Fine filtration for a dishwasher appliance using powered diverter

Abstract

A filtering system for a dishwashing appliance that can remove fine particles from the wash and rinse fluids is provided. A filter cartridge is provided with different filter media for the removal of different particulate sizes depending upon e.g., the cycle or stage of the cleaning process and/or anticipated particle size. The filter cartridge is positioned upstream from the pump inlet. A mechanism for diverting flow between filter media is provided. In certain embodiments, the filter cartridge can be removable for servicing.

What is claimed is: 
     
         1 . A dishwashing appliance, comprising:
 a wash chamber having a sump portion;   at least one spray arm assembly for providing fluid onto articles placed in the wash chamber;   a pump in fluid communication with the spray arm assembly, the pump having a pump inlet;   a filter system positioned at the sump portion of the wash chamber, the filter system and in fluid communication with, and upstream from, the pump inlet, the filter system comprising
 a removable filter cartridge having a plurality of filter media positioned about the filter cartridge, each of the filter media configured for removing different sized particulates than the other filter media; 
 a plurality of fluid channels, each fluid channel having a fluid inlet positioned to receive filtered fluid from one of the plurality of filter media, and a fluid outlet positioned downstream of the fluid inlet; 
 a diverter mechanism positioned downstream of the filter cartridge and upstream of the pump inlet, the diverter mechanism configured to selectively place any one of the fluid outlets of the fluid channels in fluid communication with the pump inlet. 
   
     
     
         2 . A dishwashing appliance as in  claim 1 , wherein the filter system further comprises a filter receptacle, the filter receptacle comprising:
 a cavity for the removable receipt of the filter cartridge; and   a plurality of openings spaced apart from each other about the filter receptacle, each opening positioned adjacent to one of the filter media and configured to allow fluid to flow from the chamber, through the opening, through the filter media, and into one of the fluid channels.   
     
     
         3 . A dishwashing appliance as in  claim 2 , wherein each filter media of the plurality of filter media is positioned at one of the plurality of openings and one of the fluid inlets of the plurality of fluid channels. 
     
     
         4 . A dishwashing appliance as in  claim 1 , wherein the diverter defines a slot positioned proximate to the outlets of each of the plurality of fluid channels, and wherein the diverter further comprises a gate that is slidably received into the slot and is configured to move along the slot so that the flow of fluid through all but one of the plurality of fluid channels is blocked based on the position of the gate. 
     
     
         5 . The dishwashing appliance of  claim 1 , wherein the plurality of filter media comprises a first filter media, a second filter media, and a third filter media positioned beside each other along a circumferential direction of the filter cartridge. 
     
     
         6 . The dishwashing appliance of  claim 5 , wherein the third filter media is configured for the removal of particles of about 50 microns in size or larger from a fluid circulated through the filter system. 
     
     
         7 . The dishwashing appliance of  claim 6 , wherein the second filter media is configured for the removal of particles of about 300 microns in size or larger from a fluid circulated through the filter system. 
     
     
         8 . The dishwashing appliance of  claim 7 , wherein the first filter media is configured for the removal of particles of about 0.030 inches in size or larger from a fluid circulated through the filter system. 
     
     
         9 . The dishwashing appliance of  claim 1 , wherein the sump portion defines a receptacle into which the filter cartridge is received. 
     
     
         10 . A dishwashing appliance, comprising:
 a wash chamber having a sump portion, the sump portion including a filter receptacle having a plurality of openings for the egress of filter fluid;   a pump for circulating fluid through the wash chamber, the pump having a pump inlet whereby the pump may receive filtered fluid from the filter receptacle; and   a filter cartridge removably received into the filter receptacle, the filter cartridge defining a cylindrically-shaped wall surrounding an internal cavity and defining axial and circumferential directions, wherein the cylindrically-shaped wall comprises a plurality of filter media positioned proximate to each other along the circumferential direction, each of the filter media configured for removing different sized particulates than the other filter media, each one of filter media positioned adjacent to one of the openings of the filter receptacle; and   a diverter mechanism positioned downstream of the filter cartridge and upstream of the pump inlet, the diverter mechanism configured to selectively place any one of the openings of the filter receptacle in fluid communication with the pump inlet.   
     
     
         11 . A dishwashing appliance as in  claim 10 , further comprising:
 a plurality of fluid channels, each fluid channel having a fluid outlet, each fluid channel providing fluid communication between one of the openings of the filter receptacle and the fluid outlet of such fluid channel;   wherein the diverter mechanism is configured to selectively place the fluid outlet of each fluid channel in fluid communication with the pump inlet.   
     
     
         12 . A dishwashing appliance as in  claim 11 , wherein the filter cartridge defines a radial direction, and wherein the fluid channels are positioned radially outward of the filter cartridge. 
     
     
         13 . The dishwashing appliance of  claim 10 , wherein at least one of the filter media is configured for removal of particles of about 50 microns in size and larger. 
     
     
         14 . The dishwashing appliance of  claim 10 , wherein the plurality of filter media comprises a first filter media, a second filter media, and a third filter media positioned beside each other along a circumferential direction of the filter cartridge. 
     
     
         15 . The dishwashing appliance of  claim 14 , wherein the third filter media is configured for the removal of particles of about 50 microns in size and larger from a fluid circulated through the filter cartridge. 
     
     
         16 . The dishwashing appliance of  claim 15 , wherein the second filter media is configured for the removal of particles of about 300 microns in size and larger from a fluid circulated through the filter cartridge. 
     
     
         17 . The dishwashing appliance of  claim 16 , wherein the first filter media is configured for the removal of particles of about 0.030 inches in size and larger from a fluid circulated through the filter cartridge. 
     
     
         18 . The dishwashing appliance of  claim 10 , wherein the filter cartridge is removable from the receptacle by sliding along the axial direction. 
     
     
         19 . The dishwashing appliance of  claim 10 , further comprising a controller configured to cause the diverter mechanism to place any one of the openings of the filter receptacle in fluid communication with the pump inlet based on different portions of a cleaning process of the dishwashing appliance. 
     
     
         20 . The dishwashing appliance of  claim 10 , wherein the plurality of filter media comprises a first filter media, a second filter media, and a third filter media positioned beside each other along a circumferential direction of the filter cartridge; and
 wherein the dishwashing appliance further comprises a controller configured for causing the diverter mechanism to place either the first filter media, the second filter media, or the third filter media in fluid communication with the pump inlet at different times during a cleaning process of the dishwashing appliance.