Filtration System

Abstract

A filtration system and methods for using same are disclosed. The filtration system can include a frame, and a plurality of filters coupled to the frame and coupled to each other in series. A pump can provide a pressure differential that causes fluid to flow through the filters in series. The first filter can be provided as a pre-filter, and one or more additional filters can include pleated, calendared, micro-fiber filters. Another filter can be a percentage removal nano-filter that is adapted to remove sub-micron particles from the fluid. The nano-filter can include three pleated filter layers. Each pleated filter layer can be oriented approximately concentrically about a common longitudinal axis.

1 . A fluid filtration system configured to remove particles from a fluid, the filtration system comprising:
 a frame;   a first filter supported by the frame, the at least one filter including a filter media configured to remove particles having a dimension greater than a first size; and   a nano-filter supported by the frame and disposed downstream of the first filter with respect to fluid flow, the nano-filter adapted to remove sub-micron particles from the fluid, the sub-micron particles having a largest dimension smaller than the those filtered by the first filter, the nano-filter including a plurality of adjacent pleated filter layers, each pleated filter layer being oriented substantially concentrically about a common longitudinal axis, and at least a portion of each pleated filter layer being spaced from its adjacent pleated filter layer.   
     
     
         2 . The filtration system of  claim 1 , wherein the plurality of pleated filter layers comprise electro-positive fibers. 
     
     
         3 . The plurality of pleated filter layers of  claim 2  wherein the electro-positive fibers comprise nanoalumina fibers grafted onto microglass structural fibers. 
     
     
         4 . The filtration system of  claim 1 , wherein at least one of the filters further comprises a filter head having a mounting hub and castellations located around the periphery of the mounting hub, the filter head coupling the filter to a respective conduit that carries the fluid. 
     
     
         5 . The filtration system of  claim 1  wherein the pleated filter layers each have different numbers of pleats. 
     
     
         6 . The filtration system of  claim 1 , wherein the nano-filter comprises three pleated filter layers. 
     
     
         7 . The filtration system of  claim 1 , wherein at least a portion of a select one of the pleated filter layers overlaps its adjacent filter layer. 
     
     
         8 . The filtration system of  claim 7 , wherein at least a portion of the select one of the pleated filter layers does not overlap its adjacent filter layer. 
     
     
         9 . A nano-filter cartridge comprising:
 an outer support cage;   an inner support core disposed inside the outer support cage so as to define a void disposed between the inner support core and the outer support cage; and   at least a first pleated filter layers disposed within the void and a second pleated filter layer disposed within the void at a location adjacent the first pleated filter layer, such that at least a portion of the first and second filter layers is spaced from each other.   
     
     
         10 . The nano-filter cartridge of  claim 9  wherein the first and second pleated filter layers is oriented substantially concentrically about a common longitudinal axis. 
     
     
         11 . The nano-filter cartridge of  claim 10  further comprising a third layer disposed adjacent at least one of the first and second layers and oriented substantially concentrically about the common longitudinal axis. 
     
     
         12 . The nano-filter cartridge of  claim 11  wherein the first, second, and third layers comprise respective inner, middle, and outer layers, and the outer layer has more pleats than the inner layer. 
     
     
         13 . The nano-filter cartridge of  claim 9  wherein the filter layers comprise a plurality of electropositive fibers that define pores therebetween. 
     
     
         14 . The nano-filter cartridge of  claim 13  wherein the electropositive fibers are nanoalumina fibers grafted onto microglass structural fibers. 
     
     
         15 . The nano-filter cartridge of  claim 9  further comprising an upper end cap, the upper end cap comprising at least two grooves adapted to accommodate insertion of respective o-rings. 
     
     
         16 . A method of removing submicron particles from a fluid comprising:
 passing the fluid through a first filter, wherein the first filter removes particles that are larger than a first size; and   passing the fluid through a second filter, wherein the second filter removes particles that are smaller than the first size and wherein the second filter is a nano-filter having a filter layer that comprises a web of electropositive fibers defining fluid receiving pores therebetween.   
     
     
         17 . The method of  claim 16  further comprising attracting submicron particles from the fluid to the electropositive fibers.