Purge gas filter

Sealing gas filter ( English seal-gas-filter ) protect labyrinth seals on turbo compressors and turbocompressors from the effects of water droplets. If the labyrinth seal is destroyed , the purge gas filter must be dimensioned in such a way that no dangerous or toxic media can escape from the turbo compressor, but the turbine wheels are also protected from water droplets and the associated droplet erosion.

Mode of action

The sealing gas filter consists of a purely mechanical part, a coalescer filter element and a switching unit. The switching unit is used to commission redundant filter systems when carrying out maintenance measures, e.g. B. Element change. In the case of dangerous and / or poisonous media, the switchover unit can also be designed in double block and bleed for flushing . The mechanical part works due to the inertia of the different substances.

If the mass flow of a gas is initially slowed down and accelerated again by changing the direction, taking into account changes in cross-section, gas molecules behave differently than liquid molecules . These are then only collected in a suitable form. With an optimal dimensioning from a change in direction to a change in cross section, a separation of gas or liquid molecules of different densities would also be conceivable. The fact that when looking at the flow change in the media involved, the masses of the molecules involved are simply omitted by shortening them, is an essential feature of this design with regard to process reliability.

The coalescer filter element is a close-meshed wire mesh 3 µm nominal made of stainless steel. At low flow rates, the water droplets coalesce in the tissue. These then run down through gravity in the filter element where they are then caught.