Vertical tube heat exchanger panel for waste-recovery boilers such as black liquid boilers or household waste incinerator furnaces, and methods of manufacture

Claim 1

In a heat exchanger panel comprising; a plurality of vertical tubes interconnected alternately by top loops and by bottom loops to extend in a sinuous path from an inlet to an outlet, the improvement comprising: means fixed to said inlet and outlet of said vertical tubes for suspending said panel from a rigid structure solely via said inlet and said outlet, and wherein tubes come into contact via their outer surfaces with a soot-laden gas and are subject to differential thermal expansion from the inlet to the outlet, adjacent vertical tubes being separated from one another at a pitch which is a little greater than their diameter and being laterally interconnected by longitudinal fins, and wherein short fixing members are welded on either side to adjacent tubes at a level which is below the level of the top loops of the panel to fix the end ones of said tubes which are directly suspended from said rigid structure to one another and to the immediately adjacent tube with is not directly suspended thereby, with the interconnecting fins between said end tubes and said immediately adjacent tubes extending below said short fixing members, but not thereabove.