IMPROVEMENTS IN AND RELATING TO OVENS

摘要

A tunnel oven contains a plurality of transversely extending radiant heating elements (17, 18) arranged at intervals along the length of the oven (1), the oven (1) being provided with means (10) for transporting material to be heated through the oven, means for supplying energy to the radiant heating elements (17, 18) a sensing tube (31, 32) which extends within the oven (1) over a part of the length of the oven (1) that contains at least two radiant heating elements (17 or 18) that are spaced from each other along the length of the oven (1), the sensing tube (31 or 32) being arrangement to absorb radiation from the said at least two heating elements (17 or 18), means (34) for causing a liquid to flow through the sensing tube (31 or 32) at a controlled rate, means (35, 36) for producing a signal that provides a measure of the temperature increase of the liquid resulting from its passage through the sensing tube (31, 32) within the oven, and control means (29, 30) arranged to control the rate of emission of radiant heat by a radiant heating element or elements (17, 18) in accordance with the signal.