US20120118336A1

US20120118336A1 - Dishwasher with filter cleaning assembly

Info

Publication number: US20120118336A1
Application number: US12/947,226
Authority: US
Inventors: Rodney M. Welch
Original assignee: Whirlpool Corp
Current assignee: Whirlpool Corp
Priority date: 2010-11-16
Filing date: 2010-11-16
Publication date: 2012-05-17
Also published as: DE102011053666A1

Abstract

A dishwasher having a filter system to remove soils from the recirculated liquid and a heating element for pyrolytically cleaning the soils from the filter system.

Description

BACKGROUND OF THE INVENTION

Contemporary treating appliances, an example of which includes automatic dishwashers, have a filter system in the wash tub to filter out and drain various food soils released from utensils and the treating chamber. The filter system may include a screen filter against which the food soils may be trapped. To clean the filter system of the trapped food soils, the filter may be removed by a user from the dishwasher.

SUMMARY OF THE INVENTION

The invention relates to a dishwasher having a wash tub at least partially defining a treating chamber, a rack located within the treating chamber, at least one sprayer providing a spray of liquid, a liquid recirculation system providing liquid to the at least one sprayer, a filter having a housing defining an interior fluidly coupled with the liquid recirculation system to filter the recirculated liquid, and a pyrolytic heating element extending into the interior of the filter, wherein the heating element pyrolyzes soil material caught on the filter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic, side view of a dishwasher having a pyrolytically cleaned filter according to a first embodiment of the invention.

FIG. 2 is a schematic, side view of a lower portion of the dishwasher of FIG. 1.

FIG. 3 is a controller of the dishwasher of FIG. 1.

FIG. 4 is a flow chart for operating the dishwasher according to a second embodiment of the invention.

FIG. 5 is a schematic, cross-sectional view of a lower portion of a dishwasher, similar to FIG. 1, according to a third embodiment of the invention, with an alternative pump assembly having a cylindrical filter, which is pyrolytically cleaned by a pyrolytic heating element.

FIG. 6 is a schematic, side view of a lower portion of the dishwasher, similar to FIG. 1, according to a fourth embodiment of the invention, but showing an alternative pyrolytic heating element.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The invention is generally directed toward a dishwasher with a filter cleaning system. One aspect of the invention is to have a heating element in the interior of the filter system to pyrolyze any fibrous food soils on the filter system. A beneficial result of the pyrolytic cleaning is that the filter assembly does not need to be removable, which simplifies the filter assembly. Another beneficial result is that the dishwasher may automatically initiate the cleaning of the filter and not have to rely on the user to remember to clean the filter.
FIG. 1 is a schematic, side view of a treating appliance according to a first embodiment of the invention, which is illustrated in the context of a dishwasher 10. While the illustrated treating appliance is a dishwasher 10, other treating appliances are possible, non-limiting examples of which include other types of dishwashing units, such as in-sink dishwashers, multi-tub dishwashers, or drawer-type dishwashers. The dishwasher 10, which shares many features of a conventional automated dishwasher, will not be described in detail herein except as necessary for a complete understanding of the invention.
The dishwasher 10 may have a cabinet 12 defining an interior, which is accessible through a door 13. The cabinet 12 may comprise a chassis or frame to which panels may be mounted. For built-in dishwashers, the outer panels are typically not needed. At least one wash tub 14 is provided within the interior of the cabinet 12 and at least partially defines a treating chamber 16 to receive and treat utensils according to a cycle of operation, which may be a wash cycle. The wash tub 14 may have an open face that is closed by the door 13.
For purposes of this description, the term “utensil(s)” is intended to be generic to any item, single or plural, that may be treated in the dishwasher 10, including, without limitation; dishes, plates, pots, bowls, pans, glassware, and tableware.
One or more utensil racks, such as a lower utensil rack 18 and an upper utensil rack 20 may be provided in the treating chamber 16. The racks 18, 20 hold utensils (not shown) that may be treated in the treating chamber 16. The racks 18, 20 may be slid in and out of the treating chamber 16 through the opening closed by the door 13.
A chemistry dispenser 22 may be provided for dispensing a treating chemistry, which can include detergent and/or rinse aid, into the treating chamber 16. As illustrated, the chemistry dispenser 22 may be located on an inside surface of the door 13. Alternatively, the chemistry dispenser 22 may be located anywhere inside the wash tub 14 or in the cover (not shown). It will be understood that depending on the type of dishwasher and the type of treating chemistry used, the chemistry dispenser 22 may be incorporated into one dispensing mechanism. The chemistry dispenser 22 may be of a single-use dispenser, which stores a single dose of treating chemistry, or a bulk dispenser, which stores multiple doses of treating chemistry. In the case of bulk dispensing, the treating chemistry can be selectively dispensed into the treating chamber 16 in a regulated quantity and at a predetermined time or multiple times during a cycle of operation. A common chemistry dispenser 22 is a single-use dispenser mounted to an inside surface of a door or any wall of a cabinet 12. The dispenser may have a door that automatically opens during a washing phase.
A heating element 24 may be positioned in the lower portion of the wash tub 14 or sump 34 to selectively provide heat energy to the liquid collected in the sump 34 or the lower portion of the wash tub 14. The heating element 24 may be an immersion heater in direct contact with liquid in the lower portion of the wash tub 14 to provide the liquid with a predetermined amount of heat energy. For example, the heating element 24 may have at least a metallic tube and an electric resistance heating element inside the metallic tube, with any shape or configuration, two-dimensional or three-dimensional, inside the wash tub, such as a circular, tubular, meandering or combination thereof. The heating element 24 may be configured to be provided with multiple electric power levels.
A temperature sensor such as a thermistor 26 may be provided in the sump 34 to provide an output that is indicative of the temperature of any fluid, liquid or air, in the sump 34.
A liquid recirculation system is provided for recirculating liquid from the treating chamber 16 to at least one or more liquid sprayers, which are illustrated in the form of lower, mid, and upper level spray arms 28, 30, 32 as part of a wash cycle for treating any utensils supported within the racks 18, 20. The liquid sprayers are provided within the treating chamber 16 and are oriented relative to the racks 18, 20 such that liquid sprayed from the spray arms 28, 30, 32 may be directed into one or more of the racks 18, 20.
It should be noted that the stacked arrangement of the utensil racks and the spray arm assemblies are not limiting to the invention, and merely serve to illustrate the invention. For example, the invention may be implemented in a stacked arrangement having a silverware basket, the lower and upper utensil rack, and with upper, middle, and lower level spray arm assemblies having spray heads for the silverware basket alternatively arranged in between the lower and upper utensil rack.
The liquid recirculation system further comprises a sump 34 to collect by gravity liquid sprayed within the treating chamber 16. The sump 34 is illustrated as being formed with or affixed to a lower portion of the wash tub 14 to collect liquid that may be supplied into or circulated in the wash tub 14 during, before or after a cycle of operation. However, the sump 34 may be remote from the wash tub 14 and fluidly coupled by suitable fluid conduits.
The liquid recirculation system further comprises a pump assembly 36 fluidly coupled to the sump 34 by a sump conduit 38 and control valve 39, and as illustrated, may include a wash pump 40 and a drain pump 42. The wash pump 40 fluidly couples the sump 34 to the spray arm assemblies 28, 30, 32 through a spray arm supply conduit 44 and a control valve 45 to recirculate liquid that collects in the sump 34 to the spray arm assemblies 28, 30, 32 for spraying on the racks 18, 20. The drain pump 42 fluidly couples the sump 34 to a drain conduit 46 for draining liquid collected in the sump 34 through the filter drain conduit 66 and a control valve 68 to a household drain, such as a sewer line, or the like. The spray arm assemblies 28, 30, 32 may have at least one or more outlets (not shown) fluidly coupled to the spray arm supply conduit 44 to be provided with a liquid of spray from the sump 34
While the pump assembly 36 may include the wash pump 40 and the drain pump 42, in an alternative embodiment, the pump assembly 36 may include a single pump, which may be operated to supply liquid to either the drain conduit 46 or the spray arm support conduit 44, such as by rotating in opposite directions or by valves.
The liquid recirculation system further comprises a water supply conduit 48 fluidly coupling a household water supply to the sump 34. A control valve 50 may control the flow of water from the household water supply to the sump 34.
As illustrated, a filter system 58 may be positioned in fluid communication with the liquid recirculation system, such as in the sump 34, to filter the liquid as it is recirculated from the treating chamber 16 back to the sprayers.
Referring to FIG. 2, the filter system 58 comprises a sieve wall 64 overlying the sump 34 and a fine filter 59 removably received within an opening of the sieve wall 64. The sieve wall 64 in the form of a mesh that spans the sump 34 such that an outer periphery of the sieve wall 64 may rest on a portion of the wash tub 14.
The fine filter 59 has a housing 60 defining an interior 61 accessible through a top opening 63 that is fluidly coupled to the treating chamber 16. The housing 60 terminates in a grate 62 that extends above the sieve wall 64. The sieve wall 64 may have openings with a similar size to the fine filter 59 while their openings sizes may be dissimilar. The grate 62 prevents large particles caught on the sieve wall 64 from entering the opening 63 of the fine filter 59.
As illustrated, the housing 60 is cylindrical. However, any other shapes may be used. The housing 60 defines a frame with multiple openings and a fine mesh screen may be mounted to the frame. The housing 60 defines a body axis 65, which in the case of a cylinder is a central axis that is spaced equidistant from the frame. While illustrated as non-rotational and removably mounted, the fine filter 59 may be rotatable, such as about the body axis, and it may be non-removable.
The side of the housing 60 is fluidly coupled to the sump conduit 38 via the surrounding sump 34. This configuration provides for liquid entering the interior 61 to pass through the fine mesh screen to filter the liquid prior to being recirculated. The bottom of the housing 60 is fluidly coupled to the filter drain conduit 66, such as by providing an opening in housing 60 or fine mesh screen such that the interior 61 of the housing 60 may be drained through the filter drain conduit 66. This permits many of the soils trapped in the interior 61 to be removed during draining. However, fibrous material has a tendency to remain affixed to the interior of the fine filter 59 even after draining.
A pyrolytic cleaning system 70 is provided to clean the fine filter 59 of any collected soils, especially the removal of the fibrous material. The pyrolytic cleaning system 70 may include a pyrolytic heating element 72, which extends into the interior 61 of the fine filter 59. For example, the pyrolytic heating element 72 may be a solid cylinder, such as a wire, that projects through the bottom of the fine filter 59 into the interior 61. In this configuration, the pyrolytic heating element 72 may extend along the body axis 65 on the bottom of the housing 60. It is noted that the heating element 72 and the housing 60 may be structurally configured such that the distance from the surface of the pyrolytic heating element 72 to the surrounding housing 60 would be uniform and the entire housing 60 may be uniformly heated.
In another embodiment, the pyrolytic heating element 72 may be horizontally arranged in the interior of the filter system 58 such that the longitudinal side of the heating element 72 may be parallel to the bottom of the filter system 58, which will be described in detail in FIG. 5.
Similar to the heating element 24 described above, the pyrolytic heating element 72 may be an immersion heating element. The pyrolytic heating element 72 may also be configured to provide multiple electric power levels. That said, it is contemplated that a power level of around 60 watts is sufficient for the pyrolytic heating element 72, whereas the heating element 24 is around 800 watts. A thermistor 74 may be provided next to the filter system 58 to monitor the temperature of the housing 60.
The dishwasher 10 may further comprise a controller 80 coupled to various components and sensors for controlling the flow and condition of the liquid to implement a wash cycle. As best seen in FIG. 3, the controller 80 may be provided with a memory 82 and a central processing unit CPU 84. The memory 82 may be used for storing control software that may be executed by the CPU 84 in completing a cycle of operation using the dishwasher 10 and any additional software. For example, the memory 84 may store one or more pre-programmed cycles of operation that may be selected by a user and completed by the dishwasher 10. Non-limiting examples of cycles include normal, light/china, heavy/pots and pans, and rinse only. The memory 82 may also be used to store information, such as a database or table, and to store data received from one or more components of the dishwasher 10 that may be communicably coupled with the controller 80.
The controller 80 may be communicably and/or operationally coupled to one or more components to receive an output signal from the components and control the operation of the dishwasher 10 to implement one or more cycles of operation. A user interface 86 may be provided to enable the user to input commands to the controller 80 and receive information about a specific treatment cycle 86. The user interface 86 may be provided on the dishwasher 10 and operably coupled with the controller 80. Alternatively, the user interface 86 may be provided on the front of the cabinet 12, or on the outer panel of the door 13, and may include operational controls such as dials, lights, switches, and displays enabling a user to input commands to the controller 80 and receive information about the selected cleaning cycle and operating parameters.
The controller 80 may be operably coupled with one or more components of the dishwasher 10 for communicating with and controlling the operation of the components to complete a cycle of operation. For example, the controller 80 may be coupled with the heating elements 24, 72 for heating the wash liquid or filter system during a cycle of operation, or components of the liquid spraying system including the pump assembly 36 such as the wash pump 40 and drain pump 42, chemistry dispenser 22 for detergent or rinse aid, and control valves 39, 45, 50, 68 for controlling the flow of wash liquid of the dishwasher 10 during a cycle of operation.
The controller 80 may also receive input from one or more sensors for use in controlling the components, such as thermistors 26, 74. The controller 80 may also receive inputs from one or more other sensors, which are known in the art and not shown for simplicity. Non-limiting examples of other sensors that may be communicably coupled with the controller 80 include a temperature sensor, a pH sensor, a turbidity sensor, a moisture sensor, a door sensor, a chemical sensor, a detergent and rinse aid presence/type sensor(s).
In operation, water may be provided to the wash tub 14 from the water supply conduit 48 from the wall through the control valve 50. The water may be mixed with a treating chemistry in the wash tub 14 to form a wash liquid. The wash liquid may recirculate in the wash tub 14 to remove any food soils coupled to the utensils or the interior of the wash tub 14. The wash liquid may be collected in the lower portion of the wash tub 14 by gravity through the sieve wall 64 coupled to the lower portion of the wash tub 14. Alternatively, the wash liquid may pass through the grate 62 and housing 60 to be received in the sump 34 or the lower portion of the wash tub 14. The food soils with the sizes equal to or less than the openings of the housing 60 and/or the sieve wall 64 may pass through the openings and collect in the sump 34 for further recirculation in the current or subsequent wash phase.
Once the wash liquid collects in the sump 34, the wash liquid may be supplied to the wash pump 40 through the sump conduit 38 and control valve 39. The wash liquid may be then supplied to the wash tub 14 by the wash pump 40 through the spray arm supply conduit 44 and the control valve 45 to provide a liquid of spray to the utensils in the racks 18, 20.
While the food soil passing through the openings collects in the sump 34, the food soil with the sizes greater than the opening of the sieve wall 64 may not pass the sieve wall 64. Instead, the food soil may stay on the sieve wall 64. Alternatively, the food soil may move on the sieve wall 64 during recirculation until the soils are received by the housing 60 through openings of the grate 62. The food soil, such as fibrous food soil, received in the housing 60 may be trapped on the housing 60 by an inflow of the wash liquid into the housing 60 as well as residing within the interior 61.
The food soil in the filter system 58 may be drained outside the dishwasher 10 through the control valve 68 and the drain conduit 46. The frequency and time of drainage of the food soil through the control valve 68 may be determined by the controller 80. For example, a cycle of operation may be programmed such that the food soil may drain only in the pre-wash and/or wash phase during an operation of the dishwasher 10.
The pyrolytic heating element 72 may be implemented as desired for cleaning the filter 59. It is contemplated that under normal circumstance, the pyrolytic heating element 72 will be energized when liquid is not being recirculated and/or liquid has been drained. Under these conditions, to the extent any liquid remains in the sump 34, it will be insufficient to interfere with the radiant heat from the pyrolytic heating element 72. When the heat energy radiated from the pyrolytic heating element 72 reaches the housing 60 and food soil that is coupled to the housing 60, the heat energy may pyrolyze the food soil such as fibrous food soil may turn into ashes including mainly carbon. The electric power level of heat energy applied to the housing 60 and correspondingly to the food soil may be configured to vary in multiple levels. For example, for heavy food soil caught up with the housing 60, the heating element 72 may be configured to provide more heat energy to completely pyrolyze any heavy food soils. The ashes may not have enough bonding strength to stay coupled to the housing 60, and almost all of the ashes may be decoupled from the housing 60. The ashes still coupled to the housing 60 may be easily removed from the housing 60 only by a mechanical impact of the wash liquid flowing into the interior 61 of the housing 60 from the treating chamber 16, which may be provided by either recirculation or draining of the liquid.
FIG. 4 is a flow chart of one possible implementation of the pyrolytic cleaning system 70 incorporated into a cycle of operation for the dishwasher 10 according to a second embodiment of the invention. The sequence of steps depicted in FIG. 4 is for illustrative purposes only, and is not meant to limit the method in any way as it is understood that the steps may proceed in a different logical order, additional or intervening steps may be included, or described steps may be divided into multiple steps, without detracting from the invention. The method may be incorporated into a cycle of operation for the dishwasher 10, such as prior to or as part of any phase of the wash cycle, such as a wash phase, rinse phase, and drying phase. The method may also be a stand-alone cycle. It is noted that the method may be used with or without the utensils placed within the treating chamber 18.
The method 400 may begin at 402 by implementing the wash phase. It is assumed that the utensils are already loaded in the racks. The wash phase provides a recirculated spray of liquid to the utensils stored in at least one of the racks 18, 20 in the treating chamber 18 to clean the utensils according to a cycle of operation selected by the user interface 86 or automatically selected by controller 80. The wash phase may also include draining the wash liquid outside the wash tub 14 after the completion of the spraying. The wash phase may also include providing the chemistry dispenser 22, such as a bulk dispensing system, with one or more treating chemistries inside the chemistry dispenser 22.
For some cycles of operation, the wash phase may include a pre-wash phase and main-wash, where at least one of the water and the treating chemistry such as detergent or other treating aids may be provided to the utensils to complete the pre-wash and/or main wash. In this manner, the wash phase may include multiple washing phases based on different treating chemistries or repeated use of the same chemistry, with or without intervening draining phases.
It is also noted that the wash phase may include monitoring the characteristics of the wash liquid using one or more sensors or components of the dishwasher 10 to send any output signals indicative of the operating condition of the wash phase to the controller 80 such that the controller 80 may communicably control or complete the operation of the dishwasher 10.
At 404, the rinse phase may typically follow the wash phase. The rinse phase may include providing rinse liquid such as fresh water or a fresh treating chemistry-water solution to the treating chamber 16. The rinse liquid may be recirculated through the wash pump 40 and the spray arm supply conduit 44 to the utensils stored in the treating chamber 18.
The rinse phase may also include monitoring the physical and/or chemical characteristics of the liquid before, during, or after the recirculation step using one or more sensors or components. Similar to the wash phase, the rinse phase may include multiple rinsing phases using at least one of treating aids and water, with or without intervening draining. It is noted that the wash phase and the rinse phase may be iterated multiple times according to a cycle of operation.
At 406, a drying phase may be implemented after the wash phase. Similar to 404, the drying phase may be typically performed using the heating element 24 located in the lower portion of the wash tub 14. The heating element 24 may be selectively energized or de-energized to impart heat energy to the treating chamber 16 to evaporate any residual liquid from the surface of utensils in the treating chamber 16.
Drying conditions such as drying temperature and/or duration time for drying phase may be selected from a cycle of operation by the controller 80. Alternatively, the drying conditions may be selected by the user through the user interface 86 by pushing a button or rotating a knob.
At 408, a pyrolytic phase may be implemented following the drying phase. During the pyrolytic phase, liquid has been removed from the sump 34. This permits the radiant heat from the pyrolytic heating element 72 to be directed to any soils, especially fibrous materials, still remaining on the fine filter 59. The duration of the pyrolytic phase is sufficient for the output of the pyrolytic heating element 72 to reduce the fibrous materials to ashes or another easily washed away or dissolvable form. Once sufficient heating is applied, liquid may be introduced and drained to flush the ashes from the fine filter 59. This process may be repeated as desired.
While the pyrolytic phase is described as following the drying phase, it is possible for the pyrolytic phase to be implemented concurrently with the drying phase. Alternatively, the pyrolytic phase may be a stand-alone phase or cycle, and may be implemented automatically by the controller 80 or it may be selected and implemented by the user through the user interface 86.
The pyrolytic phase may be incorporated at other locations within a cycle of operation. For example, the pyrolytic phase may be implemented during, before or after any pre-wash, wash, dry phase of a cycle of operation. Further, the pyrolytic phase may be implemented every time a cycle of operation is implemented. Alternatively, the pyrolytic phase may be implemented after a predetermined number of cycles of operation, which may be set by the controller based on the sensed soil loads or which may be entered by the user through the user interface 86.
It is noted that the pyrolytic phase may be controlled over certain cycles of operations. For example, the pyrolytic phase may be prevented from performing an operation when the controller 80 implements the cycle of, for example, light/china that may include the utensils that are sensitive to the heat energy, such as china or glass.
The pyrolytic phase using the pyrolytic heating element 72 adds several benefits to the filter system 58 over other conventional filter systems. Typical filter systems may require removing the filter system 58 from the dishwasher 10 on a regular basis to remove any food soil coupled to the filter system 58, which may take time and can be cumbersome. By using the pyrolytic heating element 72 operably coupled to the filter system 58, consumers may not need to remove the filter system 72 from the dishwasher 10, or at least not as often.
FIG. 5 illustrates a schematic, cross-sectional view of a lower portion of a dishwasher, similar to FIG. 1, according to a third embodiment of the invention, with an alternative pump assembly 136 having a rotatable, cylindrical filter 158, which is pyrolytically cleaned by the pyrolytic heating element 172. The alternative pump assembly 136 is in the form of a module having a housing 88 defining a remote sump 134 to which a drain pump 142 and wash pump 140 are mounted. An air supply conduit 90 may wrap around the housing 88, with a blower (not shown) located at the opposite side of the alternative pump assembly 136. The air supply conduit may be used to provide forced air to the treating chamber 16 during drying. A heating element 124 may be provided within the air supply conduit 90 and wrapped around the housing 88 to provide heat for either the liquid in the sump 134 or the air in the air supply conduit 90.
The housing 88 may have a housing inlet 92 and a housing outlet 94. The cylindrical filter 158 is located in the housing 88 and fluidly disposed between the housing inlet 92 and housing outlet 94 to filter liquid passing through the sump 134. Because the housing 88 is located within the cabinet 12 but physically remote from the wash tub 14, the cylindrical filter 158 is not directly exposed to the wash tub 14. In this manner, the housing 88 and cylindrical filter 158 may be thought of as defining a filter unit, which is separate and remote from the wash tub 14.
The cylindrical filter 158 may be a fine filter, which may be utilized to remove smaller particles from the liquid. The cylindrical filter 158 may be a rotating filter and such a rotating filter is set forth in detail in U.S. patent application Ser. No. 12/643,394, filed Dec. 21, 2009, and titled “Rotating Drum Filter for a Dishwashing Machine,” which is incorporated herein by reference in its entirety. The rotating filter according to U.S. patent application Ser. No. 12/643,394 may be operably coupled to an impeller 96 of the wash pump 140 such that when the impeller 96 rotates the cylindrical filter 158 is also rotated.
The wash pump 140 may be adapted to draw liquid from the housing outlet 94 in through a sump conduit 138 and to pump the liquid out through a spray arm supply conduit 144 to the sprayers (not shown) in the tub 14. The directional arrows in FIG. 5 illustrate the liquid flowing into the housing 88 and the sump 134 where it may then be drawn through the cylindrical filter 158 and the wash pump 140 when the wash pump 140 is operated. In this manner, the cylindrical filter 158 fluidly separates the housing 88 from the sump conduit 138 of the wash pump 140. The drain pump 142 may also be fluidly coupled to the housing 88. The drain pump 142 may include an impeller 98 which may draw liquid from the housing 88 and pump it through a drain conduit (not shown) to a household drain. The cylindrical filter 158 is not fluidly disposed between the housing inlet 92 and the drain conduit such that unfiltered liquid may be removed from the sump 134.
The pump assembly 136 may be fluidly coupled to the recirculation system in the same manner as the first embodiment and controlled in the same manner, including the operation of the pyrolytic heating element.
FIG. 6 is a schematic, side view of a lower portion of the dishwasher 10, similar to FIG. 1, according to a fourth embodiment of the invention, but showing an alternative pyrolytic heating element. The elements in common with FIG. 1 are referred to with the same reference numerals. The dishwasher 10 may have identical mechanical structure as the dishwasher 10 described in FIG. 1, with a noticeable difference being in the configuration of the heating element 224 operably coupled to the filter system 58. As illustrated, a portion of the heating element 224 may be configured to extend downward into the interior 61 of the filter system 58 through the opening 63, with the portion of the heating element 224 being operably coupled to the bottom of or floating in the filter system 58. The downwardly extended portion of the heating element 224 may be positioned at or near the center of the bottom of the filter system 58, similar to FIG. 1, when viewed from the top. Both ends of the heating element 224 may extend through a portion of the wash tub 14 to operably couple the heating element 224 to the controller 80.
In this embodiment, when the heating element 224 is energized, the portion of the heating element 224 extending downward into the filter system 58 may be also energized. Therefore, every time the heating element 224 is energized for heating the wash liquid or drying utensils in the treating chamber 16, downwardly extending portion of the heating element 224, operably coupled to the filter system 58, may be also energized to heat the surrounding filter system 58. Depending on the electric power levels applied to the heating element 224, the heat energy from the heating element 224 may pyrolyze food soils, such as fibrous food soils, caught on the housing 60 during an operation of the dishwasher 10.
This embodiment would have multiple benefits over a conventional filter system. Similar to the embodiment shown in FIG. 1, the user may not need to remove the filter system from the dishwasher to clean the food soil off the filter system. Further, the dishwasher according to the present embodiment may be configured to have simpler mechanical structure due to the reduction of the number of components such as the pyrolytic heating element 72.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. Reasonable variation and modification are possible within the scope of the foregoing disclosure and drawings without departing from the spirit of the invention which is defined in the appended claims.

Claims

1. A dishwasher configured to treat utensils according to an automatic cycle of operation, comprising:

a tub at least partially defining a treating chamber in which utensils are received for treatment;

at least one rack located within the treating chamber for supporting the utensils within the treating chamber;

at least one sprayer providing a spray of liquid into the treating chamber;

a liquid recirculation system for recirculating liquid from the treating chamber to the at least one sprayer;

a filter having a housing defining an interior in fluid communication with the liquid recirculation system to filter the recirculated liquid; and

a pyrolytic heating element extending into the interior of the filter;

wherein an operation of the heating element pyrolyzes soil material caught on the filter.

2. The dishwasher of claim 1 wherein the housing has a body axis and the pyrolytic heating element extends along the body axis.

3. The dishwasher of claim 2 wherein the housing comprises a screen filter that is spaced from the body axis.

4. The dishwasher of claim 2 wherein the housing comprises a cylinder having a longitudinal axis defining the body axis.

5. The dishwasher of claim 2 wherein the filter comprises a closed end and the pyrolytic heating element extends upwardly into the interior from the closed end.

6. The dishwasher of claim 1 wherein the filter comprises an open top and the pyrolytic heating element extends downwardly into the interior through the open top.

7. The dishwasher of claim 6 further comprising a wash liquid heating element located within the treating chamber to heat the recirculated liquid and the pyrolytic heating element comprises part of the wash liquid heating element.

8. The dishwasher of claim 7 wherein the wash liquid heating element comprises a downwardly extending folded portion forming the pyrolytic heating element.

9. The dishwasher of claim 8 wherein the tub comprises a bottom wall and the wash liquid heating element overlies the bottom wall, with a portion extending into the interior of the housing.

10. The dishwasher of claim 1 wherein the filter rotates about a rotational axis.

11. The dishwasher of claim 10 wherein the pyrolytic heating element extends along the rotational axis.

12. The dishwasher of claim 10 wherein the liquid recirculation system further comprises a sump housing and the filter is located in a sump housing.

13. The dishwasher of claim 12 wherein the sump housing is remote from the tub.

14. The dishwasher of claim 10 wherein the liquid recirculation system comprises a pump with an impeller and the filter has one end operably coupled to the impeller such that rotation of the impeller rotates the filter.

15. The dishwasher of claim 1 wherein the tub comprises a filter recess forming part of the liquid recirculation system and the filter is located within the filter recess.

16. The dishwasher of claim 15 wherein the filter is removably mounted within the filter recess.