TEMPERATURE-CONTROLLED DISHWASHER AGENT DISPENSER

Description

TECHNICAL FIELD

This disclosure relates generally to warewashing machine and more particularly to a method and apparatus for controlling dispensing of a dishwashing agent into a liquid in a washing machine, such as a dishwasher, based on the temperature of the liquid.

BACKGROUND

A dishwasher, also referred to as a warewasher or warewashing machine, is a machine for automatically cleaning articles, such as dishes, trays, laboratory equipment, dinnerware, and kitchenware. A batch of objects to be cleaned (for example, dishes) can be loaded into the dishwasher to be cleaned in a cleaning cycle that include washing and rinsing periods. During the washing period, a cleaning mixture formed by water and dishwasher detergent is sprayed into the loaded dishwasher to blast the dishes. The cleaning mixture is then drained before the rinsing period starts. During the rinsing period, water or a rising mixture formed by water and a rinsing agent is sprayed into the loaded dishwasher to remove residue of the cleaning mixture. After the rinsing period completes with the rinsing water being drained, the dishes can optionally be dried using air and/or heat during a drying period. A dishwasher may have various user-selectable settings for each cleaning cycle. The settings may define, for example, time, temperature, and repetition of each of the washing, rinsing, and drying period. The setting may also allow the user to choose which periods to include (e.g., rinsing only, drying only, rinsing and drying, or washing and rinsing without drying).

A common domestic dishwasher is an undercounter unit intended to be installed under a kitchen counter. Other types of dishwasher include industrial or commercial dishwashers for use in restaurants, hotels, and other commercial establishments with food services. Dishwasher detergents used in these dishwashers can include chemicals capable of cleaning, sanitizing, and/or reducing surface tension of water (and hence water spots on dishes). Such dishwasher detergents are made into various solid and liquid forms. Effectiveness and efficiency of dishwashing may depend on concentration of the dishwasher detergent in the cleaning mixture as well as the temperature of the cleaning mixture. For example, a low concentration may result in incomplete removal of food waste from the washed dishes, and a high concentration may unnecessarily increase the cost of dishwashing and/or leave a detergent residue on the washed dishes, while the optimal concentration or range of concentration depends on chemical properties of the dishwasher detergent that may be a function of the temperature.

SUMMARY

A dishwasher dispenses a dishwashing agent to form a dishwashing liquid including water and the dishwashing agent and controls an amount of the dishwashing agent to be dispensed based on a sensed temperature indicative of the temperature of the dishwashing liquid. In various examples, the dishwashing agent can include a detergent and/or a rinse aid. In various examples, the dishwasher dispenses the detergent during a washing period and dispenses the rinse aid during a rinsing period.

An example of a dishwasher is provided. The dishwasher may be configured to perform cleaning cycles each including a washing period and a rinsing period for cleaning objects is provided. The dishwasher may include a tank, a temperature sensor, an agent dispenser, and a dispenser controller. The tank may be configured to receive water and a dishwashing agent to form a liquid including the received water and the received dishwashing agent. The liquid is to be applied to the objects. The temperature sensor may be configured to be placed in the tank to sense a temperature of the liquid. The agent dispenser may be configured to dispense the dishwashing agent into the liquid, to receive a dispensing signal indicative of an amount of the dishwashing agent to be dispensed, and to control the dispensing of the dishwashing agent according to the amount. The dispenser controller may be configured to receive the sensed temperature from the temperature sensor and to generate the dispensing signal based on the temperature. The dishwashing agent may include a detergent, a rinse aid, and/or any chemical agent or any combination of chemical agents dispensed during the cleaning cycles of the dishwasher.

An example of a method for operating a dishwasher is also provided. The dishwasher may be configured to performing cleaning cycles each including a washing period and a rinsing period for cleaning objects. The method may include: sensing a temperature of a liquid in a tank, the liquid including at least water; generating a dispensing signal using the sensed temperature, the dispensing signal indicative of an amount of a dishwashing agent to be dispensed; dispensing the dishwashing agent into the liquid; controlling the amount of the dishwashing agent dispensed into the liquid using the dispensing signal; and spraying the liquid onto the objects after the dishwashing agent is dispensed into the liquid. The dishwashing agent may include a detergent, a rinse aid, and/or any chemical agent or any combination of chemical agents dispensed during the cleaning cycles of the dishwasher.

This Summary is an overview of some of the teachings of the present application and not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details about the present subject matter are found in the detailed description and appended claims. The scope of the present invention is defined by the appended claims and their legal equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate generally, by way of example, various embodiments discussed in the present document. The drawings are for illustrative purposes only and may not be to scale.

FIGS. 1A, 1B, 1C, and 1D are illustrations of an embodiment of a dishwasher, with FIG. 1A showing a front view, FIG. 1B showing a side view with a hood of the dishwasher closed, FIG. 1C showing a side view with the hood open, and FIG. 1D showing a top view.

FIG. 2 is an illustration of an embodiment of the dishwasher of FIGS. 1A-1D with examples of accessories.

FIG. 3 is an illustration of an embodiment of a hydraulic system of the dishwasher of FIGS. 1A-1D.

FIG. 4 is a block diagram illustrating an embodiment of a dishwashing agent dispensing system of a dishwasher, such as the dishwasher of FIGS. 1A-1D.

FIG. 5 is a block diagram illustrating an embodiment of a dishwashing agent dispensing system of a dishwasher, such as the dishwasher of FIGS. 1A-1D.

FIG. 6 is a flow chart illustrating an embodiment of a method for dispensing a dishwashing agent in a dishwasher.

DETAILED DESCRIPTION

The following detailed description of the present subject matter refers to subject matter in the accompanying drawings which show, by way of illustration, specific aspects and embodiments in which the present subject matter may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present subject matter. References to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. The scope of the present invention is defined by the appended claims, along with the full scope of legal equivalents to which such claims are entitled.

The present subject matter relates to methods and devices for dispensing detergent in a dishwasher and controlling the dispensing using a temperature sensed from the dishwasher. As used in the present disclosure, a “dishwasher” (also known as dish washing machine, warewasher, or warewashing machine) can include any type of washing machine that can use detergent for cleaning and/or sanitizing purposes in domestic or commercial settings. Objects to be washed in a dishwasher can include dinnerware, flatware, pots and pans, cutlery, flatware, glasses, kitchenware, serving pans, trays, and the like. Such objects can be placed in a dishwasher rack in the dishwasher. The “dishwasher rack” (also known as warewashing rack) can include any rack that is used in a dishwasher for holding any objects to be washed. Unless noted otherwise, a “rack” in the present disclosure refers to a dishwasher rack. The rack can be a built-in part of the dishwasher or a removable accessory suitable for use in the dishwasher. The rack can be a peg rack or an open rack and can have any size and shape suitable for the dishwasher. Each dishwasher can include one or more built-in racks and/or can host one or more removable racks.

As used in the present disclosure, a “cleaning cycle” of the dishwasher can include various operational periods, such as one or more of a descaling period, a washing period, a rinsing period, and a drying period, depending on the availability of respective operational modes in the dishwasher and settings entered by a user of the dishwasher. “Cleaning” can include cleaning only, sanitizing only, cleaning and sanitizing, descaling and cleaning, or descaling, cleaning, and sanitizing. A “descaling period” includes a period or operational mode that is intended for a descaling liquid formed by water and a descaler to be applied to the objects being cleaned. A “washing period” includes a period or operational mode that is intended for a washing liquid formed by water and a detergent to be applied to the objects being washed. A “rinsing period” includes a period or operational mode that is intended for water, or a rinsing liquid formed by water and a rinse aid and/or a sanitizer, to be applied to the objects being cleaned. Some dishwashers (e.g., commercial dishwashers) may include a rinsing period that is primarily for sanitizing through heat and/or chemical means. The descaler, detergent, rinsing aid, and sanitizer can each be a chemical agent or a mixture of chemical agents in liquid or solid form. A “drying period” includes a period or operational mode that is intended for the cleaned objects to be dried by air flow and/or heat, without additional water and/or chemical agent applied.

A trend of franchising food service businesses has raised a need for miniaturizing stores while maximizing store area utilization and the diversifying kitchen equipment. A store (e.g., restaurant) may face the challenge of increasing usage of electrically powered equipment without increasing the capacity of the existing electrical power system. The electrical power available for operating a dishwasher, an electrical appliance commonly used in a restaurant or other food service establishment, may be limited, while the cleaning effectiveness of the dishwasher is not to be compromised.

In an existing dishwasher, a limited electrical power consumption may mean that when operating continuously, the cleaning water sprayed onto the objects being washed cannot reach a temperature at which the dishwasher detergent has the expected cleaning power. This may in turn raise food safety and customer satisfaction issues. Operation of such an existing dishwasher may require a detergent to be manually added to a detergent dispenser in the dishwasher before starting each cleaning cycle. The amount of the detergent may be manually controlled and hence not accurate each cleaning cycle and consistent over the cleaning cycles. An excessive amount unnecessarily raises the cost of cleaning and may leave residue on the objects being washed. An insufficient amount may leave the objects unclean. While the cleaning power of the detergent is known to be temperature-dependent, the amount of the detergent when being manual controlled is not usually and easily adjusted based on the water temperature in the dishwasher. This may result in inefficient utilization of the detergent's cleaning power.

A practice under such circumstances includes increasing the amount of the detergent dispensed for each washing load during each cleaning cycle to compensate for the reduced cleaning power of the detergent at lower temperatures. This may include manually increasing the amount of the detergent loaded into the dispenser of the dishwasher before starting each cleaning cycle when the temperature of the cleaning mixture is expected to be below a specified range. However, this practice has multiple disadvantages. First, the increased amount of the detergent used increases the cost for operating the dishwasher. Second, there is a limit beyond which a higher concentration no longer improves cleaning effect. Additionally, increasing the concentration of the detergent raises the risk of residue of the detergent on the objects being washed.

Therefore, there is a need for controlling dispensing of the detergent automatically and intelligently to provide the dishwasher with consistent results of cleaning in an efficient way, taking the chemical properties of the detergent, including their temperature dependency, into consideration. Being efficient may include ensuring effectiveness of cleaning while maintaining or lowering the electrical power consumption of the dishwasher.

The present subject matter can provide a dishwasher with automatic and dynamic adjustment of the amount of a chemical agent (e.g., detergent and/or rinse aid) being dispensed based on the temperature sensed from the dishwater. The sensed temperature can represent or otherwise indicate the temperature of the chemical agent at work. The adjustment can increase the efficiency in utilizing the cleaning power of a detergent and/or the surfactant power of a rinse aid at the instant temperature. In various embodiments, an optimal concentration of the chemical agent can be determined as a function of the temperature, and the amount of the chemical agent being dispensed can be controlled to maintain the concentration of the chemical agent around the optimal concentration for a sensed instant temperature.

The present subject matter can be applied to a dishwasher for meeting or exceeding cleaning requirements using a reasonable amount of detergent and/or rinse aid at varying levels of water temperature. By reducing the amount of the detergent and/or rinse aid used in each cleaning cycle while ensuring effectiveness of the cleaning by better utilizing the temperature-dependent chemical properties, application of the present subject matter can reduce the cost and other risks (e.g., chemical residue and/or electrical power over-capacity) associated with using an excessive amount of the detergent and/or raising the water temperature.

Application in a dishwasher is discussed as an example, but not a limitation, for the present subject matter. The present system for temperature-controller dispensing of detergent and/or rinsing aid can be applied in any washing machine that uses a chemical agent with temperature-dependent characteristics.

FIGS. 1A, 1B, 1C, and 1D are illustrations of an embodiment of a dishwasher 100. As shown in FIGS. 1A-1D and discussed as an example for illustrative but not restrictive purposes, dishwasher 100 is a hood-type dishwasher that includes a hood 102 to cover a wash chamber (also known as a main wash chamber) 101 during each cleaning cycle. A hood lifting handle 103 can be elevated by a user to open hood 102 for loading objects to be washed into wash chamber 101 before a cleaning cycle, lowered by the user to close hood 102 to cover the wash chamber 101 before starting the cleaning cycle, and elevated by the user to open hood 102 for unloading the cleaned objects after the cleaning cycle is completed. A hood lock 104 installed on hood 102 is automatically locked when a cleaning cycle starts to prevent hood 102 from being accidentally opened during the clean cycle. FIG. 1A shows a front view of dishwasher 100 when hood 102 is closed. FIG. 1B shows a side view of dishwasher 100 when hood 102 is closed. FIG. 1C shows a side view of dishwasher 100 when hood 102 is open. FIG. 1D shows a top view of dishwasher 100.

Dishwasher 100 includes a dispenser 105 that contains various chemical agents for dispensing during different periods of the cleaning cycle. Each chemical agent may be in liquid or solid form, and dispenser 105 is configured to accommodate liquid and/or solid forms for each chemical agent, depending on the form(s) of the chemical agent that is available and intended to use. Each chemical agent in dispenser 105 is refillable. In one example, dishwasher 100 can perform cleaning cycles including a descaling period, a washing period, and a rinsing period, and dispenser 105 is an integrated dispenser that can contain a descaler, a detergent, and a rinse aid and can dispense the descaler for use during the descaling period, the detergent for use during the washing period, and the rinse aid for use during the rinsing period.

Dishwasher 100 includes a user interface 106 that visually and/or audially indicates its operational status and allows the user to control its operations. User interface 106 can include a display screen, such as a touchscreen that can display the operation status of dishwasher 100 and receive commands and other information from the user. User interface 106 can include a power switch for the user to turn the electrical power for dishwasher 100 on and off. User interface 106 allows the user to start a cleaning cycle, optionally after indicating to the user that the cleaning cycle is ready to start (e.g., after hood 102 is closed). In one example, user interface 106 allows the user to select which period(s) to include in the cleaning cycle. The user may select only the rinsing period when, for example, dishes are known to be clean but needs disinfection. The user may select the washing and rinsing periods only when a need for descaling dishes is not indicated. In another example, user interface 106 is configured (e.g., programmed) for following a hygiene procedure and/or complying with a regulation for ensuring food safety.

Dishwasher 100 provides high space and power efficiency to lower operational cost and/or allowing a food service establishment to operate under limited space and/or electrical power capacity. For example, dishwasher 100 includes an internal wastewater recycling system 107 and an internal steam reduction system 111 to recover thermal energy resulting from the operations during each cleaning cycle for heating clean water to be used in the operations. Wastewater recycling system 107 includes a wash tank (also known as main wash tank) 108 recycling a hot washing liquid to be sprayed into, and returning from, wash chamber 101 during the washing period and a wastewater tank 109 (also known as overflow tank) to receive excessive hot washing liquid from wash tank 108 as wastewater. A heat exchange module is placed in wastewater tank 109 to heat clean water while cooling the wastewater before it is discharged to a drain (e.g., a drain connected to the sewage of the building). The heated clean water is to be added to wash tank 108 and a booster tank (also known as rinse tank) 110 as needed. In the illustrated example, booster tank 110 receives the clean water and the descaler to form a descaling liquid to be sprayed into wash chamber 101 during the descaling period and receives the clean water and the rinse aid to form a rinsing liquid to be sprayed into wash chamber 101 during the rinsing period. Steam reduction system 111 includes a fan 112 to draw steam from wash chamber 101 and a condenser 113 positioned in the steam path to condense the steam while heating the clean water (in addition to the heat recovery from the wastewater). Fan 112 blows the remaining steam out of dishwasher 100.

Dishwash 100 can be sized to allow for easy operation and maintenance by a user having a height of 150 cm or taller. Force required to open hood 102 by elevating hood lifting handle 103 can be around 3.5 kg or lighter. In one example, wash tank 108 has a capacity of about 24 L, wastewater tank 108 has a capacity of about 12 L, and booster tank 110 has a capacity of about 10 L.

FIG. 2 is an illustration of an embodiment of dishwasher 100 with several accessories. As shown in FIG. 2 as an example for illustrative but not restrictive purposes, the accessories can include a dirty dish stand 220, a clean dish stand 223, a dishwasher rack 224, and a vent hood 225. Dirty dish stand 220 includes one or more sinks 221 and one or more faucets 222. When necessary or convenient, dishes and/or other objects to be cleaned can be placed in sink(s) 221 and pre-washed using water from faucet(s) 222 before being loaded into wash chamber 101 (with hood 102 open). Rack 224 can be placed in wash chamber 101 when empty, and the dishes and/or other objects can be placed into rack 224 for each cleaning cycle. After the cleaning cycle is completed, rack 224 loaded with the cleaned dishes and/or other objects can be removed from wash chamber 101 (with hood 102 open) and placed on clean dish stand 223 before use and/or further distribution. Vent hood 225 can vent the steam blown out of dishwasher 100 by fan 112 to outside of the building in which dishwasher 100 is placed.

FIG. 3 is an illustration of an embodiment of a hydraulic system 329 of dishwasher 100. As shown in FIG. 2 as an example for illustrative but not restrictive purposes, hydraulic system 329 can support liquid movement functions during the descaling period, the washing period, and the rinsing period.

Hydraulic system 329 includes a main water valve 335 (e.g., an electromagnetically controlled valve) that can be opened to receive clean water from a water source (e.g., a water main of the building). The clean water can be heated in wastewater tank 109 and then routed to wash tank 108 and booster tank 110. The clean water can also be routed to dispenser 105, when needed (e.g., for dissolving one or more chemical agents in solid form(s)), through a dispenser valve 336.

During the descaling period, the descaler is dispensed from dispenser 105 into booster tank 110 to form the descaling liquid with the heated clean water in booster tank 110. The descaling liquid is pumped by a rinse pump 333 to rinse arms 330. Rinse arms 330 are positioned above and under wash chamber 101 and rotated to spray the scaling liquid into wash chamber 101 from above and under. The descaling liquid flows into wash tank 108 after passing through wash chamber 101.

During the washing period, the detergent is dispensed from dispenser 105 into wash tank 108 to form the washing liquid with the heated clean water in wash tank 108. The washing liquid is pumped by a wash pump 331 to wash arms 332. Wash arms 332 are positioned above and under wash chamber 101 and rotated to spray the washing liquid into wash chamber 101 from above and under. The washing liquid returns to wash tank 108 after passing through wash chamber 101.

During the rinsing period, the rinse aid is dispensed from dispenser 105 into booster tank 110 to form the rinsing liquid with the heated clean water in booster tank 110. The rinsing liquid is pumped by rinse pump 333 to rinse arms 330. Rinse arms 330 are rotated to spray the rinsing liquid into wash chamber 101 from above and under. The rinsing liquid flows into wash tank 108 after passing through wash chamber 101.

Thus, wash tank 108 collects all the liquid sprayed into wash chamber 101. When the level of the liquid in wash tank 108 exceeds a set threshold, the excessive liquid flows into wastewater tank 109 as the wastewater. In an example, as illustrated in FIG. 3, hydraulic system 329 includes a wastewater recycling system that includes a drain valve 337 and two watertight or waterproof seals 338 and 339 to separate the wastewater from drain water (which is the wastewater ready to be discharged from dishwasher 100 to the drain. A drain pump 334 pumps the drain water out of the wastewater recycling system to the drain. When drain pump 334 is turned off and drain valve 337 is closed, the wastewater flows out of the wash tank 108 into wastewater tank 109 and then flows out of wastewater tank 109 and turns into the drain at seal 339. When drain pump 334 is turned on and drain valve 337 is closed, the wastewater flows out of wastewater tank 109 (as being pumped) through the path including drain pump 334 and turns into the drain at seal 339. When drain valve 337 is open, the wastewater flows from wash tank to the drain directly (without flowing through wastewater tank 109 or drain pump 334. A heat exchange coil 363 is placed in wastewater tank 109. The clean water flows through heat exchange coil 363 to be heated by the wastewater before being routed into wash tank 109 or booster tank 110, while the wastewater is cooled by the clean water before being discharged to the drain.

FIG. 4 is a block diagram illustrating an embodiment of a dishwashing agent dispensing system 450 of a dishwasher, such as dishwasher 100. System 450 includes a tank 451, a temperature sensor 452, an agent dispenser 453, and a dispenser controller 454. Tank 451 can receive water from a clean water source and a dishwashing agent from agent dispenser 453 to form a liquid including the received water and the received dishwashing agent. The liquid is to be applied to objects being cleaned in the dishwasher. The temperature of the water received from the clean water source can vary within a large range (e.g., 40-70° C.). Temperature sensor 452 can be placed in tank 451 to sense a temperature of the liquid. Agent dispenser 453 can dispense the dishwashing agent into the liquid, receive a dispensing signal indicative of an amount of the dishwashing agent to be dispensed, and control the dispensing of the dishwashing agent according to the amount. Dispenser controller 454 can receive the sensed temperature from temperature sensor 452 and generate the dispensing signal based on the sensed temperature.

In various embodiments, the dishwashing agent can include any chemical agent used in any period of a cleaning cycle of the dishwasher. When a chemical agent has temperature-dependent characteristics, system 454 can be implemented in the dishwasher for controlling the dispensing of that chemical agent based on the temperature of the liquid for optimizing its effect at various temperatures. Examples of the chemical agent include a descaler, a detergent, a rinse aid, or any of their combinations (e.g., a “2-in-1” or “3-in-1” detergent). While the detergent and the rinsing aid are specifically discussed as examples of the chemical agent to be dispensed using system 450, the present subject matter can be applied to other one or more chemical agents used in the dishwasher or other washing machine when such one or more chemical agents have temperature-dependent characteristics.

FIG. 5 is a block diagram illustrating an embodiment of a dishwashing agent dispensing system 550 of a dishwasher, such as dishwasher 100. System 550 is an example of application of system 450 for dispensing a detergent and a rinse aid in a dishwasher that can perform a cleaning cycle including at least a washing period and a rinsing period. In the illustrated embodiment, system 550 includes a detergent dispensing system (awash tank 551A, a washing temperature sensor 552A, a detergent dispenser 553A, and a dispenser controller 554), a rinse aid dispensing system (a rinse tank 551B, a rinsing temperature sensor 552B, a rinse aid dispenser 553B, and dispenser controller 554), and a user interface 560 that allows the user to control operations of the dishwasher including settings of the detergent dispensing system and the rinse aid dispensing system for their automatic dispensing operations.

Wash tank 551A can receive water from a clean water source and the detergent from detergent dispenser 553A to form a washing liquid including the water and the detergent. A hydraulic system of the dishwasher (e.g., hydraulic system 329) can draw the washing liquid from wash tank 551A and spray the washing liquid into a wash chamber of the dishwasher (e.g., wash chamber 101) during the washing period. The temperature of the water received from the clean water source can vary within a large range (e.g., 40-70° C.). Washing temperature sensor 552A is placed in wash tank 551A to sense a washing temperature representing the temperature of the washing liquid. An example of washing temperature sensor 552A includes a thermocouple. Detergent dispenser 553A can dispense the detergent into the washing liquid. The detergent can include any chemical agent or combination of chemical agents suitable for use in the dishwasher during the washing period. In one example, detergent dispenser 553A can receive a detergent dispensing signal and control the dispensing of the detergent using the detergent dispensing signal. The detergent dispensing signal can be used to specify an amount of the detergent to be dispensed. The amount can be controlled directly with the detergent dispensing signal indicating a volume or weight of the detergent to be dispensed (e.g., 3 drops or 3 grams),), and detergent dispenser 553A can measure that amount for dispensing. Alternatively, the amount can be controlled by controlling a duration of the dispensing of the detergent (e.g., 3 seconds), and detergent dispenser 553A can dispense the detergent while the detergent dispensing signal is present.

Rinse tank 551B can receive water from the clean water source and the rinse aid from rinse aid dispenser 553B to form a rinsing liquid including the water and the rinse aid. The hydraulic system of the dishwasher can draw the rinsing liquid from rinse tank 551B and spray the rinsing liquid into the wash chamber of the dishwasher during the rinsing period. Rinsing temperature sensor 552B is placed in rinse tank 551B to sense a rinsing temperature representing the temperature of the rinsing liquid. An example of rinsing temperature sensor 552B includes a thermocouple. Rinse aid dispenser 553B can dispense the rinse aid into the rinsing liquid. The rinse aid can include any chemical agent or combination of chemical agents suitable for use in the dishwasher during the rinsing period. In one example, rinse aid dispenser 553B can receive a rinse aid dispensing signal and control the dispensing of the rinse aid using the rinse aid dispensing signal. The rinse aid dispensing signal can be used to specify an amount of the rinse aid to be dispensed. The amount can be controlled directly with the rinse aid dispensing signal indicating a volume or weight of the rinse aid to be dispensed (e.g., 3 drops or 3 grams),), and rinse aid dispenser 553B can measure that amount for dispensing. Alternatively, the amount can be controlled by controlling a duration of the dispensing of the rinse aid (e.g., 3 seconds), and rinse aid dispenser 553B can dispense the rinse aid while the rinse aid dispensing signal is present.

Dispenser controller 554 can control the operation of detergent dispenser 553A and rinse aid dispenser 553B. In one example, dispenser controller 554 is part of a main electronic control board of the dishwasher that can also control operation modes of the dishwasher (e.g., a washing mode during the washing period and a rinsing mode during the rinsing period).

Dispenser controller 554 can control detergent dispenser 553A using the washing temperature and control rinse aid dispenser 553B using the rinsing temperature. In one example, dispenser controller 554 can control detergent dispenser 553A in real time, using the washing temperature sensed by washing temperature sensor 552A in real time, and control rinse aid dispenser 553B in real time, using the rinsing temperature sensed by rinsing temperature sensor 552B in real time.

Dispenser controller 554 can receive the washing temperature from washing temperature sensor 552A and generate the detergent dispensing signal based on the washing temperature and a detergent-temperature relationship during the washing period. The detergent-temperature relationship maps values or value ranges of the washing temperature to values of the amount of the detergent to be dispensed. An example of the detergent-temperature relationship includes a look-up table mapping each value or value range of the washing temperature to a value of the amount of the detergent to be dispensed. Dispenser controller 554 can also receive the rinsing temperature from rinsing temperature sensor 552B and generate the rinse aid dispensing signal based on the rinsing temperature and a rinse aid-temperature relationship during the rinsing period. The rinse aid-temperature relationship maps values or value ranges of the rinsing temperature to values of the amount of the rinse aid to be dispensed. An example of the rinse aid-temperature relationship includes a look-up table mapping each value or value range of the rinsing temperature to a value of the amount of the rinse aid to be dispensed. An example illustrating a format of a look-up table for the detergent-temperature relationship or the rinse aid-temperature relationship is provided in Table 1.

In various examples, dispenser controller 554 can generate the detergent dispensing signal upon beginning of the washing period, periodically during the washing period, and/or in response to significant changes in the washing temperature during the washing period. A significant change in the washing temperature can include, for example, a drop in the washing temperature that requires an additional amount of the detergent according to the detergent-temperature relationship. Dispenser controller 554 can detect significant changes in the washing temperature and generate the detergent dispensing signal according to the newly sensed washing temperature in response to each detection of the significant changes. Dispenser controller 554 can also generate the rinse aid dispensing signal upon beginning of the rinsing period, periodically during the rinsing period, and/or in response to significant changes in the rinsing temperature during the rinsing period. A significant change in the rinsing temperature can include, for example, a drop in the rinsing temperature that requires an additional amount of the rinse aid according to the rinse aid-temperature relationship. Dispenser controller 554 can detect significant changes in the rinsing temperature and generate the rinse aid dispensing signal according to the newly sensed rinsing temperature in response to each detection of the significant changes.

The detergent-temperature relationship can be determined for each specific detergent that may be used in the dishwasher, for example based on known temperature-dependent characteries of the specific detergent and/or experiments. The detergent-temperature relationship can be determined to exert the strongest effect of the detergent at various temperatures that may be encountered during the washing period. The rinse aid-temperature relationship can be determined for each specific rinse aid that may be used in the dishwasher, for example based on known temperature-dependent characteries of the specific rinse aid and/or experiments. The rinse-temperature relationship can be determined to exert the strongest effect of the rinse aid at various temperatures that may be encountered during the rinsing period.

Controlling the dispensing of the detergent and rinse aid according to the present subject matter can reduce a risk of incomplete cleaning of the objects being washed, for example by reducing residue of food waste, residue of the detergent, and water stain on the objects. Costs of the detergent and rinse aid can be reduced by accurately controlling the amount of the detergent to be dispensed to provide a concentration of the detergent that ensures cleanness of the objects at the end of each cleaning cycle (e.g., without food stains or residue of the detergent) and by accurately controlling the amount of the rinse aid to be dispensed to provide a concentration of the rinse aid that ensures cleanness of the objects at the end of each cleaning cycle (e.g., without water stains or residue of the detergent). Duration of the washing period and/or duration of the rinsing period can be reduced due to the increased efficiency.

User interface 560 includes a presentation device 561 and a user input device 562. In one example, user interface 560 includes a touchscreen functioning as both presentation device 561 and user input device 562. Presentation device 561 can present operational status of the dishwasher (e.g., cleaning cycle in progress, in washing period, in rinsing period, cleaning cycle complete, and the like), including information specific to operations of system 550 (e.g., washing temperature, rinsing temperature, detergent being dispensed, rinse aid being dispense, and the like). User input 562 can receive user commands for operating the dishwasher (e.g., to start a cleaning cycle) and information for programming the dishwasher. The information for programming the dishwasher can include the detergent-temperature relationship and the rinse aid-temperature relationship.

When system 550 is implemented in dishwasher 100, user interface 560 can be included in user interface 106, dispenser controller 554 can be included in dispenser 105 and/or user interface 106, detergent dispenser 553A and rinse aid dispenser 553B can be included in dispenser 105, wash tank 551A can be wash task 108, and rinse tank 551B can be booster tank 110. System 550 provides dishwasher 100 with intelligent control of detergent and rinse aid dispensing to reduce risks of unsatisfactory cleaning results while increasing accuracy and efficiency in use of the chemical agents.

FIG. 6 is a flow chart illustrating an embodiment of a method 670 for dispensing a dishwashing agent in a dishwasher capable of performing cleaning cycles each including a washing period and a rinsing period for cleaning objects. An example of the dishwasher is dishwasher 100. Examples of the dishwashing agent include a detergent that is to be dispensed for the washing period and a rinse aid that is to be dispensed for the rinsing period. The dishwashing agent can be in liquid or solid form when contained in a dispenser.

At 671, a temperature of a liquid in a tank of the dishwasher. The liquid includes at least water. Examples of the tank includes a wash tank (e.g., wash tank 108) when the dishwashing agent is the detergent or a rinse tank (e.g., booster tank 110) when the dishwashing agent is the rinse aid.

At 672, a dispensing signal is generated using the sensed temperature. The dispensing signal is indicative of an amount of the dishwashing agent to be dispensed. The dispensing signal can be generated using the sensed temperature and a predetermined agent-temperature relationship between the amount of the dishwashing agent to be dispensed and the sensed temperature. The agent-temperature relationship can be in the form of a look-up table mapping each value or value range of the sensed temperature to a value of the amount of the dishwashing agent to be dispensed. The agent-temperature relationship can be determined using known characteristics of the dishwashing agent and/or experiments for the dishwashing agent to exert a desirable effect for each temperature or temperature range of multiple temperature or temperature range at that temperature or temperature range. The dispensing signal can be generated at the beginning of the washing or rinsing period, periodically during the washing or rinsing period, or in response to each significant change detected during the washing or rinsing period or detected between the cleaning cycles.

At 673, the amount of the dishwashing agent to be dispensed into the tank is controlled using the dispensing signal. At 674, the dishwashing agent is dispensed to be added to the liquid, for example in the tank or another point in the path of the liquid to be sprayed onto the objects. At 675, the liquid is sprayed onto the objects after the dishwashing agent is added to the liquid.

Method 670 can be performed in real time, including sensing the temperature in real time and generating the dispensing signal using the sensed temperature in real time. This allows dynamic adjustment of the amount of the dishwashing agent to be dispenses based on the instant temperature of the liquid, which may vary substantially during the operation of the dishwasher.

Performance of method 670 has been verified using a prototype apparatus implementing system 550. Plates were used as objects to be cleaned. Cleanness, dewetting, pinhole, and sheeting of the plates were checked after steps of method 670 were performed. The results verified the effectiveness of the washing and rinsing as expected.

Some non-limiting examples (Examples 1-22) of the present subject matter are provided as follows:

In Example 1, a dishwasher configured to perform cleaning cycles each including a washing period and a rinsing period for cleaning objects is provided. The dishwasher may include a tank, a temperature sensor, an agent dispenser, and a dispenser controller. The tank may be configured to receive water and a dishwashing agent to form a liquid including the received water and the received dishwashing agent. The liquid is to be applied to the objects. The temperature sensor may be configured to be placed in the tank to sense a temperature of the liquid. The agent dispenser may be configured to dispense the dishwashing agent into the liquid, to receive a dispensing signal indicative of an amount of the dishwashing agent to be dispensed, and to control the dispensing of the dishwashing agent according to the amount. The dispenser controller may be configured to receive the sensed temperature from the temperature sensor and to generate the dispensing signal based on the temperature.

In Example 2, the subject matter of Example 1 may optionally be configured such that the dispenser controller is configured to receive the sensed temperature from the temperature sensor and to control the agent dispenser using the received temperature in real time.

In Example 3, the subject matter of Example 2 may optionally be configured such that the agent disperser is configured to control the dispensing of the dishwashing agent by controlling a duration of the dispensing of the dishwashing agent.

In Example 4, the subject matter of Example 2 may optionally be configured such that the agent disperser is configured to control the dispensing of the dishwashing agent by controlling a volume or weight of the dishwashing agent to be dispensed.

In Example 5, the subject matter of Example 2 may optionally be configured such that the dispenser controller is configured to generate the dispensing signal based on the sensed temperature and a predetermined agent-temperature relationship between the amount of the dishwashing agent to be dispensed and the sensed temperature.

In Example 6, the subject matter of Example 5 may optionally be configured such that the dispenser controller is configured to generate the dispensing signal based on the sensed temperature and a look-up table mapping each value or value range of the sensed temperature to a value of the amount of the dishwashing agent to be dispensed.

In Example 7, the subject matter of Example 5 may optionally be configured to further include a user interface configured to receive the agent-temperature relationship.

In Example 8, the subject matter of any one or any combination of Examples 1 to 7 may optionally be configured such that the dishwashing agent includes a detergent to be dispensed during the washing period, the tank includes a wash tank configured to receive the water and the detergent to form a washing liquid of the liquid, the temperature sensor includes a washing temperature sensor configured to be placed in the wash tank to sense a washing temperature being the temperature of the washing liquid, and the agent dispenser includes a detergent dispenser configured to dispense the detergent into the washing liquid, to receive a detergent dispensing signal indicative of an amount of the detergent to be dispensed, and to control the dispensing of the detergent according to the amount, and such that the dispenser controller is configured to receive the sensed washing temperature from the washing temperature sensor and to generate the detergent dispensing signal based on the sensed washing temperature during the washing period.

In Example 9, the subject matter of Example 8 may optionally be configured the dishwashing agent further includes a rinse aid to be dispensed during the rinsing period, the tank further includes a rinse tank configured to receive the water and the rinse aid to form a rinsing liquid of the liquid, the temperature sensor further includes a rinsing temperature sensor configured to be placed in the rinse tank to sense a rinsing temperature being the temperature of the rinse aid, and the agent dispenser further includes a rinse aid dispenser configured to dispense the rinse aid into the rinsing liquid, to receive a rinse aid dispensing signal indicative of an amount of the rinse aid to be dispensed, and to control the dispensing of the rinse aid according to the amount, and such that the dispenser controller is further configured to receive the sensed rinsing temperature from the rinsing temperature sensor and to generate the rinse aid dispensing signal based on the sensed rinsing temperature during the rinsing period.

In Example 10, the subject matter of any one or any combination of Examples 1 to 7 may optionally be configured such that the dishwashing agent includes a rinse aid to be dispensed during the rinsing period, the tank includes a rinse tank configured to receive the water and the rinse aid to form a rinsing liquid of the liquid, the temperature sensor includes a rinsing temperature sensor configured to be placed in the rinse tank to sense a rinsing temperature being the temperature of the rinse aid, and the agent dispenser includes a rinse aid dispenser configured to dispense the rinse aid into the rinsing liquid, to receive a rinse aid dispensing signal indicative of an amount of the rinse aid to be dispensed, and to control the dispensing of the rinse aid according to the amount, and such that the dispenser controller is configured to receive the sensed rinsing temperature from the rinsing temperature sensor and to generate the rinse aid dispensing signal based on the sensed rinsing temperature during the rinsing period.

In Example 11, a method for operating a dishwasher is also provided. The dishwasher is configured to performing cleaning cycles each including a washing period and a rinsing period for cleaning objects. The method may include: sensing a temperature of a liquid in a tank, the liquid including at least water; generating a dispensing signal using the sensed temperature, the dispensing signal indicative of an amount of a dishwashing agent to be dispensed; dispensing the dishwashing agent into the liquid; controlling the amount of the dishwashing agent dispensed into the liquid using the dispensing signal; and spraying the liquid onto the objects after the dishwashing agent is dispensed into the liquid.

In Example 12, the subject matter of sensing the temperature as found in Example 11 may optionally include sensing the temperature in real time. The subject matter of generating the dispensing signal using the sensed temperature as found in Example 11 may optionally include generating the dispensing signal using the sensed temperature in real time.

In Example 13, the subject matter of generating the dispensing signal as found in Example 11 may optionally include generating the dispensing signal using the sensed temperature and a predetermined agent-temperature relationship between the amount of the dishwashing agent to be dispensed and the sensed temperature.

In Example 14, the agent-temperature relationship as found in Example 13 may optionally include a look-up table mapping each value or value range of the sensed temperature to a value of the amount of the dishwashing agent to be dispensed.

In Example 15, the subject matter of Example 14 may optionally further include determining the agent-temperature relationship for the dishwashing agent to exert a desirable effect for each temperature or temperature range of multiple temperature or temperature range at that temperature or temperature range.

In Example 16, the subject matter of generating the dispensing signal as found in Example 11 may optionally include detecting significant changes in the sensed temperature and generating the dispensing signal in response to each detection of the significant changes.

In Example 17, the subject matter of dispensing the dishwashing agent as found in Example 11 may optionally include dispensing a solid dishwashing agent.

In Example 18, the subject matter of dispensing the dishwashing agent as found in Example 11 may optionally include dispensing a liquid dishwashing agent.

In Example 19, the dishwashing agent as found in any one or any combination of Examples 11 to 18 may optionally include a detergent.

In Example 20, the dishwashing agent as found in Example 19 may optionally include a rinse aid.

In Example 21, the subject matter of sensing the temperature as found in Example 19 may optionally include sensing a washing temperature of a washing liquid in a wash tank. The subject matter of generating the dispensing signal as found in Example 19 may optionally include generating a detergent dispensing signal using the sensed washing temperature during the washing period, the detergent dispensing signal indicative of an amount of a detergent to be dispensed. The subject matter of dispensing the dishwashing agent as found in Example 19 may optionally include dispensing the detergent into the washing liquid. The subject matter of controlling the amount of the dishwashing agent dispensed into the tank as found in Example 19 may optionally include controlling the amount of the detergent dispensed into the washing liquid using the detergent dispensing signal. The subject matter of spraying the liquid as found in Example 19 may optionally include spraying the washing liquid onto the objects during the washing period after the detergent is dispensed into the washing liquid.

In Example 22, the dishwashing agent as found in any one or any combination of Examples 11 to 18 may optionally include a rinse aid. The subject matter of sensing the temperature as found in any one or any combination of Examples 11 to 18 may optionally include sensing a rinsing temperature of a rinsing liquid in a rinse tank. The subject matter of generating the dispensing signal as found in any one or any combination of Examples 11 to 18 may optionally include generating a rinse aid dispensing signal using the sensed rinsing temperature during the rinsing period, the rinse aid dispensing signal indicative of an amount of a rinse aid to be dispensed. The subject matter of dispensing the dishwashing agent as found in any one or any combination of Examples 11 to 18 may optionally include dispensing the rinse aid into the rinsing liquid. The subject matter of controlling the amount of the dishwashing agent dispensed into the tank as found in any one or any combination of Examples 11 to 18 may optionally include controlling the amount of the rinse aid dispensed into the rinsing liquid using the rinse aid dispensing signal. The subject matter of spraying the liquid as found in any one or any combination of Examples 11 to 18 may optionally include spraying the rinsing liquid onto the objects during the rinsing period after the rinse aid is dispensed into the rinsing liquid.

This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. The scope of the present invention should be determined with reference to the appended claims, along with the full scope of legal equivalents to which such claims are entitled.