Patent Application
20110214695
The present disclosure relates generally to domestic dishwashers, and more particularly to a dishwasher that has a separate sump for a concentrated fluid supply.
A dishwasher machine is a domestic appliance into which dishes and other cooking and eating wares (e.g., plates, bowls, glasses, flatware, pots, pans, bowls, etcetera) are placed to be washed. During a wash cycle, a sump in the bottom of the dishwasher tub fills with water. A heating element inside the tub heats the water. Detergent released from a dispenser mixes with the heated water. Sprayers circulate the water and detergent mixture over the dishes. The wash cycle is followed by a rinse cycle, in which the sprayers circulate clean water over the dishes. At the end of each cycle, the used liquid is drained from the tub.
Some dishwashers have multiple washing and rinsing periods within a complete wash cycle. For example, some dishwashers provide washing periods in which wash liquid is directed to a specific area of the tub, such as an area where heavily soiled pots and dishes tend to be located.
According to one aspect, a dishwashing method performed by a dishwashing machine includes directing fluid into a first sump located in a bottom wall of a tub of the dishwashing machine, directing wash fluid from the first sump to a spray system located in the tub, directing a second volume of fluid into a second sump located in the bottom wall of the tub and spaced from the first sump, creating a concentrated wash fluid in the second sump, where the concentrated wash fluid has a higher wash chemistry concentration than the wash fluid from the first sump, and directing the concentrated wash fluid to the spray system.
The method may include draining the concentrated wash fluid from the tub, or recirculating the concentrated wash fluid to the spray system. Further, the method may include directing the wash fluid from the first sump to a first sprayer of the spray system and directing the concentrated wash fluid from the second sump to a second sprayer of the spray system.
The method may include selectively directing fluid from one of the first and second sumps to the other of the first and second sumps through a communication chamber located underneath the tub. The method may include closing a lid to cover the second sump. Further, the method may include sensing the concentration of wash chemistry in the second sump and sending an output signal indicative of the sensed wash chemistry concentration to an electronic control unit of the dishwashing machine.
According to another aspect of this disclosure, a dishwashing method performed by a dishwashing machine includes directing a first volume of fluid into a first sump located in a bottom wall of a tub of the dishwashing machine, directing wash fluid from the first sump to a first fluid delivery device located in the tub, directing a second volume of fluid into a second sump located in the bottom wall of the tub and spaced from the first sump, creating a concentrated wash fluid in the second sump, the concentrated wash fluid having a higher wash chemistry concentration than the wash fluid in the first sump, and directing the concentrated wash fluid to a second fluid delivery device.
The method may include activating a wash chemistry activation device located in the second sump. The method may include receiving fluid from the first sump into the second sump. The method may include receiving fluid from a fluid supply located outside the tub into the second sump. The method may include releasing a gas into the second sump.
The method may include activating an indicator on the dishwashing machine, where the indicator indicates a status of the second sump. The method may include directing by the second fluid delivery device the concentrated wash fluid to a wash area in the tub. The method may include activating at least one of a foamer, nebulizer, fan, sprayer, mister, and injector.
The method may include opening a lid of the second sump. The method may include selectively opening and closing by an electronic control unit a lid of the second sump. The method may include selectively opening and closing a valve coupled to the second sump. The method may include sensing the concentration of wash chemistry in the second sump and sending an output signal indicative of the sensed wash chemistry concentration to an electronic control unit of the dishwashing machine.
The detailed description particularly refers to the following figures, in which:
While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Referring to
As shown schematically in
A door 24 is hinged to the lower front edge of the tub 12. As shown in
A control panel 26 is supported by the door 24. The control panel 26 includes a number of controls 28, such as buttons or knobs, which enable a user to activate or deactivate a wash cycle of the dishwasher 10, or to perform other functions. The control panel 26 may also include one or more indicators 22, which communicate a status of a component or feature of the dishwasher, or other information, to the user. For example, one of the indicators 22 may be illuminated when the dishwasher or a feature thereof (e.g., a pre-treating feature) is activated and not illuminated when the feature is not activated, or vice versa. Another of the indicators 22 may include a number of illuminatable sections, such that the section or sections that are illuminated relative to the whole indicates a status of a component of the dishwasher (e.g. a sump or dispenser being full, partially full, or empty). A handle 30 facilitates opening and closing of the door 24.
The tub 12 includes a bottom wall 40 and a top wall 42. A back wall 38 and a pair of side walls 36 extend upwardly from the bottom wall 40 to the top wall 42 to define the wash chamber 14.
Inside the wash chamber 14, the bottom wall 40 of the tub 12 has a pair of sumps 50, 52 formed (e.g. stamped) therein. Each of the sumps 50, 52 defines a reservoir that extends downwardly in a direction away from the bottom wall 40 of the tub 12. Each of the reservoirs holds a volume of wash fluid. The size of the reservoir defined by the sump 52 is smaller than the size of the reservoir defined by the sump 50. Thus, the sump 52 holds a smaller volume of wash fluid than does the sump 50.
The dishwasher 10 has a spray system that includes a number of sprayers 54, 56 positioned in the wash chamber 14. The spray system may include other sprayers, spray arms, or fluid delivery devices, alternatively or in addition to those shown and described herein.
At the start of a wash cycle, water enters the wash chamber 14 through an inlet 48. Portions of the bottom wall 40 of the tub 12 may be shaped (e.g. ridged, channeled or sloped downwardly) so that water is directed toward one or both of the sumps 50, 52 by the force of gravity.
Wash chemistry is released at the appropriate time from the dispensers 32, 34. Referring to
Typically, wash chemistry released from the dispenser 32 mixes with fluid in the sump 50. At the appropriate time (e.g., the beginning of a “normal” wash cycle), the pump 66 draws the wash fluid from the sump 50 and directs it to the sprayer 54 through a supply tube 58. The sprayer 54 directs the wash fluid through outlets 82 toward a wash area defined by the sprayed wash fluid. As illustrated, the sprayer 54 is a rotating spray arm that sprays wash fluid in an upward direction toward the dish racks 16, 18. As such, the wash area covered by the sprayer 54 typically includes the wash areas 88 and 90, and may also include portions of the wash area 86.
At the same time, or during another portion of the wash cycle (e.g. a pre-treating or post-treating phase), wash chemistry is released from the dispenser 34 and mixed with fluid in the sump 52. As illustrated, the dispenser 34 is mounted in the door 24 of the dishwasher 10. Alternatively, the dispenser 34 may be integrated into the sump 52 (i.e., as an open or closed cup, a cartridge receptacle, or the like). As another alternative, or in addition, wash chemistry released from the dispenser 32 could be mixed with fluid in the sump 52 at the appropriate time during the wash cycle, in which case, the dispenser 34 may be omitted.
In the sump 52, the wash chemistry mixes with a relatively small volume of water. In one example, the volume V2 of the sump 52 is at least one-third smaller than the volume V1 of the sump 50. In this example, the volume V2 is in the range of about one liter, while the volume V1 is in the range of about three to seven liters or more. In other versions, the volume V2 may be in the range of about 20 milliliters up to about 200 milliliters or up to about 2.5 liters. As a result, a highly concentrated wash fluid is created in the sump 52. For example, the sump 52 may provide a concentrated wash fluid in the range of about two to about five times that of the sump 50. In many instances, the concentrated wash fluid is a concentrated detergent and water mixture. However, the concentrated wash fluid could include a gas, vapor, fog, liquid (e.g. aqueous, non-aqueous polar, non-aqueous nonpolar), gel, or the like, or a combination of any of these. The sump 52 could also be used to create a concentrated rinsing agent rather than a concentrated cleaning agent. It is contemplated that any chemical composition suitable for use in the apparatus and methods described herein may be incorporated into the wash fluid.
The pump assembly 62 draws the concentrated wash fluid from the sump 52 and directs it to the sprayer 56 through a supply tube 60. The sprayer 56 directs the concentrated wash fluid through outlets 56 outwardly toward the wash area 90. The wash area 90 typically includes a portion of the wash area 88, but may include portions of the wash area 86. For instance, the wash area 90 could include a utensil basket or a stemware rack. As illustrated, the wash area 90 is smaller than the wash areas 86, 88, but this need not be the case. Regardless of the size of the wash area 90, the chemical action of the concentrated wash fluid aids the mechanical action of the sprayer 56. The combined action may be useful in removing tough stains or baked-on soils from glasses, pots, dishes or other wares located in the wash area 90.
In the illustration of
Once the concentrated wash fluid is delivered to the wash area 90, it may be drained from the tub 12 by an outlet (not shown), or recirculated to the wash area 90 by the sump 52, the pump assembly 62, and the sprayer 56. The electronic control unit 78, 80, 108 sends electrical signals to the pump assembly 62, 64, 120 to control whether the wash cycle includes one or multiple applications of the concentrated wash fluid, as may be suitable or desired for a given configuration of the dishwasher 10.
As shown in
The pump assembly 62 and electronic control unit 78, along with the associated valves, wiring and plumbing, are located below the tub 12 in a machine compartment 32. The machine compartment 32 is sealed from the tub 12 in that water does not enter the machine compartment 32 during wash cycles.
The sumps 50, 52 may be connected to each other underneath the tub 12 (i.e., in the machine compartment 32) by a communication chamber 96 and a valve 98. The communication chamber 96 can be open or closed, depending upon the position of the valve 98. If the valve 98 is closed, then the sumps 50, 52 work independently of each other. If the valve 98 is open, then fluid can be passed from the sump 50 to the sump 52 and vice versa. The valve 98 may have additional positions that allow fluid to flow through the communication chamber 96 in only one direction at a time (e.g., from sump 50 to sump 52 or vice versa).
The communication chamber 96 is a supply tube, made of polypropylene, for example. The valve 98 is a straight-through valve, such as an electronically-controlled (e.g. solenoid) on-off valve. The electronic control unit 78 sends signals to the valve 98 to control its position.
In the embodiment of
An embodiment of a pump assembly 64 is shown schematically in
As illustrated, fluid from only one of the sumps 50, 52 is pumped out to the spray system at any given time. However, the valve 92 may be configured to assume intermediate positions (e.g. controlled by a variable-bleed solenoid), in which case fluid from both of the sumps 50, 52 is mixed according to a specified mixing ratio, which is programmed into the electronic control unit 80.
A valve 94 controls the destination of the fluid output by the pump 70. Depending on the position of the valve 94, fluid is directed to the sprayer 54 only, to the sprayer 56 only, or to both of the sprayers 54, 56. The valve 94 may be a diverter valve, rotating selector disk, or similar mechanism as will be understood by those skilled in the art.
As illustrated in
One or a number of sensors 104 may be integrated into the sump 52 to detect changes in the water level or the wash chemistry concentration, to detect a malfunction in the sump 52, or to obtain other information from the sump 52. The sensor output is transmitted to the electronic control unit 78, 80, 108. Computer logic at the electronic control unit 78, 80, 108 determines whether a response is required and if so, initiates the appropriate action in response to the sensor output. For example, if the sensor 104 detects a low chemistry concentration in the sump 52, the electronic control unit 78, 80, 108 may activate an LED or other visual indication to alert the user that chemistry needs to be added to the sump 52.
As another example, the sensor 104 may be a temperature sensor that measures the temperature of fluid in the sump 52. The electronic control unit 78, 80, 108 may be configured to control the valving 96, 112 based on temperature readings from the sensor 104. Alternatively or in addition, a temperature sensor may be positioned in the sump 50. In this way, the flow of fluid into the sump 52 may be controlled based on the temperature of the fluid in either the sump 50 or the sump 52. For example, fluid may be retained in the sump 50 or in the fluid supply 110 until it reaches a desired temperature (e.g. 70 degrees Fahrenheit or more). Once the fluid reaches the desired temperature, the electronic control unit 78, 80, 108 controls the valving 96, 112 to open the fluid flow into the sump 52.
In some embodiments, the electronic control unit 78, 80, 108 may include a timer (not shown). The timer may be used to coordinate dispensing of fluid from the sumps 50, 52. For example, dispensing of fluid from the sump 50 may be delayed relative to dispensing of fluid from the second sump 52, or vice versa. The delay may occur within the cycle or within a cycle element (e.g., wash, rinse, dry). The delay time may be in the range of about 5-30 minutes within a cycle element.
Also, the order of dispensing fluid from the sumps 50, 52 may be interchanged (e.g. dispensing from the sump 52, then dispensing from the second sump 50), based on the chemistry of the fluid in one or both of the sumps 50, 52 or another condition.
One or more chemical activation devices 106 may be provided in the sump 52. The device or devices 106 may be used to activate or aid the activation of chemistry in the sump 52. Such chemical activation devices 106 may include a source of ultraviolet radiation, electrolysis, heat, or other type of electromagnetic radiation, or a chemical catalyst, for example.
The fluid supply 110 retains a wash chemistry in an enclosed compartment. The wash chemistry is directed into the sump 52 at the appropriate time during a wash cycle by the fluid conduit and valving 112. The selective opening and closing of the valving 112 may be electronically controlled, e.g. by the control unit 78, as shown in
Fluid entering the sump 52 from the fluid supply 110 may be mixed with water and/or other substances in the sump 52 to create a wash chemistry mixture. For example, if the lid 102 is open, fluid entering the sump 52 from the fluid supply 110 may be mixed with water that enters the tub 12 via the inlet 48 and drains into the sump 52. Alternatively, if the lid 102 is closed, fluid from the fluid supply 110 may remain isolated from liquid and/or other substances in the tub 12, and be routed in its original form directly to the delivery device 118 (e.g. by a pump 114 and conduit 116 as shown in
The fluid delivery device 118 may be a conventional or a specially-configured spray device, but may also take the form of a foamer, mister, steamer, venturi, nebulizer, fan, injector, or other suitable device for directing wash fluid into the tub 12 or a portion thereof. Likewise, the pump 114 may be an air pump or other suitable mechanism for directing wash fluid from the sump 52 to the fluid delivery device 118. In some embodiments, the pump 114 may be eliminated entirely. For example, if the wash chemistry includes a gas, such as carbon dioxide, the force provided by the release of the gas into the sump 52 may be sufficient to direct the wash fluid to the fluid delivery device 118. As such, the fluid supply 110 may include a tank, cartridge, cylinder or other source of a gaseous fluid, such as carbon dioxide. As another example, heating the wash fluid in the sump 52 (e.g. by the chemical activation device 106) may be used to convert the wash fluid to a mist or vapor that flows through the delivery device 188.
A variety of different types and forms of chemistry may be used to create the wash fluid that is retained in the sump 52. As noted above, the chemistry may take the form of a liquid or non-liquid substance. The chemistry may initially be in the form of a solid (e.g. powder, crystals, or tablets) that dissolves or otherwise changes state in the sump 52.
Elements such as the valves 92, 94, 112, lids 100, 102, sensors 104, and activation devices 106, are generally in electrical communication with the electronic control unit (e.g., 78, 80, 108); however, electrical communication links are omitted from the drawings for clarity.
As will be understood by those skilled in the art, the electronic control units 78, 80, 108 include analog and/or digital circuitry to process electrical signals received from components of the dishwasher 10 and provide electrical control signals to components of the dishwasher 10. For example, the electronic control units 78, 80, 108 may comprise one or more microcontrollers that execute firmware routines to control the operation of the dishwasher 10.
There are many advantages of the present disclosure arising from the various features described herein. It will be noted that alternative embodiments of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the method, apparatus, and system that incorporate one or more of the features of the present invention and fall within the spirit and scope of the present disclosure as defined by the appended claims.
