GB804721A - Improved flame-trap - Google Patents

Abstract

804,721. Crank chambers. BRITISH INTERNAL COMBUSTION ENGINE RESEARCH ASSOCIATION. April 11, 1956 [April 18, 1955], No. 11107/55. Class 7(2) [Also in Group XXI] A flame-trap in an engine crank case is provided with a plurality of relatively small passageways therethrough, the structure defining the passageways being coated or adapted in use to be coated with a vaporizable substance, vaporization of which quenches the flames. In Fig. 1 a flame-trap consists of strips of wire gauze 1, one or more layers (preferably the inner layers) of which are coated with grease, circumferentially arranged within a perforated container 2 secured to the wall of door 5 of an engine crankcase in which is mounted a housing 6 carrying an explosion relief valve 7. In Fig. 2 the flame-trap consists of flat sheets of wire gauze 8 fastened to a frame 9 mounted inside the crankcase door 10 provided with a relief valve 11. The gauze assembly may be so placed that oil from lubricated moving parts of the engine reaches it directly, but it is preferred to supply it with oil from an oil feed pipe which may be connected to the lubricating system of the engine or may be separate from the lubricating system of the engine so that the supply of oil to the gauze may be continued for some time after the engine has stopped, and before re-starting whilst the engine is still hot. In Fig. 2 the oil is distributed over the gauze 8 from a perforated trough 12 supplied by an oil feed pipe 14, and in Figs. 3-5 (not shown) a series of nozzles fed from a feed pipe distribute oil over the whole surface of the gauze. A flame arrestor which stores a supply of oil against the event of an explosion occurring when the engine is stationary comprises gauzes 21, Fig. 8, and a grid formed by arcuate or other section strip metal elements 19 forming a series of receptacles for oil which are filled either by oil splash or by a perforated trough 20. The grid itself acts as a flame arrestor and if the spacing between the elements 19 is sufficiently close, some or all of the layers of gauze 21 may be unnecessary. In another embodiment, Figs. 9-11 (not shown), flametraps provided in apertures in partitions separating several crank chambers of a large multi-cylinder engine are wetted with oil from troughs supplied by a feed pipe.