Abstract: In a filtration system, in particular for cleaning the intake air of a gas turbine, including a flow channel surrounded by walls with an inflow opening and an outflow opening, a partition wall with at least two openings between a dirty side and a clean side which is positioned between the inflow opening and the outflow opening and limited by the walls of the flow channel, and at least two filters for purifying a flowing fluid. At least one filter is installed at a first opening on the dirty side of the partition wall and at least one filter at a second opening on the clean side of the partition wall.

Abstract: Disclosed herein is an improvement in microcellular or supermicrocellular polymer extrusion systems. Both conventional and microcellular systems employ an extruder which plasticates polymer pellets into a polymer melt; a gas metering system, whereby a gas is injected directly in the polymer melt flow in the extruder; a mixing and homogenizing section of the extruder, which creates a single-phase solution of the polymer and the gas; and a nucleation device at the outlet end of the extruder. In this invention, the improvement to the conventional system comprises the nucleation means attached to said extruder which is a gear pump acting as a throttle rather than a pump. With this improvement, the discharge pressure is dictated by die resistance and flow rate as delivered by the gear throttle, and the pressure drop of the polymer/gas single-phase solution is nearly instantaneous.