| 摘要 |
A microwave convection oven has a gas burner 90 positioned outside the oven cavity 12. Combustion products are circulated through the oven 12 through screens 16 and 18 for preventing escape of the microwave energy from the oven cavity 12. The burner 90 is the multi-portion ribbon type providing a high burner density and having secondary air closely adjacent to all portions of the burner, to reduce its incandescent flame length while permitting the burner to be positioned in a region between the screened vapour outlet region 18 and the inlet 66 of a blower system. The blower system 64 is used for mixing the output of the burner 90 with the vapour drawn from the oven 12; thus the temperature of the vapour outlet region 20 is maintained below that at which ionization of the vapour being drawn from the oven 12 might produce leakage of microwave energy through the screen 18. The burner is controlled by a temperature sensor 178 responsive to the oven vapour temperature. A temperature probe 150 stuck into the food body 32 signals when the body has reached a preset temperature and/or turns off the microwave generator 54. <IMAGE> |
