Abstract: A reciprocating engine (10) comprises separate cylinders (12 and 15) for air compression and expansion with heating of the compressed air taking place in a heat exchanger (17) or combustor (64) located between the cylinders (12 and 15). The flow of gas into the expander cylinder (15) is controlled by an admission valve (37). The stem (41) of the admission valve (37) extends transversely across the expander cylinder (15) and is cooled by the flow of exhaust gases out of the expander cylinder (15).

Abstract: A bearing assembly comprises a piston mounted within and capable of reciprocating with respect to a fixed bearing shell. The bearing shell is provided with openings for the supply of a bearing medium, such as compressed air, into a clearance between the piston and the bearing shell. The bearing shell is tapered circumferentially which renders the bearing shell flexible. As the diameter of the piston increases due to thermal expansion, the diameter of the bearing shell changes automatically to maintain the clearance therebetween.

Abstract: A fossil fuel air burner nozzle is provided with a wall (22) at its inlet, in which are apertures (34) which narrow in a direction radially outward of the nozzle. Each aperture is axially aligned with a respective bluff member (18) at the outlet so as to deliver thereto a fuel air mix flow at a velocity which is graded in said radial direction so as to ensure flame retention on the bluff members (18).

Abstract: A burner (10) for the combustion of fuel comprises a passage (32) through which in operation a mixed flow of fuel and air passes for primary combustion at it's outlet. Two further annular passages (34, 36), concentric with and radially outward of the passage (32), are provided through which supplementary flows of air pass to support the primary combustion. The outlets of the two annular passages (34, 36) diverge to discharge the supplementary flows of air at an angle to the mixed flow of fuel and air. Members (62) are provided in the annular passage which obstruct the discharge of the supplementary flow of air. Furnace gases circulate in the region downstream of the obstruction members (62). Circulation of the furnace gases delays the mixing of the fuel and air mixture with the supplementary air flows to reduce the nitrogen oxides produced.

Abstract: A bearing assembly comprises a piston mounted within and capable of reciprocating movement with respect of a fixed bearing shell. The bearing shell is provided with openings for the supply of a bearing medium, such as compressed air, into a clearance between the piston and the bearing shell. The bearing shell is resilient so that as the diameter of the piston increases due to thermal expansion, the diameter of the bearing shell changes to automatically maintain the clearance therebetween.

Abstract: A solid particulate fuel/air burner has opposing fluted members within a rectangular conduit which in operation forms a nozzle. Splitter plates with the fluted members define passages through which a particulate solid fuel and air flow to a combustion chamber. The passages so defined provide and control separate streams of the mix such that flame retention at the exit of the conduit is achieved and reduced NOx is produced and the gathering of ash in the conduit avoided by the obviation of recirculation of the products of combustion into the conduit.

Abstract: An apparatus and method are provided for reducing NO.sub.x production during combustion in an tangential burner. Air nozzles are arranged tangentially to a fuel/air nozzle and are tilted relative to the fuel air nozzle. Upon operation, spaces are formed between the air flow and the fuel flow which entrain laterally combustion gases thereby delaying mixing of the air and fuel flows. By this delay, NO.sub.x production is reduced.

Abstract: Apparatus for use in expanding tubes into holes in tubeplates including walls of drums and headers especially in boilers in which an annular body of elastomeric material is compressed axially and expands radially to force the tube into close engagement with the wall of the hole. The elastomeric material is supported at its ends by radially expansible supports each made up of pieces sliding on adjacent pieces, the sliding surfaces being forced together by the applied force, the pieces being located on reduced diameter end portions of the body. The invention enables applied pressures of the order of 70,000 psi (4830 bar) to be used to stress the tubeplate beyond its elastic limit without damage to the body caused by extrusion.