GB846855A - Improvements in filtering units - Google Patents

Abstract

846,855. Filters. KOMLINE-SANDERSON ENGINEERING CORPORATION. May 13, 1959, No. 16493/59. Class 46. The mixture to be filtered is delivered by a pipe 27, Fig. 1, to an open-bottomed hopper 28 having sealing engagement with the upper run 10a of an endless filter belt 10 which is driven intermittently by clockwise rotation of a roller 12 through actuation of a ratchet wheel 35 by pawls 36, 37. A cycle of operations is performed automatically by a motor 92 which drives continuously a wheel 88 having linked to it a segmental rack bar 85, Fig. 6. From the Fig. 6 position, the first movement leftwards of the rack bar serves to rotate a valve 60 which thereupon connects to atmosphere a header 62, Fig. 1, communicating by pipes 63 with a series of suction boxes 33 arranged on the underside of the upper run 10a of the belt. Valve 60 is left in this position, whilst the rack bar rotates a valve 78 which thereupon directs hydraulic fluid from a pump 55 to the upper end of a cylinder 72, Fig. 6, whereby through piston rod 74 a frame 68 sliding on bearings 69, Fig. 3, is moved downwards to the left and through links 70 moves a frame 65, carrying all the suction boxes, downwards vertically to the position of Fig. 3. The suction boxes are thus moved out of contact with the belt 10. Next, a valve 47 is rotated by the rack bar so as to cause fluid to be admitted to the lower ends of cylinders 42, 43, Fig. 1, and drained from the upper ends, to bring about movement of the belt 10, through actuation of ratchet wheel 35 by pawl 36 only, a distance equal to half that between suction box centres. The rack bar is now in the Fig. 1 position, and its first operation on the return movement is to restore valve 47, which reverses the fluid flows in cylinders 42, 43, and completes the movement of the belt 10 by ratchet 37. Then valve 78 is restored to effect the return of the suction boxes to contact with the belt 10, and finally valve 60 is restored to connect the suction boxes to vacuum and thus effect filtration. This continues until the rack bar rotates valve 60 once more on its next leftward movement and the cycle is repeated. Cake not falling from the belt at roller 12 is removed by a scraper 25.