METHOD AND APPARATUS FOR ENERGY EFFICIENT WASH APPLIANCES

Abstract

An electronic controller used with a washing appliance, such as a dishwasher, operatively connected to a hot water delivery system having a hot water heater, hot water delivery piping, and a circulation pump that when activated circulates water in the delivery piping back to the hot water heater. The washing appliance structured to perform a cleaning process that includes a pre-wash cycle and a wash cycle that utilizes hot water received from the hot water delivery piping. The pre-wash cycle having a water fill step, a water spray step, and a water drain step. The electronic controller on sensing the completion of the water fill step, or, alternatively, the water spray step, sends a first signal to the circulation pump causing the pump to become activated, and upon sensing the completion of the water spray step, or, alternatively, the water drain step, sends a second signal to the circulation pump causing the deactivation of the pump.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates in general to washing appliances, and more particular to apparatus and methods for energy efficiently operating a dishwasher.

2. Prior Art

It is known that one of key factors for a dishwasher to properly clean dishes, cookware, silverware, glassware and other similar articles is supplying the dishwasher during the washing cycle with hot water at a predetermined temperature, typically at least 120° F. In a typical residential setting this hot water is supplied by a conventional hot water heater that is used to supply hot water not only to the dishwasher, but other water outlets such as found in showers, bath tubs, wash basins and kitchen sinks, as well as other washing appliances, such as a clothes washing machine. In this setting generally cool water from a municipal water company, or similar source, is supplied to the hot water heater under low pressure (typically, 15-120 psig). The hot water heater has gas or electrical heating units that then heat the water to the desired temperature. Because the hot water will be used in a shower, bath tub or wash basin, the temperature can not be set above about 120° F. to prevent burns to a person's body or hands. This hot water is then discharged from the hot water heater and through plastic or metal pipes to various hot water outlets, including the dishwasher.

The problem is that the discharged hot water cools as it sits in the pipes waiting for the dishwater water inlet valve or the hot water faucet of the other devices to be opened. As a result the water in the pipes is likely to be at some temperature significantly less than the desired 120° F., resulting in energy inefficient washing of the dishes or other articles. It is not until the cooled water has been emptied from the pipes and replaced with fresh hot water from the hot water heater at the desired 120° F. does one obtain at the dishwasher or hot water sink faucets or other washing appliances hot water at the desired temperature. Considering that the distance between the hot water heater and the dishwasher can be significant, not only is there a large water waste and loss of the energy used to initially heat the now cooled water, but it will likely take considerable time before hot water at the desired temperature arrives at the dishwasher water intake valve. In the case of a dishwasher this means that the dishes and other articles are not being cleaned for a significant portion of the dishwasher cleaning process at the temperature necessary to achieve the desired level of cleaning. This requires the dishwasher cleaning process to include more or longer washing cycles than would otherwise have been required.

One solution has been to utilize a return line that permits the hot water to be continuously circulated out of and back into the hot water heater when no hot water valve has been opened to better insure that the circulating water remains at the desired 120° F. temperature. Although this solution does result in maintaining the water at the desired temperature for effective cleaning, the energy costs to maintain the water at the desired temperature during the circulation, as well as the capital cost to install the return line makes such solution impractical. The capital cost in such circulation systems can be reduced by re-circulating the cooled hot water back to the hot water heater using the existing cold water line used to deliver cold water to the various appliances or sink faucets. However, the energy cost to continuously pump and reheat the water in the circulation lines makes even these modified systems economically impractical. Also, it is not possible for the other connected cold water outlets to receive cold water during the circulation process. Alternatively, it is necessary to install various control devices to stop the re-circulation when the home owner wants to use the cold water. In an attempt to reduce the energy costs of such systems more modern systems install a pump and pump controller in the circulation lines to reduce the time that the water is being circulated. In these systems until the pump is activated there is no circulation of the water through the circulation lines. To activate the pump a timer is utilized to regulate the time periods during a day that the pump will run. It is also known to utilize a temperature gauge to measure the water temperature in the circulation lines and to activate the pump once the water temperature has dropped below the set level. Finally, some the pump controllers will permit a manual activation of the pump. These systems still do not overcome the problems associated with using the cold water lines to re-circulate the cooled hot water back to the hot water heater for reheating to the desired 120° F. Although the use of such activation controls and equipment are in many cases effective in reducing the energy costs, the amount of reduction is generally less than what is desired. Part of the problem of such systems is that there is not some normal short time period in which one would wish to operate the dishwasher or other washing appliance. Thus, the pump may not be running at the desired time or may be running for too long a period to achieve the desired saving. In addition, manual activation of the pump controller may be very inconvenient depending on where the pump and pump controller are installed in the residence, or one may forget to activate the pump controller and thus lose all energy saving benefits.

A method or apparatus that would automatically provide real on-demand hot water at the desired 120° F. to a dishwasher or other washing appliance during its washing process at low energy costs would be of particular use to the home appliance industry.

OBJECTS AND SUMMARY OF THE INVENTION

Therefore, one object of this invention is to provide an electronic controller that will automatically activate a pump operatively positioned in a hot water delivery piping within a predetermined time period before a washing appliance, such as a dishwasher is activated to begin the wash cycle of the washing process.

Another objective of this invention is to provide on-demand hot water at a desired temperature to a washing appliance that permits other hot water faucets to receive the hot water at the same time as the washing appliance.

Still another object of this invention is to provide an electronic controller that will activate a circulation pump in a hot water delivery line upon receipt of a signal from the washing appliance controller representative of a predetermined time period before a washing appliance is activated to begin its wash cycle.

A further object of this invention is to provide a relatively inexpensive and easy to install electronic connection between the dishwasher controller and the pump controller permitting a signal from the dishwasher controller to be received by the pump controller for the purpose of activating the circulation pump a predetermined period of time prior to beginning the dishwasher wash cycle.

A still further object of this invention is to provide a relatively inexpensive and easy to install after-market electronic connection between the dishwasher controller and the pump controller permitting a signal from the dishwasher controller to be received by the pump controller for the purpose of activating the circulation pump a predetermined period of time prior to beginning the dishwasher wash cycle.

An alternative object of this invention is to provide an energy efficient method to wash dishes, pots and pans, silverware, glassware and other similar objects utilizing during a dishwasher washing cycle hot water at a desired temperature.

Another alternative object of this invention is to provide a method utilizing a signal from the dishwasher controller to ensure an energy efficient delivery from a hot water heater of hot water at a desired temperature to the dishwasher during the washing cycle.

A still further object of this invention is to provide a method utilizing a signal from the dishwasher controller representative of the completion of the water fill step, or, alternatively, the water spray step, of the washing process to activate the circulation pump, and utilizing a signal from the dishwasher controller representative of the completion of the water spray step, or, alternatively, the completion of the water drain step of the washing process to deactivate the circulation pump.

These and other objects of this invention shall become apparent from the ensuing drawings and descriptions of the invention.

Accordingly, an electronic controller for use with a hot water delivery system comprising a hot water heater, hot water delivery piping and a circulation pump operatively connected to circulate hot water from the hot water heater through the hot water delivery piping and back to the hot water heater when the circulation pump is activated, and for use with a washing appliance having a hot water inlet valve and operatively connected to the hot water delivery system to receive hot water from the hot water delivery piping when the hot water inlet valve is open, wherein the washing appliance performs a washing process comprising a pre-wash cycle and a wash cycle, the pre-wash cycle including a water fill step, a water spray step, and a water drain step, the electronic controller constructed (a) upon sensing completion of the water fill step or the water spray step to send a first signal to activate the circulation pump and (b) upon sensing the completion of the water spray step or the water drain step to send a second signal to deactivate the circulation pump.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate a preferred embodiment of this invention. However, it is to be understood that this embodiment is not intended to be exhaustive, nor limiting of the invention. It is but one example of the construction of this invention.

FIG. 1 is an illustration of a prior art home hot water circulation system having dedicated hot water pipes to permit hot water to be circulated from the hot water heater to the various home fixtures utilizing hot water and then back to the hot water heater.

FIG. 2 is an example of a prior art dishwasher illustrating only those components needed for an understanding of this invention.

FIG. 3 illustrates a typical control panel of the dishwasher controller that permits the dishwasher operator to select the wash procedure program to be executed by the dishwasher.

FIG. 4 is an example of a typical prior art dishwasher wash cycle progression.

FIG. 5 is an electrical circuitry schematic of a typical dishwasher.

FIG. 6 is an electrical circuitry schematic of the device of this invention that can be used with the electrical circuitry schematic of FIG. 5.

PREFERRED EMBODIMENTS OF THE INVENTION

Without any intent to limit the scope of this invention, reference is made to the figures in describing the preferred embodiments of the invention for use in washing dishes and other articles in a dishwasher.

Referring now to FIG. 1, a conventional residential hot and cold water delivery system 1 for use in a residence, office building or similar type construction is illustrated that incorporates a hot water return system 2 including a hot water return line 3, a hot water circulation pump 4 that is activated and deactivated by a timer assembly 5. In this configuration cold water from an outside source, such as a municipal water company or water well, is delivered under pressure of typically 15-120 psi to the building 6 through a cold water pipe 7. For each plumbing fixture or appliance that utilizes cold water, pipe 7 will have pipe t-connectors to permit the cold water in pipe 7 to be circulated through auxiliary cold water pipes 7A-7G to the respective plumbing fixture, such as showers, toilets and wash basins, and respective washing appliances, such as clothes washers and dishwashers. Each of the auxiliary cold water lines 7A-7G is operatively connected downstream to the cold water valve 8A-8G, respectively, used to control the flow of cold water into the fixture or appliance. When the cold water valves 8A-8G are opened cold water will flow into the corresponding fixtures and appliances as desired. These fixtures and appliances are typically provided with drains that connect to the building sewer lines to permit the cold water to flow to the sewer lines.

A portion of the cold water from the municipal water company or water well is delivered through separate water pipe 9 to a hot water heater 10 by its inlet valve 11. When the inlet valve 11 is opened the cold water will flow into the hot water heater 10 that is provided with one of the conventional heating assemblies 12 to raise the water temperature to a predetermined level. This level is determined by the use that will be made of the water. One use that is common in most buildings 6 is delivery of the hot water to a sink 13 used for a person to wash their hands. To prevent the person from being burned by the hot water delivered to the sink 13, the desired temperature of the water in the hot water heater 10 is generally set at 120° F.

One of the undesired features of the typical hot water delivery system 14 is the heated water may leave the hot water heater 10 at 120° F., but if it there are no open hot water valves open, it will sit in the hot water pipes 15 and auxiliary hot water pipes 15A, 15C-15D, and 15F-15H and begin to cool. The longer it sits the cooler it is likely to become. Thus, when one of the hot water valves 16A, 16C-16D, 16F-16G or 33 is ultimately opened the initial water flowing through the valve will not be at the desired temperature. It is not until enough of the cooled water flows through the opened hot water valve that hot water at the desired temperature will be delivered through the opened hot water valve. Depending on the distance between the hot water heater 10 and the opened hot water faucet valve, the insulation on the hot water pipe 15 and auxiliary hot water pipes 15A, 15C-15D, and 15F-15H, the temperature within the areas of the building 6 that the pipes 15, 15A, 15C-15D, and 15F-15H are located, and the frequency in which the various hot water valves are opened and closed, the longer the time and the more of the cooled water that must be drained before hot water at the desired temperature is received.

Not even considering the frustration for waiting until the hot water arrives, in a typical residence occupied by a family of four it has been estimated that up to 14,000 gallons of water per year are wasted waiting for the hot water to arrive at the desired temperature. In addition the cost to heat the original 14,000 gallons of water is substantially lost.

This problem is particularly acute for dishwashers 17 and clothes washers 18, which are generally the appliances utilizing the most hot water, whose various washing cycles depend on the hot water entering the appliance to be at 120° F. for their washing cycles to be effective and energy efficient.

One solution to this problem has included operatively connecting hot water pipe 15 to cold water line 7 in a manner to permit the hot water to be circulated to hot water heater 10. This solution has several major drawbacks. Additional plumping and controls must be utilized to allow simultaneous demand for both cold water and hot water at one or more of the wash basins, showers, etc. In addition, because the cold water in cold water line 7 is delivered under 15-120 psi pressure, this solution requires more pump energy to overcome this cold water pressure to effect the circulation of the hot water back to the water heater 10.

An alternate solution which is illustrated in FIG. 1 has been the extension of the main hot water pipe 15 to circulate back to the hot water heater 10. Although this solution requires extra capital expense to install the extension of hot water pipe 15, this expense can be justified by the energy savings costs. However, these savings are significantly reduced by the energy costs to operate circulation pump 4.

In this solution operatively connected in hot water delivery line 15 is circulation pump 4. Pump 4 is preferably positioned in hot water return line 3 after the last fixture or appliance that utilizes the hot water, and, more preferably, in close proximity to this last fixture or appliance. Thus, when activated pump 4 will circulate the cooled hot water back to the hot water heater 10. In current hot water delivery systems providing for circulation of the hot water back to hot water heater 10, pump 4 is activated and deactivated by a timer control assembly 5 that can be manually activated or set to activate pump 4 at specific time intervals for specified time intervals. These modified “on-demand” hot water circulation systems permit circulation of the hot water in line 15 during predetermined times back to the hot water heater 10 to better ensure that the hot water will be delivered at the desired 120° F. to a hot water fixture valve 16A, 16C-16D, 16F-16G or 33 when it is opened. These modifications while satisfying to some extent the need to deliver “on demand” the hot water at the desired 120° F. to the hot water fixture valve 16A, 16C-16D, 16F-16G or 33, do so at increased capital expense and with only a small reduction in energy costs due to the frequency when the circulation pump 4 must be activated to satisfy the “on demand” hot water delivery. In addition, the timer controller assembly 5 is impractical because the time period when a hot water fixture valve 16A, 16C-16D, 16F-16G or 33 may be opened is not consistently the same. The use of a manual or a RF control switch is also impractical because the number of hot water fixture valves is numerous and the capital costs to install a large number of such switches would reduce to a great extent any energy saving achieved. In addition limiting the number of switches then makes their use inconvenient and still would not allow for the “on demand” delivery of the hot water at the desired 120° F.

However, it has now been found that the “on demand” delivery of the desired 120° F. hot water for washer appliances, such as a dishwasher 17 or clothes washer 18 can be achieved with minimal capital costs while at the same time achieving significant reduction in energy costs. This is achieved by utilizing the existing start or pre-wash cycle transmitted signals from the electronic controller of the washer appliance to timely activate and then de-activate, respectively, the hot water delivery line circulation pump 4. This may be achieved utilizing a hard wired, RF or other known electronic transmitter device that will transmit the selected signals to the controller of pump 4 or to timer controller 5 that is operatively connected to the controller of pump 4. The preferred embodiments of this invention are described utilizing a conventional dishwasher 17.

FIG. 2 illustrates the major components of a conventional dishwasher 17 relevant to this invention. Dishwasher 17 has an electronic controller 20 in which at least one wash procedure program for controlling the various cycles of the wash procedure for the items to be washed is stored. Typically, a number of wash procedure programs are stored in controller 20, so that by selecting a suitable wash procedure program, the sequence of a wash procedure directed by the controller 20 can be custom adapted to the amount of the items loaded in the dishwasher 17 for cleaning, the degree or type of soiling of the items and/or the desired duration of each of the wash procedure cycles. The wash program can in this case include at least one pre-wash cycle, at least one wash cycle, at least one rinse cycle and at least one drying cycle. Some dishwasher controllers have wash procedure programs that can modify the procedure steps from temperature, turbidity and other operating conditions during the wash procedure.

The operator of dishwasher 17 can select the desired stored program by pressing the appropriate program activator buttons 21 on the control panel interface 22 of controller 20, such as illustrated in FIG. 3. The interface 22 may also include a digital display 23 indicating the selection made by the operator or other information.

Dishwasher 17 comprises a washing compartment 24 formed by side and back walls 25 and a front wall 26 capable of being closed off by a door 27. In FIG. 2, door 27 is shown in the closed position. The door 27 is able to be moved into an opened position, in which it is essentially aligned horizontally, by hinging it around an axis arranged at right angles to the plane of the drawing and which allows dishes to be loaded or unloaded. Controller interface 22 is typically affixed to the front wall 26 or to door 27 in a position that allows the operator to easily select the desired washing process.

Dishwasher 17 has an upper basket 28 and a lower basket 29 for holding the various items to be washed. In this case the upper basket 28 is arranged on telescopic rails 30 which are attached to the inside wall surface 31 of side walls 25 of the washing container 24 in a manner that permits upper basket 28 to be pulled out from the washing compartment 27 when door 26 is opened. The lower basket 29 is arranged in a similar manner on telescopic rails 32.

Dishwasher 17 also includes a schematically represented hot water feed 33 that receives hot water from hot water delivery line 15H. In this embodiment hot water feed 33 has a valve 34, such as a magnetic valve which is able to be electronically opened and closed by controller 20, as well as a feed hose 35. The input side of valve 34 is embodied so that it can be attached to a connecting member 36 of the output side of a standard water faucet 37 whose input side is operatively connected to hot water delivery line 15H to receive the hot water. The output side of valve 34 is connected to feed hose 35, with its downstream end being operatively affixed by a connecting member 38 to the back wall 39 of washing compartment 24 to permit hot water HW flowing through valve 34 and hose 35 to enter into washing compartment 27. In a preferred embodiment a temperature sensor 34A is operatively positioned in the proximity of faucet 37 to measure the water temperature of the hot water that will flow through valve 34. Temperature sensor 34A is embodied to transmit signals to controller 20 representative of measured temperature.

The bottom portions of front wall 26, side and back walls 25, along with floor 40 of washing container 24 form sump 41 having a drain area 42 in which hot water entering into washing compartment 27 collects. Sump 41 is operatively connected to a dishwasher water circulation pump 43 to circulate water collected in sump 41 to a heater 44 and then to a water switch 45. Controller 20 is operatively connected to pump 43, heater 44 and to switch 45 to control their operations during the washing process. In this illustration heater 44 is embodied as a continuous water heater, although other known heating devices can be used to heat the water or the air inside of the washing compartment 24.

Water switch 45 is used to direct the water (and other cleaning compounds if present) in sump 41 to the upper rotating spray arm 46 and the lower rotating spray arm 47 having nozzles that direct the water spray WS into the upper basket 28 and the lower basket 29, respectively. Further water outputs can also be provided if desired.

To be able to control heater 44, a temperature sensor 48 is positioned in drain area 42 to detect the temperature of the collected water. Temperature sensor 48 is operatively connected to controller 20 whereby a signal representative of the temperature readings from sensor 48 is received by controller 20. Utilizing these temperature readings, controller 20 can alter the selected wash procedure to better ensure a more efficient cleaning of the items in baskets 28 and 29. Similarly, a turbidity measurement device (not shown) can also be positioned in drain area 42 to measure the turbidity of the water in drain area 42. Likewise the controller 20 can be operatively connected to the turbidity measurement device to receive signals representative of the turbidity readings, and with the use of these readings alter the selected wash procedure to better ensure a more efficient cleaning of the items.

Dishwasher 17 can also be provided with a dosing device 49, typically positioned on door 27, which can be activated by controller 20 to dispense cleaning compounds or rinsing aids into the water collected in sump 41.

Furthermore, dishwasher 17 has a drain pump 50 that when activated by controller 20 will drain waste water WW in sump 41 out of the washing compartment 27 after a pre-wash cycle, a wash cycle or a rinsing cycle via a drain valve 51 that typically directs the water to the sewer line 52 for the home. Controller 20 is also operatively connected to drain valve 51 to open or close drain valve 51 depending on the amount of time that a particular cycle has been active.

FIG. 4 illustrates what cycles a typical dishwasher undergoes depending on whether a “heavy” or “normal” or “quick” or “rinse” wash procedure is selected. As indicated above, the human operator utilizing the controller interface 22 can select what wash procedure is to be utilized by dishwasher 17. Based on the selected wash procedure, the activation of dishwasher 17 initiates electronic controller 20 to begin sending at predetermined time intervals a series of program signals to the various components of the dishwasher to permit the dishwasher to execute the programmed pre-wash, wash, rinse and dry cycles used to clean the dishes, glasses, cookware and other articles placed in the dishwasher for cleaning. In this illustration the components include the water fill valve 34, drying fans 66, water circulation pump 43, drain pump 50, water heater 44, and soap and or water conditioner dosing device 49. These signals are transmitted by use of an electrical circuitry 53 such as illustrated in FIG. 5. The specifics of the electrical circuitry 53 vary from dishwasher manufacturer and dishwasher model.

In operation the wash procedure is first selected. In this electrical circuitry a low voltage (12V) source 54 will deliver power to controller 20 through low voltage DC lines 55 and 56. However, until door switch 57 is closed by the closing of dishwasher door 27, the low voltage DC current from controller 20 cannot flow to various solenoids 58-61 of the relays in the electrical circuitry 53 used to control water valve 34, soap dispenser 49, drain pump 50, drain valve 51, respectively. Once dishwasher door 27 is closed and the controller interface start button 62 has been pushed, the controller 20 utilizing the program for the wash procedure selected will begin transmitting signals at predetermined time periods to the various selected transistor switches SW1-SW8 to close the electrical circuit to corresponding dishwasher components and water overflow monitor to be utilized in a particular step of the active cycle as indicated in FIG. 5.

In one embodiment of the invention, dishwasher controller 20 is operatively connected to circulation pump 4 that is operatively positioned in hot water return line 3, and to timer 63 and programmed when start button 62 is activated to send a first pump signal to start pump 4 to begin circulating the water in hot water delivery line 15 through hot water return line 3 to the hot water heater and to initial timer 54 to for a predetermined amount of time. After the predetermined amount of time timer 54 will transmit a first timer signal to controller 20 that the predetermined amount of time has expired. Controller 20 will then transmit a second pump signal to stop pump 4. At the same time controller 20 would send a first fill signal to valve 34 causing valve 34 to open and permit the hot water to enter the washing compartment 24. The predetermined amount of time is set to ensure that hot water from line 15H will enter dishwasher 17 at the predetermined temperature, which is typically 120° F.

In an alternate embodiment of some dishwashers, the operator may select a specific time for the wash procedure to begin by programming a delay start time into timer 63 forming part of controller interface 22. In this embodiment activating the start button 62 will activate the delay timer 63 to begin tracking the selected delay start time. When the delay start time has occurred, delay timer 63 will send the delay time completion signal to controller 20. Upon receipt of this signal controller 20 will commence operation of the selected wash procedure.

In this alternate embodiment the controller program upon receipt of the delay start completion signal will also transmit the first pump signal to start pump 4 to begin circulating the water in hot water delivery line 15 through hot water return line 3 to the hot water heater 10 and to delay timer 63 to begin counting a predetermined amount of time. After the predetermined amount of time, timer 63 will transmit a first timer signal to controller 20 that the predetermined amount of time has been reached. Controller 20 will then transmit a second pump signal to stop pump 4. At the same time controller 20 would send a first fill signal to valve 34 causing valve 34 to open and permit the hot water to enter the washing compartment 27.

Depending on the controller electrical circuitry there are other alternative electrical paths the signals can be sent and still be within the scope of this invention. Important in this embodiment of the invention is that controller 20 will utilize a received signal prior to initiation of the washing cycle to start the circulation pump 4, that the pump 4 be allowed to operate for a predetermined period of time before it is stopped and fill valve 34 is opened.

In another alternate preferred embodiment, a temperature sensor 64 will be operatively positioned in the hot water delivery line 15H near the hot water feed into water faucet 37, and embodied and operatively attached to controller 20 to send, after pump 4 has been started, a first temperature signal to controller 20 when it senses the hot water in line 15 has reached the predetermined temperature. In this embodiment controller 20 would use the first temperature signal to transmit the second pump signal to stop pump 4. At the same time controller 20 would use the first temperature signal to transmit a first fill signal to valve 34 to cause valve 34 to open and permit the hot water to enter the washing compartment 27.

In most normal wash procedures of a dishwasher the first step is a pre-wash cycle. The purpose of this pre-wash cycle is to remove the larger food particles from the items being cleaned. In this step while it is preferred that the water temperature be at least 120° F. the use of water at that temperature is less critical, as the dishwasher is relying on the force of water sprayed onto the items to remove these larger food particles. The first step in the pre-wash cycle is to open the dishwasher fill valve 34 to permit water in the hot water delivery line to fill the dishwasher tub or sump area 41 with a pre-determined amount of water. A typical dishwasher will hold about 1.2-1.5 gallons of water in its tub or sump area 41, and depending on the manufacturer of the dishwasher this first step generally takes 40-90 seconds. At the end of this first pre-set time period the controller 20 will power solenoid 72 of relay 73 to connect the 110 AC circuit to wash pump 43 that will draw the water into its intake port and from its discharge port direct it into a water line operatively connected to one or more spray arms 46, 47 positioned within dishwashing compartment 27. Water from the spray arms 46, 47 will strike the articles in the dishwasher with sufficient force to dislodge the larger food particles from the articles. At the end of the spray portion of the pre-wash cycle which typically takes 4-8 minutes, the dishwasher controller 20 will send a second signal to the wash pump 43 to deactivate the wash pump 43. It will then transmit a third signal to a drain pump 50 and drain valve 51 to open the drain valve 51 and to activate the drain pump 50 to remove from the dishwasher the water and suspended food particles that has settled back into the dishwasher tub or sump area 41. The draining of the water and suspended food particles typically takes 40-60 seconds.

It is common that the water and suspended food particles stream that is being pumped from the dishwasher 17 will be sent through drain pipes to a sewer line 52. As the water and suspended food particles leave the dishwasher it is typical in many of the more expensive dishwashers for them to pass through a glass tube for measurement of the turbidity of the stream by a turbidity sensor. It is also common that that turbidity sensor 65 has an associated tub thermistor positioned at the bottom of the dishwasher tub to measure the temperature of the stream being drained from the dishwasher 17. In such dishwashers a signal representative of the measured turbidity and temperature level is transmitted to the dishwasher controller 20 which uses this information to determine if a second pre-wash cycle is needed to achieve the desired level of pre-wash cleaning. In most wash options there will be one to four pre-wash cycles.

If it is not necessary for the hot water to be at 120° F. during the pre-wash cycle, then, in an alternate embodiment, controller 20 can utilize the signals associated with the pre-wash cycle to ensure that the hot water is at 120° F. for the next wash cycle. More particularly, controller 20 can use the transmission of the signal transmitted to activate the drain valve 50 and/or drain pump 51 to transmit the first pump signal to pump 4 to start the circulation of the water in hot water delivery line 15 back to hot water heater 10 as before. Then controller 20 can use the transmission of any one or more of the signals transmitted to drain valve 50 and/or drain pump 51 to close drain valve 50 and/or stop drain pump 51. Alternatively, controller can use the transmission of the signal to open fill valve 34 to transmit the second pump signal to stop pump 4. It has been found that the time period between the initiation of draining the sump area 41 and the commencement of re-filling of the sump area 41 provides sufficient time to circulate the water in hot water delivery line 15 back to the hot water heater 10, reheat the water to the desired temperature, and then return the reheated water back in hot water delivery line 15 to refill valve 34. Thus, the objects of this invention can be achieved utilizing the already programmed controller circuitry to provide the necessary signals to the circulation pump 4.

The only hardware required is a simple circuit such as illustrated in FIG. 6. In this circuit the low voltage DC (12V or 24V) line 74 is used to power solenoid 75 forming part of relay 76 to close switch 77 that completes the high voltage AC (120V) circuit used to operate circulation pump 4. A transistor switch 78 is operatively connected to the neutral line 79 from solenoid 75. Controller 20 would be programmed to transmit the first pump signal to transistor switch 78 to close switch 78, and, thus, activate pump 4 when it is desired to circulate the hot water in line 15 back to hot water heater 10. Controller 20 would also be programmed to transmit the second pump signal to transistor switch 78 to open switch 78 to shut off pump 4 when it is desired to stop the circulation of hot water in line 15.

Once the pre-wash cycle or cycles are completed the dishwasher controller will send another signal to activate whatever mechanism 49 is used to permit the cleaning detergent to be emptied into the dishwasher tub or sump area 41. The controller 20 will then again activate the inlet water valve 34 to open to re-fill the tub or sump area 41 with hot water. It is at this juncture of the washing cycle that it is most critical that the fill water be at 120° F. to ensure that the items are properly washed to remove any oils or other material remaining on the articles to be removed. Should it be desired that the water be at a higher temperature a dishwasher is typically provided with heating rods or other type heater 44 that can be used to further heat the water. At the end of a wash cycle that, depending on the wash procedure selected, will take 5-45 minutes, the water and suspended material that settle back into the sump area 41 is drained. If desired more than one wash cycle can be used in the cleaning. Once the wash cycle or cycles have been completed, the dishwasher controller again activates the water inlet valve 34 to refill the tub to begin a rinse cycle that sprays the articles to remove any soap or soap residue that are on the articles. In many cases it is desirable that the water temperature during the rinse cycle also be at the desired 120° F. to achieve a more efficient removal of the soap from the washed articles, as well as to maintain the higher temperature within the dishwasher cavity for the subsequent drying cycle. This can be achieved by using the controller signal sent to the drain valve 51 and drain pump 50 at the end of the wash cycle to activate the circulation pump 4, and by using the controller signal sent to the water fill valve 34 to begin the water fill for the rinse cycle. Again using the information from the turbidity sensor 65 the dishwasher controller can determine if an additional rinse cycle is necessary to obtain the desired cleaning. Once the rinse cycles are completed, the dishwasher controller 20 activates transistor switches SW2 and/or SW3 to complete the electrical circuit to one or more fans 66 positioned inside the dishwasher, as well as activates the heating rods 67 by sending electrical power to solenoids 68 and 69 to activate the associated heater relays 70 and 71, respectively to create a hot air flow over the articles to assist in the drying of the articles.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

1. An electronic controller for use with a hot water delivery system comprising a hot water heater, hot water delivery piping and a circulation pump operatively connected to circulate hot water from the hot water heater through the hot water delivery piping and back to the hot water heater when the circulation pump is activated, and for use with a washing appliance having a hot water inlet valve operatively connected to the hot water delivery system to receive hot water from the hot water delivery piping when the hot water inlet valve is open, wherein the washing appliance performs a washing process comprising a pre-wash cycle and a wash cycle, the pre-wash cycle including a water fill step, a water spray step, and a water drain step, the improvement to which comprises:

a. the electronic controller upon sensing completion of the water fill step or the water spray step or initiation of the water drain step being constructed to send a first signal to activate the circulation pump, and

b. the electronic controller upon sensing the completion of the water spray step or the water drain step to send a second signal to deactivate the circulation pump.

2. The electronic controller according to claim 1 wherein the electronic controller upon sensing initiation of the water drain step being constructed to send a first signal to activate the circulation pump, and upon sensing the completion of the water drain step to send a second signal to deactivate the circulation pump.

3. In an assembly for operation of a dishwasher including:

a. the dishwasher having a body forming an interior cavity having a sump area, a water inlet valve operatively attachable to a hot water source, a washing system, a heater system, a drain system, and an electronic controller operatively attached to (i) the water inlet valve to close or open the water inlet valve, (ii) upon receiving wash process signals from the controller, the washing system to initiate at least one of a pre-wash cycle, a wash cycle and a rinse cycle, (iii) upon receiving water draining signals from the controller, the drain system to initiate a water drain step to remove water from the dishwater sump, and (iv) upon receiving drying cycle signals from the controller the heater system to initiate a drying cycle;

b. a hot water delivery system including a hot water heater, a first pipe operatively connected to the hot water heater to receive heated water from the hot water heater and operatively connected to a circulation pump constructed when activated to pump heated water from the first pipe to a second pipe operatively connected to the hot water heater for delivery of the heated water back to the hot water heater for reheating; the improvement to which comprises the electronic controller constructed to transmit a first signal representative of (i) completion of the water fill step, (ii) initiation of the water spray step, (iii) completion of the water spray step or (iv) initiation of the water drain step of the pre-wash cycle to the circulation pump to activate the circulation pump, and to transmit a second signal representative of the completion of the pre-wash cycle to the circulation pump to deactivate the circulation pump.

4. The assembly of claim 3 further comprising the electronic controller constructed to transmit a third signal to the water inlet valve to open the water inlet valve and permit the heated water to flow though the water inlet valve and into the dishwasher cavity.

5. A method utilizing heated water from a hot water heater for supplying hot water at a pre-determined temperature to a dishwasher upon initiation of a wash cycle of the dishwasher by an electronic controller transmitting a signal to open a water inlet valve operatively attached to the hot water heater by a hot water deliver piping to receive the hot water upon opening of the water inlet valve, wherein the hot water delivery piping comprises a first pipe operatively attached at one end to the hot water heater and operatively attached at an opposite end to the water inlet valve, a second pipe operatively attached at one end to the first pipe and operatively attached to an intake port of a circulation pump, and a third pipe operatively attached at one end to a discharge port of the circulation pump and operatively attached at an opposite end to the hot water heater; comprising the steps of:

a. sending a first signal from the controller upon activation of a pre-determined pre-wash cycle to the circulation pump to activate the circulation pump, and

b. sending a second signal from the controller upon completion of a water drain step of the pre-determined pre-wash cylce to the circulation pump to de-activate the pump.

6. A method utilizing heated water from a hot water delivery system comprising a hot water heater, a hot water delivery piping operatively attached to the hot water heater to receive hot water from the hot water heater and to circulate the heated water back to the hot water heater upon activation by a controller of a circulation pump operatively attached to the hot water delivery piping, the hot water delivery piping operatively connected to a dishwasher to deliver hot water through the hot water delivery piping at a pre-determined temperature to the dishwasher upon initiation of a wash cycle of a pre-determined washing process of the dishwasher, comprising:

a. sending to the circulation pump a first signal from the controller upon the controller sensing completion of a water fill step or a water spray step or initiation of a water drain step of a pre-determined pre-wash cycle of the washing process, the first signal causing activation of the circulation pump, and

b. sending to the circulation pump a second signal from the controller after a predetermined period of time prior to the initiation of the wash cycle of the washing process, the second signal causing deactivation of the circulation pump.

7. The method according to claim 6 wherein

a. the dishwasher comprises a dishwasher controller that transmits control signals to selected components of the dishwasher to initiate and complete the water fill step, the water spray step, and the water drain step of the pre-wash cycle;

b. the controller is the dishwasher controller;

c. the water fill step includes the controller sending a first water inlet valve signal to the water inlet valve causing opening of the water inlet valve operatively connected to the hot water delivery piping to receive hot water from the hot water heater, maintaining the water inlet valve opened for a pre-determined period of time to permit the received hot water to collect in an interior sump area of the dishwasher, and upon expiration of the pre-determined time the controller sending a second water inlet valve signal to the water inlet valve causing closing of the water inlet valve;

d. the water spray step includes the controller sending a first sump pump signal to the sump pump of the dishwasher causing activation of the sump pump operatively positioned upon activation to collect the hot water collected in the interior sump area and to deliver the collected hot water to a spray arm having nozzles positioned to direct the collected hot water to contact articles to be washed, and the controller sending a second sump pump signal to the sump pump causing deactivation of the sump pump to terminate the collection of the hot water from the interior sump area;

e. the water drain step includes the controller sending a first drain valve signal to a drain valve of the dishwasher located in the interior sump area causing opening of the drain valve to permit water collected in the interior sump area to be removed from the dishwasher, the controller sending a first drain pump signal to a drain pump of the dishwasher positioned to collect water in the interior sump area causing activation of the drain pump to direct the collected water to the drain valve, after a pre-determined period of draining time, the controller sending a second drain pump signal to the drain pump causing deactivation of the drain pump and sending a second drain valve signal to the drain valve causing closing of the drain valve;

f. sending the first signal by the controller to the circulation pump upon sending one of the following signals (i) second water inlet valve signal, (ii) first sump pump signal, (iii) second sump pump signal, (iv) first drain valve signal, or (v) first drain pump signal.

8. The method according to claim 7 wherein

a. the first signal is sent to the circulation pump when the second water inlet valve signal is sent to the water inlet valve, and

b. the second signal is sent to the circulation pump upon sending one of the following signals: (i) second sump pump signal, (ii) the first drain valve signal, (iii) the first drain pump signal, (iv) the second drain valve signal, or (v) the second drain pump signal.

9. The method according to claim 7, wherein:

a. the first signal is sent to the circulation pump when the first sump pump signal is sent to the sump pump, and

b. the second signal is sent to the circulation pump upon sending one of the following signals: (i) second sump pump signal, (ii) the first drain valve signal, (iii) the first drain pump signal, (iv) the second drain valve signal, or (v) the second drain pump signal.

10. The method according to claim 7, wherein:

a. the first signal is sent to the circulation pump when the second sump pump signal is sent to the sump pump, and

b. the second signal is sent to the circulation pump upon sending one of the following signals: (i) the second drain valve signal, or (ii) the second drain pump signal.

11. The method according to claim 7, wherein:

a. the first signal is sent to the circulation pump when the first drain valve signal or the first drain pump signal is sent to the sump pump, and

b. the second signal is sent to the circulation pump upon sending one of the following signals: (i) the second drain valve signal, or (ii) the second drain pump signal.