Filter apparatus with improved extraction

摘要

An apparatus for removing droplets of a liquid from a flow of air through the apparatus, comprises a centrifugal separator 100 having an outer wall in which is provided an off-take 104 through which a portion of the air flowing through the separator flows into a first conduit 106. The apparatus also includes a filter unit 2 having a drain 40 into a second conduit 52 for liquid separated from the air flow by the filter unit. The second conduit has a smaller cross-section than the first conduit. Preferably the filter unit is mounted to the centrifugal separator such that air containing oil mist flows upwards through the centrifugal separator 100 and then enters the filter unit 2 through an opening in a base 12. The first conduit may comprise an internal wall profile shaped as a venturi to provide for a reduced pressure. Advantageously the portion of air taken from the centrifugal separator is used to create a suction effect to enhance extraction of liquid from the filter unit. This provides an efficient and self-contained apparatus for enhanced liquid extraction from an air flow carrying liquid droplets such as oil.