Mass transfer plate with long, slot-shaped vapour risers and bubble caps

摘要

A mass transfer plate with movable caps (10) consists of a number of parallel U-shaped profiles (5), the spaces between which define the vapour risers (7). Each cap is movably carried on at least two supports (11) in such a way that it more or closes the vapour riser at the lower limit of its travel, and has to overcome a resistance consisting at least of its own weight on lifting. The resistance is generated by two-armed leaf springs (15) located above the caps. The springs are fixed in slots (14) in the supports (11) and form a stop which limits upward movement of the cap. The spring strength can be varied by variations in the length of the shanks (L), by cut-outs in the shanks, or by the use of different material thicknesses. In their lowest position, the caps sit on studs attached to the supports, and the degree of vertical movement may be varied using washers (23). The vertical location of the supports (11) and the studs is adjustable. A number of supports (11) can be mounted on a common spar (12) below the plate, whilst the U- profiles (5) are connected together at their ends by strips (6), which also serve to seal the vapour risers against the liquid on the plate. The strips (6) extend below the level of the plate, and have open-ended slots at their lower ends to permit mounting of the plate components on the carrier (4) using screws (9).