Patent ID: 8517185
Filing Date: 2013-08-27
Classification: B01D

Abstract:
1. A two stage fluid filter comprising: an outer coalescer stage surrounding an inner separator stage with a gap therebetween, the outer coalescer stage including a pleated cylinder of polymeric media configured to coalesce water that is in a fluid, the pleated cylinder of polymeric media having pleat valleys and downstream pleat tips, and release sites located at or adjacent to the downstream pleat tips; the pleated cylinder of polymeric media of the outer coalescer stage having opposite ends that are fixed to endcaps; the inner separator stage including a non-pleated cylinder of polymeric media surrounding a multi-layer pleated cylinder of polymeric media, and the inner separator stage is configured to separate coalesced water from the fluid and remove fine solid contaminants from the fluid; and the non-pleated cylinder of polymeric media and the multi-layer pleated cylinder of polymeric media of the inner separator stage each have opposite ends that are fixed to endcaps, wherein the pleated cylinder of polymeric media of the outer coalescer stage comprises from upstream to downstream at least the following layers: (i) a top layer comprising a polymeric nonwoven, the top layer having a mean fiber diameter of >10 μm, the top layer having a higher porosity, a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately downstream of the top layer; (ii) a nanofiber layer comprising a polymeric nonwoven, the nanofiber layer having a mean fiber diameter of 0.1-1.0 μm, the nanofiber layer having a mean pore size of <8 μm; the nanofiber layer having a maximum to mean pore size ratio of less than about 3; and the nanofiber layer having a basis weight of greater than about 20 gsm; and (iii) a support layer comprising a polymeric nonwoven, the support layer having a mean fiber diameter of >20 μm, the support layer having a higher porosity, a larger pore size, a larger mean fiber diameter, a higher Frasier permeability, and a lower contaminant removal efficiency than a layer immediately upstream of the support layer.