| 摘要 |
<p><PICT:0660587/III/1> <PICT:0660587/III/2> A drum &c. 1, Fig. 1, for an oil cracking still is reinforced at the location of the usual tube holes 5 by one or more plates 6 each of which conforms to the shape of the drum and is welded to the latter, or to adjacent plates, along its edges 8, holes 7, to mate with the holes 5, being provided in the plates 6 before or after application to the drum. The holes 7 are of such size as to provide a clearance around the tubes 10, which are welded at 11 or expanded at 12 into the holes 5, and the inner edges of some of the holes 7, Fig. 6, may be welded to the drum at 18. In a modification the, or each, plate 6 is located within the drum and the tubes 10 are welded thereto. The plate 6 may be of laminated form, and a colloidal graphite filling composition is preferably interposed between the plate and drum. Specifications 575,226, [Group XVIII], and 660,588, [Group XXII], are referred to.</p> |
