| 摘要 |
A novel bayonet tube, heat-exchange reactor is provided herein. The reactor includes an outer tube with an inlet end for introducing a process stream therethrough and a closed outlet end. An inner tube, which is open at both ends, is coaxially-arranged within the outer tube and is spaced-apart from the outer tube. A catalyst is disposed within an annular space confined between the outer tube and the inner tube. The reactor includes a sleeve which externally surrounds the outer tube and defines therebetween a conduit for passage of a heat-transferring medium between the sleeve and the outer tube. The sleeve includes a plurality of perforations extending over a portion of the length thereof from a region close to the outlet end of the outer tube to a region between the outlet end and the inlet end for introducing the heat-transferring medium into the conduit. The components are arranged in such a way that the heat-transferring medium is progressively-supplied to the conduit and flows through the perforated length of the sleeve and along the external surface of the outer tube, in counterflow and indirect heat-exchange with the process stream passing through the catalyst in the annular space between the outer and inner tubes of the reactor. The heat-exchange reactor has a structure which includes one or more of the following: a) the perforations in the sleeve have a diameter of between 1 mm and 3mm, the perforations being arrayed with a pitch of between 10 mm and 100 mm, b) the perforated length of the sleeve constitutes between 5% and 75% of the length of the sleeve extending from the outlet end to the inlet end of the outer tube, and c) the conduit has a width of between 0.01 and 0.08 times that of the internal diameter of the outer tube. By having such structure, the lifetime of the reactor tubes is increased through reduced wall temperatures in critical parts of the tubes.
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