The Vympel company has developed an impact-gravity filter (IGF) allowing for filtration of discontinuous (and solid) phase from gas without any impact on the sample quality
The IGF consists of the impact and gravity filters unified in a single unit.
The impact filtration principle is in abrupt change in movement direction of gas with solid and liquid particulates. Since the particulates are several times as dense as the gas, they keep moving on inertia in the same direction, separating from the gas.
The gravity filter unit is designed as a vertical flow settling chamber. In the settling chamber, the pre-purified gas flow moves vertically upwards. The gas sample ascension speed is lower than the descension speed of the particles remaining in the gas. As a result, the solid particles contained in the analyzed gas move against the flow, i.e. down, under their own weight and are carried away by the flushing gas flow.
Thank to the absence of solid mechanical or membrane filtering elements, the filter does not need cleaning or replacement.
Use of IGF makes it possible to avoid using membrane, carbon and other cellular filters and keep the cost low, the design simple and the operation expenses minor.
IGF is included in the Model-003 gas purification system (also developed by Vympel). The Model-003 system is used for gas sample purification for the CONG-Prima series analyzers.