GB1164628A - Improvements in or relating to the Filtration of Fluids - Google Patents

Abstract

1,164,628. Oil filter. BLACKSTONE & CO. Ltd. 4 Nov., 1966, No. 49501/66. Heading BID. [Also in Division F2] A filter for lubricating oil in a marine diesel engine comprises two filter elements (43, 44) in separate bowls clamped to a common head, the head comprising inlet and outlet connections 72, 73 and spool valves 67, 68, which are moved in unison by an external handle (21) to direct oil through one or other of the elements and may be arranged so that oil flows through both elements in parallel during changeover. Alternatively, a pressure operated by-pass valve (94-100), (Fig. 7 not shown) opens during changeover to maintain the flow. During running-in of the engine, flow may be through pleated paper element (43), after which the flow is transferred to coarser gauze element (44), while the element (43) is replaced by a further gauze element for reserve. The spool valves 67, 68 carry teeth engaging a cog rotated by the handle (21) which has a locking means (30-34) for holding it in either of two extreme positions in which the handle obscures characters indicating which filter element is in use (Figs. 1-3, not shown). Connections 72, 73 open into respective chambers 80, 78 communicating by passages 71, 70 with chambers 81, 79, and as shown flow is through bores 88, 89 to and from the left hand element which is enclosed in a removable bowl (41) in series between ports 35, 37. Connections 72, 73 could equally open into chambers 81, 79 by apertures shown closed by plugs 75, 74, or all four positions could be used, with the filter connected between two engines or circuits in one engine. The various lands 87, 91, 83 on the spool valves carry sealing rings and vary stepwise in diameter along the valve to facilitate manufacture. A three-way valve (110) is used to direct filtered oil from one element to fill the bowl of the other after replacement, valves (115) being unscrewed to permit the trapped air to vent (Figs. 4, 6, not shown). The filter also comprises a differential pressure alarm switch (117) and plugs (118), 77 providing access for cleaning the valve interiors.