Abstract:
A conveyor warewasher for washing wares includes a first tank including a drain system having a drain outlet and a drain stop movable between a drain outlet closed position and a drain outlet open position. A second tank includes a drain system having a drain outlet, an associated drain path that leads to the first tank and an associated drain path stop moveable between a drain path open position and a drain path closed position. A drain control assembly includes a common drain actuator operatively connected to cause both (i) movement of the drain stop from the drain outlet closed position to the drain outlet open position and (ii) movement of the drain path stop from the drain path closed position to the drain path open position.

Description:
CROSS-REFERENCES 
       [0001]    This application claims the benefit of U.S. Provisional patent application Ser. No. 61/040,439 filed Mar. 28, 2008, the entirety of which is hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This application relates generally to warewasher systems which are used in commercial applications such as cafeterias and restaurants and, more particularly, to such a warewash system including a drain system for a secondary pumped rinse system. 
       BACKGROUND 
       [0003]    Commercial warewashers commonly include a housing area which defines washing and rinsing zones for dishes, pots pans and other wares. In certain zones, water is typically pumped from a tank through a pump intake, delivered to the wares via a spraying operation and collected in the tank for re-use. In operation of a warewasher with a secondary pumped rinse system, a rinse tank may be separated from a primary wash system tank, creating a need for the ability to readily drain the secondary pumped rinse tank. 
       SUMMARY 
       [0004]    In one aspect, a conveyor warewasher for washing wares includes a first spray zone and a second spray zone. The first spray zone includes multiple nozzles for spraying liquid onto wares passing through the first spray zone, and a first tank for collecting sprayed liquid. The first tank includes a drain outlet and a drain stop movable between a drain outlet closed position and a drain outlet open position. The second spray zone includes multiple nozzles for spraying liquid onto wares passing through the second spray zone, and a second tank for collecting sprayed liquid. The second tank includes a drain outlet, an associated drain path that leads to the first tank and an associated drain path stop moveable between a drain path open position and a drain path closed position. A drain control assembly includes a common drain actuator operatively connected to cause both (i) movement of the drain stop between the drain outlet closed position and the drain outlet open position and (ii) movement of the drain path stop between the drain path closed position and the drain path open position, such that upon draining of the first tank via movement of the common drain actuator, the second tank drains into the first tank along the drain path enabling liquid in the second tank to exit the drain outlet of the first tank. 
         [0005]    In another aspect, a method is provided for handling a draining operation in a conveyor warewashing machine of the type including a first spray zone with multiple nozzles for spraying liquid onto wares, the first spray zone including a first tank for collecting sprayed liquid, the first tank including a drain outlet and a drain stop movable between a drain outlet closed position and a drain outlet open position, and a second spray zone with multiple nozzles for spraying liquid onto wares, the second spray zone including a second tank for collecting sprayed liquid. The method involves: providing a drain system in the second tank, the drain system including a drain outlet, an associated drain path that leads to the first tank and an associated drain path stop moveable between a drain path open position and a drain path closed position; and operating a common drain actuator that causes both (i) movement of the drain stop from the drain outlet closed position to the drain outlet open position and (ii) movement of the drain path stop from the drain path closed position to the drain path open position, such that upon draining of the first tank via operation of the common drain actuator, the second tank drains into the first tank along the drain path enabling liquid in the second tank to exit the drain outlet of the first tank. 
         [0006]    In yet another aspect, a conveyor warewasher for washing wares includes a first tank including a drain system having a drain outlet and a drain stop movable between a drain outlet closed position and a drain outlet open position. A second tank includes a drain system having a drain outlet, an associated drain path that leads to the first tank and an associated drain path stop moveable between a drain path open position and a drain path closed position. A drain control assembly includes a common drain actuator operatively connected to cause both (i) movement of the drain stop from the drain outlet closed position to the drain outlet open position and (ii) movement of the drain path stop from the drain path closed position to the drain path open position. 
         [0007]    In a further aspect, a warewasher for washing wares includes a chamber for receiving wares. The chamber has an associated liquid delivery system for spraying liquid onto wares within the chamber. A primary tank collects the sprayed liquid. A secondary tank is fluidly connected to the primary tank via a conduit. A liquid recirculation system moves liquid from the primary tank back to the liquid delivery system. A drain system is located within the primary tank. The drain system includes a well, a liquid recirculation system inlet within the well and a drain opening within the well. A drain control assembly includes a drain stopper member for closing the drain opening, a strainer connected with the drain stopper member and a valve that controls liquid flow from the conduit into the primary tank. The drain stopper member and the valve are both controlled by a drain lift linkage such that both the drain opening and an outlet of the conduit are opened and closed using the drain lift linkage. 
         [0008]    The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a diagrammatic side, section view of an embodiment of a warewash system; 
           [0010]      FIGS. 2-6  are various views of another embodiment of a drain system; 
           [0011]      FIGS. 7 and 8  illustrate operation of a system for use in opening and closing the drain system; 
           [0012]      FIGS. 9-11 , illustrate a drain lift linkage that is also used in draining a second tank; 
           [0013]      FIGS. 12 and 13  illustrate an embodiment of a valve for use in draining the second tank in closed and open positions, respectively; and 
           [0014]      FIG. 14  is a perspective view of another embodiment of a warewasher. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Referring to  FIG. 1 , an exemplary conveyor-type warewash system, generally designated  10 , is shown. Warewash system  10  can receive racks  12  of soiled wares  14  from an input side  16  which are moved through tunnel-like chambers from the input side toward a dryer unit  18  at an opposite end of the warewash system by a suitable conveyor mechanism  20 . Either continuously or intermittently moving conveyor mechanisms or combinations thereof may be used, depending, for example, on the style, model and size of the warewash system  10 . The conveyor machine includes multiple spray zones for cleaning the wares passing therethrough. In the illustrated embodiment, the racks  12  of soiled wares  14  enter the warewash system  10  through a flexible curtain  22  into a pre-wash chamber or zone  24  where sprays of liquid from upper and lower pre-wash manifolds  26  and  28  above and below the racks, respectively, function to flush heavier soil from the wares. The liquid for this purpose comes from a tank  30  via a pump  32  and supply conduit  34 . As will be described below, a drain system  120  provides a single location where liquid is pumped from the tank  30  using the pump  32  and where liquid can be drained from the tank, for example, for a tank cleaning operation. 
         [0016]    The racks proceed to a next curtain  38  into a main wash chamber or zone  40 , where the wares are subject to sprays of cleansing liquid from upper and lower wash manifolds  42  and  44  with spray nozzles  47  and  49 , respectively, these sprays being supplied through a supply conduit  46  by a pump  48 , which draws from a main tank  50 . A heater  58 , such as an electrical immersion heater provided with suitable thermostatic controls (not shown), maintains the temperature of the cleansing liquid in the tank  50  at a suitable level. Not shown, but which may be included, is a device for adding a cleansing detergent to the liquid in tank  50 . During normal operation, pumps  32  and  48  are continuously driven, usually by separate motors, once the warewash system  10  is started for a period of time. 
         [0017]    The warewash system  10  may optionally include a power rinse chamber or zone (not shown in  FIG. 1 ) that is substantially identical to main wash chamber  40 . In such an instance, racks of wares proceed from the wash chamber  40  into the power rinse chamber, within which heated rinse water is sprayed onto the wares from upper and lower manifolds. 
         [0018]    The racks  12  of wares  14  exit the main wash chamber  40  through a curtain  52  into a final rinse chamber or zone  54 . The final rinse chamber  54  is provided with upper and lower spray heads  56 ,  58  that are supplied with a flow of fresh hot water via pipe  60  under the control of solenoid valve  62 . A rack detector  64  is actuated when rack  12  of wares  14  is positioned in the final rinse chamber  54  and through suitable electrical controls, the detector causes actuation of the solenoid valve  62  to open and admit the hot rinse water to the spray heads  56 ,  58 . The water then drains from the wares into tank  50 . The rinsed rack  12  of wares  14  then exit the final rinse chamber  54  through curtain  66 , moving into dryer unit  18 . 
         [0019]      FIGS. 2-6  illustrate a drain system embodiment  120  for use with the tank  30  including pump inlet  78  and drain port  76  that are both in communication with well  72 . A drain control assembly  128  is used to control draining of liquid from the tank  30 . The drain control assembly  128  includes a support member (e.g., in the form of a standpipe  130 ) that supports a strainer  132  thereon.  FIG. 2  illustrates the drain control assembly  128  removed from the well  72 . A drain plug portion  134  is located at an end of the standpipe  130 , which can be positioned within the drain port  76  to prevent liquid from passing thereby. The drain plug portion  134  includes a tapered end  135  that is used to guide the drain plug portion into the drain port  76 . 
         [0020]    Referring briefly to  FIG. 2A , the standpipe  130  includes an opening  131  extending from an upper end  133  of the standpipe through the tapered end  135 . A deflector  141  may be included that is connected at the upper end  133  to the standpipe  130 . The deflector  141  is spaced from the upper end  133  to allow liquid to pass therebetween during an overflow condition. The deflector  141  prevents large food particles and tableware (or other objects) from entering the opening  131 . 
         [0021]    Referring back to  FIG. 2 , the strainer  132  includes a wall  37  that extends about the standpipe  130  (e.g., in a cylindrical manner). The wall  37  includes openings through which liquid can pass while preventing passage of particles (e.g., large food particles) or other items such as tableware (e.g., knives, spoons, forks, etc.) thereby. A solid upper wall  136  covers a top of the wall  37 . The upper wall  136  includes an opening sized to slidingly receive the standpipe  130 . Other strainer shapes and configurations are contemplated. The upper wall  136  may also include strainer openings. 
         [0022]    Referring now to  FIG. 3 , the strainer  132  and standpipe  130  are moveable relative to each other.  FIG. 3  (and  FIG. 2A ) illustrates the strainer  132  in its fully lowered position, while  FIG. 2  shows the strainer in its fully raised position relative to the standpipe  130 . In some embodiments, the deflector  141  is at a height h 1  relative to the bottom end of the standpipe  130  that is greater than about two times (e.g., about three times or more) a height h 2  of the top of the strainer  132  from the bottom end of the standpipe  130  with the strainer at its fully lowered position (see  FIG. 2A ). Referring to  FIG. 4 , as the drain control assembly  128  is lowered into the well  72 , the strainer  132  rests on the bottom surface of the tank  30 . The combination of the tank surface and strainer  132  prevents passage of potentially obstructing items into the well  72 . 
         [0023]      FIG. 5  illustrates the drain control assembly  128  in a configuration to allow strained liquid to drain through the drain port  76 . In this configuration, the drain plug portion  134  of the standpipe  130  is lifted away from the drain port  76 . The standpipe  130  may be lifted mechanically into this position and/or manually. As can be seen, in this position, the strainer  132  remains seated against the bottom of the tank  30 . Thus, a user can effect tank draining by lifting the standpipe  130  slightly, without lifting the strainer  132  from its blocking position. 
         [0024]    To prevent draining of liquid through the drain port  76 , the standpipe  130  and drain plug portion  134  are lowered relative to the strainer  132 . A seal member  136  (e.g., an O-ring) is provided on the drain plug portion  134  to provide a seal between the drain port  76  and the drain plug portion. With the drain plug portion  134  sealed with the drain port  76 , filtered liquid can be drawn into the recirculation system from the well  72  and provided to the liquid delivery system while liquid is prevented from draining from the tank through the drain port. As can also be seen in  FIG. 5 , a stop  137  (e.g., a snap ring) is located on the standpipe  130  to prevent the strainer  132  from sliding thereby and off of the standpipe, for example, when the drain control assembly  128  is removed from the well  72  (e.g., for a cleaning operation). The stop  137  is located far enough down on the standpipe  130  to allow the standpipe to be removed from the drain port  76  while the strainer  132  remains seated against the bottom of the tank. The stop  137  may be removable to facilitate separation of the strainer  132  from the standpipe  130 . There may be another stop located above the strainer  132  on the standpipe  130  to prevent the strainer from being raised off of the standpipe. In the head  139  of the standpipe there is an enlarged end that can act as a stop.  FIG. 6  shows the strainer  132  in a raised position with the drain plug portion  134  located in the drain port  76 . 
         [0025]    Referring again to  FIG. 5 , in some embodiments, a tube member  138  is connected to the upper wall  136  of the strainer  132 . The tube member  138  includes an opening through which the standpipe  130  extends. The tube member  138  interacts with the standpipe  130  to provide lateral stabilization of the strainer  132  on the standpipe. The opening of the tubular member  138  or may be free sliding. 
         [0026]      FIGS. 7 and 8  illustrate an example of a drain lift linkage  140  for use in lifting and lowering the standpipe  130 . The drain lift linkage  140  includes a support bracket  142  that is mounted on an upper surface  144  of a pump housing  146 . The support bracket  142  slidably supports a moveable member  148  that includes a pair of L-shaped slots  150  and  152  within which fasteners  154  and  156  are received. The moveable member  148  includes an engageable end  160  that includes a graspable portion  162  that can be grasped and pulled by an operator to lift the moveable member and pull the moveable member toward the operator. Due to the L-shape of the slots  150  and  152 , the moveable member  148  can remain in the raised position until a horizontal force is applied thereto. The moveable member  148  is connected to a connector  164  that connects the standpipe  130  to the moveable member. In particular, the connector  164  is illustrated as being releasably engaged with the deflector  141 , however, other configurations are possible. 
         [0027]      FIG. 7  illustrates the standpipe  130  positioned in the raised position by the drain lift linkage  140 . The slots  150  and  152  are sized such that moveable member  148  can be raised only so high (e.g., about ¾ inch) as to lift the standpipe  130  from the drain port  76  to allow liquid to pass therethrough while the strainer  132  remains seated against the bottom of the tank  30 . 
         [0028]      FIG. 8  illustrates the standpipe  130  in the lowered position, blocking the drain port  76 . To place the standpipe  130  in the lowered position from the raised position, an operator can exert a horizontal force on the moveable member  148  thereby aligning the fasteners  154  and  156  with the vertical portions of the slots  150  and  152 . The weight of the standpipe  130  causes the standpipe and the moveable member  148  to drop, thereby locating the standpipe within the drain port  76 . In one embodiment, door  166  includes a ledge  168  that extends outwardly from the door. The ledge  168  is sized and positioned so as to contact the graspable portion  162  with the moveable member  148  in the raised position and the door  166  closed to apply the horizontal force to the moveable member to cause the standpipe to lower into its lowered position. This can prevent the standpipe  130  from being in the raised position if the door  166  is closed. The ledge  168  may also be sized so that is does not contact the graspable portion  162  with the moveable member  148  in its lowered position. The standpipe  130  and strainer  132  assembly can be removed from the drain port  76  for cleaning. 
         [0029]    The above-described drain systems and drain control assembly can provide a number of advantages. For example, by locating both the pump intake  78  and drain port  76  within a single well, cleaning of the warewasher  10  can be simplified. Additionally, locating the pump intake  78  at the drain port  76  places the pump intake below the bottom of the tank  30  thereby increasing the head above the intake. This increase in head above the pump intake  78  can improve performance of the pump  32 . 
         [0030]    Referring now to  FIGS. 9-11 , the drain lift linkage  140  can also be used in draining a secondary tank  170  (of a secondary pumped rinse system). The secondary tank could also be any other tank within the conveyor machine (e.g., in some other spray zone of the machine). The secondary tank  170  is fluidly connected to the tank  30  (now referred to as primary tank  30 ) via a drain conduit  172  or other drain path having an inlet end  174  associated with the drain outlet of the secondary tank and through which liquid travels from the secondary tank to an outlet end  176  through which the liquid can be introduced into the primary tank. Typically, the inlet end  174  is at a higher elevation than the outlet end  176 . A valve  178  (e.g., a flapper valve) acts as a drain path stop and is used to control inlet of liquid from the secondary tank  170  through the conduit  172  and into the primary tank  30 . The valve  178  includes an openable member or stopper  180  that is mechanically linked via linkage  182  to the moveable member  148  of the drain lift linkage  140 . Thus, moveable member  148  acts as a common actuator for both moving the standpipe  130  and drain plug  134 , which acts as a drain stop of the drain outlet of the primary tank, and moving the flapper valve  178 . Lifting of the moveable member  148  of the drain lift linkage  140  causes the openable member  180  to open the outlet end  176  of the conduit  172  thereby causing liquid to flow into the primary tank  30 . As indicated above, the drain lift linkage  140  is also connected to the standpipe  130  such that lifting of the moveable member  148  also raises the standpipe  130  from the drain port  76  to allow liquid to pass therethrough while the strainer  132  (see  FIG. 7 ) remains seated against the bottom of the primary tank  30 . Lowering of the moveable member  148  of the drain lift linkage  140  closes the openable member  180  to prevent entry of liquid into the primary tank  30  from the conduit  172  and also lowers the standpipe  130  to seal against the drain port  76  as described above. Thus, both the secondary and the primary tanks  170  and  30  can be drained by pulling the moveable member  148  of the drain lift linkage  140 . Additionally, both the valve  178  and the drain port  76  can be closed by lowering the moveable member  148 , for example, through contact with the ledge  168  of the door  166 , as described above. 
         [0031]      FIGS. 12 and 13  illustrate, in detail, the valve  178  in closed and open positions, respectively. In  FIG. 12 , the openable member  180  is seated against a seating surface  184  to form a fluid-tight seal thereby preventing liquid from entering the tank  30 . In  FIG. 13 , the openable member  180  is lifted from the seating surface  184  by lifting the moveable member  148  and the linkage  182 . The linkage  182  is pivotally connected to the openable member  180  to cause the openable member  180  to pivot about axis P when the moveable member  148  is raised. Lifting the openable member  180  from the seating surface  184  allows fluid from the secondary tank  170  to flow into the primary tank  30 . 
         [0032]    The above-described drain system can provide a number of advantages. For example, no electric power is required to drain the warewasher, thus both primary and secondary tanks  30 ,  170  can be drained while the warewasher&#39;s power is off. The primary and secondary tanks  30 ,  170  can be drained using a single moveable member  148 , which acts as a common actuator, thereby requiring a single operator motion for draining both tanks. Passing liquid from the secondary tank  170  through the drain of the primary tank  30  can reduce cleaning time. 
         [0033]    Notably, in the illustrated embodiment, when the drain plug  134  is in the drain outlet closed position (e.g., the position of  FIGS. 8 and 9 ), drain suction in the primary tank  30  aids in maintaining the drain plug in the drain outlet closed position. When the valve member  178  is in the drain path closed position (e.g., the position of  FIG. 12 ) the drain valve works against head pressure in the secondary tank to maintain the drain path closed. The rigid linkage  182  that connects the upper part of the standpipe to the valve  178  through the connector  164  acts such that the drain suction in the primary tank  30  acting on the drain plug  134  aids in holding the valve  178  in the drain path closed position. Also, in embodiments where, as noted above, closure of the machine door causes the actuator  148  to move out of its drain position into its non-drain position, the drain outlet of both of the tanks will be caused to close by such action. 
         [0034]    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, and that changes and modifications are possible. For example, rather than the manual actuator  148 , a powered actuator (e.g., solenoid or motor controlled) could be provided for automated draining of both tanks. Moreover, the drain systems (represented by the dotted lines) can be utilized in non-conveyor type machines, such as warewasher  110  illustrated by  FIG. 14  or an undercounter warewasher. Accordingly, other embodiments are contemplated and modifications and changes could be made without departing from the scope of this application.