Patent GB-261808-A (GB)
Title: Improvements in and connected with gaseous fuel burners
IPC: F23C3/00
Filed: 1925-06-02
Abstract: 261,808. Hammond, C. F., and Shackleton, W. June 2, 1925. Spray, atmospheric, gas, and pulverulent fuel burners; burners, attaching.-A submersible burner comprises two freely communicating tubular parts of different bores the part of smaller bore constituting a mixing tube in which the fuel and air are thoroughly mixed at a low temperature and travel at a high velocity greater than that of flame propagation and the part of larger bore constituting a combustion chamber maintained at a high temperature. Liquid. gaseous or powdered fuel may be supplied to the burner which is suitable for use in steam generation, chemical concentration and other heating operations. Fig. 1 shows a burner comprising a cylindrical metal casing a containing a metal bushing or sleeve f forming the high velocity mixing tube, a refractory nozzle m having an internally flared spigot portion m<1>, a hollow refractory cylinder n constituting the combustion chamber, and a burner nozzle c through which the combustion gases are discharged into the liquid to be heated. The nozzle c which preferably has a coned or vena contracta aperture abuts against an internal flange b on the casing a. Gas and compressed air are supplied to the mixing tube by a fitting i formed with a flange h by which it is secured against a flange g on the bushing f by a resilient attachment consisting of nuts e and springs k on studs e projecting from a flange d on the casing a. The fitting i comprises two concentric chambers q, r, the outer chamber g having a lateral compressed air connection and communicating through ports t with the inner chamber r which encloses a contracted gas nozzle u. The combustion chamber n is insulated from the casing a by asbestos cord w or a dead air space in order to maintain a high temperature. The bushing being of metal or alloy is sufficiently conductive to prevent it from becoming overheated. Fig. 3 shows a modified form of burner in which the air and gas are supplied through a fitting 7 comprising two annular chambers 8, 9 to a high velocity mixing tube 2 which is surrounded by a water jacket 1. A ring 21 having an expanding opening connects the mixing tube 2 with a combustion chamber 20 which is insulated from the metal burner .casing 28 by a dead air space 30. A smaller dead air space is also provided between the casing 28 and the water jacket 1. The gas and air are ignited before the full pressure is turned on by means of a sparking plug or torch inserted in an ignition chamber 3 provided in the mixing chamber 2. A nest of tubes, a gauze grating or a MÚker grid 17 may be arranged in the mixing tube to prevent the flame from lighting back. Resilient bodies 34 are arranged below the nuts 35 on the studs 33 by which the mixing tube is secured to the casing 28. An inspection window 12 is arranged at the rear of the fitting 7. In other modifications the cooling jacket is extended so as to enclose the combustion chamber or the outer casing is of refractory material and is integral with the wall of the combustion chamber. Fig. 8 shows a further modification in which the outer casing is formed of refractory material and is attached by a socket ring 79 containing a rubber gasket 81 to a flange ring 77 on a metal liner 84. The mixing tube comprises inner and outer walls 96, 97 and an intermediate partition 98 arranged to form a cooling jacket for the circulation of air which may afterwards be employed for combustion purposes. The combustion chamber comprises two parts 91, 92 shaped at their ends to provide a nozzle-shaped outlet 93 and a flared inlet 94. When the burner is to be immersed in corrosive liquids it may be provided with an acid-proof covering of rubber or vulcanite and the combustion chamber may be made of silica.