This application relates generally to washing machines and more particularly to a method and apparatus for recirculating water in a washing machine such as a dishwasher.
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 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.
Common types of dishwashers include dump-and-fill type machines and recirculating type machines. Dump-and-fill type machines drain completely between washing and rinsing cycles, whereas recirculating type machines reuse wash water from cycle to cycle. Dump-and-fill type machines typically use a longer duration for cleaning and inherently waste water and energy, and recirculating type machines can leave residual detergent or soil and may require additional heating and machine complexity to maintain water temperature.
What is needed is an improved dishwasher that provides cleaner dishes, reduced cycle times and minimal additional heating or machine complexity.
A system and method for operating a recirculating chemical-sanitizing dishwasher includes filling a wash tank of the dishwasher with water, and performing a first cycle of washing by circulating the water through a wash chamber of the dishwasher. A partial drain is performed of a first amount of water from the bottom of the wash tank, and new water is injected into the wash tank in a second amount of water approximately equal to the first amount. A second cycle of washing is performed by circulating the water through the wash chamber of the dishwasher.
In one example, the first amount of water is approximately 20 to 30 percent of capacity of the wash tank. In some examples, the mini drain is performed several times over several cycles, and the wash tank is subsequently completely drained and refilled before proceeding with a next cycle.
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.
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.
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.
This application discusses, among other things, a chemical-sanitizing dish machine that utilizes a recirculating wash to save water, energy, and chemistry while maintaining proper wash water heat by draining a small portion of wash water prior to the rinse step (referred to herein as a partial drain or a mini-drain), running frequent cycles where the tank fully drains, and utilizing a small tank size.
The present system, apparatus and method provides a low-temperature, chemical sanitizing dish machine utilizing digital controls that allow operational modes that save water and energy and decrease total wash cycle time, to replace the current dump-and-fill low-temp dish machine, which is inherently wasteful in terms of water, energy, and chemistry. The present system enables running the machine in a recirculating mode to reuse wash water from cycle to cycle while maintaining wash temperature without a dedicated heat source, including preserving wash temperature by partially draining a portion of wash water prior to rinse introduction.
According to various embodiments, a recirculating system is provided where the tank is not fully drained every cycle, and the rinse is introduced through a separate set of rinse nozzles from a freshwater source. The present system maintains wash tank temp by utilizing a smaller tank size (approximately 2 gallons in an embodiment) and displaces a large amount of this with rinse water (approximately 0.75 gallons/rack in an embodiment). Additionally, a small portion of cooler wash water is drained (a partial drain or mini drain) from the bottom of the tank prior to the rinse being introduced. In some embodiments, the partial drain may be performed from other portions of the tank. In some embodiments, the tank is fully drained approximately once every 5 cycles to refresh the tank and manage food soil loads. Since these refresh cycles will introduce higher water volumes into the machine that need to be concentrated with additional chemistry, the present system may introduce a detergent boost on the cycle immediately following the tank refresh. This boost automatically lengthens the detergent dispense time by an amount proportional to the extra time that the fill valve is open during the refresh.
Various embodiments provide a system for operating a recirculating chemical-sanitizing dishwasher. The system includes a dishwasher with a wash tank, wash chamber and drain. A wash tank of the dishwasher is filled with water, and a first cycle of washing is performed by circulating the water through a wash chamber of the dishwasher. A partial drain is performed of a first amount of water from the bottom of the wash tank, and new water is injected into the wash tank in a second amount of water approximately equal to the first amount. A second cycle of washing is performed by circulating the water through the wash chamber of the dishwasher. In one example, the first amount of water is approximately 20 to 30 percent of capacity of the wash tank. In some examples, the partial drain is performed several times over several cycles, and the wash tank is subsequently completely drained and refilled before proceeding with a next cycle.
Benefits of the recirculating machine of
Benefits of the dump-and-fill machine of
In various embodiments, adding additional water in a second amount includes adding rinse water. In various embodiments, adding additional water includes adding water directly to the wash tank. Persons of skill in the art will appreciate that a variety of ways to add water to the tank may be employed without departing from the scope of the present subject matter.
According to various embodiments, the first amount of water is approximately 20 to 30 percent of capacity of the wash tank. In some embodiments, the method further includes performing a partial drain of the first amount of water from the bottom of the wash tank, injecting new water into the wash tank in the second amount of water approximately equal to the first amount, and performing a third cycle of washing by circulating the water through the wash chamber of the dishwasher. The method also includes performing a partial drain of the first amount of water from the bottom of the wash tank, injecting new water into the wash tank in the second amount of water approximately equal to the first amount, and performing a fourth cycle of washing by circulating the water through the wash chamber of the dishwasher, in various embodiments. In some embodiments, the method further includes performing a full drain of a third amount of water from the bottom of the wash tank, the third amount approximately equal to capacity of the wash tank, injecting new water into the wash tank in a fourth amount of water approximately equal to the third amount, and performing a fifth cycle of washing by circulating the water through the wash chamber of the dishwasher.
In various embodiments, the present subject matter provides a washing sequence including:
Those of skill in the art upon reading and understanding the present subject matter will appreciate that the order of steps and quantity of each step may vary without departing from the scope of the present subject matter.
In this application, a “dishwasher”, which can also be referred to as a dish machine, a warewasher or a warewashing machine, includes any type of wash machine that can use detergent for cleaning and/or sanitizing purposes. One example includes an undercounter dishwasher for washing dinnerware, flatware, pots and pans, cutlery, flatware, glasses, kitchenware, serving pans, trays, and so on. Commercial dishwashing equipment examples can also use the present subject matter. A dishwasher includes a washing tub formed by interior walls and a door of the dishwasher. In an example of the undercounter kitchen dishwasher, the door rotates up to about 90 degrees about a horizontal axis to switch between a fully closed state and to a fully open state. The door has an interior side and an exterior side that are both substantially vertical when the door is fully closed and substantially horizontal when the door is fully open.
A “cleaning cycle” can include other periods, such as one or more of a washing period, a rinsing period, and a drying period, depending on settings made by a user of the dishwasher. The door is opened at least once between two consecutive cleaning cycles to allow loading of the dishes and/or other objects to be cleaned and unloading of the cleaned dishes and/or other objects. “Cleaning” can include cleaning only, sanitizing only, or cleaning and sanitizing, depending on, for example, whether the solid detergent blocks are capable of cleaning only, sanitizing only, or cleaning and sanitizing. A “washing period” includes a period or operational mode that is intended for a cleaning mixture formed by water and detergent to be applied to the dishes and/or other objects. A “rinsing period” includes a period or operational mode that is intended for water, or water and a chemical rinsing aid and/or a chemical sanitizer, to be applied to the dishes and/or other objects. Some dishwashers (e.g., commercial dishwashers) may include a rinsing period that is primarily for sanitizing through heat and/or chemical means. A “drying period” includes a period or operational mode that is intended for the cleaned dishes and/or other objects to be dried by air flow and/or heat, without additional water and/or detergent applied. The dishwasher usually allows the user to choose whether to include the drying period in the cleaning cycle because the user can open the dishwasher door to allow the washed and rinsed dishes to dry naturally or remove the washed and rinsed dishes to another place for drying.
A batch of objects to be cleaned (for example, dishes) can be loaded into a tub of the dishwasher, typically including racks and utensil holders, 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 tub to blast the dishes. Typically, the cleaning mixture is then drained before the rinsing period starts. During the rinsing period, water is sprayed into the washing chamber to remove residue of the cleaning mixture. After the rinsing period complete 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).
Application in a dishwasher is discussed as an example, but not a limitation, for the present subject matter. The present system for can be applied in any washing machine that sprays water that can be partially drained during a cleaning cycle.
Some non-limiting examples (Examples 1-5) of the present subject matter are provided as follows:
In Example 1, a method for operating a recirculating chemical-sanitizing dishwasher may include providing a tank of water in a wash tank of the dishwasher, using the tank of water for a first wash process of the dishwasher, partially draining a first amount of water from the tank of water in the wash tank, adding additional water to the wash tank in a second amount approximately equal to the first amount, thereby creating a partially refreshed tank of water, wherein the additional water does not include the water drained from the tank, and using the partially refreshed tank of water for another wash process of the dishwasher. In various embodiments the steps of partially draining, adding additional water, and using the partially refreshed tank of water can be repeated a number of times, such as 1 to 5 times. In various embodiments, the method includes fully draining the wash tank. In various embodiments, the method includes adding new water to refill the wash tank. In various embodiments, the method includes using a rinse process for adding additional water. In various embodiments, the method includes using a rinse process for adding new water.
In Example 2, the subject matter of Example 1 may optionally be configured to further include the first amount of water may approximately 20 to 30 percent of capacity of the wash tank.
In Example 3, the subject matter of any one or any combination of Examples 1 and 2 may optionally be configured to further include partially draining the first amount of water from the partially refreshed tank of water, injecting new water into the wash tank in the second amount approximately equal to the first amount, thereby creating a second partially refreshed tank of water, and circulating the second partially refreshed tank of water through the wash chamber of the dishwasher.
In Example 4, the subject matter of Example 3 may optionally be configured to further include partially draining the first amount of water from the second partially refreshed tank of water, injecting new water into the wash tank in the second amount approximately equal to the first amount, thereby creating a third partially refreshed tank of water, and circulating the third partially refreshed tank of water through the wash chamber of the dishwasher.
In Example 5, the subject matter of Example 4 may optionally be configured to further include draining a third amount of water from the third partially refreshed tank of water, the third amount approximately equal to capacity of the wash tank, injecting new water into the wash tank in a fourth amount of water approximately equal to the third amount, thereby creating a fully refreshed tank of water, and circulating the fully refreshed tank of water through the wash chamber of the dishwasher.
In Example 6, the subject matter of Example 1 may further include dispensing detergent in an amount relating to the amount of fresh water injected into the wash tank.
In Example 7, the subject matter of Example 6 may optionally be configured where the dispensing is performed using a solid detergent chemistry.
In Example 8, the subject matter of Example 6 may optionally be configured where the dispensing is performed using a liquid detergent chemistry.
In Example 9, the subject matter of Example 6 may optionally be configured where the amount of detergent is proportional to the amount of new water injected into the wash tank.
In Example 10, the subject matter of Example 1 may optionally be configured where adding the additional water includes using rinse water.
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.
This patent application claims the benefit of U.S. Provisional Patent Application No. 63/328,200, filed Apr. 6, 2022, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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63328200 | Apr 2022 | US |