GB689126A - Improvements in apparatus for simultaneously producing steam and gas - Google Patents

Abstract

689,126. Steam generators. SOC. DE CONSTRUCTIONS MECANO-THERMIQUES C.O.M.E.T. Oct.31,1950 [Dec.2,1949], No. 26602/50. Class 123 (ii) [Also in Group XXIX] A steam generator comprises one or several hot gas passageways 1 receiving the hot gases from a boiler firebox 5 fired by burners 6 (not shown) each passageway 1 consisting of a ring of small diameter tubes 2 welded side by side to form the passageway and strengthened by support hoops 3 and 12. The water or other liquid flows inside each of the small tubes 2 from a larger ring of tubes 7 also welded together to form the wall of the firebox 5. The hot gases flowing from 5 to 1 may then flow through a superheater composed of similar ring of small superheater tubes 2a Fig. 3, to supply the superheat after which the gases may pass through an economiser of similar construction. The successive sections although welded together as at 10 may be unwelded at a thinner part 11 of the weld. Coupling bolts 9 allow inspection of the weld. The ring of tubes 2 flares out into a cone 8 where the individual tubes are jointed to the corresponding tubes 7 of the furnace 5. The tubes 7 then join up with other converging tubes 8a near the burners 6. The inside of the furnace 5 is under gaseous pressure or forced draft to counteract the pressure inside the tubes 7. The furnace 5 has a partial refractory lining 13. In Fig. 2 the water tubes 2 are arranged helically around a steam separator wall bored to form tubular ducts therein. Pressure control. A relay system Fig. 9 operating the fuel supply valve when the steam pressure rises beyond working pressure, and controlled stop valve 45 is arranged in the hot gas outlet. The pressure of the furnace gases at 36 and the steam tube pressure at 37 adjust a common piston rod 33 whereby an attached arm 38 moves piston valves 39 of a pressure oil relay supplied with pressure oil at 43 passing through pipes 40, 40a, 41, 41a to control the fuel supply valve 45. The relay oil flows out at 44 to return to the relay system. Balancing springs 48, 48a tend to keep the control arm 38 at position for normal working pressure. The thickness of the tubes of these boilers can be thinner than boilers where the tubes are not joined together and so do not strengthen each other. Further the pressure of the hot gases on the ring of tubes counteracts the bursting pressure inside each tube. Such possible thinness of tube facilitates heat transfer from the hot gases to the water. Two or more fluids may be circulated through separated groups of pipes 2 and such fluids may be heated to different pressures (through larger or smaller total exposed areas of tube) so that such boilers may supply different steam pressures.