Patent GB-338510-A (GB)
Title: Improvements in leaf filters
IPC: B01D29/00
Filed: 1929-08-15
Abstract: 338,510. Alliott, E. A., and Manlove, Alliott, & Co., Ltd. Aug. 15, 1929. Leaf filters.-The filter leaves are supported on a header within the casing so that they can be withdrawn as a unit from the casing after the door of the casing has been opened. The filtrate is discharged from the leaves through the header. In Fig. 5 the door 3, which is hinged to the casing 2, is shown in the open portion. The header 6 is provided with wheels 8 which are normally supported on rails 9 within the casing. When the door is open side arms 10, which have a pin-and-slot connection with the casing and hang vertically during normal operation of the filter, are turned up to form continuations of the rails 9, along which the header can be drawn forward to expose the filter leaves. The outer ends of the arms 10 are turned up to form stops 10a and the impact of the forward wheels 8 with these stops causes material on the leaves to be detached. Alternative means from bringing the leaves out of the casing is shown in Figs. 17 and 18. The header 6 is provided with pivoted links 52. When the door is opened these are turned up into a position where they can be engaged by hooks 53 on levers pivoted at the ends of a carrier 54 adapted to slide on longitudinal rods 55 secured to the top of the casing. The tail ends 53a of the levers are connected together by a turn-buckle arrangement with hand-wheel 58 and, after the hooks 53 are engaged with the links 52, they are slightly raised to lift the header off the rails 9. The leaves can then be brought out of the casing on the carrier. The header 6, Fig. 8, is hollow and divided by a longitudinal partition into two compartments 6<b>, 6<c>, into which filtrate from the upper and lower portions of each leaf 7 is discharged through pipes 24, 25 respectively as described in Specification 338,567. The compartments 6<b>, 6c have outlets 6<d>, 6e respectively which make joints with outlet ports 2a 2b in the casing. To make the joints water-tight the header is forced into position by means of a screw 22 working through a cross piece 16 secured to arms 15 the ends of which are connected by a pin which engages a hook 21 on the casing. The liquid under treatment is supplied to the casing 2 through a passage 39, Fig. 5a and a passage 40, formed between the opposing surfaces of the casing 2 and cover 3 and opening into the casing through, a gap 41. A spreader or deflecting plate 42 is secured to the cover or casing under the gap. Means are provided for ensuring that the cover is tightly closed on the casing. For this purpose, the cover is fitted with shackles 43, Fig. 11, adapted to engage with hooks 44, pivoted on the casing and connected in pairs to links 46, the ends of which are jointed to togglelevers 47 connected to a slide 48 on a rod 49. The arrangement is such that on closing the cover the shackles first turn the hooks which then engage the shackles and are tightened in position by a hand-wheel 51, which rotates the rod 49 and this causes a nut 50 on a screw portion of the rod to move the slide 48. Adjustment of the hooks 44 is effected by turn-buckles in the links 46. The shackles have screwthreaded stems which allow of their adjustment. The hinges of the casing and door may be adjustably mounted in a similar manner to the shackles.