Fine filtration for a dishwashing appliance

Abstract

A filtering system for a dishwashing appliance is provided that can remove fine particles from the wash and rinse fluids. The system includes a filter cartridge that can be rotated between filter media equipped for 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. In certain embodiments, the filter cartridge can be removable for servicing.

What is claimed is: 
     
         1 . A dishwashing appliance, comprising:
 a wash chamber having 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 in fluid communication the sump portion of the wash chamber and in fluid communication with, and upstream from, the pump inlet, the filter system comprising
 a rotatable, cylindrically-shaped 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; and 
 a motor in mechanical communication with the filter cartridge; and whereby the filter cartridge may be rotated to select between different filter media for filtering fluid travelling to the pump inlet from the filter system. 
   
     
     
         2 . 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. 
     
     
         3 . The dishwashing appliance of  claim 2 , 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. 
     
     
         4 . The dishwashing appliance of  claim 3 , 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. 
     
     
         5 . The dishwashing appliance of  claim 4 , wherein the third 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. 
     
     
         6 . The dishwashing appliance of  claim 1 , wherein the sump portion defines a receptacle into which the filter cartridge is received. 
     
     
         7 . The dishwashing appliance of  claim 6 , wherein the receptacle defines a fluid outlet, and wherein the motor is further configured for positioning one of the plurality of filter media to filter a fluid flowing through the fluid outlet and to the pump inlet. 
     
     
         8 . The dishwashing appliance of  claim 1 , further comprising a plurality of gear teeth positioned along a circumferential direction of the filter cartridge. 
     
     
         9 . A dishwashing appliance, comprising:
 a wash chamber having a sump portion, the sump portion including a filter receptacle having a fluid outlet;   a pump for circulating fluid through the wash chamber, the pump having a pump inlet in fluid communication with the filter receptacle whereby fluid may be received by the pump from the filter receptacle; and   a rotatable filter cartridge received into the filter receptacle, the filter cartridge defining a cylindrically-shaped wall surrounding an internal chamber 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; and   a motor connected with the rotatable filter cartridge and configured for rotating the filter cartridge so that one of the plurality of filter media is positioned in fluid communication with the fluid outlet of the receptacle.   
     
     
         10 . The dishwashing appliance of  claim 9 , wherein at least one of the filter media is configured for removal of particles of about 50 microns in size and larger. 
     
     
         11 . The dishwashing appliance of  claim 9 , 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 the circumferential direction of the filter cartridge. 
     
     
         12 . The dishwashing appliance of  claim 11 , 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 system. 
     
     
         13 . The dishwashing appliance of  claim 12 , 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 system. 
     
     
         14 . The dishwashing appliance of  claim 13 , wherein the third 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 system. 
     
     
         15 . The dishwashing appliance of  claim 9 , further comprising a plurality of gear teeth positioned along a circumferential direction of the filter cartridge. 
     
     
         16 . The dishwashing appliance of  claim 9 , wherein the filter cartridge is removable from the receptacle by sliding along the axial direction. 
     
     
         17 . The dishwashing appliance of  claim 9 , further comprising a controller configured for causing the motor to rotate the filter cartridge about the axial direction during different portions of a cleaning process of the dishwashing appliance. 
     
     
         18 . The dishwashing appliance of  claim 9 , 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 the circumferential direction of the filter cartridge; and
 wherein the dishwashing appliance further comprises a controller configured for causing the motion to rotate the filter about the axial direction so as to position the first filter media, the second filter media, and the third filter media adjacent to the fluid outlet of the receptacle at different times during a cleaning process of the dishwashing appliance.