| 摘要 |
<p><PICT:1045894/C6-C7/1> Continuous products are heat treated whilst passing through at least one fluidized bed whilst simultaneously undergoing physio-chemical reactions with the bed sustaining fluid. Metal strip 2 undergoes a hot oxido-reduction in fluidized beds 35 and 28 contained in refractory chambers 3, 4 respectively, then after passing through pressurized transfer chamber 7 undergoes controlled cooling in fluidized beds 44,45, contained in chambers 11, 12 prior to metallic coating by hot immersion. Combustible gas and oxidant in proportions to provide a reducing atmosphere are introduced into the bottom of chamber 4 through boxes and tubes 22, 24, 25 having porous end covers, ignite in stationary bed 27 and provide the reducing heat treating, bed sustaining fluid for fluidized bed 28 in which annealing or tempering may be performed. Excess oxidant to provide an oxidizing atmosphere is introduced at the top of bed 28 via porous refractory tubes 29, and the resultant oxidizing bed fluidizing gases pass through refractory tile 32 and stationary bed 34 to sustain the oxidizing fluidized bed 35 before passing out via discharge flue 39. A neutral gas is introduced in a similar manner to the base of chamber 11 to act as a sustaining fluid for beds 44, 45 in which the sheet is cooled, the heat released being transferred to hairpin tube clusters 46, 49 to generate steam. The neutral gas may be recycled. In modifications electrical heating or radiant tubes together with the chemically active bed sustaining gas may be used in place of the combustion occurring within the fluidized bed and the fluidized bed particles may be active to the continuous product which, if in the form of wire or bar may travel in a horizontal path. Alternatively fluidized beds may be used within which the product undergoes reversal of motion both entering and leaving through the upper surface of the beds.</p> |
