GB1354112A - Gas ovens - Google Patents

Abstract

1354112 Gas-fired cooling ovens; gas burners HOOVER Ltd 19 May 1971 [20 May 1970] 24430/70 Headings F4W and F4T A cooling oven has a fan 28 mounted adjacent a backplate 23 within the oven, a combustion chamber 21 with one or more gas burners 31 behind the backplate, the fan being arranged to induce a flow of combustion products through outlets 24 between the backplate and a wall of the oven. A casting 20 is mounted in the back wall 11 of the oven to form the back wall of the combustion chamber, and has a boss 22 to which the backplate 23 is secured. A gas manifold 30, burner nozzles 31 and secondary air inlets 32 are formed in the casting 20, and the shaft 25 of the fan, mounted in the boss 22, is cooled by air drawn in through holes 34. The backplate 23 is formed as a flow guide. In another embodiment, Fig. 4, a centrifugal fan 37 behind an annular guard plate 38 is mounted adjacent a backplate 36 forming the front wall of a combustion chamber 40 with radially directed burner nozzles. The backplate may be formed with forwardly directed flanges 71, Fig. 8, and the burner 61 is formed integrally with the hub for the fan. An outlet 80 for excess combustion products leads to a flue with an inlet 81 for dilution air. The burner may be formed of two annular plates 125, 126, Figs. 15, 16, sleeves 128, 129 surrounding holes in the plates fitting one within the other. The space 134 between the plates forms a gas manifold, and flutes 130 in the sleeves 128 fitting outside the sleeves 129 allow gas to pass from the manifold 134 to burn in air flowing through the holes in the plates. The burners may be two or more straight bar burners arranged on two sides of a triangle or in a polygon, or may be a ring burner, or a part ring burner with a pilot at one end or at the mid point of its arc. A semicircular burner may be arranged entirely above or entirely below the fan axis.