GB707827A - Improvements in or relating to method and apparatus for electric baking of food - Google Patents

Abstract

707,827. Dielectric heating. FELBER, N. April 24, 1952 [April 25, 1951], No. 10384/52. Class 39 (3) Bread, biscuits and the like are baked while exposed simultaneously to a H.F. electric field and to infra-red radiation. Thus bread placed on a conveyer 1 is advanced between network electrodes 15, 16, the space between which is increased in the direction of movement of the bread to allow for its rising and to give a weaker field towards the end of the baking so as to prevent formation of arcs to the bread. Infrared lamps 8, 12 are mounted above the electrode 16 and preferably below the electrode 15, the walls 5, 6 of the container forming reflectors to help crust formation on the side of the bread. The metal ceiling 11 forms a reflector and may be apertured around the lamps to allow them to be cooled by a fan forcing air into the oven. The conveyer 1 may be of metal and may be earthed to form one electrode, which is imperforate when the lower lamps 12 are not fitted and is darkened to absorb infra-red rays. The upper electrode 16 may be in two straight portions 16a, 16b or may be curved to give a similar shape and may be pivoted at its front end 26. The electrode may be adjusted by bolts moving in vertical slots at its rear end. The lamps 8 may be replaced by other infra-red heat generators, such as wires wound helically or bars of resistor material; or gas-heated infrared radiators may be placed below a continuous sheet metal reflector bent into segments of cylinders above the heaters. The electrodes are connected at their ends 18, 19 to the H.F. supply, the voltage of which may be adjusted. For non-continuous operation, the bread is placed on an imperforate metal sheet forming the lower electrode, the upper electrode being a grid through which passes infra-red heat from radiators above it. Reference has been directed by the Comptroller to Specification 631,395.