compressed air or by radial worms instead of by rakes. In each plate 3 is a slot w, in which an arm 2 is oscillated on a ball joint by means of a rocking shaft 11 and agitates washing-liquid supplied to the discs and passing outward through them. The arm 2 may be formed to have a brushing action. The part 3<a> of the plate 3 may be made narrower so that the wash liquor is mixed with the freshly-supplied material in the sector a. The end 30 of the central shaft is carried as a valve plug in a stationary head 22, which has two series of apertures with which the passages 6 leading respectively to the discs F and the discs B successively communicate as the shaft is rotated. Fig. 7 shows an alternative arrangement in which a plug 34 situated between the shaft 30 and the stationary head 22 rotates with the shaft for one-twelfth part of a revoultion and is then returned sharply to its original position by a spring or the like. In the arrangement shown in Fig. 3 the hubs are held together on a central shaft 20, but this shaft may be omitted, the hubs being then formed with engaging tongues and grooves, and the whole pressed together by hydraulic or pneumatic plunger pistons on the end walls of the casing. When a shaft 20 is not used, the central passage formed through the hubs may be filled with a liquid such as oil or a mixture of hydrocarbons. An index 15 on the central shaft moves over a disc R on the head 22. In dismounting the apparatus, the plates 3 are separated by means of a shaft 10, Fig. 10, formed of mutually-displaceable parts, which engaged by means of projections in grooves in the plates 3; or the shaft 10 may be in a single piece and the relative dimensions of grooves and projections such that the plates 3 can be drawn apart for equal distances.