Dual-action sliding ring seals, e.g. for pulp pump drive shafts in the cellulose/paper industries, has a sealed barrier fluid zone between paired sliding rings with passages to give a fluid flow through chambers

摘要

The dual-action sliding ring seal assembly, especially for sealing pulp pump drive shafts in the cellulose and paper industries, has a pair of sliding ring seals (4,5) with an exterior sealing action spaced axially apart to define a barrier fluid zone (6) between them. After filling e.g. with water, the zone is sealed to prevent any barrier fluid flow to and from the ambient environment. Each sliding ring seal has a pair of sliding rings (7-10), working together, where one rotates on the shaft (3) with a sleeve (13) on the shaft and the other is keyed at a seal housing (2). One sliding ring seal has an axial movement, with a spring tension against the other. A number of passages (23) are distributed around the periphery, extending into a chamber (21,22) formed within the barrier fluid zone at a radially inward section (17) of the sealing housing to give a fluid flow between the chambers. The rotation of the sleeve on the shaft uses external structures (24) which rotate the barrier fluid, to move through the passages. The sleeve supports a carrier, which carries all the components of the sliding ring seal assembly.