| 摘要 |
Heat treating apparatus for continuous painted strip, comprising an elongated, convective heating oven through which painted strip is passed while jets of hot gas are directed against the top and bottom surfaces of the strip to dry and cure the paint film. The strip is suspended from tension bridles at opposite ends of the oven, and hangs in a relatively flat catenary curve therefrom. Spaced longitudinally within the oven is a plurality of pairs of headers which are arranged to follow the catenary curve of the strip, each of said pairs comprising an upper header located above the strip and a lower header located below the strip. Each of the headers has a plurality of jet nozzles directed toward the strip, and duct means is provided for supplying hot gas to the headers so that the nozzles send jets of hot gas impinging against the strip. The static and dynamic pressure of the jets of hot gas cause the strip to float while still following the catenary curve that the strip takes when merely hanging by gravity from the bridles. However, when the strip is floated by the hot gas jets, all or most of the weight of the strip is carried by the gas, and tension in the strip is correspondingly reduced. Each of the headers is adjustable vertically so that it can be positioned to closely approximate the catenary curve of the strip, and also so that it can be moved closer to or further away from the strip so as to increase or decrease the amount of flotation.
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