Drainage medium for gas filter

A gas filter for coalescing at least one dispersed liquid phase present in a gas, the gas filter comprising:

• an inlet for supplying the gas to a filter element present in the gas filter, which filter element comprises a coalescence medium for coalescing the at least one dispersed phase during a displacement of the gas through the coalescence medium in a flow direction,
• wherein the filter element downstream of the coalescence medium comprises a drainage medium for draining the at least one coalesced dispersed phase leaving the coalescence medium in a drainage direction which is transverse to the flow direction,
• wherein the filter element is composed of a single package of the coalescence medium, the drainage medium and a barrier layer,
• wherein the barrier layer is located downstream of the coalescence medium,
• wherein the coalescence medium and the barrier layer are held at a distance from each other by one or more spacers extending in the flow direction to provide a drainage layer in the drainage medium between the barrier layer and a surface of the coalescence medium facing the barrier layer, the coalescence medium, the drainage medium and the barrier layer being layer-like materials positioned adjacent to each other,
• wherein pores in the drainage medium have an average pore diameter greater than an average pore diameter of pores of the barrier layer and greater than an average pore diameter of pores of the coalescence medium,
• wherein the drainage medium has a thickness greater than a thickness of the coalescence medium and a thickness of the barrier layer,
• wherein the drainage medium contains the drainage layer with a drainage surface for receiving and draining the at least one coalesced dispersed phase, the drainage surface facing the coalescence medium, wherein the drainage medium contains an anisotropic porous material having a higher air permeability than the barrier layer, and
• wherein the barrier layer is positioned downstream of the drainage medium, the drainage medium having a permeability for the at least one coalesced dispersed phase in the drainage direction which is higher than a permeability in the flow direction of the fluid.