摘要 |
In order to improve the thermal efficiency of a multi-zone, indirect-heated, travelling baking oven, with a closed-circuit gas heating system which heats at least the major part of the length of the oven and which includes at least two heaters which are spaced apart in the direction of gas flow in the heating system, the gas flow is passed along the bottom of the oven to adjacent the delivery end of the oven and then back along the top of the oven, the temperature generally falling throughout the circuit so that the maximum bottom heat is adjacent the input end of the oven and the maximum top heat is adjacent the delivery end of the oven. |