GB477740A - Improvements in and relating to filters - Google Patents

Abstract

477,740. F i l t e r s. DUNLAP, A. C. March 1, 1937, No.- 6017. [Class 46] A filter element comprises a flat plate with drainage channels on both faces and formed of two or more sections, 5, 5A, Fig. 2, which are placed in position within an envelope 12, Fig. 4, of filtering material through an opening 14 in one of its faces. The element is arranged horizontally in a tank 1 containing the liquid to be filtered and the filtrate passes from the drainage channels to channels formed between the plate sections, which are spaced apart or have their adjacent edges suitably shaped to form channels, and thence to a cavity at the centre of the plate. A clamping bar 9 is fixed by bolts 15 over the opening 14 and has a central aperture to which a filtrate pipe 3 is secured. This pipe is fixed by nuts 17 to the lid 4, so that the lid and filter element can be removed together. The liquid can' be forced through the filter under pressure of air supplied to the tank 1 or drawn by suction through the pipe 3. A plate 20, supported below the filter element by means of the bolts 15, serves to receive portions of the cake which become detached from the element. Two plates 20 may be provided with an electric heating element 6 between. Alternatively, the bar 9 may be constructed as a heating element. The heating device may be controlled by a thermostat or by a cut-out actuated by variation of pressure or of liquid level in the tank. The filter element may be coated initially with filter aid and filter aid may be added to the liquid under treatment. A pile of filter elements may be associated with a single outlet pipe 3.