Abstract:
An automatic, or “one touch,” filtering system for filtering a cooking medium in a cooking apparatus, e.g., a fryer, includes a cooking vessel, e.g., a frypot; a drain valve disposed on a drain path between the cooking vessel and a filter container; a fill valve disposed on a fill path between the filter container and the cooking vessel; a pump disposed on one of the first path and the second path for conveying the cooking medium from the drain path to the fill path through the filter container; a controller configured to selectively operate the drain valve and the fill valve to regulate a flow of cooking medium to and from the cooking vessel; and a single switch configured to send a control signal to the controller in response to actuating the switch. The systems and methods of the invention provide automatic filtering that may reduce or eliminate incorrect valve operation, so that the filtering process may be performed correctly each time.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to systems and methods for automatically filtering a cooking medium in a cooking apparatus, such as a fryer. 
         [0003]    2. Description of Related Art 
         [0004]    Known fryers, e.g., open-well fryers and pressure fryers, are used to cook various food products, e.g., poultry, fish, or potato products. Such fryers include a cooking vessel, e.g., a frypot, and the cooking vessel is filled with a cooking medium, e.g., an oil, a liquid shortening, or a meltable-solid shortening. Such fryers also include a heating element, e.g., an electrical heating element, such as a heating coil, or a gas heating element, such as a gas burner and gas conveying tubes, which heat the cooking medium in the cooking vessel. After the cooking medium reaches a preset cooking temperature, the food product is placed into the cooking medium, such that the food product is cooked in the cooking medium. For example, the food product may be positioned inside a product holder, e.g., a wire basket, and submerged in the cooking medium for a predetermined amount of time sufficient to cook or to complete the cooking of the food product. The amount of time sufficient to cook or to complete the cooking of the food product at a given cooking temperature depends on the type of food product which is cooked. Moreover, the cooking medium is used during several cooking cycles before the cooking medium inside the cooking vessel is filtered, replaced, or supplemented with a new or filtered supply of cooking medium. 
         [0005]    Cooking medium may be filtered periodically to maintain cooking quality and to prolong the operational lifetime of the cooking medium. The filtering process removes cooking by-product, e.g., suspended food particles, ranging from dust-sized particles to larger pieces of crackling and small pieces of food product. Known contemporary filtering systems require the operator to manipulate manual valves to route the cooking medium through the filter and to return it to a cooking vessel, e.g., a frypot, disposed within the fryer. Even experienced operators may open or close the valves incorrectly, which increases operating expenses through lost time. Periodically, the drain pan under the fryer may be removed for cleaning or to discard the cooking medium. If the operator forgets to replace the drain pan and opens the drain valve, the cooking medium drains onto the floor and be wasted, which greatly increases operating expenses. Moreover, it is desirable to filter the cooking medium for an appropriate time period. If the filter time is too short, the cooking medium may not be not adequately filtered. If the filter time is too long, operating efficiency is impaired, and cooking medium quality may be unnecessarily degraded by mechanical agitation and oxidation. 
         [0006]    In addition, multiple frypots may be connected to a single drypan. Each frypot may be designated for cooking a different food product, e.g., chicken, french-fried potatoes, and fish. The flavor characteristics of each of these food products may become infused in the cooking medium. As a result, mixing cooking medium from frypots designated for different food products during filtering may adversely affect food quality, e.g., cooking chicken in a significant quantity of fish flavored cooking medium may result in “fishy” chicken. A manual filtering system may permit an operator to simultaneously filter cooking medium for frypots designated for different food products, which may reduce the quality of cooked food product for the reasons noted above. 
         [0007]    Referring to  FIGS. 1 and 2 , a fryer apparatus  10  comprising a known manual cooking medium filtering system and a known method for operating such a filtering system are depicted. Fryer apparatus  10  includes a frypot  16  having an open top  14  for receiving a food product. A cabinet  20 , shown without a door for illustrative purposes, has brackets  32  supporting a drain pan  30  having a filter (not shown). Drain pan  30  includes a handle  34  that allows drain pan  30  to be removed from cabinet  20  for cleaning. Drain pan  30  is fluidly connected to frypot  16  via a drain hose  24  and a filter pipe  28 . Disposed on filter pipe  28  is a filter pump  27  for drawing cooking medium to frypot  16  from pan  30 . Frypot  16  includes a drain valve handle  22  that operates a drain valve (not shown) for selectively permitting cooking medium to drain from frypot  16  via hose  24 . Frypot  16  also includes a filter valve handle  26  that operates a filter valve (not shown) for selectively permitting the introduction of cooking medium to frypot  16  from drain pan  30 . Fryer apparatus  10  further may include a power supply  40  for powering filter pump  27 , which may be actuated via a switch on control panel  18 . 
         [0008]    Referring to  FIG. 2 , a method for operating a known filtering system is depicted. To filter the cooking medium of fryer apparatus  10 , the operator first ensures that the filter valve is closed  50 . The operator turns drain valve handle  22  clockwise to manually open the drain valve  55 , which uses gravity to permit the cooking medium to drain into drain pan  30 . Next, the operator turns the filter valve handle  26  counter-clockwise to manually open the filter valve  60 . The operator then turns drain valve handle  22  counter-clockwise to manually close the drain valve  55 . The operator then actuates filter pump  70  using a switch that may be located on control panel  18 . Next, the operator de-actuates the filter pump  75  to end the filtering process. Finally, the operator turns filter valve handle  26  in a clockwise direction to manually close the filter valve  80 , so that operation of the fryer apparatus may resume. 
         [0009]    Handles  22 ,  26  may be located in cabinet  20  beneath frypot  16 , and may not be clearly marked. The above-described procedure is not intuitive unless the operator understands the logic and plumbing of the filter system, which generally is not the case for untrained operators. In known filtering systems, handles  22 ,  26  may be turned opposite directions to achieve the same result, in part because of design limitations within cabinet  20 , which may add another element of complexity that may lead to operator error. Further, if one of the sequence of steps is omitted or executed out of order, then, at best, the operating efficiency of the fryer apparatus is impaired, and, at worst, the pump or frypot may be damaged. Even trained, experienced operators may omit or switch steps during the rush of peak cooking periods, e.g., the “lunch-rush.” 
       SUMMARY OF THE INVENTION 
       [0010]    Therefore, a need has arisen for filtering systems and methods for a cooking apparatus that overcome these and other shortcomings of the related art. A technical advantage of the present invention is that automatic filtering prevents incorrect valve operation, so that the filtering process is performed substantially correctly each time. Another technical advantage of the invention is that operating profits may be increased by reducing the personnel training needed by providing a “one-touch filtering” system where the operator need only actuate a single switch to accomplish filtering. Yet another technical advantage of the invention is that precise control of the filtering cooking medium may be achieved. Still another technical advantage of the invention is that mixing of significant amounts of cooking medium from frypots used to cook different food products, which may adversely affect cooked food product quality, may be reduced or eliminated. 
         [0011]    The systems and methods of the invention are suitable for use with automatic cooking medium level control systems and methods, such as those disclosed in the nonprovisional patent application, Attorney Docket No. 018853.0773, filed on Nov. 27, 2006, entitled “AUTOMATIC OIL LEVEL CONTROL SYSTEMS AND METHODS,” the disclosure of which is hereby incorporated by reference in its entirety. 
         [0012]    According to an embodiment of the present invention, a method for automatically filtering a cooking medium of a cooking apparatus comprises the steps of requesting filtering of the cooking medium; determining whether the cooking medium in a cooking vessel of the cooking apparatus is in suitable condition for filtering in response to the filtering request; and filtering the cooking medium in the cooking vessel upon the determination that the cooking medium in the cooking vessel is in suitable condition for filtering. The filtering step further comprises the steps of: opening a drain valve for draining the cooking medium from the cooking vessel; opening a fill valve for introducing the cooking medium to the cooking vessel before closing the drain valve; draining the cooking medium from the cooking vessel; passing the cooking medium through a filter; introducing the filtered cooking medium into the cooking vessel; closing the drain valve before closing the fill valve; and closing the fill valve. 
         [0013]    According to another embodiment of the present invention, a system for automatically filtering a cooking medium of a cooking apparatus comprises: a first cooking vessel; a first drain valve disposed on a first fluid communication path between the first cooking vessel and a drain manifold; a filter container having fluidly connected to the drain manifold on a manifold drain path; a fill manifold fluidly connected to the filter container on a manifold fill path; a first fill valve disposed on a second fluid communication path between the fill manifold and the first cooking vessel; a pump for conveying the cooking medium from the drain path to the fill path through the filter container; a controller configured to selectively operate the first drain valve and the first fill valve to regulate a flow of cooking medium to and from the first cooking vessel; and a single switch configured to send a control signal to the controller upon actuation of the switch. 
         [0014]    According to yet another embodiment of the invention, a system for automatically filtering a cooking medium of a cooking apparatus comprises a cooking vessel; a drain valve disposed on a first fluid communication path between the cooking vessel and a filter container; a fill valve disposed on a second fluid communication path between the filter container and the cooking vessel; a pump disposed on one of the first path and the second path for conveying the cooking medium from the first path to the second path through the filter container; a controller configured to selectively operate the drain valve and the fill valve to regulate a flow of cooking medium to and from the cooking vessel; and a single switch configured to send a control signal to the controller in response to actuating the switch. 
         [0015]    According to still yet another embodiment of the invention, a system for automatically filtering a cooking medium of a cooking apparatus comprises means for requesting filtering of the cooking medium; means for determining whether the cooking medium in a cooking vessel of the cooking apparatus is in suitable condition for filtering; means for filtering the cooking medium in the cooking vessel upon a determination that the cooking medium in the cooking vessel is in suitable condition for filtering; and means for indicating one of the means for filtering is operating and the cooking medium is not suitable for filtering. The means for filtering further comprises a drain valve means for operating a drain valve for draining the cooking medium from the cooking vessel; a fill valve means for operating a fill valve for introducing the cooking medium to the cooking vessel; means for draining the cooking medium from the cooking vessel; means for passing the cooking medium through a filter; and means for introducing the filtered cooking medium into the cooking vessel. 
         [0016]    Other objects, features, and advantages of the present invention will be apparent to persons of ordinary skill in the art in view of the foregoing detailed description of the invention and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    For a more complete understanding of the present invention, needs satisfied thereby, and the objects, features, and advantages thereof, reference now is made to the following description taken in connection with the accompanying drawings. 
           [0018]      FIG. 1  is a front view of a fryer apparatus utilizing a known manual filtering system. 
           [0019]      FIG. 2  is a flow chart showing a known method for operating the filter system shown in  FIG. 1 . 
           [0020]      FIG. 3  is a schematic view of an automatic cooking medium filtering system according to an embodiment of the invention. 
           [0021]      FIG. 4A  is a perspective view of a cooking vessel according to an embodiment of the invention. 
           [0022]      FIG. 4B  is a plan view of a cooking vessel according to another embodiment of the invention. 
           [0023]      FIG. 5  is a schematic view of an automatic cooking medium filtering system according to another embodiment of the invention 
           [0024]      FIG. 6  is a flow chart showing a method for automatically filtering a cooking medium according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Preferred embodiments of the present invention, and their features and advantages, may be understood by referring to  FIGS. 3-6 , like numerals being used for corresponding parts in the various drawings. 
         [0026]    Referring to  FIG. 3 , a filtering system  100  according to an embodiment of the present invention is depicted. Fryer apparatus  100  may comprise at least one cooking vessel  116 , e.g., a frypot, which may be configured to hold a cooking medium, e.g., an oil, a liquid shortening, a meltable-solid shortening, or the like. Cooking vessel  116  may include an opening  114  for receiving a food product. A heating element (not shown), which may be a heating coil, is disposed within cooking vessel  116  for heating the cooking medium within vessel  116 . Filtering apparatus  100  may be utilized in a gas or electric fryer appartus.  FIG. 3  depicts vessel  116  suitable for an open-well fryer, but filtering system  100  also be used in a pressure fryer. 
         [0027]    Cooking vessel  116  may comprise a drain at an inlet of a drain path  124  fluidly connecting vessel  116  to a filter container  130 , e.g., a drain pan or a filter canister. A drain valve  122 , which may be a solenoid valve, may be disposed on drain path  124  to selectively permit cooking medium to drain from vessel  116  in response to a control signal from a controller C. Preferably, drain valve  122  is a linearly actuated valve to reduce the likelihood that cooking by-product may obstruct valve  122 . Cooking medium may pass through filter container  130  and return to vessel  116  via a filter or a fill path  128 . A second filter container (not shown) that may serve as a backup filter also may be connected to paths  124 ,  128 , when a filter in container  130  requires replacing or otherwise malfunctions. A filter or a fill valve  126 , which also may be a solenoid valve, may be disposed on filter path  124  to selectively permit cooking medium to be intoduced into vessel  116  in response to a control signal from controller C. 
         [0028]    Referring to  FIG. 3 , a pump  127  is disposed on drain path  124  to convey the cooking medium along drain and fill paths  124 ,  128 , but pump  127  also may be disposed on fill path  128 . Pump  127  actuates and de-actuates in response to a control signal from controller C. Controller C may comprise a processor coupled to a physical memory, an operator input, e.g., a push-button manual switch or an electronic switch, and a mechanism to detect whether the cooking medium is in suitable condition for filtering. Controller C may be coupled to an indicator  142 , e.g., a visual or audible alarm that indicates either that a filtering process is being performed by system  100  or that the cooking medium in vessel  116  is not in suitable condition for filtering. Indicator  142  may be a light, e.g., incandescent, fluorescent, LED, or the like, or indicator  142  may be incorporated into the fryer apparatus&#39; current display, such as on an LCD screen. If indicator  142  is an LED light, it may be on to indicate filtering of the cooking medium, and may blink to indicate the cooking medium is not suitable, i.e., not ready for, filtering. 
         [0029]    Drain and fill manifolds (not shown) may be disposed on the respective drain and fill paths, such an arrangement may permit the use of a smaller filter container that has an insufficient capacity to hold the entire volume of cooking medium within vessel  116 , or may allow multiple vessels to be connected to the same filter container wherein a multiple vessel, fryer apparatus may use a single filtering system, as shown, for example, in  FIG. 5 . 
         [0030]    Referring to  FIG. 4A  and  FIG. 4B , arrangements for cooking medium inlets fluidly connected to filter path  128  according to embodiments of the invention are depicted. As shown in  FIG. 4A , a pair of inlets  226 A,  226 B may be formed within a surface of cooking vessel  116  disposed at opposite ends of a longitudinal axis, i.e. a length, of vessel  116 . For example, here inlets  226 A,  226 B are shown as formed within opposing sidewalls of vessel  116 . Inlets  226 A,  226 B may be separated by a lateral distance that is substantially a width of vessel  116 . Arranging inlets  226 A,  226 B in this configuration may facilitate “swirling” of the cooking medium on a bottom surface  216  of vessel  116  to clean bottom surface  216 , wherein cooking by-product or any other particles may exit vessel  116  through a drain  220 . Bottom surface  216  may be sloped towards drain  220  to assist cooking medium, and any cooking by-product therein, to exit vessel  116 . Preferably, inlets  226 A,  226 B are disposed proximate bottom surface  216 . 
         [0031]    Referring to  FIG. 4B , an alternative inlet arrangement is depicted. A pair of linear diffuser headers  236 A,  236 B may extend along opposing sides of bottom surface  216 . Diffuser headers  236 A,  236 B also may be disposed on opposing sidewalls of vessel  116  proximate to the bottom surface  216 . Preferably, diffuser headers  236 A,  236 B extend substantially parallel to a longitudinal axis, i.e., along a length, of vessel  116 . Diffuser headers  236 A,  236 B may comprise a plurality of inlet holes  238  for introducing cooking medium via filter path  128 . Preferably, inlet holes  238  are configured to direct cooking medium towards a center axis of bottom surface  216  to promote the swirling of cooking medium for the reasons described above. Again, bottom surface  216  may be sloped towards drain  220 . 
         [0032]    Referring to  FIG. 5 , a filtering system  300  according to another embodiment of the present invention is depicted. A filtering system may comprises a plurality of cooking vessels  316 ,  356 ,  376 , e.g., frypots. Each vessel  316 ,  356 ,  376  may comprise a drain path  324 ,  364 ,  384  fluidly connected to a common, drain manifold  340 . If two vessels, e.g., vessels  316  and  356 , are designated for a same first food product, and the third vessel, e.g., vessel  376 , is designated for a different second food product, then vessels  316 ,  356  may be fluidly connected to a first drain manifold, while vessel  376  may be fluidly connected to a second drain manifold to segregate further the flavors infused in the cooking mediums for the respective first and second food products. A drain valve  322 ,  362 ,  382  responsive to a control signal from controller C may be disposed in each drain path  324 ,  364 ,  384 . 
         [0033]    Drain manifold  340  may be connected fluidly to filter container  330  on a manifold drain path  345 . An outlet (not shown) a filter container  330  may be fluidly connected to a filter or a fill manifold  350  through a manifold filter or fill path  355 . A pump  327  may be disposed on either manifold path  345 ,  355  to draw cooking medium through filter container  330 . Here, pump  327 , which may be responsive to a control signal from controller C, is shown as disposed on manifold drain path  345 . Filter manifold  350  may be fluidly connected to each vessel  316 ,  356 ,  376  via a respective filter path  328 ,  368 ,  388 . A filter valve  326 ,  366 ,  386  responsive to a control signal from controller C may be disposed on each filter path  326 ,  366 ,  386 . 
         [0034]    Controller C may be actuated by an operator using a single switch  344 , e.g., a mechanical or an electronic switch. An indicator  342  coupled to controller C may give a visual or audible indication that filtering of cooking medium from at least one vessel  316 ,  356 ,  376  is being performed, or that the cooking medium in at least one of the vessels is not suitable, i.e., not ready, for filtering. Indicator  342  may also indicate that the cooking medium needs filtering, such indication may be based on a predetermined number of cooking cycles for which the cooking medium has been used or sensing the condition of the cooking medium to determine that it is no longer suitable or efficient for cooking food product. 
         [0035]    Referring to  FIG. 6 , a method for automatically filtering a cooking medium of a cooking vessel, e.g., a frypot, is depicted. First, the operator may request the cooking medium in a cooking vessel to be filtered, e.g., by actuating a switch. Next, a controller may determine whether the cooking medium in the vessel is suitable, i.e., ready, for filtering. Parameters used for determining whether the cooking medium is ready for filtering may include, but are not limited to, the temperature of the cooking medium, any turbulence detected in the cooking medium, or whether food product is within the vessel. Further, if the method is used with a fryer apparatus having a plurality of cooking vessels, not more than one vessel may be suitable for filtering at any time, so that multiple vessels will not be filtered concurrently, in part, to prevent mixing of a significant amount of cooking medium from different vessels. Once it is determined that the cooking medium is suitable for filtering, then filtering of the cooking medium may begin. 
         [0036]    Referring to  FIG. 6 , a method  600  for automatically filtering the cooking medium according to one embodiment of the invention is depicted. First, in step  610 , a drain valve may be automatically opened to permit cooking medium to exit, or drain, the cooking vessel. Next, in step  615 , a filter valve may be automatically opened to permit introduction of cooking medium into the vessel. Subsequently, a filter pump may be energized in step  620  to pass the cooking medium through a container, such as a drain pan or filter canister, to filter the cooking medium. Both the drain valve and the filter valve may be open concurrently when the pump is energized to enable a flow of cooking medium to coat or swirl on a bottom surface of the cooking vessel for cleaning purposes. After letting the cooking medium “clean” the bottom surface of the vessel for a predetermined period, the drain valve may be closed automatically in step  625  to allow purging of the filter container and filling of the vessel with cooking medium in step  630 . Next, the pump may be de-energized in step  635  after filling the vessel. Finally, the filter valve may be closed automatically in step  640  to prevent drainage of cooking medium into the filter container and complete the filtering of cooking medium from the cooking vessel. 
         [0037]    While the invention has been described in connection with preferred embodiments, it will be understood by those of ordinary skill in the art that other variations and modifications of the preferred embodiments described above may be made without departing from the scope of the invention. Other embodiments will be apparent to those of ordinary skill in the art from a consideration of the specification or practice of the invention disclosed herein. The specification and the described examples are considered as exemplary only, with the true scope and spirit of the invention indicated by the following claims.