GB622414A - Improvements relating to the silencing and disposal of exhaust gases from internal combustion power plant of marine craft - Google Patents

Abstract

622,414. Propelling ships. DU CANE, P., and VOSPER, Ltd. March 20, 1947, No. 7736. [Class 114] [Also in Group XXVII] Exhaust, gases from the gas or internalcombustion turbines of a marine craft are silenced in a compartment formed as part of the craft's hull, or an extension aft thereof, and preferably cooled by being mixed with water therein before discharge below water level. The compartment 10 may be located amidships in front of the power plant, but as shown it is at the rear of the hull 1. It contains two chambers 9 connected by twin pipes 8, having expansion joints 14, to twin internal-combustion turbines. The pipes 8 are surrounded by a jacket 15 having expansion joints 16, a forwardly pointed scoop collecting cooling air which leaves at 22. Sloping baffles in the scoops prevent " en bloc " entry of water, and adjacent water-collecting sumps are provided, fairings 20 being located round the expansion joints. The chambers 9 are connected by sliding joints 11 which themselves slide in depressions 12 in the deck. Spreaders 26 disperse the exhaust gases which are discharged by submerged outlets 35 arranged so that motion of the craft produces ejector action on the gas. Cooling water is fed through jets 32 in tubes 29 having filters 31 by scoops 30. Further cooling water is fed by a pump to jackets 33 having perforated walls 28. When the craft is at rest, exhaust escapes through outlets closed by spring-loaded flap valves 36. The chambers 9 are lagged with heat-resisting material, and inspection doors 37, 38 are provided. Skin friction is reduced by locating the chambers in a midships compartment and arranging the exhaust outlets on both the sides and bottom of the hull, and " jet propulsion " is produced by the release of the exhaust below water line.