Patent Grant
7021321
The present invention relates to a commercial washer for washing large quantities of commercial kitchenware and, more specifically, to a washer having improved tank features and an automated control system for automatically dispensing cleaning agent into the tank and for automatically controlling fluid turbulence and temperature in the tank to increase the effectiveness of the washer and to allow the washer to clean dishware having varied fragility.
Commercial washers have been in the marketplace for decades. Examples are shown in U.S. Pat. Nos.: 5,927,309; 5,775,347; 5,983,908; and 4,773,436, incorporated herein by reference. Many of the commercial washers that are currently on the market include multiple tanks for various cleaning stages (e.g., a scraping tank, washing tank, rinsing tank, and sanitizing tank). The washing tank, at a basic level, typically includes features such as a rectangular tank with a drain, a valve for closing the drain, outlet nozzles attached to walls of the tank for directing water down into the tank, and a pump to circulate water from within the tank into a manifold that feeds the water through the nozzles.
U.S. Pat. No. 4,773,436 discloses a tank of the variety discussed above. That patent discloses placing the nozzles on the rear wall and the pump intake valve on a sidewall. The nozzles are directed downwardly into the tank to direct water against the bottom wall of the tank near the front wall to create a circular water flow within the tank. As is common with commercial washers on the market, the pump is a single speed pump that creates a constant level of turbulence.
A problem not satisfactorily addressed by prior art and preexisting commercial washers is that, even within the commercial environment, not all dishware is sturdy or durable. For example, most restaurants use glassware, and fancier restaurants also include china or expensive ceramic plates. Prior commercial washers of the variety disclosed in U.S. Pat. No. 4,773,436 are not satisfactory for handling more delicate dishware. Rather, such prior art systems are best suited for handling larger pots and pans that are not subject to breaking under turbulent tank conditions. Moreover, some dishes contain inordinately “caked-on” food debris that requires higher turbulence than that provided for by existing commercial washers. The prior art does not provide a commercial washer with variable speeds to handle a variety of cleaning needs.
Further, the prior art commercial washers do not provide programmable cycles that enhance the cleaning process. Prior art commercial washers typically only provide an “on” or “off” mode. When in the “on” mode the washer runs at one speed (i.e., flow rate) and thus provides only one level of turbulence. It is, nonetheless, desirable to provide a tank that varies the cleaning parameters to tackle kitchenware that is more difficult to clean because food or grease has become caked-on the kitchenware during the cooking or food preparation process. The prior art systems do not, however, provide programmable controllers to provide cycles that vary the tank turbulence and/or temperature for predetermined time cycles.
Another problem associated with the prior art commercial washers is that pipes and nozzles unnecessarily extend from the side or back walls downwardly into the tank to supply water to the tank. Because most commercial washing tanks are typically full of dishware, the pipes and nozzles get in the way because they are under the surface of the water during normal operating conditions. Further, it is possible for personnel washing the dishes to catch their hands on the pipes and nozzles during the dishwashing process, thus causing injury. The pipes and nozzles also unnecessarily increase the cost of the dishwasher.
And yet another problem not solved by the prior art is the need for automatically introducing desired amounts of cleaning agent into the tank. In typical operation, a commercial washer will be used for several hours with a batch of water and a specified amount of cleaning agent (e.g., soap or intensified cleaners for tougher cleaning problems) in the water. If too much soap is added to the water, it leads to waste and “soap suspension,” which diminishes the ability of the soap to attack grease. Adding too much soap also increases business overhead. Adding too little soap leads to the obvious problem that the dishware is not satisfactorily cleaned and sanitized. Further, commercial soaps and detergents are almost always contained in large, heavy containers. Employees manually lifting such heavy containers to pour cleaner into the water in the tank risk serious back and related injury, not to mention that it is difficult to control the amount of cleaning agent being dispensed into the tank in this manner. The prior art does not disclose an automated cleaner dispensing system that automatically dispenses a predetermined, desired amount of cleaner into the tank when necessary.
This invention is directed to a washing device and, more specifically, to an automated commercial washing tank for washing commercial kitchenware. The automated tank comprises a tank that is adapted to hold a fluid for washing kitchenware. The washing tank also includes outlets in the tank wall. A pump system includes a pump and fluid conduit system to couple the pump between an intake opening through one of the walls and the outlets. The pump draws cleaning fluid from within the tank through the intake opening into the fluid conduit system to the outlets into the tank. In the preferred embodiment, the outlets are discharge openings that are formed as openings in at least one of the walls, and do not include pipes or nozzles.
In a more specific aspect of the invention, the tank has a bottom wall and an enclosure wall. The enclosure wall is coupled to the bottom wall and extends upwardly from the bottom wall. The enclosure wall includes an angled portion directed generally downwardly into the tank. At least some of the discharge openings are located in the angled portion. In an even more preferred embodiment, the enclosure wall includes two angled portions and a group of discharge openings located, at least in part, in each angled portion. The angled portions are preferably opposed and directed downwardly into the tank to direct cleaning fluids from the openings generally downwardly into the tank in a crossing pattern.
In another aspect of the invention, a control system is coupled to the pump for controlling the flow rate with which the pump supplies the cleaning fluid to the outlets. The control system comprises a controller coupled to the pump system for causing the pump to alter the flow rate with which it pumps fluid, and a control that is adapted to allow a user to activate the controller to select between at least two different flow rates for pumping the cleaning fluid to the outlets. In the preferred embodiment, five different flow rates are available. In an even more preferred embodiment, the controller provides at least one preset program that, when activated by the control system, automatically adjusts the pump flow rate and/or temperature in the tank for at least two predetermined cycles to enhance the cleaning effectiveness of the tank.
In another aspect of the invention, the automated washer provides an overflow that comprises a cutaway portion in one of the walls. The cutaway portion preferably extends the full length of one of the sidewalls and is located at a height above the discharge openings. The overflow is preferably located adjacent a side tank that has a drain for fluid that spills over the overflow. Because grease and other debris float, the overflow also serves to dispose the grease and floating debris from the washing tank over the overflow.
In another aspect of the invention, an automated cleaner dispensing system is provided that automatically dispenses cleaner (e.g., soap or detergent) into the fluid in the tank. In the preferred embodiment, a fluid level sensor determines when the fluid level has dropped below a desired level and detects when the fluid level is thereafter increased above the desired level, indicative that the tank has been emptied and refilled. The control system, upon detecting the low level condition and the refill condition, causes a predetermined amount of cleaner to be dispensed into the tank.
Thus, the automated dishwasher disclosed herein overcomes problems associated with the prior art. The use of discharge openings for directing cleaning fluid in the tank eliminates the need for pipes and nozzles to do so. Thus, the nuisance of having the pipes and nozzles in the tank is eliminated and the overall cost of the dishwasher is decreased. Further, by providing outlets on more than one wall, and preferably opposed walls, tank turbulence is increased, thereby enhancing the washer's effectiveness in cleaning kitchenware. The control system aspect of the invention allows the pump pressure to be increased or decreased to account for varied conditions of kitchenware that must be cleaned. The preset program feature automates the cleaning process and also facilitates cleaning kitchenware having caked-on food by, for example, providing various cycles that can operate automatically overnight. The control system also allows for automated control of the cleaner dispenser and the heater. Thus, the dishwasher is adapted to clean all dishware, regardless of how fragile or dirty, and is much more effective and automated than prior art commercial kitchenware washers.
The present invention is adapted to be included in a typical commercial washer system for commercial or large-scale kitchens. See
Referring to
Tank 20 includes a bottom wall 40 and an enclosure wall 42. The enclosure wall is connected to the bottom wall along its outer edge. The enclosure wall 42 extends upwardly from the bottom wall 40. Preferably, four walls, 44, 46, 48, and 50, form the enclosure wall to maximize the tank volume. In use, the walls 44 and 46 are sidewalls, wall 48 is the front wall, and wall 50 is the back wall. Walls 44 and 46 are preferably shorter than walls 48 and 50 such that the tank 20 is wider than it is deep. The walls 44 and 46 are preferably about 28 inches in length and 18 inches in height. Walls 48 and 50 are preferably about 42 inches in length at the bottom edge and about 36 inches at its top edge, the difference accounting for the angled portions of walls 44 and 46. Wall 48 is preferably the same height as walls 44 and 46. Back wall 50 is preferably slightly higher by a few inches to provide a backsplash 51 (see
The shorter depth of the tank allows workers standing at the front wall to reach the back wall to obtain all dishes. The longer width of the tank increases the tank volume to allow it to hold more kitchenware. Workers are able to move laterally to reach all dishes along the longer front wall. Again, the configuration could be different. For example, all walls could be the same size or the tank could be circular or some other geometric configuration. The walls are preferably stainless steel to provide a sturdy, long-lasting structure, but other materials could be used. For example, the tank could be molded in one piece from a durable plastic or other suitable material. The preferable thickness is fourteen-gauge stainless, type 304.
Bottom wall 40 is typically sloped to cause water to siphon to drain and valve system 35 when the drain is open. The drain and valve system is conventionally connected to the facility plumbing and drainage system (not shown). System 35 also includes a shutoff valve (not shown) that allows the user to open and close the drain to allow the tank to be filled and emptied as desired. The system 35 also preferably includes a screen or perforated cover (not shown) to prevent debris from siphoning down the drain and clogging or partially clogging it. The drain and valve system and its connection to facility plumbing is standard and in use in most commercial washers.
A commercial washer of the variety disclosed herein should be able to circulate fluid within the tank through a pump and back into the tank to create turbulence in the tank. The turbulence helps to clean kitchenware and loosen tough food residues or remnants that become caked-on kitchenware during the cooking or food preparation process. The following components generally provide this function in the present invention: the intake opening 26, the pump system 23, and outlets or discharge openings 32.
In the preferred embodiment, the pump system 23 is coupled in fluid communication with the tank through back wall 50. Referring to
The outlet piping 68 is preferably 3 inches in diameter. The side plenums 69 are configured as shown best in
The pump 67 draws cleaning fluid in the tank through intake opening 26 in back wall 50 through the intake plenum 65. The pump directs the cleaning fluid through the outlet piping 68 to side plenums 69 and out the discharge openings 32. The pump is a closed-coupled, end suction 4×3×5. It has a maximum capacity of 1800 rpms at 300 hundred gallons per minute. The pump includes an 1800 rpm, 4 pole 1–3 horsepower frequency drive duty motor.
As attached to intake opening 26, intake plenum 65 forms a sump 75 (see
Referring to
The automated washer has outlets for directing fluid from the pump system 23 into the tank. As used herein, the term outlet broadly includes any opening, including prior known means such as pipes and nozzles for directing fluid into the tank. Pipes or nozzles could be used in combination with other inventive features of the present invention, such as the automated control system. In the preferred embodiment, the outlets are discharge openings 32. The term discharge openings, as used herein, refers to mere holes in the wall, or equivalent openings, that do not include separate parts such as pipes, nozzles, or the like for directing the fluid flow. Because it is desirable to have the fluid directed down into the tank 20 to avoid shooting fluid out of the tank, the walls 44 and 46, in the preferred embodiment, include a portion that is angled downwardly and at least some of the discharge openings are located on the angled portion, and, most preferably, all discharge openings are located on the angled portion. The same effect could be accomplished by angling the entire wall, but that configuration would reduce the size of the opening at the top of the tank. By providing openings on angled portions of walls, without angling the entire wall, the need to include separate pipes and nozzles to direct fluid down into the tank is eliminated and the size of the opening at the top of the tank is maximized. The present invention will, however, work fine by angling the entire wall and locating the discharge openings on the wall. If the entire wall is angled it, of course, includes angled portions, but, in the preferred embodiment, the angled portions are less than the entire wall, as shown, for example, in
In the preferred embodiment, the outlets or discharge openings 32 are provided on opposed walls, or in the case of a circular or oval tank, opposed portions of the curved wall. The automated washer will work with openings on only one wall, or on more than two walls, but placing the openings on two opposed walls is preferred. With the opposed configuration, turbulence in the tank is increased to facilitate cleaning kitchenware. In the most preferred embodiment, the opposed discharge openings are on the angled portions of walls 44 and 46 to form a crossing pattern, as shown in
The openings on each wall are also preferably arranged in the pattern show in
Sidewalls 44 and 46 include angled portions upon which outlets or discharge openings are located. The angle portions 86 and 88, corresponding to walls 44 and 46, respectively, are shown best in
The automated washer also includes an overflow 90, shown best in
Referring to
The controller 100 is preferably a multi-sequence microprocessor controller. It has real-time clock features, battery back-up for saving the wash cycle schemes (described below). It also includes 5 dc output features, including an alarm. It includes a programmable EPROM chip that allows custom software to be applied to control the various components of the washer, including the pump and heater. The specific unit is a “Mini-Chef” 2000 by Watlow Electric, although there are many options available to control the system, as well understood by those skilled in the art.
The microprocessor is programmable and is coupled to the frequency motor drive controller 102 to cause it drive the motor at a desired pump speed. The software in the microprocessor causes the frequency drive to lower or increase the hertz cycle of the motor to therefore cause the motor to speed up or slow down. That, in turn, causes the pump pressure to increase or decrease. In the preferred embodiment, the microprocessor is programmed to provide 5 speeds or flow rates from which to choose, varying from a delicate cycle to handle the most fragile dishware and for soaking to the most robust cycle that is adapted to break away caked-on food debris on commercial pots and pans. In another aspect of the invention, the microprocessor is programmed to provide at least one preset wash cycle program and preferably several programs.
The microprocessor 100 is also coupled to heater 77 to control the heat. The control system includes controls that control the microprocessor to cause the heater to heat the fluid in the tank to a specified temperature. The microprocessor 100 is coupled to the heater 77 through a solid-state relay 108. The microprocessor can be programmed to provide a wash cycle program that provides cycles for predetermined time periods and the pump speed (i.e. tank turbulence) and/or heat can be varied to provide predetermined cleaning cycles. Thus, the tank may operate at a mild presoak turbulence level at a higher (uncomfortable to the touch) heat to loosen caked-on food from the dishware, followed by a more turbulent pressure in the tank to break away loosened food debris, followed by a final cycle at reduced temperature during which employees can finish the cleaning process. As one example program, the following sequence is provided: upon activation of the control to activate the program, the following logic steps are performed by the controller and associated sensors: determine whether the fluid temperature is at 110 degrees; if it is not, cause the heater to heat the fluid to 110 degrees; when the fluid temperature is at 110 degrees, initiating a 3 minute presoak cycle during which time the motor operates at between about 30–35 hertz; next proceeding to a 3 minute intermediate cycle during which time cycle the pump is increased to 40–45 hertz, thus increasing tank turbulence and cleaner agitation; followed by a heavy duty clean cycle during which time cycle the pump is increased to 50–60 hertz for 8 minutes; followed finally by an idle mode at about 30 hertz which prevents grease suspended in the cleaning fluid from settling back onto the kitchenware and allows removal of the kitchenware from the tank. It is contemplated that overnight cycles can also be provided that allow the tank temperature to be increased to much higher temperatures of around 150 degrees or higher to further facilitate cleaning. Because such temperatures are too hot for the human touch, the most difficult-to-clean kitchenware could be cleaned overnight for extended periods of time while personnel are not around and thus are not exposed to the hot tank of water. It is also contemplated that a cover could be provided to prevent personnel from putting their hands in the water and/or alarms can be activated to warn of the hot water temperature. The microprocessor of the preferred invention provides preprogrammed wash cycle programs, but is also adapted to allow the user to create programs to cater to specific cleaning needs.
A terminal block 107 is also provided for incoming power and/or junction points for wiring connections. A solid state heater relay 108 is also provided to interface the heater 77 to the controller 100.
In another aspect of the present invention, an automatic cleaner dispenser system is provided to automatically dispense cleaner into fluid in the tank to clean the kitchenware in the tank. The controller 100 is coupled to a cleaner dispenser 110, e.g., a peristaltic dosing injection pump, through the dc relays 104 to automatically dispense a specified amount of cleaner in the tank based upon a predetermined, monitored condition. While the microprocessor/controller can be programmed to cause the dispenser 110 to provide cleaner at specified time intervals or based on other parameters, the preferred method is based upon fluid changes within the tank. The microprocessor is coupled to the fluid level sensor 81. When the fluid level drops below the heating element, the fluid level sensor detects that condition, a condition typically only resulting from a water change in the tank, but, regardless, a condition that requires fluid (typically tap water) to be added to the tank. When fluid is added to the tank, there is no cleaning agent in the fluid, and cleaning agent should therefore be added. In the past, employees would manually add cleaning agent to the water upon refilling the tank. Adding too much soap creates a “soap suspension” problem, which diminishes the ability of the soap to attack grease and also leads to added cost due to overuse of the cleaner. Adding too little cleaner or soap is not sanitary and not efficient in removing grease, films, and other food debris from the kitchenware.
In the present invention, when the fluid level sensor 81 detects that the fluid level is too low, i.e., below the heating element, the control system shuts down the automated washer. When fluid is added to the tank, typically during a refill operation, the fluid level sensor detects that the fluid level is sufficient again. Prior to reinitiating the pump and heater, the microprocessor causes the soap dispenser (e.g., the peristaltic pump) to dispense a predetermined amount of cleaner into the intake plenum, and, thus, into the tank's water or fluid. The cleaner dispenser 110 is preferably located behind the control panel and includes a feed line 112 that supplies cleaner into intake plenum 65, thus the cleaner injection process is performed out of the way of the tank and kitchenware in the tank. In the case of a peristaltic pump, the dispenser includes a line that couples the pump to a supply of cleaner (not shown). The dispenser and cleaner supply are positioned to be out of the way to prevent damage to the dispenser 110 during operation of the washer. The cleaner dispenser system could, however, be located anywhere on the tank that allows the dispenser to dispense cleaner into the tank, as is understood by those skilled in the art.
The control system preferably includes a control panel 96 (shown in
While a preferred automated washer has been described in detail, various modifications, alterations, and changes may be made without departing from the spirit and scope of the washer according to the present invention as defined in the appended claims.
This application is a divisional of U.S. patent application Ser. No. 09/784,750, filed Feb. 15, 2001, now U.S. Pat. No. 6,659,114, the entire disclosure of which is incorporated herein by reference.
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| Number | Date | Country | |
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| Number | Date | Country | |
|---|---|---|---|
| Parent | 09784750 | Feb 2001 | US |
| Child | 10674913 | US |
