WARMING HOLDING CABINET

An holding cabinet is provided. The cabinet encloses first and second cavities and an includes an airflow system for convection heating. The cabinet also includes conductive and radiant heating of food therein. The cabinet includes a baffled flow path to provide even heated air flow through each of the first and second cavities.

BACKGROUND OF THE INVENTION

This disclosure relates to holding cabinets to receive previously cooked food to maintain them warm for future presentation to a customer or for future processing before serving to a customer.

BRIEF SUMMARY

A first representative embodiment of the disclosure is provided. The embodiment includes a holding cabinet. The holding cabinet includes a housing that includes first and second receiving cavities and an air flow compartment, the first and second receiving cavities each configured to receive one or more trays therein, the first and second receiving cavities arranged in a vertically stacked arrangement with the first receiving cavity disposed above the second receiving cavity. The air flow compartment comprises a heat treatment portion, an inlet portion, and a return portion, wherein air flows from the heat treatment portion and into the inlet portion, from the inlet portion and into one of the first or second receiving cavity, from the respective receiving cavity into the return portion, and from the return portion to the heat treatment portion. The first and second receiving cavities each comprising a floor and a ceiling, opposite inlet and outlet side walls, and at least one opening to allow access into the respective receiving cavity to allow one or more trays to be inserted within the respective receiving cavity and removed from the respective receiving cavity. The inlet portion comprises a baffle that establishes a first plenum and a second plenum, wherein the first plenum is aligned to direct air flowing therethrough into the first receiving cavity and the second plenum is aligned to direct air flowing therethrough into the second receiving cavity, wherein the baffle includes a vertical portion with an upper edge proximate to a transition between the heat treatment portion and the inlet portion, and an oblique portion that extends from a bottom of the vertical portion to the inlet side wall of the first receiving cavity; the oblique portion comprises a plurality of apertures to allow air to flow from the first plenum and into the second plenum.

Another representative embodiment of the disclosure is provided. The embodiment includes a holding cabinet. The holding cabinet includes a housing that includes first and second receiving cavities and an air flow compartment, the first and second receiving cavities each configured to receive one or more trays therein, the first and second receiving cavities arranged in a vertically stacked arrangement with the first receiving cavity disposed above the second receiving cavity. The air flow compartment comprises a heat treatment portion, an inlet portion, and a return portion, wherein air flows from the heat treatment portion and into the inlet portion, from the inlet portion and into one of the first or second receiving cavity, from the respective receiving cavity into the return portion, and from the return portion to the heat treatment portion. The first and second receiving cavities each comprising a floor and a ceiling, opposite inlet and outlet side walls, and at least one opening to allow access into the respective receiving cavity to allow one or more trays to be inserted within the respective receiving cavity and removed from the respective receiving cavity. The inlet portion comprises a baffle that establishes a first plenum and a second plenum, wherein the first plenum is aligned to direct air flowing therethrough into the first receiving cavity and the second plenum is aligned to direct air flowing therethrough into the second receiving cavity, wherein a transition between the heat treatment portion and the inlet portion includes a narrowing portion that includes a step decrease of cross-sectional area for flow therethrough, and downstream of the narrowing portion includes an increase of cross-sectional area for air flow therethrough.

Another representative embodiment of the disclosure is provided. The embodiment includes a holding cabinet. The housing that includes first and second receiving cavities and an air flow compartment, the first and second receiving cavities each configured to receive one or more trays therein, the first and second receiving cavities arranged in a vertically stacked arrangement with the first receiving cavity disposed above the second receiving cavity. The air flow compartment comprises a heat treatment portion, an inlet portion, and a return portion, wherein air flows from the heat treatment portion and into the inlet portion, from the inlet portion and into one of the first or second receiving cavity, from the respective receiving cavity into the return portion, and from the return portion to the heat treatment portion. The first and second receiving cavities each comprising a floor and a ceiling, opposite inlet and outlet side walls, and at least one opening to allow access into the respective receiving cavity to allow one or more trays to be inserted within the respective receiving cavity and removed from the respective receiving cavity. The inlet portion comprises a baffle that establishes a first plenum and a second plenum, wherein the first plenum is aligned to direct air flowing therethrough into the first receiving cavity and the second plenum is aligned to direct air flowing therethrough into the second receiving cavity. The floor of each of the first and second receiving cavities comprises a heating pad upon which a tray disposed within the respective receiving cavity rests directly upon the heating pad, wherein a top surface of the heating pad is flush mounted with a remaining portion of the floor within the respective receiving cavity. The ceiling of each of the first and second receiving cavities includes a second heating pad. Each of the heating pads mounted upon the floor and each of the heating pads mounted upon the ceiling of the respective first and second receiving cavities includes first and second spaced insulation layers fixed with respect to a side of the heating pad within the respective floor or ceiling. The housing further comprises a shelf that is disposed between the first and second receiving cavities, with a top of the shelf establishing the floor of the first receiving cavity and the bottom of the shelf establishing the ceiling of the second receiving cavity, wherein the heating pad upon the floor of the first receiving cavity and the heating pad upon the ceiling of the second receiving cavity are aligned such that there is a space between the innermost of the first and second spaced insulation layers of the heating pad mounted upon the floor of the first receiving cavity and the first and second spaced insulation layers of the heating pad mounted upon the ceiling of the second receiving cavity

Another representative embodiment of the disclosure is provided. The embodiment includes a holding cabinet. The holding cabinet includes a housing that includes first and second receiving cavities and an air flow compartment, the first and second receiving cavities each configured to receive one or more trays therein, the first and second receiving cavities arranged in a vertically stacked arrangement with the first receiving cavity disposed above the second receiving cavity. The air flow compartment comprises a heat treatment portion, an inlet portion, and a return portion, wherein air flows from the heat treatment portion and into the inlet portion, from the inlet portion and into one of the first or second receiving cavity, from the respective receiving cavity into the return portion, and from the return portion to the heat treatment portion. The first and second receiving cavities each comprise a floor and a ceiling, opposite inlet and outlet side walls, and at least one opening to allow access into the respective receiving cavity to allow one or more trays to be inserted within the respective receiving cavity and removed from the respective receiving cavity. The inlet portion comprises a baffle that establishes a first plenum and a second plenum, wherein the first plenum is aligned to direct air flowing therethrough into the first receiving cavity and the second plenum is aligned to direct air flowing therethrough into the second receiving cavity. The floor of each of the first and second receiving cavities comprises a heating pad upon which a tray disposed within the respective receiving cavity rests directly upon the heating pad, wherein a top surface of the heating pad is flush mounted with a remaining portion of the floor within the respective receiving cavity. The ceiling of each of the first and second receiving cavities includes a second heating pad. The inlet side wall of both of the first and second receiving cavities includes a plurality of first apertures that allows flow from the respective first or second plenum into the respective first or second receiving cavity, wherein the outlet side wall of the both of the first and second receiving cavities includes a second plurality of apertures that allows flow from the respective receiving cavity and into the return portion. All or an overwhelming majority of the second plurality of apertures within each of the first and second receiving cavities are disposed at or below a horizontal plane through respective receiving cavity that is positioned at half of a total height of the respective receiving cavity.

Advantages of the present disclosure will become more apparent to those skilled in the art from the following description of the preferred embodiments of the disclosure that have been shown and described by way of illustration. As will be realized, the disclosed subject matter is capable of other and different embodiments, and its details are capable of modification in various respects. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.

DETAILED DESCRIPTION OF THE INVENTION

Turning now toFIGS.1-8, a holding cabinet10is provided. The holding cabinet10is configured to hold cooked food items for a period of time before presentation to a customer or until the cooked food items are used in another step in a preparation or cooking procedure. The holding cabinet10is configured to create a warming environment, which can provide heat to food items within the receiving cavities32,34using one, two, or all of conduction heat transfer, convection heat transfer, and radiant heat transfer to the food items. The structure and operation associated with each of these three types of heat transfer to the food within the holding compartments is discussed below.

The holding cabinet10may be configured to hold any types of foods that need to be or are best maintained in a hot or warm environment before serving or further using in a cooking or preparation process. The holding cabinet10in some embodiments may be configured to receive food upon trays600that rest upon a floor42of a receiving cavity, with the food for receipt in the holding cabinet10received upon the trays600. The trays600may be conventional trays within the restaurant industry. In some embodiments the food sits directly upon the bottom surface601of the trays600, while in other embodiments, the trays600may include racks (not show) therein such that the food resting upon the racks is set off from the bottom surface601of the tray600. In some food storage procedures (or recipes) a liquid may be disposed within the bottom surface601of the tray and the food resting upon the rack may be able the liquid. As can be understood with by one of ordinary skill in the art with a thorough review of the subject specification, the liquid may boil, which creates a steam within the holding compartment32,34to further warm or cook the food.

The holding cabinet10includes a housing20that encloses at least a first receiving cavity (holding compartment)32and a second receiving cavity34. In other embodiments, additional receiving cavities, such as third and fourth receiving cavities (constructed like the first and second32,34discussed herein) may be provided. In a preferred embodiment, the first receiving cavity32may be disposed above the second receiving cavity34in a vertically stacked arrangement. Alternatively the two receiving cavities32,34may be formed as a row, i.e. at the same height within the housing20. In this embodiment, the two cavities32,34may be separated by a vertical wall.

The first and second receiving cavities32,34may be constructed in the same manner, and may have the same size and geometry. A shelf29may be positioned between the first and second receiving cavities32,34, such that the shelf29forms the floor42of the first (top) receiving cavity32and the ceiling45of the second (bottom) receiving cavity34. In embodiments with three or more vertically stacked receiving cavities shelves29may separate the adjacent receiving cavities as discussed herein.

The first and second receiving cavities may include a floor42, a ceiling45, an inlet inner wall43and an outlet inner wall44. Each of the first and second receiving cavities includes a side opening23to allow trays600with food disposed thereon to be placed into an removed from the cavity. The side opening may be on a single side of the housing20, while in other embodiments like the embodiment depicted in the figures, both opposite (i.e. front and rear) sides of housing may be open to allow access into the cavity therethrough. In some embodiments, the floor42may be in-line with the bottom of the opening such that a tray can be slid directly onto the floor42when inserted into or removed from the cavity32,34. The openings into the first and second cavities32,34may be closed with doors21that are moveable (i.e. slid, on hinges, etc.) to enclose the cavity to aid in the retention of heat therein and prevent hot air from blowing out of the cavity when closed, but to be opened to allow access into the cavity32,34. In some embodiments, the cavities32,34are configured to receive one, two, or more trays upon the floor42and neighboring each other. These embodiments may include the same number of doors21as the cavity is configured to receive trays.

The housing20further encloses an air flow compartment110, which includes the air flow plenums and electrical and mechanical components (discussed herein) that result in the heated air flow through the receiving cavities32,34as discussed herein as well as the remaining operations of the cabinet10.

The air flow compartment110includes a mechanical section110a, a return portion140and an inlet portion120. The mechanical section110asupports and encloses an air handling unit112and a heating element114. The air handling unit112may be a fan that draws a suction (arrow A,FIG.4) of air from the return portion140, and discharges air (arrow B,FIG.4) across or proximate to the heating element114, such that air leaving the fan is heated by the heating element114. Air flowing past or proximate to the heating element114is then directed to the inlet portion120. Air flows through the inlet portion120(arrows D1, D2, D3;FIG.4) and into one of the first or second receiving cavities32,34(arrows E1, E2;FIG.4). Air flows through the first or second receiving cavities32,34(arrows F1, F2;FIG.4) and then flows into the return portion140(arrow G;FIG.4). Air again flows into the mechanical section110aand is drawn into the air handling unit112.

The mechanical section110amay include a temperature sensor116(schematic) that measures a temperature of air flowing therethrough. In some embodiments, the temperature sensor116may be disposed within the air flow path that flows into the suction of the air handling unit112. In other embodiments, the temperature sensor may be disposed within the air flow path that discharges from the air handling unit112, such as before the air flows past the heating element114.

The temperature sensor116may be a thermocouple, RTD, or other types of temperature sensors that can provide real-time signals that are proportional to a measured air temperature that flows past the temperature sensor116. The temperature sensor116may send a signal that is proportional to the measured temperature to a controller2000(schematic). The controller2000may operate the heating element114using conventional temperature feedback control to assist with maintaining the sensed air temperature within a desired temperature band. One of ordinary skill in the art with a thorough review and understanding of this disclosure will be able to select and program a controller2000to operate the heating element114based upon the measured temperature within merely routine optimization.

In some embodiments, the controller2000may sense the position of the doors21and cause the air handling unit112to stop when a door21is opened to avoid pushing the hot air (flow paths F1, F2,FIG.4) from blowing out of the openings in the housing20.

The housing20may include a transition115between the mechanical section110aand the inlet section120. The transition115includes a step change reduction in the flow area for air flow as the air flow leaves the mechanical section110a. This step change reduction will be understood to increase the resistance to air flow, i.e. the head loss, or air flow leaving the mechanical section110a. This step change reduction increases the pressure within the mechanical section110aat the discharge of the air handling unit112, and in some embodiments causes the air that approaches the transition to exhibit turbulent flow. In some embodiments, the transition115may be a 50% reduction in flow area, while in other embodiments the transition115may result in a step reduction of over 50% such as within a range of 50% to 75%, inclusive of all values within this range.

The transition115may include a constant flow area along its length, while in other embodiments the transition115may include a changing (decreasing) flow area along its length such that the transition115acts as a nozzle along its length.

In some embodiments, after the transition115, the flow area within the entry of the inlet section120may include a step increase in flow area, such as a step increase to the same or even larger flow area that existed within the mechanical section110athat bordered the transition115. This step increase may aid the air flow leaves the transition115to a laminar flow as the air approaches the baffle120, discussed below. In other embodiments, depicted inFIG.8, after the transition115, the flow area within the entry of the inlet section120may increase for a portion of the inlet section120downstream of the transition, where the inlet section120may include angled walls132to increase the flow area. The angled walls132may reach the full width of the housing (i.e. the full space within the housing inside of the structural and insulative walls that construct the housing within the inlet section120) just above the top edge124eof the baffle124, as discussed below.

In some embodiments, the inlet portion of the inlet section (i.e. just downstream of the transition115) may include a plurality of vertical separators119that extend from the transition, or just below the transition115with an open space above top edges of the vertical separators119and below the transition115.FIG.8depicts4parallel separators119, but in some embodiments six, eight or other numbers of separators119may be provided. The separators119may be consistently spaced and extend across the front to back length of the transition115(seeFIG.8), or may extend at a larger total area than the front to back width of the transition115. The separators119may serve to urge laminar flow through the inlet section120before reaching the baffle124, and/or to assist with evening out the air mass flow rate in the front to back direction (i.e. the direction of arrows Z inFIG.8).

The inlet section120includes a baffle124that is positioned with a top edge124ebelow the transition115. The baffle124separates air (arrow C) that leaves the transition115into a first flow path D1through a first plenum120athat is directed to flow into the first receiving cavity32and through a second plenum120bthat directs air to flow in a second flow path D2that is directed to flow into the second receiving cavity34. The baffle124includes a vertical portion124athat is positioned below the transition115(and below the separators119when provided). The vertical portion124amay be planar along its length. The vertical portion124amay connect to an oblique portion124bat a bottom of the vertical portion124. In embodiments where the vertical portion is planar along its length the connection with the oblique portion124bis at the bottom edge of the vertical portion124a. The oblique portion124bis attached to the inner inlet wall43of the first receiving cavity32. In some embodiments, the inner inlet wall43may be multiple sheets that are fixed together or with respect to each other to establish a wall between the receiving cavity and the inlet section120. The oblique portion124bmay connect to the inner inlet wall43of the first receiving cavity at a distance above the floor42of the first receiving cavity32.

In some embodiments, the oblique portion124amay include one or a plurality of apertures124ctherein that allows air flow from the first plenum120aand into the second plenum120b(air flow D3depicted inFIGS.4and5a) and toward the second baffle126(discussed below).

The construction and arrangement of the baffle124is provided to separate the air entering the inlet section120into two even quantities of air such that about the same mass flow rate of air flows into and through each of the first and second receiving cavities32,34. The term about the same is defined herein to include the exact same as well as ratios where the mass flow rates of air into the first and second receiving cavities32,34is are within 15 percent of each other, including all differences below 15 percent. Because air through the second plenum120bneeds to flow through a longer distance until reaching the second receiving cavity34, in some embodiments, the size of the cross-sectional area of the second plenum120b(along the portion that flows adjacent to the vertical portion124a) may be larger than the cross-sectional area of the first plenum120ato balance the flow. The apertures124cmay be provided, sized, and positioned to allow some flow from the first plenum120aand into the second plenum120bto further balance the flow into the first and second receiving cavities32,34.

In some embodiments, a second baffle126is provided to decrease the cross-sectional flow area within the second plenum120bbelow the oblique portion124b. The second baffle126may include a second oblique portion126aand a vertical portion126bbelow the second oblique portion126a. The second oblique portion126amay be parallel to and below the oblique portion124bof the baffle. The second oblique portion126amay extend from an outer wall of the housing20that is most proximate to and parallel with the inlet inner wall43of the second receiving cavity34and extend toward the inlet inner wall43.

The first and second receiving cavities32,34are configured to receive air (flows E1, E2;FIG.4) from the inlet portion120through the first inlet wall43that borders the inlet portion120. Each of the first and second receiving cavities32,34have a plurality of inlet apertures43athat allow for flow from the inlet portion120into the respective cavity. Each of the first and second receiving cavities32,34further have a plurality of outlet apertures44athat allow for air flow from the cavity into the return portion140. The plurality of outlet apertures44aare upon the first outlet wall44that borders the return portion140.

The first receiving cavity32is positioned such that air flowing through the first plenum120aflows through the plurality of inlet apertures43adisposed within the first cavity32to flow therein. The second receiving cavity34is positioned such that air flowing through the second plenum120bflows through the plurality of inlet apertures43adisposed within the second cavity34to flow therein.

The plurality of inlet apertures43amay be consistently spaced from adjacent first apertures and may be aligned upon the inlet inner wall43to form a repeating pattern. In other embodiments, the spacing of specific inlet apertures43afrom neighboring first apertures43amay vary depending upon the location of the specific inlet aperture43aupon the inlet inner wall43. For example, the inlet apertures43anear a center of the front to rear width of the respective cavity may be spaced at a further distance from adjacent inlet apertures43athan first apertures near the front or rear side of the cavity (with the front being a side of the housing20with a door21, and the rear being the opposite side of the housing also in some embodiments having a door21a), which promotes even air mass flow rate across the entire front to rear width of the cavity. Similarly the inlet apertures43anear the center of the front to rear width of the respective cavity may have a cross-sectional area that is smaller than first apertures43athat are near the front or rear side of the cavity, to promote even mass flow rate across the entire front to rear width of the cavity.

The plurality of first inlet apertures43awithin the first receiving cavity32are aligned such that all of the inlet apertures43aare positioned upon the inner inlet wall43above an intersection of the oblique portion124bof the baffle124and the inner inlet wall43such that in some embodiments all of the air flowing into the first plenum120aflows into the first receiving cavity32through the inlet apertures43a. In other embodiments where the oblique portion124bhas a plurality of holes124c, some of the air that enters the first plenum120aflows into the second plenum120bthrough the holes124c(flow path D3;FIG.4).

The plurality of second, outlet apertures44aare disposed upon the outlet inner wall44to allow air to flow from the respective receiving cavity32,34and into the return portion140(FIG.4). disposed within the second cavity34to flow therein.

The plurality of outlet apertures44amay be consistently spaced from adjacent outlet apertures and may be aligned upon the outlet inner wall44to form a repeating pattern. In other embodiments, the spacing of specific outlet apertures44afrom neighboring first apertures44amay vary depending upon the location of the specific outlet aperture44aupon the outlet inner wall44. For example, the outlet apertures44anear a center of the front to rear width of the respective cavity may be spaced at a further distance from adjacent apertures44athan first apertures near the front or rear side of the, which promotes even air mass flow rate across the entire front to rear width of the cavity. Similarly the outlet apertures44anear the center of the front to rear width of the respective cavity may have a cross-sectional area that is smaller than outlet apertures44athat are near the front or rear side of the cavity, to promote even mass flow rate across the entire front to rear width of the cavity.

Each receiving cavity32,34is sized with a shape, typically with a rectangular or square base and a height. In some embodiments, the first plurality of inlet apertures43amay be disposed upon the inlet inner wall43such that the same or about the same number of inlet apertures43aare disposed above a horizontal plane3000a,3000bthat is halfway up the height of the respective cavity32,34(FIG.4) as the number of apertures43athat are disposed below the horizontal plane3000a,3000b. The horizontal plane3000a,3000bmay cross through some of the apertures43a.

In some embodiments, the plurality of outlet apertures44aare positioned upon the outlet inner wall44such that in some embodiments all, or in other embodiments an overwhelming majority, of the outlet apertures44aare positioned below the horizontal plane3000a,3000bof the respective receiving cavity32,34. In some embodiments the upper-most apertures44amay be positioned such that the respective horizontal plane3000a,3000bextends through the upper-most apertures44a. The term overwhelming majority is defined herein to include 75% or more of the total number of apertures44aup to 100% of the total number of apertures. In some embodiments where some of the apertures44aare disposed above the respective plane3000a,3000b(FIG.5) all of the apertures44athat are above the respective plane3000a,3000bmay be positioned such that they are closer to the respective plane3000a,3000bthan they are to the ceiling45of the respective cavity32,34.

In some embodiments, the plurality of inlet apertures43are positioned upon the inlet inner wall43such that as many inlet apertures43aare disposed above the horizontal plane3000a,3000bas are disposed below the horizontal plane. In some embodiments, some of the inlet apertures43aare disposed such that the horizontal plane runs through the inlet apertures43a.

One of ordinary skill in the art with a thorough review and understanding of this disclosure will understand that the placement of all or an overwhelming majority of the outlet apertures44aat or below the respective horizontal plane3000a,3000bwill cause the air flowing through the cavity to flow downwardly toward the trays600disposed within the cavity to more interact with the food disposed upon the trays, than in embodiments if many of the outlet holes were above the plane3000a,3000b(which would allow air to flow from relatively upwardly positioned inlet apertures43adirectly to relatively upwardly (i.e. above the plane3000a,3000b) positioned outlet apertures44a, such that that air flow would not interact with the food positioned within the cavity32,34. The positioning of the outlet apertures44ato promote downward flow within the cavity (F1, F2;FIG.4—schematic) has been found to promote turbulent air flow across the trays600and the food upon the trays, which improves heat transfer efficiency from the air flowing to the food.

The air heated air flow through the first and second receiving cavities32,34as discussed above establishes a convection heating system of heating food disposed within the cavities. The device10further includes a conduction and radiant heating system as discussed herein. The floor42within each receiving cavity32,34includes one or multiple heating pads62(specifically the a number of heating pads62spaced upon the floor42that is equal to the number of trays600that can be received upon the floor of the cavity) disposed thereon. The heating pads62are electric resistance heating pads that generate heat due in proportion to the amount of electric current that flows through the pads. The heating pads62may be operated by the controller2000to adjust the duty cycle of the heating pad62and the operating temperature of the pad62. The housing20may include a display15, or in some embodiments specific displays for each zone (e.g. location within each cavity to receive different trays—e.g. the top left display corresponds to the zone with in the left side of the top cavity32) that displays operational information about the heating pad62. The display15may also include measured ambient temperature within the specific zone.

The heating pads62may be flush mounted within a recess in the floor42(or may make up the structure of the floor42at the location with the heating pad62such that a tray600can smoothly slide between a portion of the floor42and the heating pad62, and such that the bottom of tray600rests directly upon the heating pad62.

In some embodiments, the bottom side of the heating pad62(i.e. the side opposite from the exposed side of the heating pad62that forms a part of the floor42) may contact or be adjacent to insulative materials72to establish resistance to heat flow therethrough. In some embodiments, one or two or more layers72of planar insulative materials may be fixed to the bottom side of the heating pad62. In embodiments with two planar insulative materials72may be arranged with an air gap between the two layers, or with a structural component between the two layers. A further structural component may be outboard of the outermost insulative layer72.

As can be understood, the heating pad62, during operation, provides heat directly to the tray600that rests thereon via conduction heat transfer. The heating pad62also radiates a portion of its heat upwardly toward the tray600and the food that rests upon the tray600.

The ceiling45of each receiving cavity32,34may also include one or more top heating elements82, which may be resistive heating elements. The top heating elements82during operation generate heat that is radiated downwardly into the respective zone and onto the food that is disposed upon the tray600within the zone below the top heating element82. For example, each zone may include a top heating element82that is disposed above the zone, and above the corresponding heating pad62for each zone. The top heating elements82are fixed to the ceiling (and therefore extend minimally downward into the cavity from the ceiling) or may form a portion of the ceiling45. The top heating elements45are controlled by the controller2000, similar to the heating pads62discussed above. The display15, or the specific display15associated with each zone, may include operational information about each top heating element82that is disposed above the respective zone.

As with the heating pads62, the back side of the top heating element82(i.e. the opposite the side exposed within the cavity) may contact or be adjacent to insulative materials92to establish resistance to heat flow therethrough. In some embodiments, one or two or more layers92of planar insulative materials may be fixed to the back side of the top heating element82. In embodiments with two planar insulative materials92may be arranged with an air gap between the two layers, or with a structural component between the two layers. A further structural component may be outboard of the outermost insulative layer92.

As discussed above, a shelf29is formed between the floor42(top of the shelf29) of the first receiving cavity32and the ceiling45of the second receiving cavity34(bottom of shelf). As depicted inFIG.6, the heating pad62and associated insulative layers72is disposed within the shelf29. Similarly the top heating element82and associated insulative layers92is disposed upon (with respect to the top heating element82) and within (with respect to the insulative layers92) the shelf29. In some embodiments, there is a space between an inner-most (i.e. furthest from the heating pad62) insulative layer72associated with the heating pad62and the inner-most (i.e. furthest from the top heating element82) insulative layer associated with the top heating element82.

One of ordinary skill in the art with a thorough review of the subject disclosure will understand how to modify the placement and shape of the baffle124and the second baffle126in embodiments where the first and second receiving cavities32,34are positioned horizontally in a row instead of vertically to result in about the same mass flow rate of air into each of the first and second (horizontally aligned) cavities. For example, plenums downstream of a transition115within an inlet portion120may be provided to direct air to the inlet inner wall43of each plenum, and each outlet inner wall44may allow air leaving each cavity to enter a return portion140. In some embodiments, a wall that separates the two adjacent horizontally aligned cavities may include the inlet portion120and a baffle is provided to divide the flow of air (like flow paths D1and D2of the embodiment disclosed herein) such that the flow to both cavities is about the same. The outer inner wall44of each cavity may be on opposite sides of the housing, and with return flows G of air that flows through the apertures in the outlet inner wall44meeting within the mechanical section110aproximate a suction of the air handling unit112(air flow A).

The specification and be readily understood with reference to the following representative paragraphs:

Representative Paragraph 1: A holding cabinet, comprising:a housing that includes first and second receiving cavities and an air flow compartment, the first and second receiving cavities each configured to receive one or more trays therein, the first and second receiving cavities arranged in a vertically stacked arrangement with the first receiving cavity disposed above the second receiving cavity;the air flow compartment comprises a heat treatment portion, an inlet portion, and a return portion, wherein air flows from the heat treatment portion and into the inlet portion, from the inlet portion and into one of the first or second receiving cavity, from the respective receiving cavity into the return portion, and from the return portion to the heat treatment portion;the first and second receiving cavities each comprising a floor and a ceiling, opposite inlet and outlet side walls, and at least one opening to allow access into the respective receiving cavity to allow one or more trays to be inserted within the respective receiving cavity and removed from the respective receiving cavity;the inlet portion comprises a baffle that establishes a first plenum and a second plenum, wherein the first plenum is aligned to direct air flowing therethrough into the first receiving cavity and the second plenum is aligned to direct air flowing therethrough into the second receiving cavity, wherein the baffle includes a vertical portion with an upper edge proximate to a transition between the heat treatment portion and the inlet portion, and an oblique portion that extends from a bottom of the vertical portion to the inlet side wall of the first receiving cavity; the oblique portion comprises a plurality of apertures to allow air to flow from the first plenum and into the second plenum.

Representative Paragraph 2: The holding cabinet of Representative Paragraph 1, further comprising a transition between the heat treatment portion and the inlet portion includes a narrowing portion that includes a step decrease of cross-sectional area for flow therethrough, and downstream of the narrowing portion includes an increase of cross-sectional area for air flow therethrough.

Representative Paragraph 3: The holding cabinet of Representative Paragraph 2, further comprising a plurality of vertical separators disposed below the step change increase of cross-sectional area to separate the air flowing therethrough into a plurality of separate paths, wherein the vertical separators have bottom ends that are proximate to the upper edge of the vertical portion of the baffle.

Representative Paragraph 4: The holding cabinet of Representative Paragraph 3, wherein the oblique portion contacts the inlet side wall of the first receiving cavity at a distance above the floor of the first receiving cavity.

Representative Paragraph 5: The holding cabinet of Representative Paragraph 4, wherein the inlet side wall of both of the first and second receiving cavities includes a plurality of first apertures that allows flow from the respective first or second plenum into the respective first or second receiving cavity, wherein the outlet side wall of the both of the first and second receiving cavities includes a second plurality of apertures that allows flow from the respective receiving cavity and into the return portion;wherein all of the plurality of first apertures of the first receiving cavity are disposed above the position were the oblique portion contacts the inlet side wall of the first receiving cavity.

Representative Paragraph 6: The holding cabinet of Representative Paragraph 5, wherein all or an overwhelming majority of the second plurality of apertures within each of the first and second receiving cavities are disposed at or below a horizontal plane through respective receiving cavity that is positioned at half of a total height of the respective receiving cavity.

Representative Paragraph 7: The holding cabinet of Representative Paragraph 6, wherein a same number of the plurality of first apertures are disposed above the horizontal plane as the number of the plurality of first apertures that are disposed below the horizontal plane.

Representative Paragraph 8: The holding cabinet of any one of Representative Paragraphs 1-7, wherein the heat treatment portion comprises an air handling unit that includes a suction inlet that draws suction from air flowing from the return portion, wherein the air handling unit discharges air through a heating element disposed within the heat treatment portion.

Representative Paragraph 9: The holding cabinet of Representative Paragraph 8, further comprising a temperature detector disposed within the heat treatment portion and disposed within an air flow path proximate the suction inlet of the air handling unit, and further comprising a controller to control the operation of the heating element based upon a measured temperature of the temperature detector.

Representative Paragraph 10 A holding cabinet, comprising:a housing that includes first and second receiving cavities and an air flow compartment, the first and second receiving cavities each configured to receive one or more trays therein, the first and second receiving cavities arranged in a vertically stacked arrangement with the first receiving cavity disposed above the second receiving cavity;the air flow compartment comprises a heat treatment portion, an inlet portion, and a return portion, wherein air flows from the heat treatment portion and into the inlet portion, from the inlet portion and into one of the first or second receiving cavity, from the respective receiving cavity into the return portion, and from the return portion to the heat treatment portion;the first and second receiving cavities each comprising a floor and a ceiling, opposite inlet and outlet side walls, and at least one opening to allow access into the respective receiving cavity to allow one or more trays to be inserted within the respective receiving cavity and removed from the respective receiving cavity;the inlet portion comprises a baffle that establishes a first plenum and a second plenum, wherein the first plenum is aligned to direct air flowing therethrough into the first receiving cavity and the second plenum is aligned to direct air flowing therethrough into the second receiving cavity, wherein a transition between the heat treatment portion and the inlet portion includes a narrowing portion that includes a step decrease of cross-sectional area for flow therethrough, and downstream of the narrowing portion includes an increase of cross-sectional area for air flow therethrough.

Representative Paragraph 11: The holding cabinet of Representative Paragraph 10, wherein the baffle includes a vertical portion with an upper edge proximate to the heat treatment portion, and an oblique portion that extends from a bottom edge of the vertical portion to the inlet side wall of the first receiving cavity;further comprising a second baffle within the inlet portion and forming a boundary of the second plenum, wherein the second baffle is extends from an outlet side wall of the housing that is parallel to and proximate to the inlet side wall of the second receiving cavity and extends toward the inlet side wall of the second receiving cavity, wherein the second baffle is disposed below the first baffle.

Representative Paragraph 12: The holding cabinet of Representative Paragraph 11, wherein the second baffle is parallel to the oblique portion of the baffle.

Representative Paragraph 13: The holding cabinet of Representative Paragraph 12, wherein the oblique portion comprises a plurality of apertures to allow air to flow therethrough, wherein air flowing through the plurality of apertures flows into the second plenum and toward the second baffle.

Representative Paragraph 14: The holding cabinet of Representative Paragraph 13, wherein the baffle is configured to divide the air into the first and second plenums from the transition such that about the same volume of air enters the first plenum as the second plenum.

Representative Paragraph 15: The holding cabinet of any one of Representative Paragraphs 10-14, wherein the heat treatment portion comprises an air handling unit that includes a suction inlet that draws suction from air flowing from the return portion, wherein the air handling unit discharges air through a heating element disposed within the heat treatment portion,further comprising a temperature detector disposed within the heat treatment portion and disposed within an air flow path proximate the suction inlet of the air handling unit, and further comprising a controller to control the operation of the heating element based upon a measured temperature of the temperature detector.

Representative Paragraph 16: A holding cabinet, comprising:a housing that includes first and second receiving cavities and an air flow compartment, the first and second receiving cavities each configured to receive one or more trays therein, the first and second receiving cavities arranged in a vertically stacked arrangement with the first receiving cavity disposed above the second receiving cavity;the air flow compartment comprises a heat treatment portion, an inlet portion, and a return portion, wherein air flows from the heat treatment portion and into the inlet portion, from the inlet portion and into one of the first or second receiving cavity, from the respective receiving cavity into the return portion, and from the return portion to the heat treatment portion;the first and second receiving cavities each comprising a floor and a ceiling, opposite inlet and outlet side walls, and at least one opening to allow access into the respective receiving cavity to allow one or more trays to be inserted within the respective receiving cavity and removed from the respective receiving cavity;the inlet portion comprises a baffle that establishes a first plenum and a second plenum, wherein the first plenum is aligned to direct air flowing therethrough into the first receiving cavity and the second plenum is aligned to direct air flowing therethrough into the second receiving cavity;wherein the floor of each of the first and second receiving cavities comprises a heating pad upon which a tray disposed within the respective receiving cavity rests directly upon the heating pad, wherein a top surface of the heating pad is flush mounted with a remaining portion of the floor within the respective receiving cavity;wherein the ceiling of each of the first and second receiving cavities includes a second heating pad;wherein each of the heating pads mounted upon the floor and each of the heating pads mounted upon the ceiling of the respective first and second receiving cavities includes first and second spaced insulation layers fixed with respect to a side of the heating pad within the respective floor or ceiling;wherein the housing further comprises a shelf that is disposed between the first and second receiving cavities, with a top of the shelf establishing the floor of the first receiving cavity and the bottom of the shelf establishing the ceiling of the second receiving cavity, wherein the heating pad upon the floor of the first receiving cavity and the heating pad upon the ceiling of the second receiving cavity are aligned such that there is a space between the innermost of the first and second spaced insulation layers of the heating pad mounted upon the floor of the first receiving cavity and the first and second spaced insulation layers of the heating pad mounted upon the ceiling of the second receiving cavity.

Representative Paragraph 17: The holding cabinet of Representative Paragraph 16, wherein the baffle includes a vertical portion with an upper edge proximate to a transition between the heat treatment portion and the inlet portion, and an oblique portion that extends from a bottom edge of the vertical portion to the inlet side wall of the first receiving cavity; the oblique portion comprises a plurality of apertures to allow air to flow from the first plenum and into the second plenum.

Representative Paragraph 18: The holding cabinet of Representative Paragraph 17, further comprising a transition between the heat treatment portion and the inlet portion includes a narrowing portion that includes a step decrease of cross-sectional area for flow therethrough, and downstream of the narrowing portion includes an increase of cross-sectional area for air flow therethrough.

Representative Paragraph 19: The holding cabinet of Representative Paragraph 17, wherein the inlet side wall of both of the first and second receiving cavities includes a plurality of first apertures that allows flow from the respective first or second plenum into the respective first or second receiving cavity, wherein the outlet side wall of the both of the first and second receiving cavities includes a second plurality of apertures that allows flow from the respective receiving cavity and into the return portion;wherein all of the plurality of first apertures of the first receiving cavity are disposed above the position were the oblique portion contacts the inlet side wall of the first receiving cavity,wherein all or an overwhelming majority of the second plurality of apertures within each of the first and second receiving cavities are disposed at or below a horizontal plane through respective receiving cavity that is positioned at half of a total height of the respective receiving cavity, andwherein a same number of the plurality of first apertures are disposed above the horizontal plane as the number of the plurality of first apertures that are disposed below the horizontal plane.

Representative Paragraph 20: A holding cabinet, comprising:a housing that includes first and second receiving cavities and an air flow compartment, the first and second receiving cavities each configured to receive one or more trays therein, the first and second receiving cavities arranged in a vertically stacked arrangement with the first receiving cavity disposed above the second receiving cavity;the air flow compartment comprises a heat treatment portion, an inlet portion, and a return portion, wherein air flows from the heat treatment portion and into the inlet portion, from the inlet portion and into one of the first or second receiving cavity, from the respective receiving cavity into the return portion, and from the return portion to the heat treatment portion;the first and second receiving cavities each comprising a floor and a ceiling, opposite inlet and outlet side walls, and at least one opening to allow access into the respective receiving cavity to allow one or more trays to be inserted within the respective receiving cavity and removed from the respective receiving cavity;the inlet portion comprises a baffle that establishes a first plenum and a second plenum, wherein the first plenum is aligned to direct air flowing therethrough into the first receiving cavity and the second plenum is aligned to direct air flowing therethrough into the second receiving cavity;wherein the floor of each of the first and second receiving cavities comprises a heating pad upon which a tray disposed within the respective receiving cavity rests directly upon the heating pad, wherein a top surface of the heating pad is flush mounted with a remaining portion of the floor within the respective receiving cavity;wherein the ceiling of each of the first and second receiving cavities includes a second heating pad;the inlet side wall of both of the first and second receiving cavities includes a plurality of first apertures that allows flow from the respective first or second plenum into the respective first or second receiving cavity, wherein the outlet side wall of the both of the first and second receiving cavities includes a second plurality of apertures that allows flow from the respective receiving cavity and into the return portion;wherein all or an overwhelming majority of the second plurality of apertures within each of the first and second receiving cavities are disposed at or below a horizontal plane through respective receiving cavity that is positioned at half of a total height of the respective receiving cavity.

Representative Paragraph 21: The holding cabinet of Representative Paragraph 20, wherein a same number of the plurality of first apertures are disposed above the horizontal plate as the number of the plurality of first apertures that are disposed below the horizontal plane.