Hot air bread baking oven for rotary trolley of dough pieces - has supplementary microwave heating to increase output for peak demands

摘要

A bread-baking oven of the type in which dough pieces are supported on horizontal shelves of a trolley which is rotated about its central, vertical axis while hot air is circulated through the oven chamber. The oven is additionally equipped with a set of microwave energy generators. These are disposed one above another in a vertical stack to direct microwave radiation towards the axis of rotation of the trolley. The oven door is fitted with a metal edge-seal and has in inspection port glazed with metal-armoured glass. The circulated air is sucked from the oven chamber via a metal, intake grille. The microwave generators can be operated only when the oven door is closed to make the actuating circuit by closing a switch. The generators are pref. magnetrons each with a wave guide carrying radiation through an aperture in the wall of the oven chamber. The wave guide pref. delivers radiation via a dust filter sheet, e.g. P.T.F.E of a thickness 0.5-1.0 mm. The microwave generators provide supplementary baking energy to speed up bread prodn. in periods of peak demand. A hot air oven normally producing 400 stick loaves per hour can be supplemented to an output of 800 per hour with only 20 per cent extra energy input.