GB1166140A - Apparatus for silencing an engine - Google Patents

Abstract

1,166,140. Sound insulation. VOKES Ltd. 5 June, 1968 [22 Aug., 1967], No. 38597/67. Heading F2X. [Also in Division F1] Apparatus for silencing an engine comprises an inner box for containing the engine resiliently mounted in an outer box, a pair of air inlet apertures formed through the walls of the boxes respectively and a pair of outlet apertures formed through the walls of the boxes respectively, the apertures of at least one pair being connected by a flexible sleeve, and inlet and outlet chambers mounted on the outside of the outer box over the inlet and outlet apertures thereof respectively, the walls of the boxes and chambers being rendered sound-absorbing. An I.C. engine 10 (or a gas turbine) and a generator 11 (or a compressor) driven by it are mounted within an inner box 13 on resilient mountings 14, the inner box being mounted within an outer box 15 on resilient mountings 16. An inlet chamber 23 and an outlet chamber 34 are mounted on the outside of the outer box 15. Air enters the inlet chamber 23 through an inlet 28, passes up on either side of a shelf 27 through filters and through a fan 24 driven by an electric motor 25, and thence through aligned inlet apertures 21, 20 in the walls of the outer and inner boxes respectively into the inner box 13, where it passes over the engine to assist in cooling it. Air leaving the inner box passes through the engine radiator 31 mounted in the outlet aperture 30 of the inner box and thence through an aligned aperture 32 of the outer box into the outlet chamber 34, leaving the outlet chamber via a slot-shaped outlet 35 and a passage 36. Exhaust gases pass through an expansion chamber 40 and a straight-through silencer 42 and thence via a metal bellows 44 into a pipe 45 in the outlet chamber 34. Flexible sleeves 22, 33 join the inlet apertures and the outlet apertures respectively, but the sleeve 22 may be omitted, the apertures 20, 21 then not being opposed to one another so that the space between the inner and outer boxes acts as a silencing chamber for air entering the inner box. The walls of the inner and outer boxes and of the inlet and outlet chambers and the passage 36 are all lined with sound absorbing material covered with cloth and expanded metal 50. The floor of the inner box is lined on the outside rather than on the inside so that oil from the engine is not absorbed by the lining. The fan 24 may be mounted within the inner box 13 and driven by the engine. The silencers 40, 42 may be located in the the outlet chamber 34, and the radiator 31 may be mounted in the aperture 32.