GB646550A - Improvements in and relating to bakers' and like ovens - Google Patents

Abstract

646,550. Bakers' ovens. BAKER PERKINS, Ltd., and WARRINGTON, J. I. D. June 11, 1948, No. 15835. [Class 51(ii)] In a bakers' oven in which combustion products are normally circulated in a closed path through radiator conduits within the oven chamber, means are provided whereby some or all of the circulating gases may be diverted from their closed path and caused to enter the oven chamber through nozzle or vent means provided on some or all of the conduits, and the oven atmosphere may be exhausted back into the circulating system at a corresponding rate. In the form shown, conduits 3 and 4 are arranged above and below the conveyer 2 and extend between transverse headers 13,14 and 15, 16 respectively, which communicate through openings controlled by dampers 13a-16a with a side delivery box 5 and suction box 6, the circuit being completed by a fan 10, a return conduit 11 with vent 12, a transverse conduit containing a burner 7, and a supply conduit 8 leading to a fan 9 discharging into the delivery box. The dampers 13a-16a are interconnected by rods 21, 22 and are operable in unison through rack and pinion mechanism 20 by hand wheels 31. The suction box also communicates through openings controlled by dampers 17a and 18a with transverse exhaust boxes 17 and 18 opening directly into the oven chamber, each damper being operable through rack and pinion mechanism by a further handwheel 31 and being of such length, see Figs. 8-10 (not shown). that in opening to place the associated exhaustbox in communication with the suction box it extends over and correspondingly closes the adjacent opening to the header 14 or 16. The lower surface 23 of the conduit 3 and the upper surface 24. of the conduit 4 are provided with longitudinally-spaced rows of transverse nozzles 25 each comprising a cylindrical member 26, Figs. 6 and 7, rotatable in bearing members 27 and formed with an elongated slot or series of slots 28, the rear of which is in communication with apertures 31a registering with an aperture 32 in the associated conduit. Adjacent members 26 are connected by a muff coupling 35 and the end members are connected to handwheels 29 whereby they may be rotated to vary the direction and amount of the gases discharged into the oven chamber. In a modification, Figs. 11 and 12 (not shown), the cylindrical members are enclosed in apertured sleeves which are rotatable independently to control the amount of gas discharged. By suitably adjusting the various dampers, either or both conduits may be utilized for radiant heating alone, the circulation of heating gases through the oven chamber, or a combination of radiant and circulation heating. Similar conduits may be employed in the lower baking chamber 30 or for heating the return lap of the conveyer.