Patent Publication Number: US-2018042447-A1

Title: Filter assembly for a dishwasher appliance

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to dishwasher appliances and more particularly to filter assemblies for dishwasher appliances. 
     BACKGROUND OF THE INVENTION 
     During wash and rinse cycles, dishwasher appliances generally circulate a fluid through a wash chamber over articles, such as pots, pans, silverware, etc. The fluid can be, e.g., various combinations of water and detergent during the wash cycle, or water (which may include additives) during the rinse cycle. Typically, the fluid is circulated during a given cycle using a pump. Fluid is collected at or near the bottom of the wash chamber and pumped back into the wash chamber through, e.g., nozzles in spray arms and other openings that direct the fluid against the articles to be cleaned or rinsed. 
     Depending upon the level of soil on the articles, fluids used during wash and rise cycles can become contaminated with soils in the form of debris or particles that are carried with the fluid. In order to protect the pump and recirculate the fluid through the wash chamber, it is beneficial to filter the fluid so that relatively clean fluid is applied to the articles in the wash chamber and soils are removed or reduced from the fluid supplied to the pump. 
     Accordingly, dishwasher appliances are generally provided with a filter assembly to trap at least certain of the soils carried with the wash fluid. Such filter assemblies generally include a coarse filter and a fine filter in a series flow configuration. For example, during a wash cycle a portion of the recirculated wash fluid progressively flows through filters that have smaller and smaller holes. Additionally, blades may be provided adjacent the filters to generally unclog soil from the filters and guide the soil towards discharge areas. It is generally desirable for these blades to be in close proximity to respective filters to facilitate such cleaning. 
     While such filter assemblies provide advantages with regard to filtering, improvements could be made with respect to the discharge area. For example, filter assemblies are oriented such that a pocket of air collects within the discharge area. As such, the pocket of air is ingested by a drain pump when a drain cycle is initiated to remove filtered soil and wash fluid from discharge area. This is undesirable, because the pocket of air promotes cavitation to occur within the pump and increases the run time of the pump. 
     Accordingly, improved filter assemblies are desired. In particular, filter assemblies which remove the pocket of air from the discharge chamber and prevent cavitation within the drain pump. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
     In a first exemplary embodiment, a filter assembly for filtering a wash fluid to be circulated by a circulation pump in a dishwasher appliance is provided. The filter assembly defines an axial direction and a radial direction that is orthogonal to the axial direction. Further, the filter assembly includes a filter member, housing, discharge chamber, and relief valve. The filter member may define a discharge opening, and may include a filter panel and outer wall. The outer wall may extend around a perimeter of the filter panel. The housing may at least partially surround the filter member, and may include a peripheral wall. Further, the housing may define an aperture that extends through the peripheral wall. The discharge chamber may be defined between the outer wall of the filter member and the peripheral wall. Additionally, the discharge chamber may be in fluid communication with the filter member through the discharge opening. The relief valve may include a valve body and a valve member. The valve body may surround the aperture formed on the peripheral wall, and may define a cavity that extends from the peripheral wall along the radial direction. The valve member may be disposed within the cavity, and may be movable along the radial direction between a first position and a second position. When the valve member is in the first position, fluid communication between the discharge chamber and the cavity may be restricted. In contrast, fluid communication between the discharge chamber and the cavity may be permitted when the valve member is in the second position. 
     In a second exemplary embodiment, a dishwasher appliance is provided. The dishwasher appliance includes a tub, a sump, a circulation pump, and a filter assembly. The filter assembly defines an axial direction and a radial direction that is orthogonal to the axial direction. Further, the filter assembly includes a filter member, housing, discharge chamber, and relief valve. The filter member may define a discharge opening, and may include a filter panel and outer wall. The outer wall may extend around a perimeter of the filter panel. The housing may at least partially surround the filter member, and may include a peripheral wall. Further, the housing may define an aperture that extends through the peripheral wall. The discharge chamber may be defined between the outer wall of the filter member and the peripheral wall. Additionally, the discharge chamber may be in fluid communication with the filter member through the discharge opening. The relief valve may include a valve body and a valve member. The valve body may surround the aperture formed on the peripheral wall, and may define a cavity that extends from the peripheral wall along the radial direction. The valve member may be disposed within the cavity, and may be movable along the radial direction between a first position and a second position. When the valve member is in the first position, fluid communication between the discharge chamber and the cavity may be restricted. In contrast, fluid communication between the discharge chamber and the cavity may be permitted when the valve member is in the second position. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures. 
         FIG. 1  provides a front elevation view of a dishwasher appliance in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 2  provides a side, sectional view of the exemplary dishwasher appliance of  FIG. 1 ; 
         FIG. 3  provides a side, cross-sectional view of a sump and circulation pump in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 4  provides a perspective cross-sectional view of a filter assembly in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 5  provides a close up perspective view of a filter member of the exemplary filter assembly of  FIG. 4 ; 
         FIG. 6  provides a top, sectional view of a filter assembly in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 7  provides a cross-sectional view of a relief valve in accordance with an exemplary embodiment of the present disclosure; 
         FIG. 8  provides a cross-sectional view of a cavity formed by the relief valve of  FIG. 7 ; 
         FIG. 9  provides a cross-sectional view of a cavity formed by the relief valve of  FIG. 7 ; 
         FIG. 10  provides a cross-sectional view of an exemplary embodiment of a valve member in a first position; 
         FIG. 11  provides a cross-sectional view of an exemplary embodiment of a valve member in a first position; 
         FIG. 12  provides a cross-sectional view of an exemplary embodiment of a valve member in an intermediate third position; 
         FIG. 13  provides a cross-sectional view of an exemplary embodiment of a valve member in a second position; 
         FIG. 14  provides a cross-sectional view of an exemplary embodiment of a valve member in a second position; and 
         FIG. 15  provides a cross-sectional view of an exemplary embodiment of a valve member in a first position. 
     
    
    
     DETAILED DESCRIPTION 
     Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
     As used herein, the terms “first”, “second”, “third”, “fourth”, etc. may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. 
       FIGS. 1 and 2  depict a dishwasher appliance  100  according to an exemplary embodiment of the present subject matter.  FIG. 1  provides a front view of the exemplary dishwasher appliance  100 , and  FIG. 2  provides a side, sectional view of the exemplary dishwasher appliance  100 . 
     As shown, dishwasher appliance  100  defines a vertical direction V and includes a cabinet  102 . Cabinet  102  has a tub  104  therein that defines a wash chamber  106 . The tub  104  also defines a front opening (not shown). Dishwasher appliance  100  includes a door  120  hinged at a bottom  122  of door  120  for movement between a normally closed, vertical position (shown in  FIGS. 1 and 2 ), wherein wash chamber  106  is sealed shut for washing operation, and a horizontal, open position for loading and unloading of articles from dishwasher appliance  100 . A latch  123  is used to lock and unlock door  120  for access to wash chamber  106 . Tub  104  also includes a sump assembly  170  shown schematically positioned adjacent a bottom portion  112  of tub  104  and configured for receipt of a liquid wash fluid (e.g., water, detergent, wash fluid, and/or any other suitable fluid) during operation of dishwasher appliance  100 . More particularly, sump assembly  170  is shown attached to a bottom wall  142  of tub  104 . As will be explained in greater detail below, the exemplary dishwasher appliance  100  may further include a filter assembly (not shown), such as a filter assembly  204  (see  FIG. 3 ), disposed within sump assembly  170 . 
     A spout  160  is positioned adjacent sump assembly  170  of dishwasher appliance  100 . Spout  160  is configured for directing liquid into sump assembly  170 . Spout  160  may receive liquid from, e.g., a water supply (not shown) or any other suitable source. In alternative embodiments, spout  160  may be positioned at any suitable location within dishwasher appliance  100 , e.g, such that spout  160  directs liquid into tub  104 . Spout  160  may include a valve (not shown) such that liquid may be selectively directed into tub  104 . Thus, for example, during the cycles described below, spout  160  may selectively direct water and/or wash fluid into sump assembly  170  as required by the cycle of dishwasher appliance  100 . 
     Rack assemblies  130  and  132  are slidably mounted within wash chamber  106 . Each of the rack assemblies  130  and  132  is fabricated into lattice structures including a plurality of elongated members  134 . Each rack of the rack assemblies  130  and  132  is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber  106 , and a retracted position (shown in  FIGS. 1 and 2 ) in which the rack is located inside the wash chamber  106 . A silverware basket (not shown) may be removably attached to rack assembly  132  for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by the racks  130  and  132 . 
     Dishwasher appliance  100  further includes a lower spray assembly  144  that is rotatably mounted within a lower region  146  of the wash chamber  106  and above sump assembly  170  so as to rotate in relatively close proximity to rack assembly  132 . A mid-level spray assembly  148  is located in an upper region of the wash chamber  106  and may be located in close proximity to upper rack  130 . Additionally, an upper spray assembly  150  may be located above the upper rack  130 . 
     The lower and mid-level spray assemblies  144  and  148  and the upper spray assembly  150  are fed by a fluid circulation assembly  152  for circulating water and/or dishwasher fluid (collectively, “wash fluid”) in the tub  104 . Fluid circulation assembly  152  may include a wash or circulation pump  154  and a cross-flow/drain pump  156  located in a machinery compartment  140  located below sump assembly  170  of the tub  104 , as generally recognized in the art. Cross-flow/drain pump  156  is configured for urging wash fluid within sump assembly  170  out of tub  104  and dishwasher appliance  100  to a drain  158 . Circulation pump  154  is configured to provide a flow of recirculated wash fluid to tub  104  and wash chamber  106 . More particularly, circulation pump  154  is configured for supplying a flow of wash fluid from sump assembly  170  to spray assemblies  144 ,  148  and  150  via a plurality of circulation conduits (not labeled). 
     Each spray assembly  144  and  148  includes an arrangement of discharge ports or nozzles for directing wash fluid onto dishes or other articles located in rack assemblies  130  and  132 . The arrangement of the discharge ports in spray assemblies  144  and  148  provides a rotational force by virtue of wash fluid flowing through the discharge ports. The resultant rotation of the lower spray assembly  144  provides coverage of dishes and other dishwasher contents with a spray of wash fluid. 
     Dishwasher appliance  100  is further equipped with a controller  137  (shown in phantom) to regulate operation of the dishwasher appliance  100 . Controller  137  may include a memory and microprocessor, such as a general or special purpose microprocessor operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller  137  may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software. 
     Controller  137  may be positioned in a variety of locations throughout dishwasher appliance  100 . In the illustrated embodiment, controller  137  may be located within a control panel area  121  of door  120  as shown. In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of dishwasher appliance  100  along wiring harnesses that may be routed through the bottom  122  of door  120 . Typically, controller  137  includes a user interface  136  through which a user may select various operational features and modes and monitor progress of the dishwasher appliance  100 . In one embodiment, user interface  136  may represent a general purpose I/O (“GPIO”) device or functional block. Additionally or alternatively, user interface  136  may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. User interface  136  may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. User interface  136  may be in communication with controller  137  via one or more signal lines or shared communication busses. 
     It should be appreciated that the subject matter disclosed herein is not limited to any particular style, model or configuration of dishwasher appliance, and that the embodiment depicted in  FIGS. 1 and 2  is for illustrative purposes only. For example, instead of the racks  130  and  132  depicted in  FIG. 1 , dishwasher appliance  100  may be of a known configuration that utilizes drawers that pull out from the cabinet and are accessible from the top for loading and unloading of articles. 
     Reference will now be made to  FIGS. 3 and 4 .  FIG. 3  provides a cross-sectional view of a portion of a sump  200  and circulation pump  202  in accordance with an exemplary embodiment of the present disclosure. Additionally,  FIG. 4  provides a cross-sectional and perspective view of a filter assembly  204  in accordance with an exemplary embodiment of the present disclosure. In certain exemplary embodiments, sump  200  and circulation pump  202  may be configured as sump assembly  170  and circulation pump  154  in the exemplary dishwasher appliance  100  of  FIGS. 1 and 2 . 
     As is depicted, sump  200  generally includes a filter assembly  204  disposed within sump  200 , and filter assembly  204  defines an axial direction A, a radial direction R, and a circumferential direction C. Circulation pump  202  is positioned adjacent to filter assembly  204  and in flow communication with filter assembly  204 . Circulation pump  202  is configured to circulate or recirculate water/wash fluid from wash chamber  106  of tub  104 . More particularly, circulation pump  202  is configured to urge a flow of wash fluid to be recirculated from wash chamber  106  of dishwasher appliance  100 , through an inlet  206  in sump  200 , and through filter assembly  204 . Inlet  206  of sump  200  may be configured as an opening, e.g., in a bottom wall  142  of tub  104  of dishwashing appliance  100 . From filter assembly  204 , circulation pump  202  is configured to provide the flow of wash fluid to the tub  104  and wash chamber  106 , or more particularly to provide the flow of wash fluid through one or more circulation conduits to one or more spray assemblies, such as spray assemblies  144 ,  148 ,  150  depicted in  FIG. 2 . 
     Circulation pump  202  generally includes an impeller  208 , a shaft  210 , and an electric motor (not shown). Shaft  210  extends generally along the axial direction A, and is rotatable in the circumferential direction C (i.e., about the axial direction A) by the motor. Impeller  208  is fixed to shaft  210  and rotated by shaft  210 . Rotation of impeller  208  in the circumferential direction C by shaft  210  generates the flow of wash fluid to be recirculated through filter assembly  204  and into an outlet  212  of circulation pump  202 . Outlet  212  of circulation pump  202  may be fluidly connected with the one or more circulation conduits to circulate or recirculate the wash fluid. For example, outlet  212  of circulation pump  202  may provide wash fluid to the one or more spray assemblies, such as spray assemblies  144 ,  148 ,  150  depicted in  FIG. 2 . 
     For the exemplary embodiment depicted, filter assembly  204  generally includes a plurality of stacked filter members configured in series flow. Accordingly, wash fluid to be recirculated flows sequentially through each of the plurality of filter members prior to being recirculated by circulation pump  202 . With such a configuration, all wash fluid circulated or recirculated by circulation pump  202  is filtered by each of the plurality of filter members before reaching the circulation pump  202 . Therefore, all wash fluid to be recirculated by circulation pump  202  may be filtered in a “single-pass” through filter assembly  204 . 
     More particularly, for the embodiment depicted, the one or more filter members include a first filter member  214 , a second filter member  216 , and a third filter member  218 . First filter member  214  defines a first filter panel  220  and a first outer wall  222  extending around a perimeter of first filter panel  220 . Similarly, second filter member  216  defines a second filter panel  224  and a second outer wall  226  extending around a perimeter of the second filter panel  224 , and the third filter member  218  defines a third filter panel  228  with a third outer wall  230  extending around a perimeter of the third filter panel  228 . 
     Additionally, each of the one or more filter members are attached such that the respective filter panels are substantially parallel to one another. For example, the first filter panel  220  is substantially parallel to both second filter panel  224  and third filter panel  228 . Moreover, for the embodiment depicted, first outer wall  222  is attached to second outer wall  226  using a screw-type connection, and second outer wall  226  is attached to third outer wall  230  also using a screw-type connection. However, in other embodiments, first, second, and third outer walls  222 ,  226 ,  230  may each be attached to one another in any other suitable manner. 
     Each of first, second, and third filter panels  220 ,  224 ,  228  are configured to prevent soils, such as food particles or other debris, greater than a predetermined size for the respective filter panel from passing therethrough. Additionally, each of the plurality of filter members  214 ,  216 ,  218  are configured to sequentially filter and remove smaller particles from the wash fluid to be recirculated. More particularly, as is depicted, first filter panel  220  defines a plurality of first filter openings  232 , second filter panel  224  defines a plurality of second filter openings  234 , and third filter panel  228  defines a plurality of third filter openings  236 . First filter openings  232  are larger than second filter openings  234 , and second filter openings  234  are larger than third filter openings  236 . Accordingly, first filter member  214  may be referred to as a “coarse” filter, second filter member  216  may be referred to as a “medium” filter member, and third filter member  218  may be referred to as a “fine” filter member. Therefore, filter assembly  204  depicted may filter all particles larger than third filter openings  236  from the wash fluid to be recirculated in a single-pass through filter assembly  204 . 
     For the embodiment depicted, each of first filter panel  220 , second filter panel  224 , and third filter panel  228  are configured as a wall defining first filter openings  232 , second filter openings  234 , and third filter openings  236 , respectively. However, in other exemplary embodiments, first, second, and/or third filter panels  220 ,  224 ,  228  may instead be configured to include any other suitable filter medium, such as, e.g., a mesh filter. 
     Shaft  210  of circulation pump  202  extends through the plurality of filter members  214 ,  216 ,  218 . More particularly, for the embodiment depicted, shaft  210  extends through third filter panel  228  of third filter member  218 , through second filter panel  224  of second filter member  216 , and through first filter panel  220  of first filter member  214 . Filter assembly  204  depicted in  FIGS. 3 and 4  further includes discharge blades attached to shaft  210  adjacent to the respective filter panels  220 ,  224 ,  228 . More particularly, exemplary filter assembly  204  depicted includes a first discharge blade  240 , a second discharge blade  242 , and a third discharge blade  244 . First discharge blade  240  is attached to shaft  210  and positioned adjacent to first filter panel  220 ; second discharge blade  242  is attached to shaft  210  and is positioned adjacent to the second filter panel  224 ; and third discharge blade  244  is attached to shaft  210  and positioned adjacent to third filter panel  228 . 
     Each of the discharge blades  240 ,  242 ,  244  may be attached to shaft  210  in any suitable manner. For example, in the embodiment depicted, shaft  210  defines a plurality of circumferential threads  246  and the first, second and third discharge blades  240 ,  242 ,  244  are each screwed onto circumferential threads  246  of shaft  210 . Notably, shaft  210  includes a plurality of setpoints  248  attached to shaft  210  adjacent to each of the blades  240 ,  242 ,  244  to ensure each the blades  240 ,  242 ,  244  defines a desired gap  250  along the axial direction A with the respective filter panel  220 ,  224 ,  228 . For example, the discharge blades may be configured such that the blades define a gap  250  of between about five thousandths of an inch and about fifty thousandths of an inch. 
     It should be appreciated, however, that in other exemplary embodiments, each of the blades  240 ,  242 ,  244  may instead be set in position using any other suitable mechanism and may define any other suitable gap  250  with the respective filter panel  220 ,  224 ,  228 . For example, in other exemplary embodiments, filter assembly  204  may instead include a washer between each of the blades  240 ,  242 ,  244  and the respective filter panel  220 ,  224 ,  228 . Additionally, in other embodiments, filter assembly  204  may define a gap  250  of between about ten thousandths of an inch and about thirty thousandths of an inch, or between about fifteen thousandths of an inch and about twenty thousandths of an inch. Moreover, each of the blades  240 ,  242 ,  244  may define different gaps  250  with first, second, and third panels  220 ,  224 ,  228 , respectively. It should also be appreciated, that as used herein, terms of approximation, such as “approximately” and “about,” refer to being within a ten percent margin of error. 
     Each of the exemplary blades  240 ,  242 ,  244  are configured to rotate in the circumferential direction C with shaft  210 , and may serve the function of chopping particles greater than size of the respective filter openings  232 ,  234 ,  236 . Further, as will be discussed below, blades  240 ,  242 ,  244  may also serve the functions of lifting particles off of the respective filter panels  220 ,  224 ,  228  and simultaneously moving particles outwardly along the radial direction R. 
     Referring particularly to  FIG. 3  as well as to  FIG. 6 , sump  200  and filter assembly  204  thereof may include a housing  254  with a peripheral wall  256  extending around the one or more filter members. Peripheral wall  256  includes inner and outer surfaces  258 ,  260  and circumferentially surrounds the filter members  214 ,  216 ,  218 . More particularly, inner surface  258  of peripheral wall  256  extends around first, second and third filter members  214 ,  216 ,  218 , and defines a discharge chamber  262  with first, second, and third filter members  214 ,  216 ,  218 . More particularly, inner surface  258  of peripheral wall  256  defines discharge chamber  262  with outer walls  222 ,  226 ,  230  of the respective filter assemblies  214 ,  216 ,  218 . Discharge chamber  262  is thus defined between the outer walls  222 ,  226 ,  230  and inner surface  258  of peripheral wall  256 . Additionally, peripheral wall  256  defines an outlet  264 . Outlet  264  is in fluid communication with a drain pump (not shown), such as drain pump  156  depicted in  FIG. 2 . 
     Filter members  214 ,  216 ,  218  attach to housing  254  below inlet  206  using a screw type connection. However, in other embodiments, the one or more filter members may attach to housing  254  in any other suitable manner, or alternatively at least one of the one or more filter members may be formed integrally with housing  254  of sump  200 . In some embodiments, filter assembly  204  may include a transition member  266  attached to a filter member, or more particularly attached to third filter member  218 . Transition member  266  makes a connection between the one or more filter members and impeller  208  of circulation pump  202 . Accordingly, transition member  266  defines filter assembly outlet  268  whereby filtered wash fluid to be recirculated passes into circulation pump  202 . Alternatively, one of the filter members, such as the third filter member  218 , may connect directly to impeller  208  and define filter assembly outlet  268 . 
     Referring now also to  FIG. 5 , a close-up perspective view of second filter member  216  is provided. Outer walls  222 ,  226 ,  230  of each of the respective filter members  214 ,  216 ,  218  define one or more discharge openings that allow for soils to pass from a respective filter panel  220 ,  224 ,  228  to discharge chamber  262 . For example, first outer wall  222  of first filter member  214  defines one or more first discharge openings  270 ; second outer wall  226  of the second filter member  216  defines one or more second discharge openings  272 ; and third outer wall  230  of third filter member  218  defines one or more third discharge openings  274 . For the embodiment depicted, each filter member  214 ,  216 ,  218  further includes guide members  276  slanting inwardly along the radial direction R from the respective outer walls  222 ,  226 ,  230  adjacent to each of the respective discharge openings  270 ,  272 ,  274 . More particularly, the guide members  276  slant towards the discharge openings  270 ,  272 ,  274  to guide particles through the discharge openings  270 ,  272 ,  274  into the discharge chamber  262 . As may be more clearly seen in  FIG. 5 , the guide members  276  each define an angle with regard to the radial direction R. The angle of guide members  276  may be between about ninety degrees and about one hundred and eighty degrees, such as between about one hundred and five degrees and about one hundred and sixty-five degrees, such as between about one hundred and twenty degrees and about one hundred and fifty degrees, such as about one hundred and thirty-five degrees. 
     During operation of dishwasher appliance  100 , or more particularly, during a wash or rinse cycle of dishwasher appliance  100 , wash fluid may enter filter assembly  204  through inlet  206  and travel to first filter member  214 . The wash fluid may be filtered by first filter panel  220  wherein soils larger than the first filter openings  232  are prevented from flowing therethrough to second filter member  216 . At the same time wash fluid and soils smaller than first filter openings  232  may pass therethrough to second filter member  216 . The wash fluid may then be filtered by second filter panel  224 , wherein soils larger than second filter openings  234  are prevented from flowing therethrough to third filter member  218 , while wash fluid and soils smaller than second filter openings  234  may pass therethrough to third filter member  218 . The wash fluid may then be filtered by third filter panel  228 , wherein soils larger than third filter openings  236  are prevented from flowing to circulation pump  202 , while the wash fluid to be recirculated may pass therethrough to circulation pump  202  and be recirculated into tub  104  and wash chamber  106 . 
     Moreover, during operation of the exemplary dishwasher appliance  100 , or more particularly during a wash or rinse cycle of the exemplary dishwasher appliance  100 , the motor of circulation pump  202  may rotate shaft  210 , which in turn may rotate impeller  208  and each of first, second, and third discharge blades  240 ,  242 ,  244 . The rotation of first, second, and third discharge blades  240 ,  242 ,  244  by shaft  210  may allow discharge blades  240 ,  242 ,  244  to chop soils greater than the respective first, second, and third filter openings  232 ,  234 ,  236  and/or move soils outward along the radial direction R through the respective discharge openings  270 ,  272 ,  274 . For example, first discharge blade  240  may move soils larger than first filter openings  232  outward along the radial direction R through the one or more first discharge openings  270  and into the discharge chamber  262 . Similarly, second discharge blade  242  may move soils larger than second filter openings  234  outward along the radial direction R through the one or more second discharge openings  272  and into discharge chamber  262 . Further, third discharge blade  244  may move soils larger than third filter openings  236  outward along the radial direction R through the one or more third discharge openings  274  and into discharge chamber  262 . 
     Referring now to  FIG. 6 , as illustrated, discharge chamber  262  in exemplary embodiments is a circumferentially continuous discharge chamber  262 . In other words, discharge chamber  262  is continuous generally annularly and along the circumferential direction, such that wash fluid in the chamber  262  can freely rotate in a generally continuous flow path along the circumferential direction, such as annularly within discharge chamber  262 . Accordingly, particles that are removed from the filter members  214 ,  216 ,  218 , such as from the panels  220 ,  224 ,  228  thereof, and traversed through the discharge openings  270 ,  272 ,  274  into the discharge chamber  262  may advantageously remain in the discharge chamber  262  until particles are drained from discharge chamber  262  via filter assembly outlet  268 . 
     As discussed, particles (and wash fluid) may flow through the discharge openings  270 ,  272 ,  274  into the circumferentially continuous discharge chamber  262 . Further, as discussed, guide members  276  may guide particles through the discharge openings  270 ,  272 ,  274  into the discharge chamber  262 . The guide members  276  and openings  270 ,  272 ,  274  of each filter member  214 ,  216 ,  218  may be spaced apart from each other along the circumferential direction, as illustrated. For example, in some exemplary embodiments, each filter member  214 ,  216 ,  218  may include two openings  270 ,  272 ,  274  and two associated guide members  276 . The two openings  270 ,  272 ,  274  and two associated guide members  276  of each filter member  214 ,  216 ,  218  may, for example, be spaced between 170 and 190 degrees apart, such as between 175 and 185 degrees apart, such as approximately 180 degrees apart along the circumferential direction. Alternatively, one, three, four or more openings  270 ,  272 ,  274  and associated guide members  276  may be utilized. Further, discharge openings  270 ,  272 ,  274  and associated guide members  276  may have any suitable spacing along the circumferential direction. 
     The filtered soils along with some accompanying wash fluid may be stored in discharge chamber  264  until wash cycle is complete and a discharge cycle is activated. During a discharge cycle, the drain pump is activated and wash fluid is pulled through, e.g., discharge chamber  264  and outlet  266  into and through a drain pipe (not shown). The drain pipe may be fluidly connected with a drain or other plumbing configured to dispose of such wash fluid and filtered particles. Notably, in certain embodiments, an appropriate amount of continuous flow of wash fluid, generated by the respective blades  240 ,  242 ,  244 , may flow with filtered soils into discharge chamber  264  and through outlet  266  during a wash and/or rinse cycle of dishwasher appliance  100 . In such an embodiment, a length of the drain pipe of the exemplary dishwasher appliance  100  may be filled with filtered/discharged soils and wash fluid (i.e., wash fluid that will not be recirculated). Such a configuration may accommodate storage of the filtered/discharged soils and accompanying wash fluid during a wash and/or rinse cycle of the exemplary dishwasher appliance  100 . Additionally, in certain embodiments, the drain pump  156  may be activated for a relatively short period of time during, e.g., a wash or rinse cycle, in order to provide drainage of the wash fluid and filtered/discharged soils prior to a drain cycle. 
     Still referring to  FIG. 6 , the housing  254  defines an aperture  278  extending therethrough. More specifically, the aperture  278  extends between the inner and outer surfaces  258 ,  260  of the peripheral wall  256  along radial direction R. Also, the filter assembly  204  includes a relief valve  300  comprising a valve body  310 , a valve member  320 , and a cap  330 . The valve body  310  includes an interior surface  312  and an exterior surface  314  spaced apart from the interior surface  312  along the circumferential direction C. As shown, the interior and exterior surfaces  312 ,  314  extend from the housing  254 , or more particularly the outer surface  260  of the peripheral wall  256 , along the radial direction R. Further, the interior surface  312  is spaced apart from the aperture  278  along the circumferential direction C. More specifically, the interior surface  312  surrounds the aperture  278  such that the valve body  310  defines a cavity  318  positioned over the aperture  278  along the radial direction R. The valve member  320  is disposed within the cavity  318 , and the cap  330  is positioned on an end  316  of the valve body  310 . It should be appreciated that the valve member  320  may define any suitable shape and may be comprised of any suitable material. For example, the valve member  320  may be sphere comprised of an elastomer material (e.g., rubber). 
       FIG. 7  provides a cross-sectional view of the relief valve  300  without the valve member  320 . The cap  330  includes a bottom  332  and a top  334 . As shown, the bottom  332  is positioned on the end  316  of the valve body  310 . The cap  330  defines an opening  336  that extends therethrough, and the cap  330  further includes an inside edge  338  that defines a perimeter of the opening  336 . The outer surface  260  of the peripheral wall  256  includes an inside edge  340  that defines a perimeter of the aperture  278 . As will be discussed below in more detail, the valve member  320  is movable within the cavity  318 , and may contact the cap  330 , or more particularly the inside edge  338  of the cap  330 , to restrict fluid communication between the cavity  318  and the opening  336 . Further, the valve member  320  may also contact the outer surface  260 , or more particularly the inside edge  340  of the outer surface  260 , to prohibit fluid communication between the discharge chamber  262  and the cavity  318 . 
       FIGS. 8 and 9  provide cross-sectional views of the cavity  318  formed by the interior surface  312  of the valve body  310 . As shown, the cavity  318  defines a maximum diameter D C , the aperture  278  defines a maximum diameter D A , and the opening  336  defines a maximum diameter D O . The maximum diameter D C  of the cavity  318  is greater than both D A  and D O  to contain the valve member  320  within the cavity  318 . Further, as shown in  FIGS. 8 and 9 , the maximum diameter D O  of the opening  336  is different from the maximum diameter D A  of the aperture  278 . More specifically, the maximum diameter D O  of the opening  336  is greater than the maximum diameter D A  of the aperture  278 . However, it should be appreciated that, in other embodiments, the maximum diameter D O  of the opening  336  may be less than the maximum diameter D A  of the aperture  278 . Further, in another embodiment, the maximum diameter D O  of the opening  336  may be equal to the maximum diameter D A  of the aperture  278 . 
       FIGS. 10-15  illustrate movement of the valve member  320  within the cavity  318 . More specifically,  FIGS. 10, 11 and 15  depict the valve member  320  in a first position  400 ,  FIG. 12  depicts the valve member  320  in an intermediate third position  420 , and  FIGS. 13 and 14  depict the valve member in a second position  410 . As will be discussed below in more detail, the valve member  320  moves between the first and second positions  400 ,  410  during a drain cycle to remove air A from the discharge chamber  262 . More specifically, the valve member  320  removes the air A at the beginning of the drain cycle to reduce or eliminate the likelihood of cavitation within a drain pump (not shown), such as the drain pump  156  of  FIG. 2 . Further, removing the air A from the discharge chamber  262  improves the efficiency of the drain pump  156 , which translates into energy savings of the dishwasher appliance  100 . 
     As shown in  FIG. 11 , the valve member  320  defines a maximum diameter D S  that is less than the maximum diameter D C  of the cavity  318 . In addition, the maximum diameter D S  of the valve member  320  is greater than both the maximum diameter D A  of the aperture  278  and the maximum diameter D O  of the opening  336 . As such, movement of the valve member  320  is confined between the aperture  278  and the opening  336 , or more particularly the first and second positions  400 ,  410 . 
     In  FIG. 11 , the valve member  320  is shown in the first position  400 . In the first position  400 , a portion of the valve member  320  extends into the aperture  278 . More specifically, the valve member  320  contacts, or seals against, the inside edge  340  of the outer surface  260  to restrict fluid communication between the discharge chamber  262  and the cavity  318 . As such, when the valve member  320  is in the first position  400 , air A and water W in the discharge chamber  262  cannot enter the cavity  318  through the aperture  278 . 
     In  FIG. 12 , the valve member  320  is shown in the intermediate third position  420 . In the intermediate third position  420 , the valve member  320  is spaced apart from both the inside edge  340  of the aperture  278  and the inside edge  338  of the opening  336 . As such, air A from the discharge chamber  262  may enter the cavity  318  through the aperture  278  and subsequently exit the cavity  318  through the opening  336 . 
     When the valve member  320  is in the intermediate third position  420 , it should be appreciated that water W from the discharge chamber  262  may also enter the cavity  318 . However, unlike the air A, the water W does not subsequently exit the cavity  318  through the opening. Instead, a drain pump (not shown), such as the drain pump  156  of  FIG. 2 , draws water W back into discharge chamber  262  through the aperture  278  and subsequently removes water W from the discharge chamber  262  via the drain  158 . 
     In  FIGS. 13 and 14 , the valve member  420  is shown in the second position  410 . In the second position  410 , a portion of the valve member  320  extends into the opening  336 . More specifically, the valve member  320  contacts, or seals against, the inside edge  338  of the cap  330  to restrict fluid communication between the cavity  318  and the opening  336 . Accordingly, when the valve member  320  is in the second position  410 , water W cannot exit the cavity  318  through the opening  336 . As mentioned above, fluid communication between the aperture  278  and the cavity  318  occurs while the valve member  320  is in the second position  410 . However, the drain pump removes the fluid (that is, water W) from the cavity  318  via the aperture  278 . More specifically, the drain pump  156  draws the water W back into the discharge chamber  262  and subsequently removes the water W from the discharge chamber  262  via a drain conduit (not shown) connected to the drain  158 . 
     Referring now to  FIG. 15 , the valve member  320  moves from the second position  410  to the first position  400  once the drain pump has removed the water W from the cavity  318 . More specifically, the valve member  320  contacts the inside edge  340  of the outer surface  260 . As such, the valve member  320  restricts the flow of water W from the discharge chamber  262  to the cavity  318  via the aperture  278 . 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.