Patent Application
20090025758
The present application relates generally to machines used to wash kitchen wares such as dishes, glasses, utensils and pots and pans, and more particularly to a ware wash machine that makes effective use of one or more fluidic oscillator nozzles (or other variable stream orientation nozzles as defined below) in one or more areas of the machine.
It is known to provide varying types of ware wash machines. Two of the most common types of commercial machines are the single rack-type box unit and the conveyor-type unit. The former may include a single chamber into which a rack of soiled ware can be placed. Within the chamber, the entire cleaning process, typically including washing, rinsing and drying is performed on the rack. Multiple racks must be washed sequentially, with each rack being completely cleaned before the next can be operated upon. A conveyor-type machine, on the other hand, includes a conveyor for carrying individual items or entire racks of ware through multiple stations within the machine housing. A different operation may be carried out at each station, such as washing, rinsing, or drying. Thus, multiple items or racks of ware can be placed on the conveyor and moved continuously through the machine so that, for example, while one item or rack is being rinsed, a preceding item or rack can be dried. One difficulty encountered in the construction of such machines, regardless of type, is balancing effective washing and rinsing with the goal of limiting the amount of liquid, detergents, rinse agents and sanitizes used for such washing and rinsing.
In an aspect, a warewash machine includes a housing including an area for receiving wares to be washed and a liquid dispensing arm removably positioned within the housing, the liquid dispensing arm including a nozzle receiving opening. Removably positioned in the nozzle opening is a nozzle that is configured to output liquid in a specific output pattern. The nozzle receiving opening and the nozzle are cooperatively shaped and configured such that when the nozzle is inserted in the nozzle receiving opening the nozzle is automatically positioned such that an orientation of the specific output pattern relative to the area is automatically set to a specific orientation.
In another aspect, a warewash machine liquid dispensing arm includes a nozzle removably positioned in a nozzle opening of the liquid dispensing arm. The nozzle is configured to output liquid in a specific output pattern. The nozzle receiving opening and the nozzle are cooperatively shaped and configured such that when the nozzle is inserted in the nozzle receiving opening the nozzle is automatically positioned such that an orientation of the specific output pattern relative to an arm axis is automatically set to a specific orientation.
In another aspect, a warewash machine arm for ejecting liquid in a warewash machine includes an arm body defining an internal liquid space along an arm axis and a liquid outlet in a surface of the arm. A nozzle is configured to output liquid in a specific pattern with the nozzle removably connected with the arm body to receive liquid from the liquid outlet. The nozzle is removably connected to the arm body in a manner such that a position of the nozzle relative the arm is automatically set to a position in which an orientation of the specific pattern relative to the axis of the arm is automatically set to a specific orientation.
Referring to
The unit 10 includes an entry side 16 and an exit side 18. A wash section 20 within the housing includes one or more wash arms 22 for directing wash liquid or other wash media onto wares traveling along the conveyor 14. The wash liquid may be recirculated by a suitable pump through a wash liquid tank 24 located beneath the wash section to receive the wash liquid as it falls from the wares. The tank 24 may typically include an overflow drain as well as a manual or automatic drain mechanism to enable draining of the entire tank 24. In the illustrated embodiment the wash arms 22 are located beneath the conveyor 14 to direct wash liquid upward onto the wares. Other locations for the wash arms 22 are possible, including toward the top of the housing and on the sides of the housing. A rinse section 26 located downstream of the wash section 20 includes rinse arms 28 that direct rinse liquid onto wares traveling along the conveyor 14. In the illustrated embodiment, an upper rinse arm directs rinse liquid downward onto the wares and a lower rinse arm directs rinse liquid upward onto the wares. Other locations for the rinse arms are possible, such as toward the sides of the housing.
Referring now to the exemplary rinse arm 28 shown in
A fluidic oscillator nozzle is generally any nozzle that outputs an oscillating stream of fluid, meaning that the direction of the output stream of fluid varies in an oscillatory manner. In the case of liquids, the stream of liquid is typically made up of a series of drops of the liquid being output. The resulting fan-shape 32 covered by the sweep of the output stream of each nozzle is best seen in
In the illustrated embodiment, the rinse arm 28 extends in a direction across a conveying direction (arrows 31 of
Fanjet nozzles output water in a spread pattern, with drops simultaneously output in multiple directions within the spread, rather than outputting a stream of drops with changing instantaneous direction as fluidic oscillator nozzles do. Fluidic oscillator nozzles can provide an advantage of larger output drop size (in the case of liquids) for a given flow rate than commonly used fanjet nozzles having the same flow rate, providing better washing or rinsing and also reducing heat loss to the air. In one example, fluidic oscillators outputs rinse liquid with an average drop size at least twenty-five percent greater than that output by a typical fanjet nozzle having the same flow rate. It is contemplated that the nozzles will typically be fed by a relatively constant pressure fluid, but a pulsing output from the nozzles could be produced, as by using a liquid manifold having an associated variable pressure mechanism to vary the pressure within the liquid manifold in a pulsed manner.
One embodiment of a fluidic oscillator nozzle 30 of the rinse arm 28 is shown in
The nozzle side parts 50A and 50B have respective internal sides 52A and 52B and respective external sides 54A and 54B. The internal sides have identical protrusions (e.g., curved ridge 56, curved ridge 58 and post 60) and identical recesses (e.g., curved recess 62, curved recess 64 and post receiving aperture 66). In final construction, the first nozzle side part 50 is arranged in mirror image orientation relative to and adjacent the second nozzle side part 52 such that the protrusions of the first nozzle side part frictionally engage into the recesses of the second nozzle side part and the protrusions of the second nozzle side part frictionally engage into the recesses of the first nozzle side part. Such engagement aids in holding the side parts together and also performs a sealing function for the cavity formed internal of the nozzle 30.
Both the first nozzle side part 50 and the second nozzle side part 52 include at least one exterior mating finger (e.g., flexible fingers 70A, 70B and rigid fingers 72A, 72B) and at least one exterior mating opening (e.g., fixed openings 74A, 74B and movable openings 76A, 76B). In final construction the first nozzle side part 50 is arranged in mirror image orientation relative to and adjacent the second nozzle side part 52 such that the exterior mating finger(s) of the first nozzle side part engage the exterior mating opening(s) of the second nozzle side part and the exterior mating finger(s) of the second nozzle side part engages the exterior mating opening(s) of the first nozzle side part.
Referring to
As shown by
The nozzle may also include at least two flexible fingers 80A and 80B to facilitate snap-fit insertion of the nozzle into an appropriately sized and shaped opening 29 of the rinse arm, such fingers including respective surfaces 82A, 82B ramped to engage an opening during insertion to flex the fingers to an insertion position (e.g., inward toward the nozzle body), and the fingers returning to a holding position after insertion. The protruding part of the nozzle 30 includes a notch 85 to receive a tool (such as a screwdriver) to enable removal of the nozzle from the opening as by a prying operation. In one example, the protruding part of the nozzle may protrude no more than about 0.4 inches in order to reduce the potential for nozzle breakage, but variations on this distance are possible. In alternative embodiments, the nozzle may include exterior threads to facilitated engagement with the opening in the opening 29. In the case of metal nozzles, they could be welded to the rinse arm or other manifold. The use of fasteners is also contemplated.
While the foregoing nozzle description primarily contemplates a nozzle in which the identical side parts are snap-fit together, it is recognized that other connection techniques could be used. For example, connection by one of an adhesive, one or more fasteners, a welding operation, such as ultrasonic welding for plastics, or a brazing operation (for metals) might be used. Further, while the foregoing nozzle description primarily contemplates first and second nozzle side parts constructed separately, they could be constructed together (e.g., as in a clamshell-type configuration including a connecting hinge could be provided between a single molded plastic piece including the two side parts, enabling the side parts to be folded against each other and connected together, as by any suitable technique previously mentioned, to form the internal cavity of the nozzle). Still further, a one piece nozzle construction could also be used. For example, an investment cast one-piece nozzle could be used.
Referring still to
Varying degrees of oscillation can be achieved by modifying the nozzle configuration. Oscillating frequency is also affected by fluid pressure and medium (e.g., gas or liquid). Further, the shape and orientation of the feedback loop provided within the nozzle could vary significantly.
It is recognized that the foregoing nozzle construction is one of many possible fluidic oscillator nozzle constructions that could be used. Further, while the typical fluidic oscillator nozzle construction provides an output stream that, more or less, moves back and forth in two-dimensions along a plane, it is contemplated that other fluidic oscillator nozzle constructions could be used where the oscillation occurs in three dimensions. Further, it is also recognized that nozzle constructions in which the output stream technically does not “oscillate” are possible, such as an output stream that moves in one direction to produce a helical or cylindrical output, an expanding helical or cone-shaped output or an output stream having an orientation that varies randomly/chaotically relative to the axis of the nozzle. As used herein the terminology “variable stream orientation nozzle” is intended to encompass any and all such nozzle constructions that output a stream of fluid with an instantaneous direction that varies over time relative to a nozzle axis, regardless of whether the variance is regular, random, oscillating or non-oscillating.
The wash arms 22 could also include fluidic oscillator nozzles or other variable stream orientation nozzles positioned therein to direct wash fluid onto the wares. It is generally contemplated that the wash arm nozzles would be constructed to produce a higher flow rate than the rinse arm nozzles, but variations are possible, including the use of identical nozzles for both rinse and wash.
While the foregoing embodiment of the conveyor-type ware wash machine contemplates a single wash section 20 and a single rinse section 26, it is recognized that conveyor-type machines having multiple wash sections and/or multiple rinse sections could be provided. It is further contemplated that other sections could be provided within the machine, such as an upstream pre-wash section using one or more variable stream orientation nozzles to output a pre-wash liquid to remove larger food materials from wares or to output steam, a downstream sanitizing section using one or more variable stream orientation nozzles to output a sanitizing liquid, a downstream drying section using one or more variable stream orientation nozzles to output air (heated or unheated) or some other gas for drying, or a downstream heating section in which heated air or steam is output by one or more variable stream orientation nozzles to heat the wares for sanitizing purposes.
Moreover, use of fluidic oscillator nozzles in undercounter and other box units is also contemplated. For example, referring to
Above the bottom wall, rails 240 provide support for standard ware racks 250, loaded with ware to be washed and sanitized, which are loaded and unloaded through the front door. The rack 250 may be a rolling rack intended to remain with the unit or may be a mobile rack intended to be removed entirely when the wares are removed. A coaxial fitting 270 is supported on the lower wall 200, centrally of the chamber, and this fitting in turn provides support for a lower wash arm 300 and lower rinse arm 320, each being rotational as is common. An upper wash arm 340 and upper rinse spray heads 360 are supported from the top wall of the chamber. The wash arms 300 and 340 may include suitable fluidic oscillator nozzles 302 (or other variable stream orientation nozzles) incorporated therein (e.g., as in the manner previously described with respect to
The fresh hot rinse water supply line 400 extends from a source of hot water and is connected to the rinse arm 320 and rinse spray heads 360. The wash water supply line 420 is connected to the upper and lower wash arms 340 and 300, and receives wash water from a pump 450 mounted to one side of and exterior of the cabinet. The pump in turn is supplied from an outlet pipe 470 that extends from sump 220 and returns or recirculates the wash water sprayed over the ware in the rack during the wash segment of the machine cycle. Thus, during the wash portion of an operating cycle, pump 450 functions as a recirculating pump means.
A solenoid operated drain valve 480 is connected by a branch or drain pipe 490 to the wash water supply line 420 immediately downstream of the outlet of pump 450, and this valve when open allows flow of the pump discharge to a drain line 500 that may be connected into a suitable kitchen drain system 520, according to the applicable code regulations. In many kitchens in newer fast food restaurants the drain system may be considerably above the floor, thus the pumped discharge from the dishwasher is a desired feature in those installations. Also, when the drain valve is open, the path of least resistance to the pump output is through drain valve 480, and flow through the recirculating wash plumbing quickly diminishes due to back pressure created at the nozzles of the wash arms. At this time the pump 450 functions as a drain pump means. During the normal cycle of operations of this machine, drain valve 480 is opened once each cycle of operation, after the wash segment and before the rinse segment of the cycle.
A solenoid-operated fill valve 550 is connected, in the embodiment shown, to control the supply of fresh water to a booster heater tank 580, which is a displacement type heater tank having its inlet connected to receive water through fill valve 550, and its outlet connected to the fresh rinse water supply line 400. The booster heater has a heating element 700 and has the usual pressure relief valve 590 which will divert hot water through an overflow pipe in the event the tank pressure exceeds a predetermined value. While the illustrated booster heater tank 580 and pump 450 are shown alongside the main dishwasher housing, it is recognized that embodiments in which the pump 450 and booster are provided internal to the main housing, such as beneath the wash chamber, are within the contemplated scope of the various inventions described herein. An atmospheric style booster could also be used.
Also, a low capacity (e.g. 500 W) heater 720 may be located in or on the sump 220. Such a heater may be, for example, a wire or similar heating strip embodied in an elastomeric pad that can be adhered to the exterior of the sump to heat water in the machine by conduction, if necessary. The heater 720 may alternatively be provided internally.
The undercounter unit of
Referring now to
As shown in
Nozzle assembly 836 is shown mounted in exemplary wash or rinse arm 840 in
It is to be clearly understood that the above description is intended by way of illustration and example only and is not intended to be taken by way of limitation. For example, while the nozzles are primarily described in association with manifolds in the form of stationary or rotating wash arms and/or rinse arms, it is recognized that other manifold types could be used, such as an oscillating arm or the wall of a wash chamber housing where the area behind the wall constitutes a manifold and nozzles are fixed in openings of the wall. Further, a manifold is not required, as each nozzle could be supplied with its fluid (liquid or gas) by an individual line not associated with any manifold. While it is contemplated that the delivery of any one fluid (e.g., any one of a rinse liquid, wash liquid or drying gas) will most often utilize multiple nozzles, it is possible that a machine could use a single nozzle to deliver a given fluid, or that the same nozzle or nozzles could be used to deliver multiple different fluids during different stages of a ware wash operation. Further, while the primary embodiments and examples described above contemplate nozzles that are fixed relative to some type of manifold, it is recognized that the nozzles could move relative to the structure to which they are mounted. Further, the terms “rinse liquid” and “wash liquid” are to be construed broadly, as each could be comprised of heated or unheated water, any heated or unheated water solution (e.g., water plus detergent as a wash liquid or water plus a rinse agent or/sanitizing agent as a rinse liquid), or in some cases non-aqueous liquids. Moreover, while the nozzle orienting feature described herein focuses on fluidic oscillator nozzles, such a feature could be provided for other types of removable nozzles, including the common fanjet type nozzle. Other changes and modifications could be made.
This application is a continuation in part of U.S. application Ser. No. 10/837,362, filed May 1, 2004, which claims the benefit of U.S. provisional application Ser. No. 60/478,380, filed Jun. 13, 2003.
| Number | Date | Country | |
|---|---|---|---|
| 60478380 | Jun 2003 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11005985 | Dec 2004 | US |
| Child | 11966120 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10837362 | May 2004 | US |
| Child | 11005985 | US |
