IMPROVEMENTS IN AND RELATING TO HEATING INSTALLATIONS

1,272,711. Water tube boilers. R. L. BARRAULT and R. E. J. WEBER. 28 April, 1970 [28 April, 1969], No. 20327/70. Heading F4A. A multitubular boiler is substantially symmetrical about an axis XY which is vertical as shown but may be up to 60 degrees from vertical. The top and bottom torroidal reservoirs 2, 1 are interconnected by three banks of vertical water tubes 3, 4, 5 which are bent at their ends to meet the reservoir surfaces perpendicularly. As indicated by arrows F1-F4 the hot gases from burner 8 pass down the centre of the boiler and are deflected around tubes 3, 4, 5 by a baffle 11 closing the reservoir 1 and annular baffles 6, 7 extending from the bottom reservoir 1 to near to the top reservoir 2 and vice versa. Finally the gases leave through bore 18 and flue 15. The water tubes may be replaced by annular water vessels having apertures for the hot gases to pass through. The boiler is enclosed by a removable insulation jacket 12 which may be surrounded by a water tank 16, 17 for preheating feedwater. Cleaning jets for steam or compressed air are provided in tubes 9, 10 for the removal of soot deposits. In hot water production cold feedwater rises through pipes 3, 4, 5 in parallel. In steam generation feedwater is introduced into the top reservoir 2 which is kept half full of water and after partly mixing with heated water descends through the cooler outer tubes 4 to reservoir 1 and returns through hotter tubes 3, 5 where steam is generated. In an alternative form for the production of both steam and hot water a third torroidal reservoir intercepts the tubes 3, 5 and thus rising hot water flows through it before entering upper reservoir 2. A further bank of tubes may be provided for superheating.