Studies of the flow in and around gas dedusters and demisters using neutrally buoyant tracer

Tracer studies of the flow in gas dedusting or demisting equipment is a problem area, since such equipment is designed to cause the paths of solid or liquid particles to deviate from the gas streamlines, conflicting with the purpose of tracer particles. This paper summarizes a number of studies of the flow in centrifugal gas cleaning equipment using neutrally buoyant tracer particles, which are helium-filled soap bubbles about 1 mm in size. The studies show vortex precession in the body of reverse-flow cyclones, vortex breakdown in the vortex finder of reverse-flow cyclones and after the outlet of once-through cyclones. They also show other features of the flow in gas cleaning equipment not visualized before. Most of the results shown a qualitative, illustrating the potential of this visualization technique.