Improvements in or relating to the cleaning of porous objects

摘要

966,858. Filters. CAVITRON ULTRASONICS Inc. Nov. 2, 1960 [Nov. 2, 1959], No. 37604/60. Headings BID and BIT. [Also in Division H4] Cleaning of a filter element, e.g. an inward flow element F, Fig. 27, having an open end j and a closed end i and made of tightly woven stainless steel, fibre glass or nylon yarn is effected by immersing it in a bath of cleaning liquid 65, Fig. 1, and subjecting it to ultrasonic vibrations emanating from the working face 7, Fig. 2, of a magneto-strictive vibrator A (see Division H4) and in a direction normal to that portion of the filter surface being cleaned thereby producing intense cavitation of the column of cleaning liquid between said face 7 and the filter surface. Prior to cleaning, the open end j-of the element F is pushed over an adapter 60, Fig. 12, capable of rotary and axial movement relatively to a tubular supporting arm 50 and thus relatively to the vibrating face 7. The tube 50 surrounds an inner tube 51 so as to form an outer passage 501 which is connected by a cylindrical manifold 53 to a duct 71 supplied with pressurized cleaning liquid by a pump 73 when a two-way reversing valve 68 is in the position shown in Fig. 22. The manifold 53 is capable of a 90 degrees movement relative to a knuckle member 52, Fig. 11, and the latter is carried by an arm 56 held by a clamp 57. The pump 73 delivers through a duct 75 from which branches a sampling duct 761, through a flow meter 79, the valve 68 and duct 71, passage 511 and the filter wall and liquid is withdrawn from the bath through duct 71, the valve 68 and a duct 72. On reversing valve 68 cleaning liquid flows inwardly through the filter wall, through passage 50 and duct 71, the valve 68 and the inlet duct 72 of pump 73 and pressurized liquid passes from duct 70 through valve 68 and duct 67 to the bath. The pressure drop so formed within the filter element is transmitted through an inner passage 511 of the tube 50, the manifold 53 and a duct 97 to a calibrated manometer 92 whereby the porosity of the filter element may be compared with that of a standard element. The cleaned filter element is tested for enlarged pore openings after removing from adapter 60 by connecting it to a plug 98 and supplying compressed air from a line 81 through a filter 84, flow and pressure regulating devices 85, 87, 88 and immersing it in the cleaning bath ; the maximum pressure at which air bubbles appear on the outer surface of the filter being a measure of its soundness. The so-cleaned and tested element F is resiliently held by a spring-biased collar o, Fig. 34, within a casing m having an inlet n1 and a cleaned fluid outlet n11. A disc-like filter element having concentric corrugations is held during cleaning in the mouth of a funnelshaped adapter 63, Fig. 18 (not shown), to the spout of which is adjustably secured the tube 50. Specification 966,859 is referred to.