GB1162356A - Baker's Tunnel Oven - Google Patents

Abstract

1,162,356. Tunnel ovens. ETAB. FRINGAND S.a.r.l. 14 Dec., 1966, No. 55989/66. Heading A2A. A tunnel oven for baking pieces of dough into rusks, pastry and bread, e.g. Viennese bread, comprises a first baking chamber having, for example, an entrance gate A, and a second or final baking chamber (not fully illustrated in the drawings. The pieces of dough are fed, e.g. through the gate A, on to the upper flight of an endless, travelling conveyer belt 15, which carries them through the first and second baking chambers, and then discharges the baked products, e.g. through an outlet gate (not shown). An operating turbine-fan 3 draws hot combustion gases from a burner 1 and its associated combustion chamber 2, and feeds these hot gases, through a distributing box 4 and hearth channels 5, into a collecting box 6. From the box 6, the gases pass, through a sheath duct 7, an upper distributing box 8 and upper vault channels 9, into an upper collecting box 10, in which means, such as a flap-valve, is provided to pass a desired fraction of the returning, slightly cooled gases, through another turbine-fan 12 and a sheath duct 11, into the combustion chamber 2 where they mix with fresh, hot combustion gases from the burner 1. The resulting mixture of hot gases is circulated, as described above, to heat the first baking chamber, into which steam may be injected in a conventional manner. The remaining fraction of said returning slightly cooled gases is discharged through a chimney 14 having a flap-valve at its base.