Patent Publication Number: US-8529705-B2

Title: Method and apparatus of controlling the release of cleaning agents into a dishwasher cycle

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a dishwashing machine and more particularly to a mechanism and method of releasing cleaning agents into a dishwashing machine. 
     BACKGROUND 
     A dishwashing machine is a domestic appliance into which dishes and other cooking and eating wares (e.g., plates, bowls, glasses, flatware, pots, pans, bowls, and etceteras) are placed to be washed. During a dishwasher cycle, different cleaning agents are released to mix with fluid to form a wash chemistry to remove soil and food residues from the wares or a rinse chemistry to sanitize and/or dry the wares. Those cleaning agents may be primary or secondary cleaning agents that include, for example, a detergent, bleach, and/or chlorine. Additionally, the cleaning agents may be finishing cleaning agents such as rinse aid. 
     Multiple cleaning agents may be included in a single dishwashing product, which commonly takes the form of a tablet. U.S. Pat. No. 6,956,016 discloses an example of one such tablet and is incorporated expressly herein by reference. In one embodiment of U.S. Pat. No. 6,956,016, a single tablet has at least three different zones or pouches carrying at least three different cleaning agents (e.g., a primary cleaning agent, a secondary cleaning agent, and a finishing cleaning agent) to be introduced into the dishwasher cycle. Each pouch has a trigger mechanism for releasing separately each of the cleaning agents. The trigger mechanism is based on temperature but may also be based on pH, conductivity, pCa, pKa, redox potential, ionic concentration, enzymatic reaction, or time. 
     SUMMARY 
     According to one aspect, a dishwashing machine is disclosed. The dishwashing machine includes a tub defining a washing chamber, the tub having a sump formed in a bottom wall of the tub, a number of dish racks positioned in the washing chamber, and a pump operable to circulate fluid from the sump onto the number of dish racks. The dishwashing machine also includes a dispenser in fluid communication with the washing chamber. The dispenser is configured to receive a dishwashing tablet having a cleaning agent. The dishwashing machine also includes a sensor configured to identify the dishwashing tablet in the dispenser and generate an electrical output signal indicative of the identity of the dishwashing tablet. The dishwashing machine includes an electronic controller configured to receive the electrical output signal from the sensor, select a dishwasher cycle associated with the identity of the dishwashing tablet, and generate a control signal to operate the pump in accordance with the selected dishwasher cycle. 
     In some embodiments, the sensor may be configured to identify each of a plurality of cleaning agents of the dishwashing tablet, and the electronic controller may be configured to select the dishwasher cycle having a plurality of stages associated with the plurality of cleaning agents. In some embodiments, the dispenser may be configured to release the cleaning agent from the dishwashing tablet. 
     Additionally, in some embodiments, the dishwashing machine may include a second pump coupled to the dispenser, and the second pump may be operable to circulate fluid from the sump to the dispenser. The dishwashing machine may include an electric heater operable to heat fluid within the dispenser such that fluid temperature in the dispenser may be controlled separately from fluid temperature in the sump. In some embodiments, the dispenser may be operable to move fluid mixed with the released cleaning agent into the sump. In some embodiments, the sensor may be configured to read an RFID tag of the dishwashing tablet to identify the dishwashing tablet. 
     According to another aspect, a method of operating a dishwashing machine is disclosed. The method includes determining an identity of a dishwashing tablet positioned in a dispenser and generating an output signal indicative of the identity of the dishwashing tablet. The method also includes selecting a dishwasher cycle from an electronic memory device based on the identity of the dishwashing tablet in response to generation of the output signal and generating a control signal to operate a dishwashing machine in accordance with the selected dishwasher cycle so as to release a chemical agent from the dishwashing tablet into the dishwasher cycle at a predetermined release time. 
     In some embodiments, determining the identity of the dishwashing tablet may include reading an RFID tag of the dishwashing tablet to identify the dishwashing tablet. In some embodiments, selecting the dishwasher cycle may include selecting the dishwasher cycle from a plurality of dishwasher cycles stored in a look-up table. Additionally, in some embodiments, determining the identity of the dishwashing tablet may include sensing the identity of any of a plurality of cleaning agents sealed in the dishwashing tablet. 
     In some embodiments, selecting the dishwasher cycle may include determining a plurality of stages associated with the plurality of cleaning agents. In some embodiments, generating the control signal may include generating a first control signal to operate the dishwashing machine to supply a quantity of fluid to the dispenser and generating a second control signal to operate the dishwashing machine to heat the quantity of fluid in the dispenser so as to release the cleaning agent at a predetermined release time. 
     Additionally, in some embodiments, selecting the dishwasher cycle may include creating a customized dishwasher cycle based on the identity of the dishwashing tablet. In some embodiments, creating the customized dishwasher cycle may include selecting a plurality of stages and selecting a duration of each of the plurality of selected stages. In some embodiments, creating the customized dishwasher cycle may include selecting a predetermined release time for each of a plurality of cleaning agents. 
     According to another aspect, the method includes determining an identity of a dishwashing tablet in a dispenser and generating an output signal indicative of the identity of the dishwashing tablet, selecting a dishwasher cycle associated with the identity of the dishwashing tablet in response to generation of the output signal, generating a control signal to operate the dishwashing machine in accordance with the selected dishwasher cycle, supplying fluid to the dispenser so as to release a cleaning agent from the dishwashing tablet, and circulating fluid mixed with the cleaning agent from the dispenser to a washing chamber of the dishwashing machine at a predetermined release time. 
     In some embodiments, supplying fluid to the dispenser may include operating a pump to circulate a fluid from a sump to the dispenser, and heating fluid to a predetermined temperature so as to trigger the release of the cleaning agent from the dishwashing tablet into the dispenser. In some embodiments, determining the identity of the dishwashing tablet may include setting the predetermined release time for the cleaning agent. 
     In some embodiments, the method may also further include refining the selected dishwasher cycle based on sensor data recorded while fluid is being circulated throughout the dishwasher cycle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description particularly refers to the following figures, in which: 
         FIG. 1  is a perspective view of a dishwashing machine; 
         FIG. 2  is a simplified block diagram of one illustrative embodiment of a control system for the dishwashing machine of  FIG. 1 ; and 
         FIG. 3  is a simplified flow chart of a method of operating the dishwashing machine of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     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. 
     The present disclosure relates to a method of operating a dishwashing machine in accordance with a selected dishwasher cycle or a selected stage of a dishwasher cycle. The dishwasher cycle and stages are selected based on the identity of the tablet to be used in the dishwasher cycle. By use of the term “dishwasher cycle,” it is meant the operation of a dishwasher upon a set of soiled wares that produces a set of cleaned wares, starting with user activation, then proceeding continuously without the need for user intervention, and including at least one washing stage and at least one rinsing stage. A washing stage involves the application of a wash chemistry, typically water and detergent, to remove soils from the wares. A rinsing stage involves the application of a rinse chemistry, typically water and rinse aid, to remove the wash chemistry and prepare the wares for drying. A dishwasher cycle may optionally include other stages, such as a drying stage in which heat is applied after the rinsing stage. A dishwasher cycle may be interrupted by a user, such as by opening a door of the dishwasher, thereby causing the dishwasher cycle to pause until the door is closed. However, without such user intervention, the dishwasher cycle will proceed continuously. 
     At the completion of a dishwasher cycle, a user will remove the set of cleaned wares, either immediately or after a period of time. The period between the dishwasher cycles of the dishwasher thus begins when the user removes a set of cleaned wares from the dishwasher and ends when the user activates a subsequent dishwasher cycle. 
     Referring to  FIG. 1 , a dishwashing machine  10  (hereinafter dishwasher  10 ) is shown. The dishwasher  10  has a tub  12  that defines a washing chamber  14  into which a user may place dishes and other cooking and eating wares (e.g., plates, bowls, glasses, flatware, pots, pans, bowls, etc.) to be washed. The dishwasher  10  includes a number of racks  16  located in the tub  12 . An upper dish rack  16  is shown in  FIG. 1 ; although a lower dish rack is also included in the dishwasher  10 . A number of roller assemblies  18  are positioned between the dish racks  16  and the tub  12 . The roller assemblies  18  allow the dish racks  16  to extend from and retract into the tub  12 , thereby facilitating the loading and unloading of the dish racks  16 . The roller assemblies  18  include a number of rollers  20  that move along a corresponding support rail  22 . 
     A door  24  is hinged to the lower front edge of the tub  12 . The door  24  permits user access to the tub  12  to load and unload the dishwasher  10 . The door  24  also seals the front of the dishwasher  10  during a dishwasher cycle. A control panel  26  is located at the top of the door  24 . The control panel  26  includes a number of controls  28 , such as buttons and knobs, which are used to control the operation of the dishwasher  10 . A handle  30  is also included on the door  24 . The user may use the handle  30  to unlatch the door  24  such that the door  24  may be opened. 
     A machine compartment  32  is located below the tub  12 . The machine compartment  32  is sealed from the tub  12 . In other words, unlike the tub  12 , which is filled with fluid and exposed to spray during the dishwasher cycle, the machine compartment  32  does not fill with fluid and is not exposed to spray during the operation of the dishwasher  10 . The machine compartment  32  houses components such as the dishwasher&#39;s water pump(s) and valve(s), along with the associated wiring and plumbing. It should be noted that, although  FIG. 1  depicts a dishwasher  10  installed in a kitchen cabinet, portable dishwashers, which may be removably connected to a faucet, are also contemplated. 
     Referring now to  FIG. 2 , a control system  38  of the dishwasher  10 , according to one illustrative embodiment, is shown in a simplified block diagram. A sidewall of the tub  12  includes a water inlet opening  40 . The water inlet opening  40  directs water received from an external water source  46  (e.g., house water supply, kitchen faucet, etceteras) into the washing chamber  14 . A water inlet valve  44  positioned between the external water source  46  and the water inlet opening  40  may be selectively opened or closed to control the flow of water through the water inlet opening  40 . In some embodiments, the water inlet valve  44  may be an electromechanical valve, such as a solenoid-controlled valve, which opens and closes in response to a control signal. 
     The dishwasher  10  further includes a sump  50  which is formed (e.g., stamped) into a bottom wall  52  of the tub  12 . In particular, the sump  50  defines a reservoir that extends downwardly in a direction away from the washing chamber  14 . The bottom wall  52  of the tub  12  has a sloped configuration that directs the wash chemistry or the rinse chemistry into the sump  50 . The sump  50  is connected to an external drain  54  (e.g., house sewer line, kitchen sink, etceteras). A drain pump  56  is positioned between the sump  50  and the external drain  54 . A control signal may selectively energize the drain pump  56  to drain fluids from the sump  50  or de-energize (turn off) the drain pump  56  to retain fluids in the sump  50 . In other embodiments, an electromechanical valve, such as a solenoid-controlled valve, that opens and closes in response to a control signal may be used in place of drain pump  56 . 
     A wash pump  60  located in the machine compartment  32  is operable to circulate fluids in the sump  50  onto the dish racks  16  (not shown in  FIG. 2 ). The wash pump  60  is connected to a rotating spray arm  62  that sprays water and/or wash chemistry onto the dish racks  16  (and hence any wares positioned thereon). Additional rotating spray arms (not shown) are positioned above the spray arm  62 . It should also be appreciated that the dishwashing machine  10  may include other spray arms positioned at various locations in the tub  12 . The spray arm  62  has a number of nozzles (not shown). A control signal may selectively energize the wash pump  60  to supply fluid from the sump  50  to the spray arm  62 , which then exits the spray arm  62  through the nozzles. 
     A dispenser  70  is also included in the dishwasher  10 . The dispenser  70  has an inlet valve  72  coupled to a dispenser pump  74 . A reaction chamber  76  sized to receive a tablet  78  is positioned between the inlet valve  72  and an outlet valve  80 . The inlet valve  72  and outlet valve  80  are each an electromechanical valve, such as a solenoid-controlled valve, which opens and closes in response to a control signal. When the inlet valve  72  is open, the dispenser pump  74  is operable to advance a quantity of fluid from the sump  50  into the reaction chamber  76  and into contact with the tablet  78 . When the outlet valve  80  is open, fluid is advanced from the reaction chamber  76  into the washing chamber  14 . It will be appreciated that the outlet valve  80  may be an actionable drain or other mechanism operable to open in response to a control signal such that fluid is advanced from the reaction chamber  76  into the washing chamber  14 . It will be further appreciated that in some embodiments the quantity of fluid advanced into the dispenser  70  may be a metered amount advanced directly from the inlet valve  72 . It will be further appreciated that in some embodiments fluid advanced into the dispenser  70  may be some amount advanced directly from the inlet valve(s)  72 , which could be controlled to modulate temperatures. 
     When the valves  72 ,  80  of the dispenser  70  are closed during a dishwasher cycle, fluid is retained in the reaction chamber  76 . An electric heater  82  is positioned adjacent to the dispenser  70  and is configured to heat the contents of the reaction chamber  76 . In that way, the temperature of fluid in the reaction chamber  76  may be controlled separately from the temperature of fluids in the washing chamber  14 . It will be appreciated that in other embodiments the electric heater  82  may be integrated into the dispenser  70 . 
     The tablet  78  received in the reaction chamber  76  has a plurality of pouches  84 . Each of the pouches  84  encloses one of a plurality of cleaning agents. A “cleaning agent” may be a primary cleaning agent that is used in, for example, a main wash stage. A cleaning agent may also be a secondary cleaning agent that is used in, for example, a pre-soak stage, a pre-wash stage, a secondary washing stage after the main washing stage, or a pre-final rinsing stage or a first rinsing stage that follows the main dishwasher cycle. In addition, a cleaning agent may also be a finishing cleaning agent, such as, for example, a glass shine or a restoration agent, a sanitizing agent, or a rinse aid that is used in an intermediate or final rinsing stage. It should be appreciated that the cleaning agent may be any liquid, gel, powder, or tablet form thereof capable of mixing with the circulating fluids to clean, sanitize, and/or dry the wares positioned in the washing chamber  14 . It should also be appreciated that in other embodiments the tablet  78  may have only a single cleaning agent that may or may not be enclosed in a pouch  84 . 
     In the illustrative embodiment, each pouch  84  has a film material that encloses one of the plurality of cleaning agents. The film material is soluble in fluid and is responsive to fluid temperature such that it dissolves only when the fluid reaches a predetermined temperature. In this way, the release of each of the different cleaning agents may be regulated and matched to specific stages of the dishwasher cycle. 
     For example, a first pouch of the tablet  78  may enclose a primary cleaning agent and a second pouch may enclose a finishing cleaning agent. The film of the first pouch may be configured to dissolve at one temperature while the film of the second pouch may be configured to dissolve at a different temperature. In such a case, using the electric heater  82  to adjust the temperature of the fluid in the reaction chamber  76  to one temperature releases only the primary cleaning agent from the first pouch such that the primary cleaning agent mixes with the fluid in the reaction chamber  76 . The finishing cleaning agent, however, remains sealed in the second pouch. After the primary cleaning agent is released from the pouch, the outlet valve  80  may be opened so that the mixture of fluid and the primary cleaning agent advances from the reaction chamber  76  into the washing chamber  14 . In the washing chamber  14 , the primary cleaning agent passes into the sump  50  and mixes with the fluid retained therein to form a wash chemistry that may be circulated onto the wares positioned in washing chamber  14 . 
     It will be appreciated that in other embodiments the pouches  84  may be responsive to other changes in the fluid. For example, the pouches  84  may be responsive to the pH level, redox potential, ionic concentration, or enzyme concentration of the fluid. In those embodiments, the dishwasher  10  would include the additional mechanisms or devices necessary to adjust those aspects of the fluid and thereby selectively release the one of the cleaning agents from its corresponding pouch  84 . It will also be appreciated that a variety of selective coatings and/or binding agents may be used as an alternative to pouches to obtain a selective and sequential dissolution effect. 
     The dishwasher  10  also includes an identification sensor  90 . The identification sensor  90  may be optionally positioned in or adjacent to the dispenser  70  to sense or otherwise determine the identity of the tablet  78  positioned in the reaction chamber  76 . For example, the tablet  78  may be equipped with an RFID tag that transmits a signal indicative of the identity of the tablet  78 . In such a case, the identification sensor  90  may be embodied as an RF reader that is operable to read the contents of such an RFID tag and transmit an output signal indicative of the identity of the tablet  78 . The signal may include characteristics of the tablet  78  such as the number or type of different cleaning agents along with the parameters (e.g., specific temperature or pH) for releasing each cleaning agent. Such information may be encoded in the signal generated by the RFID tag and looked-up in response to the signal generated by the RFID tag. Alternatively, the identification sensor  90  may be operable to sense the identity of the different cleaning agents directly and transmit an output signal indicative of the identity of each of the different cleaning agents included in tablet  78 . 
     In another embodiment, the identification sensor  90  may be a pH sensor configured to measure the pH of the fluid mixture in the reaction chamber  76  after one of the plurality of cleaning agents has been released from its corresponding pouch  84 . It will be appreciated that in other embodiments the identification sensor  90  may take the form of an optical sensor or an electrochemical sensor configured to sense the tablet  78  and generate an output signal indicative of the identity of the tablet  78  and/or any cleaning agents included therein. 
     A temperature sensor  92  may be optionally positioned in or adjacent to the dispenser  70  to measure the temperature of the contents of the reaction chamber  76 . The temperature sensor  92  is configured to take a temperature measurement of the fluid in the reaction chamber  76  and transmit a signal indicative of that measurement. 
     The dishwasher  10  also includes an electronic control unit (ECU) or “electronic controller”  100 . The electronic controller  100  may be positioned in the door  24  or the machine compartment  32  of the dishwasher  10 . The electronic controller  100  is, in essence, the master computer responsible for interpreting electrical signals sent by sensors associated with the dishwasher  10  and for activating or energizing electronically-controlled components associated with the dishwasher  10 . For example, the electronic controller  100  is configured to control operation of the water inlet valve  44 , the inlet valve  72 , the outlet valve  80 , the electric heater  82 , the dispenser pump  74 , the drain pump  56 , and the wash pump  60 . The electronic controller  100  also monitors various signals from the control panel  26 , the identification sensor  90  and determines when various operations of the dishwasher  10  should be performed. As will be described in more detail below with reference to  FIG. 3 , the electronic controller  100  is operable to control the components of the dishwasher  10  such that the dishwasher  10  operates a dishwasher cycle based on information including the identity of the tablet  78 . 
     To do so, the electronic controller  100  includes a number of electronic components commonly associated with electronic units utilized in the control of electromechanical systems. For example, the electronic controller  100  may include, amongst other components customarily included in such devices, a processor such as a microprocessor  102  and a memory device  104  such as a programmable read-only memory device (“PROM”) including erasable PROM&#39;s (EPROM&#39;s or EEPROM&#39;s). The memory device  104  is provided to store, amongst other things, instructions in the form of, for example, a software routine (or routines) which, when executed by the microprocessor  102 , allows the electronic controller  100  to control operation of the dishwasher  10 . 
     The electronic controller  100  also includes an analog interface circuit  106 . The analog interface circuit  106  converts the output signals from various sensors (e.g., the identification sensor  90 ) into signals which are suitable for presentation to an input of the microprocessor  102 . In particular, the analog interface circuit  106 , by use of an analog-to-digital (A/D) converter (not shown) or the like, converts the analog signals generated by the sensors into digital signals for use by the microprocessor  102 . It should be appreciated that the A/D converter may be embodied as a discrete device or number of devices, or may be integrated into the microprocessor  102 . It should also be appreciated that if any one or more of the sensors associated with the dishwasher  10  generate a digital output signal, the analog interface circuit  106  may be bypassed. 
     Similarly, the analog interface circuit  106  converts signals from the microprocessor  102  into output signals which are suitable for presentation to the electrically-controlled components associated with the dishwasher  10  (e.g., the wash pump  60 ). In particular, the analog interface circuit  106 , by use of a digital-to-analog (D/A) converter (not shown) or the like, converts the digital signals generated by the microprocessor  102  into analog signals for use by the electronically-controlled components associated with the dishwasher  10 . It should be appreciated that, similar to the A/D converter described above, the D/A converter may be embodied as a discrete device or number of devices, or may be integrated into the microprocessor  102 . It should also be appreciated that if any one or more of the electronically-controlled components associated with the dishwasher  10  operate on a digital input signal, the analog interface circuit  106  may be bypassed. 
     Thus, the electronic controller  100  may control operation of the dishwasher  10  based on the identity of the tablet  78 . In particular, the electronic controller  100  executes a routine including, amongst other things, a control scheme in which the electronic controller  100  monitors outputs of the sensors associated with the dishwasher  10  to control the inputs to the electronically-controlled components associated therewith. To do so, the electronic controller  100  communicates with the sensors associated with the dishwasher  10  to determine, amongst numerous other things, the state of the door  24 , the identity of the tablet  78  (including the identity of the cleaning agents present in the tablet  78 ). Armed with this data, the electronic controller  100  performs numerous calculations, either continuously or intermittently, including looking up values in preprogrammed tables, in order to execute algorithms to perform such functions as controlling the drain pump  56  to retain fluid in the sump  50 , determining when to release a cleaning agent from the dispenser  70 , controlling the wash pump  60  to apply the mixture of fluid and the cleaning agent to soils on wares in the dishwasher  10 , etceteras. 
     As will be appreciated by those of the skill in the art, the dishwasher  10  may include elements other than those shown and described above, such as, by way of example, an electric heating element to assist in drying the wares or a filter to remove particulates from the re-circulated wash chemistry or rinse chemistry. The dishwasher  10  may also include a variety of other sensors that monitor conditions within the washing chamber  14 , the sump  50 , and/or other components of the dishwasher  10 . It should also be appreciated that the location of many components (i.e., in the washing chamber  14 , in the machine compartment  32 , in or on the door  24 ) may also be altered. 
     Referring now to  FIG. 3 , an illustrative embodiment of a control routine  200  for operating the dishwasher of  FIG. 2  is illustrated as a simplified flow diagram. The routine  200  begins with step  202  in which the electronic controller  100  determines the identity of the tablet  78 . To do this, the identification sensor  90  reads an RFID tag of the tablet  78  and generates an output signal indicative of the identity of the tablet  78 . The identification sensor  90  may also be an optical sensor or any other sensor configured to scan the tablet  78  and generate an output signal indicative of its identity. 
     In step  204 , the electronic controller  100  uses the output signal to identify the tablet  78  by selecting from a look-up table stored in the memory device  104 . The look-up table includes information relating to numerous tablets  78 , including the identity of the cleaning agents sealed in each tablet  78 . Additionally, the look-up table includes a sequence or order in which each of the plurality of cleaning agents is released from a particular tablet  78 . The look-up table may also include the predetermined temperature at which each of the plurality of cleaning agents is released. 
     There are circumstances where the electronic controller  100  may not be able to identify the tablet  78 . For example, the user may choose a tablet  78  that does not include an RFID tag or other means of identification. In such a case, the electronic controller  100  selects a default base dishwasher cycle and proceeds to step  206 . In step  206 , the dishwasher  10  runs the default dishwasher cycle and the tablet  78  is released in a conventional fashion during the default dishwasher cycle. 
     If the tablet  78  is identified in step  204 , the electronic controller  100  proceeds to step  208  in which the electronic controller  100  selects a base dishwasher cycle based on the identity of the tablet  78 . The dishwasher cycle is selected from a plurality of dishwasher cycles stored in a look-up table in the memory device  104 . For example, if the tablet  78  includes a finishing cleaning agent with a sanitizer, the electronic controller  100  may select a dishwasher cycle that includes a reduced temperature drying stage. In this way, the dishwasher cycle is selected based on the identity of the tablet  78 . The electronic controller  100  also selects a predetermined release time for releasing each of the cleaning agents into the washing chamber  14 . 
     In another embodiment, the electronic controller  100  may build a customized dishwasher cycle based on the identity of each of the cleaning agents included in the tablet  78 . In that case, the electronic controller  100  selects from a look-up table a stage associated with each of the plurality of cleaning agents. The electronic controller  100  assemblies each of the selected wash stages into a customized dishwasher cycle based on the release sequence of the cleaning agents determined in step  204 . Additionally, the electronic controller  100  sets the initial planned duration of each of the selected stages based on its associated cleaning agent. The concentration, quantity, and type of cleaning agent influences the amount of time the cleaning agent requires to properly clean or sanitize the wares positioned in the washing chamber  14 . Accordingly, the electronic controller  100  adjusts the duration of each of the selected stages depending on the identity of each of the cleaning agents. The electronic controller  100  then sets a predetermined release time for releasing each of the cleaning agents into the washing chamber  14 . In some embodiments, the controller  100  may also adjust the duration and release time based on initial sensor measurements, such as, for example, the dishwasher load, soil type, or soil level. It will be appreciated that sensor measurements recorded during the various stages may be used to further refine and optimize the dishwasher cycle. 
     In step  210 , the electronic controller  100  generates a control signal to operate the dishwasher  10  in accordance with the selected dishwasher cycle. As discussed above, a typical dishwasher cycle may include at least one wash stage and at least one rinse stage but may include additional stages. The electronic controller  100  generates a series of control signals to energize or de-energize the water inlet valve  44  and the drain pump  56  to fill or drain the sump  50  over the course of the various stages of the dishwasher cycle. Similarly, the electronic controller  100  generates a control signal to activate the wash pump  60  to supply fluid from the sump  50  to the spray arm  62  and onto the wares positioned in washing chamber  14 . 
     In step  212 , the electronic controller  100  monitors the operation of the dishwasher  10  to determine the current stage of the dishwasher cycle. If one of the cleaning agents is to be released during the current stage, the electronic controller  100  generates in step  214  a control signal to activate the dispenser pump  74 . The dispenser pump  74  supplies fluid from the sump  50  to the dispenser  70 . Fluid is retained in the reaction chamber  76  by the closing the inlet valve  72  and outlet valve  80 . 
     In step  216 , the electronic controller  100  generates a control signal to activate the electric heater  82 . As described above, the electric heater  82  is configured to supply heat to the dispenser  70  to raise the temperature of the fluid within the reaction chamber  76 . The electric heater  82  heats the fluid to the predetermined temperature required to dissolve the pouch  84  and release the cleaning agent into the reaction chamber  76 . A mixture of the released cleaning agent and fluid is thereby created in the reaction chamber  76 . 
     In step  218 , the electronic controller  100  generates a control signal at the predetermined release time to open outlet valve  80 . The mixture of the cleaning agent and fluid are moved from the reaction chamber  76  into the washing chamber  14 . Any remaining pouches  84  of the tablet  78  remain in the reaction chamber  76  for release later in the dishwasher cycle. In the sump  50 , the released cleaning agent further mixes with the fluids retained therein to form a wash or rinse chemistry that may be sprayed onto the wares positioned in the washing chamber  14 . 
     There are a plurality of advantages of the present disclosure arising from the various features of the method, apparatus, and system described herein. It will be noted that alternative embodiments of the method, apparatus, and system 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.