Automatic cooking medium level control systems and methods

An automatic cooking medium level control system for a cooking apparatus, e.g., a fryer, may include a cooking vessel having a first temperature sensor at a first level of the cooking vessel and a second temperature sensor at a second level of the cooking vessel. A reservoir holding a cooking medium, such as cooking oil, may be in fluid communication with the cooking vessel. A controller may monitor temperature data from the first and second temperature sensors to determine whether the level of cooking oil in the cooking vessel has lowered. Upon determining that the cooking oil level has lowered, the controller may actuate a supply mechanism, such as a pump, which may be disposed on a fluid communication path between the reservoir and cooking vessel, which may enable the introduction of cooking medium from the reservoir to the to the cooking vessel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to systems and methods for automatic cooking medium control in the well of a cooking apparatus, such as a fryer.

2. Description of Related Art

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.

The cooking medium in an open-well or pressure fryer is maintained at a proper level to standardize or to optimize cooking performance, or both. During each cooking cycle, however, the food product may absorb a small amount of cooking medium during cooking. In addition, a quantity of cooking medium also may evaporate or spill out of the cooking vessel during. Consequently, the level of cooking medium in the cooking vessel may decline or lower over repeated cooking cycles. As a result, the surface of the food product, or the entire food product, may not be fully submerged in the cooking medium when the product holder is positioned within the cooking vessel. This may result in uneven and inconsistent cooking results that reduce the quality of the cooked food product. For example, food product may be undercooked because it is not fully submerged in the cooking medium. Unappealing color variations in cooked food product also may result from temperature variation caused by the food product being exposed alternatively to both the air and cooking medium during the cooking process. Accordingly, it is desirable to maintain an adequate level of cooking medium in the vessel for maintaining cooking quality.

During busy periods, such as the so-called “lunch rush,” it may be difficult for a fryer operator to continuously monitor the level of cooking medium. If a fryer operator notices a reduced level of cooking medium, the operator manually adds cooking medium to the cooking vessel and allows the just-added cooking medium to reach a cooking temperature and consistency before using the fryer again. Thus, the ability to maintain an adequate level of cooking medium depends largely upon the attentiveness and skill of the operator.

Most known level sensing methods, however, are not entirely suitable for use in a cooking vessel, such as a frypot. Float switches, for example, may be fragile and may fail if cooking by-product contaminates the float or float hinge. In addition, such switches often are difficult to clean and take up a significant portion of the cooking vessel's volume. Optical sensors similarly may fail due to contamination from cooking by-product. Further, optical sensors may give false readings caused by reflections from nearby cooking screens or product holders. Capacitive sensors may take up a significant amount of surface area on the cooking vessel surface and must be located in close proximity with one another, which may lead to false readings and makes these sensors difficult to clean. Ultrasonic sensors may be expensive, particularly at the resolution used for monitoring cooking medium in a cooking vessel, and also may be affected by reflections from product holders.

SUMMARY OF THE INVENTION

Therefore, a need has arisen for a fryer apparatus that overcome these and other shortcomings of the related art. A technical advantage of the present invention is that a fryer may comprise an automatic cooking medium control system, such that the level of cooking medium may be maintained automatically without any action required by the fryer operator. Another technical advantage of the invention is that the automatic cooking medium control system may use a plurality of temperature sensors at a level just below cooking medium fill line to prevent complete system failures or the occurrence of false indications caused by variations in the cooking medium temperature, or both. Yet another technical advantage of the present invention provides is that a method of automatically maintaining the cooking medium level may comprise a degree of hysteresis that prevents overcycling of the supply mechanism, such as a pump, that adds cooking medium to the fryer to maintain an adequate level of cooking medium. Still another technical advantage of the invention, the automatic cooking medium control system further may comprise a heating element that preheats a viscous cooking medium to make it less viscous, which enables the use of a less expensive supply mechanism by virtue of being more energy efficient or less powerful, or both. Moreover, preheating the cooking medium results in better temperature regulation by reducing the temperature reduction of the cooking medium in the vessel heated to a cooking temperature caused when the newly introduced cooking medium is mixed with the cooking medium already in the fryer.

The systems and methods of the invention are suitable for use with an automated one-touch filtering system, such as the one disclosed in U.S. patent application Ser. No. 11/563,597, entitled “ONE-TOUCH FILTERING SYSTEMS AND METHODS,” the disclosure of which is hereby incorporated by reference in its entirety.

According to an embodiment of the present invention, an automatic cooking medium control system may comprise a cooking vessel including an opening for receiving food product, a plurality of temperature sensors providing temperature data, a reservoir of a cooking medium in fluid communication with said cooking vessel, and a supply mechanism disposed on a fluid communication path between the reservoir and at an inlet to the cooking vessel. The plurality of temperature sensors may comprise a first temperature sensor at a first level of the cooking vessel, and a second temperature sensor at a second level of said cooking vessel. The automatic cooking medium control system may further comprises a controlling mechanism that receives temperature data from the plurality of temperature sensors. In response to the temperature data, the controlling mechanism actuates the supply mechanism to provide the cooking medium from the reservoir to the cooking vessel.

According to another embodiment of the present invention, a method for automatically maintaining a level of cooking medium in a cooking vessel may comprise detecting temperature data of the cooking vessel, comparing the temperature data, determining a level of cooking medium in the cooking vessel based on the compared temperature data, and adding an amount of cooking medium to the cooking vessel upon determining that the level of cooking medium is inadequate. Detecting the cooking vessel temperature data may comprise detecting first temperature data at a first level of the cooking vessel, and detecting second temperature data at a second level of the cooking vessel that is below the first level. Also, the comparing step may comprise comparing the first temperature data with the second temperature data.

According to yet another embodiment of the invention, an automatic cooking medium control system may comprise a cooking vessel and a temperature sensing means for providing temperature data, e.g., a resistor temperature detector (“RTD”). The temperature sensing means may comprises a first temperature sensing means at a first level of said cooking vessel, and a second temperature sensing means at a second level of said cooking vessel. The system also may comprise a reservoir of a cooking medium in fluid communication with the cooking vessel; and a supply means for supplying a quantity of cooking medium from said reservoir to said cooking vessel, e.g., a pump. Moreover, the system may comprise a controlling means for actuating said supply means in response to the temperature data, e.g., a microprocessor associated with a physical memory.

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.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention, and their features and advantages, may be understood by referring toFIGS. 1-8, like numerals being used for corresponding parts in the various drawings.

Referring toFIGS. 1 and 2, a fryer apparatus100according to an embodiment of the present invention is depicted. Fryer apparatus100may comprise at least one cooking vessel104, e.g., a frypot, which may be configured to hold a cooking medium, e.g., an oil, a liquid shortening, a meltable-solid shortening, water, or the like. Fryer apparatus100may include an opening102formed in cooking vessel104for receiving a food product. Disposed within cooking vessel104is a heating element120, which may be a heating coil, for heating the cooking medium disposed within cooking vessel104. Fryer apparatus100may be a gas or electric fryer.FIGS. 1 and 2depict an open-well fryer as fryer apparatus100, but a pressure fryer also may be used.

Cooking vessel104may comprise an inlet106and a drain108for connecting to a system for filtering the cooking medium (not shown), such as the one described in U.S. patent application Ser. No. 11/563,597. Cooking vessel104may further comprise a supply inlet110in fluid communication with cooking medium reservoir150via a supply line155. A predetermined fill line160for a desired “full” cooking medium level may be disposed proximate to opening102. At least one temperature sensor162,164may be disposed at a first sensing level slightly below fill line160. Preferably, the first sensing level is less than or equal to about 0.5 inches (about 1.27 cm) below the fill line160, and more preferably, about 0.1 inches (about 0.25 cm) to about 0.5 inches (about 1.27 cm) below fill line160. A temperature sensor172may be disposed at a second sensing level that is further from opening102than the first sensing level. Any temperature sensors suitable for use in an operational cooking vessel may be used, but resistor temperatures detectors (“RTDs”) are shown here. The RTDs may be platinum thin-film RTDs sheathed in stainless steel, which provides a relatively inexpensive, durable temperature sensor having an outer surface that is readily cleanable.

Reservoir150may be filled with a cooking medium as a source for replenishing cooking medium in cooking vessel104. Reservoir150may comprise a fill cap assembly158providing an interface between reservoir150and supply line155. Fill cap assembly158may be removably couplable to reservoir150via, e.g., a quick release, a snap assembly, or a threaded connection. A supply mechanism, e.g., pump130, may be disposed on supply line155to draw the cooking medium from reservoir150to vessel104. A valve152also may be disposed on supply line155proximate to supply inlet110to prevent cooking medium within vessel104draining towards reservoir150. Preferably, the supply inlet may be located proximate to a bottom surface of vessel104, so that the lower temperature cooking medium supplied via supply line155does not adversely affect the temperature of the cooking medium proximate to temperature sensor172. The cooking medium in vessel104may be contaminated with cooking by-product, and it is desirable to keep the cooking medium within reservoir150and supply line155as clean, as possible. Here, valve152is depicted as a one-way check-valve, but any suitable valve may be used, e.g., a solenoid actuated valve. A single reservoir may be coupled to a plurality of cooking vessels, wherein each cooking vessel may have a dedicated supply mechanism, e.g., a pump or solenoid valve controlled by a control mechanism C, to regulate an amount of cooking medium supplied by the single reservoir.

Control mechanism C may be coupled to pump130and temperatures sensors162,164,174(coupling not shown). Control mechanism C may comprises a microprocessor having a physical memory that acts a comparator to compare temperature data detected at the first and second sensing level. Control mechanism C also may comprise a controller that transmits a control signal to pump130based on the comparison of the detected temperature data. Moreover, the controller may transmit a control signal to valve152, if the valve is an electrically actuated valve, e.g., a solenoid actuated valve.

Referring toFIG. 3A, a cooking medium reservoir150according to an embodiment of the present invention is depicted. Reservoir150may comprise a fill cap assembly158, which may comprise a cap215which fits over a reservoir opening, a fill tube206which extends the height of the reservoir, and a fitting210mounted to cap215removably couplable to reservoir150at an opening thereof. Fitting210may connect to a hose or pipe serving a supply line155that leads to pump130. Fill tube206may extend nearly to a surface of the reservoir opposite the opening, e.g., a bottom surface, so that substantially all of the cooking medium may be removed from reservoir150. An inlet208of fill tube206is angled, so that the pump suction does not cause tube206to seal to the bottom surface of reservoir150. A heater220may be disposed within or surround fill tube206to preheat the cooking medium. Preheating the cooking medium may reduce its viscosity, which permits the use of a less powerful or more energy efficient pump, and, thus, a relatively less expensive pump, and may provide improved regulation of the cooking medium temperature in the vessel104by reducing or eliminating the temperature difference between the cooking medium supplied from reservoir150and the cooking medium already disposed within vessel104.

Control mechanism C may monitor the amount of cooking medium dispensed from reservoir150to determine when reservoir150is substantially empty or otherwise requires replacement. Control mechanism C may measure the fill time. If the fill time exceeds a predetermined value TFILL, control mechanism C may determine that reservoir150needs replacing, and a replacement alert may be provided via an audible alarm, a visual alarm, or both. A variety of schemes may be used to determine TFILL, but an upper limit may be set by the time required to fill vessel104from fill line160to a top edge at opening102. By setting TFILLin this manner, overflow of vessel104by cooking medium supplied from reservoir150is prevented, if the level detection system fails in some unanticipated way. Alternatively, a spring-loaded platform (not shown), strain gage (not shown), or other similar device, may be used to measure the weight of reservoir150, and this measurement may be used to determine when to replace reservoir150. Other level sensing mechanisms, such as the one described above that are not suitable for use in a cooking vessel, also may be suitable for monitoring the level of cooking medium in reservoir150.

Referring toFIG. 3B, a cooking medium reservoir250according to another embodiment of the present invention is depicted. Cooking medium reservoir250may be a collapsible reservoir having an accordion-like structure. Reservoir250may use gravity, as depicted here, to feed cooking medium to towards a supply line255. A fill tube may be omitted from a gravity-feed reservoir250. Moreover, a pump may be omitted and valve152may be a solenoid-actuated valve controlled by control mechanism C to resupply cooking medium from reservoir250. Further, a heater (not shown) may be disposed on or proximate to fill cap assembly158at an opening of reservoir250to preheat the cooking medium.

Referring toFIG. 4, a reduction in the cooking medium level of vessel104may be determined by comparing the detected temperature data at the first and second sensing levels. As the cooking medium level lowers, temperature sensors162,164may become uncovered by the cooking medium or otherwise exposed to air. On the other hand, temperature sensor172may remain submerged in the cooking medium. Bottom temperature sensor172may be dedicated to this level sensing function. To reduce the cost and complexity of the system, however, bottom temperature sensor172may serve as the temperature sensor already used for regulating the cooking medium temperature. As the difference between the temperatures sensed at the first and second sensing levels increases, control mechanism C may determine that the cooking medium level has declined to a level that adversely may affect the cooking performance of fryer apparatus100.

Temperature sensors162,164,172continually may take a plurality of temperature readings concurrently. Each group of concurrent temperature readings may be compared by the following equation 1:
DT=T1−T2(Equation 1),

T1is the temperature detected at the temperature sensors162,164at the first level, T2is the temperature detected at the temperature sensor172at the second level, and DT is the temperature difference. DT is a negative number that reflects a reduction or decrease in temperature between the first level to the second level. T1may be an average of the temperatures detected at sensors162,164, or each T1reading at sensors162,164may be compared individually with the concurrent T2reading. Preferably, the compared temperature readings from sensors162,162,174are substantially contemporaneous.

A predetermined number (n) of temperature readings then may be compared in a plurality of ways to determine whether the temperature difference, i.e., a reduction in temperature, is low, e.g., less than or equal to DTFULL, which indicates that the cooking medium level in vessel104is adequate, or whether the temperature difference is high, e.g., less than or equal to DTLOW, which indicates that the cooking medium level is inadequate.

Referring toFIG. 4, DTFULLand DTLOW, are predetermined temperature value thresholds, which may be determined empirically.FIG. 4depicts DTFULLas about 20° F. (about 11.1° C.) and DTLOWas about 30° F. (about 16.7° C.). A hysteresis is provided between DTFULLand DTLOWso that false indications are not generated that may result in excessive cycling of pump130, which may shorten the operational life of pump130.FIG. 4depicts a hysteresis of about 10° F. (about 5.6° C.). Any temperature difference DT between DTFULLand DTLOWthresholds may be categorized as indeterminate.

Control mechanism C may monitor the predetermined number (n) of temperature value thresholds to determine the adequacy of the cooking medium level in vessel104by Equation 2:
K>n/2+1  (Equation 2).

K is a predetermined level value threshold and n is the number of temperature differences monitored, i.e., a queue (1 to n) temperature differences. As a result, the level of the cooking medium may be determined by the following rules:

If KLOW≧ K, then the level is LOW;Else if KFULL≧ K, then the level is FULL.

KLOWis the number of DTLOWvalues in the queue of n monitored values and KFULLis the number of DTFULLvalues in the queue. Indeterminate values may be monitored or stored in the queue, such that they prevent the number of DTFULLor DTLOWvalues from reaching threshold K to effect a cooking medium level change to or from FULL to LOW. Moreover, the queue may be a first-in, first-out queue wherein the oldest measured difference DTnis replaced in the queue by the most recently measured difference DT1. Accordingly, an additional degree of hysteresis may be provided by requiring a majority of monitored DT values indicate a level state before cooking medium is supplied to vessel104. Referring toFIG. 4, the DT is about 80° F. (about 44.4° C.) when a LOW level, i.e., a start-fill level, of cooking medium is determined and control mechanism C signals pump130to cycle to supply cooking medium to vessel104. As DT approaches 0° F. (0° C.), a FULL level, i.e., a stop-fill level, of cooking medium is determined, and control mechanism C signals pump130to shut off to prevent overfilling of vessel140with cooking medium.

Alternatively, control mechanism C may signal pump130to supply cooking medium to vessel104for a predetermined supply time period upon a determination of a LOW cooking medium level and then shut off for a predetermined rest time period. For example, pump130may supply cooking medium for six (6) seconds, and then be shut off for 54 seconds. If the cooking medium level state is determined to be LOW after the rest period, control mechanism C again signals pump130to supply cooking medium for six (6) second time period. If the cooking medium level state is determined to be FULL after the rest period, control mechanism C does not send a control signal and pump130will remain shut off. Such a configuration of control mechanism C may reduce or eliminate overfilling of vessel104.

Temperature sensors162,164can work in conjunction with or separately from one another. For example, if n=10, the queue may comprise five (5) compared temperatures readings between sensor162and172and five (5) compared temperatures reading between sensor164and172. Alternatively, T1 may be an average of the readings from sensors162,164. Finally, each sensor may have a separate queue, such that the compared temperatures readings between sensor162and172comprise a first queue n, and the compared temperatures readings between sensor164and172may comprise a second queue n′. Another level of hysteresis may be provided by permitting actuation of pump130if only both n and n′ indicate a LOW level of cooking medium.

Preferably, the cooking medium temperature is substantially above an ambient air temperature, otherwise the temperatures detected at the first and second sensing levels will be near the ambient air temperature whether or not covered with cooking medium. The cooking medium expands when heated, so accurate level control may be obtained by adjusting the level only when the cooking medium in vessel104is substantially at or above the cooking setpoint temperature, e.g., at least 250° F. (about 121.1° C.).

Referring toFIG. 5, a filtering system of a fryer apparatus100according to an embodiment of the present invention is depicted. Cooking vessel104may comprise a drain at an inlet of a drain path124fluidly connecting vessel104to a filter container130, e.g., a drain pan or a filter canister. A drain valve122, which may be a solenoid valve, may be disposed on drain path124to selectively permit cooking medium to drain from vessel104in response to a control signal from a controller C. Preferably, drain valve122is a linearly actuated valve to reduce the likelihood that cooking by-product may obstruct valve122. Cooking medium may pass through filter container130and return to vessel116via a filter or a fill path128. A second filter container (not shown) that may serve as a backup filter also may be connected to paths124,128, when a filter in container130requires replacing or otherwise malfunctions. A filter or a fill valve126, which also may be a solenoid valve, may be disposed on filter path124to selectively permit cooking medium to be introduced into vessel104in response to a control signal from controller C.

Referring toFIG. 5, a pump127is disposed on drain path124to convey the cooking medium along drain and fill paths124,128, but pump127also may be disposed on fill path128. Pump127actuates 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 indicator142, e.g., a visual or audible alarm that indicates either that a filtering process is being performed or that the cooking medium in vessel104is not in suitable condition for filtering. Indicator142may be a light, e.g., incandescent, fluorescent, LED, or the like, or indicator142may be incorporated into the fryer apparatus' current display, such as on an LCD screen. If indicator142is 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.

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 vessel104, 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, inFIG. 5.

Referring toFIG. 6AandFIG. 6B, arrangements for cooking medium inlets fluidly connected to filter path128according to embodiments of the invention are depicted. As shown inFIG. 4A, a pair of inlets106A,106B may be formed within a surface of cooking vessel104disposed at opposite ends of a longitudinal axis, i.e., a length, of vessel104. For example, here inlets106A,106B are shown as formed within opposing sidewalls of vessel104. Inlets106A,106B may be separated by a lateral distance that is substantially a width of vessel104. Arranging inlets106A,106B in this configuration may facilitate “swirling” of the cooking medium on a bottom surface216of vessel104to clean bottom surface216, wherein cooking by-product or any other particles may exit vessel104through drain108. Bottom surface216may be sloped towards drain108to assist cooking medium, and any cooking by-product therein, to exit vessel104. Preferably, inlets106A,106B are disposed proximate bottom surface216.

Referring toFIG. 4B, an alternative inlet arrangement is depicted. A pair of linear diffuser headers236A,236B may extend along opposing sides of bottom surface216. Diffuser headers236A,236B also may be disposed on opposing sidewalls of vessel104proximate to the bottom surface216. Preferably, diffuser headers236A,236B extend substantially parallel to a longitudinal axis, i.e., along a length, of vessel116. Diffuser headers236A,236B may comprise a plurality of inlet holes238for introducing cooking medium via filter path128. Preferably, inlet holes238are configured to direct cooking medium towards a center axis of bottom surface216to promote the swirling of cooking medium for the reasons described above. Again, bottom surface216may be sloped towards drain108.

Referring toFIG. 7, a filtering system300according to another embodiment of the present invention is depicted. A filtering system may comprises a plurality of cooking vessels316,356,376, e.g., frypots. Each vessel316,356,376may comprise a drain path324,364,384fluidly connected to a common, drain manifold340. If two vessels, e.g., vessels316and356, are designated for a same first food product, and the third vessel, e.g., vessel376, is designated for a different second food product, then vessels316,356may be fluidly connected to a first drain manifold, while vessel376may 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 valve322,362,382responsive to a control signal from controller C may be disposed in each drain path324,364,384.

Drain manifold340may be connected fluidly to filter container330on a manifold drain path345. An outlet (not shown) a filter container330may be fluidly connected to a filter or a fill manifold350through a manifold filter or fill path355. A pump327may be disposed on either manifold path345,355to draw cooking medium through filter container330. Here, pump327, which may be responsive to a control signal from controller C, is shown as disposed on manifold drain path345. Filter manifold350may be fluidly connected to each vessel316,356,376via a respective filter path328,368,388. A filter valve326,366,386responsive to a control signal from controller C may be disposed on each filter path326,366,386.

Controller C may be actuated by an operator using a single switch344, e.g., a mechanical or an electronic switch. An indicator342coupled to controller C may give a visual or audible indication that filtering of cooking medium from at least one vessel316,356,376is being performed, or that the cooking medium in at least one of the vessels is not suitable, i.e., not ready, for filtering. Indicator342may 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.

Referring toFIG. 8, 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.

Referring toFIG. 8, a method600for automatically filtering the cooking medium according to one embodiment of the invention is depicted. First, in step610, a drain valve may be automatically opened to permit cooking medium to exit, or drain, the cooking vessel. Next, in step615, a filter valve may be automatically opened to permit introduction of cooking medium into the vessel. Subsequently, a filter pump may be energized in step620to 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 step625to allow purging of the filter container and filling of the vessel with cooking medium in step630. Next, the pump may be de-energized in step635after filling the vessel. Finally, the filter valve may be closed automatically in step640to prevent drainage of cooking medium into the filter container and complete the filtering of cooking medium from the cooking vessel.

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.