Patent Publication Number: US-2012031433-A1

Title: Material delivery systems and methods

Description:
RELATED APPLICATIONS 
     This patent application is a Divisional Application of and claims priority to U.S. patent application Ser. No. 11/960,350, filed on Dec. 19, 2007, now U.S. Pat. No. 8,002,898, issued on Aug. 23, 2011. Priority is hereby claimed to this patent application, the entirety of which is hereby incorporated by reference. 
    
    
     FIELD 
     The invention generally relates to material dispensing systems. More specifically, the invention relates to methods and systems of operating and controlling material dispensing systems. 
     BACKGROUND 
     As washing machines (e.g., dish washers, create washers, bottle washers, instrument washers, clothes washers, etc.) have become more sophisticated, systems have been implemented to automatically feed such machines with products (e.g., detergents, sanitizers, rinse aids, chemicals, and the like) which may be produced in liquid, condensed, compressed, granulated, and/or powdered form. Such materials may be automatically delivered to a variety of types of washing machines, and their concentration monitored using a variety of methods. 
     SUMMARY 
     In one embodiment, a method of determining one or more operational parameters of a washing system having a wash tank to which water and material are added includes monitoring a concentration of material, which is decreased at least partially due to water being added to the wash tank. The method also includes maintaining the concentration of material by dispensing material into the wash tank, which is dispensed during a material dispensing operation. Additionally, the method includes generating a parameter indicative of a rate at which the material is dispensed during the material dispensing operation. The method also includes determining a presence of a water flow abnormality based at least partially on the generated parameter. 
     In another embodiment, the invention provides a system for determining one or more operational parameters of a washing system having a tank to which water and material are added. The system includes a sensor, a dispensing device, and a controller. The sensor is positioned in the tank and generates a first signal indicative of a material concentration. The dispensing device dispenses a metered quantity of material into the tank, and generates a second signal indicative of the quantity of material that is dispensed. The material is dispensed to maintain the material concentration above a predetermined material concentration threshold. The controller receives the first signal from the sensor and the second signal from the dispensing device, determines a parameter indicative of a quantity of material that is added to the tank and a frequency at which material is added to the tank, and correlates the parameter to an amount of water added to the tank. 
     In another embodiment, a method of delivering two or more materials to a washing system having a tank to which water is added includes determining a first material concentration threshold indicative of a desired material concentration of a first material in the tank; determining a second material concentration threshold indicative of a desired material concentration of a second material in the tank; and monitoring a material concentration in the tank. During a first mode in which only the first material is delivered to the tank, the method includes determining a first dose rate of the first material necessary for the monitored material concentration to reach the first material concentration threshold, and determining a first water flow based on the first dose rate. During a second mode in which the first material and the second material are delivered to the tank, the method also includes determining a second dose rate of the second material necessary for the monitored material concentration to reach the second material concentration threshold, and determining a second water flow based on the second dose rate. A presence of a water flow abnormality is determined based at least partially on the determined first water flow or second water flow. 
     Other embodiments of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an exemplary dispensing system, according to an embodiment of the invention. 
         FIG. 2  illustrates an exemplary dispensing closure, according to an embodiment of the invention. 
         FIG. 3  illustrates an exemplary dispensing system, according to another embodiment of the invention. 
         FIG. 4  illustrates an exemplary washing system, according to an embodiment of the invention. 
         FIG. 5  illustrates an exemplary process by which water flow associated with a washing system can be determined, according to an embodiment of the invention. 
         FIG. 6  illustrates an exemplary process by which water flow associated with a washing system can be determined, according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     Embodiments of the invention relate to systems and methods of determining a quantity of material that is provided to a wash tank of a washing system while the concentration of the material is maintained above a predetermined concentration set point. This can be accomplished, for example, using a material dispensing system and one or more sensors. Embodiments of the invention also relate to determining a correlation between a quantity of material being added to a wash tank during a predetermined duration and a quantity of water entering and/or exiting the wash tank of the washing system. In an embodiment, a dose (or number of doses) of material is added to the wash tank to maintain the material concentration of the wash tank above a predetermined material concentration set point (as monitored by sensor). A controller can monitor the quantity of material dosed, and compare the quantity of material added to the wash tank to a predetermined expected or “normal” quantity of material that is added to the wash tank during typical use. The comparison can then be correlated to an amount of water that is entering and/or exiting the washing system, which can be used to identify water flow abnormalities. For example, if the quantity of material added to the wash tank is greater than the expected quantity (over a predetermined duration), excessive water use can be identified. Alternatively, if the quantity of material added to the wash tank is less than the expected quantity (over a predetermined duration), deficient water use can be identified. Identifying such water flow abnormalities provides valuable information to a user, for example, via an alarm or message. Additionally, the water flow abnormalities can be identified without the use of flow meters or other sensing devices, which may reduce the overall complexity of the washing system. 
     In other embodiments, the dose rate of the material provided to the wash tank is determined and correlated to an amount of water that is entering and/or exiting the washing system, which can be used to identify water flow abnormalities. 
       FIG. 1  illustrates an exemplary dispensing system  100 . In some embodiments, the dispensing system  100  is configured to dispense or deliver a granulated or powder material (e.g., such as a detergent, a sanitizer, a rinse aid, a chemical, etc.). In other embodiments, the dispensing system  100  may be configured to dispense material in an alternative form (e.g., a liquid material). Additionally, in some embodiments, the dispensing system  100  is adapted for use in or with a larger washing system (e.g., the washing system shown in  FIG. 3 ). For example, the dispensing system  100  can be used to deliver a granular or powder material to a dish washing machine that has several tanks or stages. However, in other embodiments, the dispensing system  100  can be used in a washing system having a single washing compartment. 
     In the embodiment shown in  FIG. 1 , the dispensing system  100  generally includes a granulated material or powder container  105  that is supported in a dispenser assembly or receptacle  110 . The container  105  is closed on one end by a metering and dispensing closure  115 , which, as described in greater detail with respect to  FIG. 2 , can deliver or dose a predetermined amount of material from the container  105  into the receptacle  110 . For example, in one embodiment, the dispensing closure  115  is rotated by a drive shaft  120  to deliver the material. The drive shaft  120  is driven by a drive member  125 , and is journalled in a collar  130  with a seal  135 . 
     The dispensing system  100  also includes a water intake conduit  140  that is controlled by a solenoid valve  145 . The water intake conduit  140  and solenoid valve  145  are utilized to introduce water into the receptacle  110 . For example, in some embodiments, when the solenoid valve  145  is energized, water from the water intake conduit  140  is allowed to enter the receptacle  110 . Alternatively, when the solenoid valve  145  is de-energized, water is prevented from entering the receptacle  110 . In other embodiments, a valve mechanism other than the solenoid valve  145  may be used. 
     A water solution outlet conduit  150  is also in communication with the receptacle  110 . For example, the outlet conduit  150  allows water to exit the receptacle  110 . In some embodiments, as described in greater detail below, water is mixed with dispensed material prior to exiting the receptacle  110  through the outlet conduit  150 . In the embodiment shown in  FIG. 1 , liquid or solution is allowed to exit the receptacle  110  through the outlet conduit  150  relatively unobstructed. In other embodiments, the outlet conduit  150  may include a solenoid valve or other valve, similar to the solenoid valve  145 . 
     In some embodiments, as described in greater detail below, the dispensing system  100  can also include electronic components such as a controller and one or more conductivity sensors. For example, in one embodiment, one or more conductivity sensors are positioned in the receptacle  110  to monitor the conductivity of the receptacle  110  (and the liquid disposed therein). 
     As shown in  FIG. 2 , the metering and dispensing closure  115  is generally composed of three basic components. For example, the closure  115  generally includes a cap member  200  with an upstanding wall  205  and internal threads  210  for engaging complementary threads on the container  105 . The second component is a rotatable disk  215  with a raised peripheral wall  220 , as well as a cutaway portion  225 . Rotatable disk  215  is configured to be seated inside the cap member  200 . The third component is a rotatable disk  230  with a raised peripheral wall  235  and a stub shaft  240  with projections  245 . These projections  245  fit through an opening  250  in the cap member  200  such that the projections  245  engage slots  255  in the rotatable disk  215 . Rotatable disks  215  and  230  are rotated by the shaft  120  (see  FIG. 1 ) connected to the stub shaft  240 . 
     Referring to  FIGS. 1 and 2 , in operation, the container  105  holding the material is supported in the receptacle  110 . Water is introduced into the receptacle  110  through the water intake conduit  140 . The metering and dispensing closure  115  is attached to the container  105 . When the disks  215  and  230  of the closure  115  are properly aligned, the material from the container  105  is free to enter into a measuring opening or chamber  260  as it is uncovered by disk  215  and cutaway  225  (see  FIG. 2 ). However, the material from the container  105  cannot pass into the receptacle  110 , as the passage is blocked by rotatable disk  230 . Activation of the drive member  125  and rotation of the drive shaft  120  causes the upper rotatable disk  215  and the lower rotatable disk  230  to move to a second position in which no more material can enter the opening  260 , which has become a measuring chamber. Continued rotation of the disks  215  and  230  allows for the opening  260  to be positioned over opening  270 , which allows the dose of material from the measuring chamber to flow into the receptacle  110  and be mixed with water from the intake conduit  140 . The mixed material then exits the receptacle  110  through the water solution outlet conduit  150 . In some embodiments, multiple doses are delivered during a single delivery cycle. 
     The embodiments shown in  FIGS. 1-2  are generally used to dispense a granulated or powder material. However, as previously described, in some embodiments, material may be delivered to a washing system by a variety of methods. For example, in an alternative embodiment, a peristaltic pump may be used to deliver a liquid material to a washing system. Other delivery material delivery systems and methods may also be employed (e.g., a gear pump, a diaphragm pump, etc.), as should be appreciated by one of ordinary skill in the art. 
     Referring to  FIG. 3 , an additional embodiment of a dispensing system is shown. In the embodiment shown in  FIG. 3 , components similar to, or the same as, the components shown in  FIGS. 1 and 2  are labeled with like numerals. For example,  FIG. 3  illustrates a dispensing system  300  that includes two containers  105 . In some embodiments, the separate containers  105  are utilized to introduce separate powder or granulated materials (e.g., a detergent and an alkali booster) to the water supply. 
       FIG. 4  illustrates an exemplary washing system  400 . In some embodiments, the washing system  400  is configured to clean and/or sanitize dishes and utensils (“ware”). In other embodiments, the washing system  400  may be configured to clean other items (e.g., a medical instrument washing system, a bottle washing system, etc.). The washing system  400  generally includes a first wash tank  405 , a second wash tank  410 , and a rinse tank  415 , although a variety of other tanks can also be implemented (e.g., a pre-rinse tank, additional wash tanks, and the like). Alternatively, the washing system  400  may include fewer tanks than those shown in  FIG. 4  (e.g., a single wash tank). A water supply  420  provides fresh water to one or more of the tanks  405 - 415  of the washing system, while a dispensing system  425  having a controller  430  and a sensor  435  provides one or more materials (e.g., detergent, sanitizer, alkali, etc.) to one or more of the tanks  405 - 415 . In some embodiments. the dispensing system  425  is configured similarly to the dispensing system  100  shown in  FIGS. 1-3 , having a dispensing closure or other device that dispenses or “doses” a predetermined (e.g., a measured) amount of material. 
     In the embodiment shown in  FIG. 4 , the first wash tank  405 , the second wash tank  410 , and the rinse tank  415  are approximately the same size. However, in other embodiments, the tanks  405 - 415  may be different sizes relative to each other (e.g., having a smaller rinse tank  415  than the first and second wash tanks  405  and  410 ). As described in greater detail below, ware generally enters the washing system  400  through the first wash tank  405 , is cleaned and/or sanitized while traveling through the first wash tank  405  and the second wash tank  410 , and is rinsed while traveling through the rinse tank  415 . The ware then exits the washing system  400 . 
     In some embodiments, the water supply  420  provides fresh water to the rinse tank  415  during a rinse cycle of the washing system  400 . For example, after ware has been washed in the first wash tank  405  and the second wash tank  410 , the ware is rinsed with incoming fresh water from the water supply  420 . As such, the water supply  420  may include an associated valve (e.g., a solenoid valve) to control the supply of water to the rinse tank  415 . In some embodiments, the water supply  420  may also provide fresh water to other tanks, or other components of the washing system  400  (e.g., the dispensing system  425 ), and thus, may include additional valves or components to control the flow of water from the water supply  420 . 
     As described above, the dispensing system  425  may be configured similarly to the dispensing system  100  shown in  FIG. 1 , in that the dispensing system  425  can include a dispensing closure which provides a predetermined amount of material to the wash tanks  405  and  410 . For example, for each actuation of the dispensing closure, one gram of material can be provided to the second wash tank  410 . In other embodiments, an alternative amount (e.g., 0.5 grams, 1.5 grams, 3 grams, etc.) can be delivered with each actuation of the dispensing closure. Additionally, an alternative type of fixed quantity (e.g., volume or weight) material metering and material dispensing apparatus may be employed. 
     Generally, the controller  430  is a suitable electronic device, such as, for example, a programmable logic controller (“PLC”), a computer, a microcontroller, a microprocessor, and/or other industrial/personal computing device. As such, the controller  430  may include both hardware and software components, and is meant to broadly encompass the combination of such components. The controller  430  is responsible for executing a variety of tasks and/or processes. For example, in some embodiments, the controller  430  determines when to actuate the water supply  420 , as well as when to dispense material into the wash tanks  405  and  410 . Additionally, the controller  430  can, in some embodiments, determine fluctuations in water flow (see, for example, the process shown with respect to  FIG. 5 ), and/or dispense material using a variety of dispensing schemes (see, for example, the process shown with respect to  FIG. 6 ). 
     To carry out the tasks and/or processes, the controller  430  communicates with a variety of components of the washing system  400 . These communications may be wired or wireless. For example, to control the water supply  420 , the controller  425  transmits a signal to the one or more valves associated with the water supply  420  to turn the valves on or off Additionally, to determine when to dispense material into the wash tanks  405  and  410 , the controller  430  receives and processes a signal from the sensor  435  positioned in one of the wash tanks  405  and  410  (as described in greater detail below). In other embodiments, the controller  430  may also be in communication with other components of the washing system  400  (e.g., other sensors, valves, and the like) and/or with external components interfaced with the controller  430 . For example, in some embodiments, the controller  430  may be in communication with a server or other storage device, allowing the controller  430  to upload data (e.g., operational parameters) of the washing system. 
     In the embodiment shown in  FIG. 4 , the sensor  435  is positioned in the second wash tank  410 , and transmits a signal to the controller  430  indicative of a material concentration (e.g., the material concentration of the water in the second wash tank  410 ). In other embodiments, the sensor  435  may be positioned in the first wash tank  405 . The sensor  435  can be configured to measure a variety of different parameters of the second wash tank  410 , which can be used to determine the concentration of material in the second wash tank  410 . For example, in some embodiments, the sensor  435  is a conductivity sensor that measures the conductivity of the water in the second wash tank  410 . That conductivity data is then used to determine the concentration of material in the second wash tank  410 . In other embodiments, the sensor  435  may be an alternative type of sensor whose signal can be used to determine a concentration of material in the second wash tank  435 . For example, the sensor  435  may be an infra-red (“IR”) sensor, an ultraviolet (“UV”) absorber, an oxidation-reduction potential (“ORP”) sensor, or other type of sensor. 
     In some embodiments, the sensor  435  also includes a temperature sensing capability. For example, in addition to transmitting a signal indicative of the conductivity of the second wash tank  410 , the sensor  435  can transmit a signal that is indicative of the temperature of the second wash tank  410 . The temperature data can then be used to provide a more accurate representation of the concentration of the material in the second wash tank  410 . Additionally or alternatively, the sensor  435  (or an additional sensor) can be used to measure the relative hardness of the water being added to the second wash tank  410 . 
     In some embodiments, the material concentration of the first wash tank  405  is estimated or inferred from the material concentration of the second wash tank  410 . For example, due to liquid (e.g., the water/material solution) cascading from the second wash tank  410  to the first wash tank (described below), the material concentration of the first wash tank  405  may be substantially the same as the concentration of the second wash tank  410 . The controller  430  may also utilize a predetermined correction factor to determine the material concentration of the first wash tank  405  relative to the material concentration of the second wash tank  410 . Alternatively, in other embodiments, a pair of sensors may be employed to independently monitor the material concentrations of the first and second wash tanks  405  and  410 . 
     In some embodiments, the material being added to the wash tanks  405  and  410  is a detergent. In other embodiments, however, the dispensing system  425  may be adapted to dispense more than one type of material (e.g., a detergent, an alkali boost, a sanitizer, a rinse aid, etc.). In such embodiments, several sensors  435  may be required to measure material concentrations for each material being added. 
     During use, ware enters the washing system  400  through the first wash tank  405  and exits the washing system through the rinse tank  415 . As such, ware is initially cleaned and/or sanitized while positioned in the first wash tank  405 . For example, heavy soil is removed from the ware and mixes with the liquid of the first wash tank  405 . The ware then moves from the first wash tank  405  to the second wash tank  410 . The second wash tank  410  also removes soil (e.g., soil that is not removed from the ware while the ware is positioned in the first wash tank  405 ), which mixes with the liquid of the second wash tank  410 . Next, the ware moves from the second wash tank  410  to the rinse tank  415 , where the ware is rinsed with fresh water. In some embodiments, the ware is moved through the tanks  405 - 415  automatically. For example, a conveyor (or similar device) moves the ware through the tanks  405 - 415 . In other embodiments, the ware may be manually moved through the tanks  405 - 415  by a user. Additionally, as described above, in other embodiments, the washing system may have more or fewer tanks than those shown (e.g., a single wash/rinse tank, additional wash tanks, a pre-rinse tank, etc.). 
     In the embodiment shown in  FIG. 4 , fresh water is generally introduced to the washing system  400  by the water supply  420  while ware is being rinsed in the rinse tank  415  (e.g., during a rinse cycle). For example, in some embodiments, during normal operation water is delivered to the rinse tank  415  by the water supply  420  at a rate of approximately seven liters per minute during a rinse cycle, although the incoming rate may vary with the configuration of the washing system  400 . Incoming fresh water fills the rinse tank  415  to a predetermined level. After the water fills the rinse tank  415 , water spills over, or cascades from, the rinse tank  415  into the second wash tank  410 . Similarly, after the second wash tank  410  is filled to a predetermined level, water cascades from the second wash tank  410  into the first wash tank  405 . After the first wash tank  405  is filled to a predetermined level, the drain  440  allows water to exit the washing system  400 . In some embodiments, the drain  440  may be configured such that water automatically flows into the drain  440  upon the level of water in the first wash tank  405  exceeding a predetermined amount (e.g., the drain  440  includes a fixed opening at the relative top of the first wash tank  405 ). In other embodiments, to avoid backflow or overflow of the tanks  405 - 415 , the water supply  420  and the drain  440  may be linked such that the water is not allowed to enter the washing system  400  unless a relatively equal amount exits the washing system  400  during operation. In some embodiments, during an initial or “fresh” fill operation (e.g., the tanks  405 - 415  are initially empty and are filled with water prior to use), water may be introduced to several of the tanks  405 - 415  concurrently. 
     As described above, material is delivered to the washing system  400  by the dispensing system  425 . In the embodiment shown in  FIG. 4 , the dispensing system  425  delivers one or more materials to the second wash tank  410 . The resulting water/material solution cascades from the second wash tank  410  into the first wash tank  405 . Accordingly, the material concentration (e.g., the concentration of material in the water) of the first wash tank  405  is approximately equal to that of the first wash tank  410 . In other embodiments, however, one or more materials may also be delivered directly to the first tank  405  (e.g., delivered by the dispensing system  425  or another system). Accordingly, the first wash tank  405  and the second wash tank  410  may be maintained at different material concentrations and/or include different materials. 
     The material concentrations of the first wash tank  405  and the second wash tank  410  are reduced by incoming fresh water (e.g., fresh water that cascades from the rinse tank  415 ), as well as by soil from the ware being washed. As such, as described in greater detail below, the rate at which the material concentration falls is variable. For example, if relatively heavily soiled ware is being washed, the material concentration may be reduced from the desired level relatively quickly. Additionally, if the washing system  400  is being continuously operated and rinse cycles are occurring frequently, a relatively large amount of fresh water may be introduced to the washing system  400 , thereby reducing the material concentration level from the desired concentration level relatively quickly. As the material concentration deviates from a desired level, material is dosed to maintain the desired level (described below). This material dosing may occur in regular and relatively predictable intervals. 
     The embodiment described with respect to  FIG. 4  includes a washing system having multiple tanks that are filled with water. Material is added to the water to create a water/material solution. However, as should be appreciated by one of ordinary skill in the art, components similar to those shown and described with respect to  FIG. 4  may be applied in an alternative system in which material is added to a liquid that is not water. For example, a facility that produces beverages may implement a material dispensing system which provides a material to a beverage solution. Alternatively, a gasoline refining facility may implement a material dispensing system that provides an additive to the gasoline. Other alternatives are also possible. In such embodiments, controlling and sensing devices (such as the controller  430  and the sensor  435 ) can be utilized. 
       FIGS. 5 and 6  illustrate exemplary processes that can be used to determine, store, and/or utilize operational parameters of a washing system. As such, the embodiments of  FIGS. 5 and 6  are described herein as being implemented with the washing system  400  shown in  FIG. 4 . However, as should be apparent to one of ordinary skill in the art, the processes may be implemented with an alternative washing system. 
       FIG. 5  illustrates an exemplary process  500  for evaluating water flow and/or use associated with a washing system. For example, as described in greater detail below, the process  500  can be used to identify excessive water flow through the washing system  400 , as well as limited or deficient water flow through the washing system  400 . The process  500  begins by establishing a communication link between the sensor  435  and the dispensing system  425 , and monitoring the material concentration of the second wash tank  410  (step  505 ). As described above, this communication link may be wired or wireless. In some embodiments, the sensor  435  may be positioned in the first wash tank  405 , and, accordingly, the material concentration of the first wash tank  405  is measured. 
     The monitored material concentration then is compared to a material concentration threshold or set point (step  510 ). For example, prior to operating the washing system  400 , a user (e.g., an installation technician) may determine a desired material concentration that effectively cleans the ware in the machine  400 , without using an excessive amount of material. This desired material concentration may be determined prior to installing the washing system  400 , for example, through testing. In some embodiments, the material concentration is maintained at 1.0 grams per liter (g/L). 
     If the monitored material concentration falls below the material concentration set point, a material dosing operation is carried out by the dispensing system  425 , and material is dosed until the desired material concentration is achieved (step  515 ). Material dosing may be delayed until the material concentration has fallen by a predetermined amount. For example, in some embodiments, the material concentration is allowed to descend from 1.0 g/L to 0.85 g/L (i.e., a material concentration reduction of 0.15 g/L) before material is dosed to elevate the material concentration back to 1.0 g/L. In other embodiments, a different allowed concentration reduction may be implemented (e.g., 0.1 g/L, 0.25 g/L, etc). Additionally, in other embodiments, as should be apparent to one of ordinary skill in the art, an alternative material concentration measurement can be used. 
     Upon achieving the desired material concentration, the dose rate during the material dosing operation (e.g., the rate at which the material was delivered by the dispensing system  425  to achieve the desired material concentration) is determined (step  520 ). The dose rate can be determined, for example, based on measured and/or stored parameters indicative of quantity and/or time. For example, in embodiments which implement a rotating enclosure that dispenses a metered quantity (e.g., volume or weight) of material every revolution, the number of revolutions can be monitored and determined over a predetermined duration (e.g., a half hour, an hour, three hours, etc.). The dose rate can be determined from such parameters and then used to determine an approximate quantity of fresh water that is entering and/or exiting the washing system  400  through the rinse tank  415  (step  530 ). In some embodiments, the water flow can be determined by monitoring whether the material concentration is maintained or changes as expected over time (e.g., whether the conductivity is maintained consistent with basic numerical assumptions or more rigorous calculations). 
     Increased or decreased water usage can be identified based on the determined water flow. For example, if the water flow is greater than an expected water flow (step  535 ), increased or excessive water usage can be identified, and an indication is provided to a user of the washing system  400  (step  540 ). Excessive water usage may be caused by, for example, the drain  440  remaining open during a washing cycle or a water supply valve that has seized up in an open position. Alternatively, if the water flow is less than an expected water flow (step  545 ), decreased or deficient water usage can be identified, and an indication is provided to a user of the washing system  400  (step  550 ). Deficient water usage may be caused by, for example, blocked rinsing nozzles associated with the rinse tank  415  or a water supply valve that has seized up in a closed position. If excessive or deficient water usage is not identified, the process  500  returns to step  505  and the process  500  is repeated. 
     In some embodiments, the indication may be a message that is sent to a user of the washing system  400  (e.g., a short messaging service (“SMS”) message, a pager message, an email message, etc.). In other embodiments, the indication may be included in a report, for example, generated by a data logging application included in the controller  430 . In other embodiments, the indication may be an audible (e.g., a beep, a buzz, or the like) and/or visual (e.g., a flashing light) indication that is provided to the user via a control panel included in the dispensing system  425 . Other alternative manners of providing an indication to the user of the washing system  400  are also possible, as should be appreciated by one of ordinary skill in the art. 
     In another embodiment (not shown), the quantity of material that was dosed during the material dosing operation (e.g., the quantity of material that was delivered by the dispensing system  425  to achieve the desired material concentration) is determined and compared to a projected or expected quantity over a predetermined duration. For example, in one embodiment, during normal operation of the washing system  400 , approximately 17.5 grams of material is required to be dosed every 2.4 minutes to maintain the material concentration between 0.85 g/L and 1.0 g/L (e.g., assuming a tank volume of 100 L and an incoming fresh water rate of 7 L/min). This dosing quantity can then be extrapolated for the predetermined duration. As should be recognized by one of ordinary skill in the art, dose quantities and rates may vary widely based on washing system configuration and usage. The comparison between the determined and expected quantity of material can be used to determine approximate water flow into, or out of, the washing system  400 . 
     In another embodiment, the quantity of material that is dosed during the dosing operation and the duration between dosing operations are gathered, and such data is used to determine the rate at which the material concentration is being reduced. In some embodiments, the determined material concentration reduction rate can then be used to determine an approximate amount of fresh water that is entering and/or exiting the washing system  400  through the rinse tank  415 . For example, increased or excessive water usage can be identified if the rate at which the material concentration is reduced is greater than an expected rate. Alternatively, a deficient water supply can be identified if the rate at which the material concentration is reduced is less than an expected rate. 
       FIG. 6  illustrates an exemplary process  600  for evaluating water flow and/or use associated with a washing system. For example, as described in greater detail below, the process  600  can be employed for contexts involving delivery of two materials. 
     The process  600  begins by initializing operation of the washing system  400  and monitoring the material concentration of the first or second wash tanks  405  and  410  of the washing system  400  (step  605 ). A determination is made whether “boost” is active (step  610 ). For example, in some embodiments, a second, or “boost” material (e.g., an alkali material) is added to the washing system  400  (in addition to the first material) during periods of increased or constant washing system operation to ensure that enough material is present to sufficiently clean the ware being washed and/or sanitized in the washing system. A boost material may also be delivered if ware having relatively heavy soil is being washed and/or sanitized by the washing system  400 . In some embodiments, boost material is automatically added to the washing system  400  during predetermined times or events. For example, if the washing system is installed in a restaurant or other eatery, a user may configure the washing system  400  to automatically add the boost material during breakfast, lunch, or dinner times in anticipation of increased washing system operation. In other embodiments, a user may manually initiate delivery of the boost material. 
     If boost is not active, the material concentration is compared to a first material concentration threshold or set point (step  615 ). If the material concentration is not less than the first set point, the process returns to step  605  to monitor material concentration. If, however, the material concentration is less than the first set point, the first material is dosed until the first set point is achieved (step  620 ). The dose rate of the first material is then determined (step  625 ). The approximate water flow is determined based on the dose rate of the first material (step  630 ). 
     If boost is active (step  610 ), the material concentration is compared to a second concentration threshold or set point (step  635 ). If the material concentration is not less than the second set point, the process returns to step  605  to monitor material concentration. If, however, the material concentration is less than the second set point, the first material is dosed at a normal dose rate (step  640 ), and the second material is dosed until the second set point is achieved (step  645 ). The dose rate of the second material is then determined (step  650 ). The approximate water flow is determined based on the dose rate of the second material (step  655 ). 
     The process  600  continues in a similar manner to steps  535  to  550  of  FIG. 5 , wherein increased or decreased water usage can be identified based on the determined water flow. Specifically, if the water flow determined in step  630  or  655  is greater than an expected water flow (step  660 ), increased or excessive water usage can be identified, and an indication is provided to a user of the washing system  400  (step  665 ). Alternatively, if the water flow is less than an expected water flow (step  670 ), decreased or deficient water usage can be identified, and an indication is provided to a user of the washing system  400  (step  675 ). If excessive or deficient water usage is not identified, the process  600  returns to step  605  and the process  600  is repeated. 
     If other embodiments (not shown), operational parameters of the washing system  400  can be monitored and/or stored for future use. For example, operational parameters such as dose quantities and durations between doses of a first material can be monitored for a predetermined amount of time during normal washing system operations (e.g., washing system operations in which the material concentration of the wash tanks  405  and  410  is being continually monitored). Those stored operational parameters can then be implemented during future operations, thereby eliminating the need to continually monitor the material concentration of the wash tanks  405  and  410  to control the delivery of the first material. This may be useful to allow a first material to be dosed based on stored operational parameters, while a second material is dosed based on a real-time evaluation of material concentration. 
     In some embodiments, a timer is utilized for monitoring and/or storing of operational parameters associated with the washing system  400 . The duration of the timer may vary according to the location and intended use of the washing system  400 . For example, in some embodiments, the washing system  400  is used to wash dishes in a restaurant that serves breakfast, lunch, and dinner. Accordingly, the duration of the timer may be long enough to capture the material dispensing variations associated with each of the meals. For example, relatively more material may be used to maintain the desired material concentration during peak meal times, and relatively less material may be used to maintain the material concentration during non-peak times. In other embodiments, the duration of the timer may be longer or shorter than an entire day (e.g., 1 hour, 4 hours, 8 hours, etc.). In this way, the timer can be optimized to the operational constraints of the setting in which the washing system  400  is installed (e.g., a restaurant, a cafeteria, a hotel, etc.). By employing a timer, the amount of data collected can be automatically implemented, without requiring a user to start and stop data collection. In other embodiments, a user may manually start and stop the collection of data. 
     As described above, for embodiments in which the washing system  400  is utilized as a ware washing machine, the material concentration of the wash tanks  405  and  410  may be reduced due to soil and fresh water. Accordingly, material may be added during operation of the washing system  400  to maintain the desired material concentration level. In some embodiments, the amount of material that is added is tracked by monitoring the number of doses of material that are added. Additionally, the amount of time that passes between each material dose may be monitored. 
     Each of the monitored parameters (e.g., number of material doses, time between each dose, temperature of the liquid in the wash tanks  405  and  410 , water hardness in the tanks  405 - 415 , amount of water added to the rinse tank  415 , etc.) can be stored in a memory associated with the controller  430 . For example, each time that the dispensing system  425  dispenses material to achieve the desired concentration, the number of doses of material that are dispensed is stored. Additionally, the frequency at which the dispensing system  425  dispenses material is stored. 
     The operational parameters can continue to be monitored and stored until the timer has elapsed. After the timer has elapsed, an indication can be provided that the operational parameters associated with the first material have been stored. This indication may be audible or visual. For example, in some embodiments, a light included in the dispensing system  425  flashes after the operational parameters have been stored and are ready for use. In some embodiments, operational parameters associated with the first material are previously stored or loaded into the controller  430 . 
     The process  600  shown in  FIG. 6  can utilize two material delivery schemes or modes (i.e., delivering a material based on stored parameters, and delivering a material based on a signal from a sensor) to deliver material to a washing system. However, as should be appreciated by one of ordinary skill in the art, materials may be delivered based on an alternative delivery scheme. For example, in some embodiments, one or more materials are delivered to the system based on a measured amount of water that flows into the rinse tank  415  from the water supply  420 . As more water is added to the washing system  400 , a predetermined proportionate amount of material is added to the wash tanks  405  and  410 . Such a material delivery scheme may be implemented in addition to, or instead of, one of the material delivery schemes described above. Additionally, the process  600  may be expanded to deliver more than two materials. For example, in other embodiments, operational parameters may be monitored and/or stored for multiple materials, allowing multiple materials to be delivered based on those operational parameters, while another material (or materials) is dosed using a different delivery scheme. 
     The embodiments described with respect to  FIGS. 4-6  are directed generally to washing systems. However, as described above, and as should be appreciated by one of ordinary skill in the art, a material dispensing and monitoring system can be adapted to a variety of applications. For example, commercial and residential pool applications may require chemicals and/or other materials to be maintained at certain material concentrations. In other embodiments, boiler systems, cooling towers, water treatment facilities, and the like, may require chemicals and/or other materials to be maintained at certain material concentrations. 
     Various features and embodiments of the invention are set forth in the following claims.