Patent GB-397907-A (GB)
Title: Improvements in or relating to filtering or straining apparatus
IPC: B01D29/00
Filed: 1932-03-02
Abstract: 397,907. Filters. AUTOKLEAN STRAINERS, Ltd. and BELDAM, W. R., 40, Trinity Square, London. March 2, 1932, Nos. 6334,25684, and 33395. [Class 46.] An oscillatory pump vane, which causes a reverse cleansing flow through a portion of the filtering-medium while the flow of filtrate is maintained, is provided in the filter chamber of apparatus of the edge filter type or having a gauze or fabric filtering- medium. Figs. 1 and 1a show apparatus in which a filtering-medium 27 is supported on a frame formed of rings 25 and vertical bars 23. The normal flow of liquid is from an inlet 3, inwards through the element and away through an outlet 5. When a vane 41 carried by a central spindle 13 is moved round towards a vertical dividing wall 33 a reverse cleansing flow is caused through the part of the filter element opposite to a plate 31 which blanks off a portion of the lower end of the element. A plate 45 is pressed outwardly by a spring in a radial slot in the vane 4, the edge of the plate being formed as a pawl to engage with internal teeth on the rings 25. The vane 41 in its movement towards the plate 33 thus causes a partial rotation of the filter element. A scraper À51 removes solid matter from the outside of the element during this partial rotation. The operating lever 19 of the spindle 13 may be moved by hand or connected to automatic operating mechanism. A modified arrangement is described in which the rotation of the element is due to the engagement of a pawl on the spindle with teeth on the interior of the boss of a spider fixed to the lower end of the element. The wall 33 may extend across the interior of the element, a vane 41 being provided in each of the two compartments into which the element is then divided. Figs. 3 and 3a show an arrangement in which filtration is outward through the element. The wall 33 and the vane 41 are in this case placed in the annular space between the element and the casing, the vane being fixed to a cap 54 which rotates with the spindle. Pawl and ratchet gearing 52, 53* ensures that the filter also rotates as the vane approaches the wall 33 but does not do so when the vane is moved in the opposite direction. Fig. 4 shows an arrangement in which a vane 41 is fixed to a central tube which serves as outlet passage for the filtrate. The wall 33 is fixed to the strainer and the latter is rotated when the vane moving counterclockwise pushes on the wall 33. As shown in Fig. 6, a vane 65 is arranged in a central tubular chamber 61 having a spout divided by a plate 63 extending to the inner face of the filter element. Oscillation of the vane 65 draws liquid in through one portion of the spout and causes a reverse cleansing flow through the other portion. The spindle is connected with the element through a ratchet 66 or so that both spindle and element oscillate. The strainer shown in Fig. 7 is stated to be applicable for removing juice from fruit pulp which is supplied to the tank 71. A vane 76 causes an outward flow of liquid as it approaches a wall 73. At the same time a vane 78 draws in air to dry the solid matter caked on the outside of the element as it approaches a scraper 79 by which the cake is removed. A pawl 45 rotates the strainer when the blade 78 moves counterclockwise. Fig. 8b illustrates an arrangement in which a vane 41 is mounted on a spindle 13 situated eccentrically of the filter element ; Fig. 10 one in which the vane is moved in one direction by a rotating cam 88 and in the opposite direction by a spring 90. In the latter case the strainer may be geared to rotate with the cam shaft. Fig. 11 illustrates an arrangement in which two moving vanes 96, 97 are brought together by a cam 98 and separated by a spring 99. The apparatus, shown in Fig. 13 and 13a, comprises a number of filtering cartridges 126 arranged around and to rotate with a pump barrel 120. The liquid filtering into each element 126 passes to a header 130 and thence through an aperture 132 into the pump barrel for drainage therefrom. When a vane 141 oscillates with a spindle 113 towards a division plate 133 liquid is forced back through one of the apertures 132 to cleanse the corresponding filter element. A pawl 145 in the vane at the same time causes the pump barrel to rotate carrying the filtering elements with it. As it passes the cleansing position each element is caused to rotate about its own spindle 128 by pegs 136 fixed to the cover 111 of the casing and engaging a star wheel 134 on the spindle. Scrapers 151 remove solid matter from the elements as they are thus rotated. Fig. 14 shows an arrangement in which two vanes 250, 251 connected together move on either side of a division wall 233, the strainer being rotated by a pawl 245 as the vanes move counterclockwise. Specifications 352,553, 367,358, and 386,132 are referred to.