Patent GB-706691-A (GB)
Abstract: 706,691. Baker's ovens. SPOONER FOOD MACHINERY ENGINEERING CO., Ltd. Aug. 21, 1951 [Aug. 22, 1950; Aug. 22, 1950], Nos. 20708/50 and 20711/50. Class 51 (2) In a continuous baking oven of the straightthrough or tunnel type, the comestibles are traversed in turn through a steaming zone, a preliminary cooking zone heated by radiation at a relatively low temperature, and a final cooking zone heated by forced convection. The steaming unit includes a motor driven fan 30 supplied with steam on the inlet side by a pipe 38 and connected at the outlet side by ducts 32, 33 to pressure chambers 34, 35 formed with convergent slit-like nozzles 36, 37 extending transversely across the conveyer 1, the steam returning to the inlet side of the fan through an opening 43 between the pressure chambers 34, 35. The cooking unit includes a fan 2 connected at its outlet by two ducts 4 to upper pressure chambers 9 and 10 located above the upper run of the conveyer 1 and through ducts 6 to opposite sides of two lower pressure chambers 11 and 12 located below the upper run of the conveyer. The pressure chambers 9 and 11, constituting the preliminary cooking zone, each have two groups of nozzles 13 oppositely inclined to one another discharging heated gases onto heat radiator plates 26, and the pressure chambers 10 and 12, constituting the final cooking zone, discharge through similar groups of nozzles directly onto the comestibles and below the upper run of the conveyer respectively, the hot gases returning to the inlet side of the fan 2 by the paths 17 and 18 respectively. The heat of the circulating gases is maintained by a gas or oil burner 21 disposed near a tubular inlet 22 in the oven wall or by electric heaters 23, 24 in the ducts 4, the burner or heaters being controlled by a thermostat 25. Gaseous flow through the ducts 5 and 6 is controlled by dampers 7 and 8 respectively and the dampers 8 may be coupled together. Hot gases may be withdrawn from the oven for use in space heating, through a duct 50 extending into the bell mouth 51 of another duct 52 containing a fan, control of the ingress of diluent air being by means of a sleeve on the duct 50. The circulating hot gases are kept within the temperature range of 300‹ F.-475‹ F. preferably between 300‹ F.-400‹ F. and are circulated at a volume rate per minute which is preferably 10-100 times the volume of the circulating gases. 706,698. Generating combustion products under pressure. ROLLS-ROYCE, Ltd. April 10, 1952 [Jan. 10, 1951], No. 761/51. Class 51 (1) In combustion equipment of a gas turbine engine in which it is required to burn fuel in a high velocity hot gas stream and comprising main fuel and pilot fuel injectors, an annular assembly of deflector blades is mounted within the duct carrying the hot gas stream so as to impart a rotational swirl to gas passing through the assembly and to provide downstream of the blade assembly an annular zone of turbulent gas in which stable combustion of the main fuel can occur. The invention is applicable, for example, when exhaust gases in a gas turbine jet propulsion engine are reheated before discharge through the propulsion nozzle, or when exhaust gases are reheated between turbine stages. In Fig. 2 the deflector blades 60 are mounted between shroud rings 61, 62 and fuel is supplied to the duct through apertures 55 in the ring manifold 54. A spider member 20 is supported within the duct by means of two pipes 21, 22 and fuel flows through the pipe 22 to the pilot fuel nozzles 51 and to the injector 40. The injector 40 is disposed within a conical baffle 42 and pilot combustion occurs within the stable zone formed by the baffle as described in Specification 667,394, combustion being started by the igniter 45. Fuel supplied to the spider member 20 through the pipe 21 flows through the pipes 53 to the ring manifold 54. The downstream end of the baffle 42 has cut-away portions in which radial channel-section members 63 are fitted, and flame from within the baffle 42 passes through the channel members to ignite fuel in the annular turbulence zone downstream of the blade assembly 61. Fairings 56 are provided downstream of the pipes 21, 22. In a second embodiment, the deflector blade assembly comprises a plurality of flat inclined plates mounted on the convex surface of a V-section ring the concave surface of which faces downstream, and the plates extending radially inwardly and outwardly of the ring.