| 摘要 |
In the control of a gas-fired tunnel furnace comprising a plurality of burners each with a respective gas valve and a main gas valve to each group of burners, the position of each main gas valve is controlled in dependence upon either the deviation from a reference value of the furnace temperature sensed by an elongated temperature sensor 3 (Fig. 1) extending the length of the furnace, or, the deviation from a reference value of gas pressure detected by sensor 19, according to which has the higher absolute value appearing at outputs of amplifiers 13, 29 respectively. <IMAGE> |
