Patent Description:
<CIT>) discloses a method that involves arranging or folding a burner surface such that fluid e.g. air, fuel/air mixture, cold fire product and exhaust gas, is partially or completely passed through porous surfaces. The porous surfaces are provided in perforated plates, fleeces, knitted fabrics, meshworks, laminations, sintered metals, or foams. Flow-guided or surface-stabilized fuel grading and/or air grading takes place in an area of reaction- or equilibrium zone. Oxygen from the exhaust gas for oxidation of carbon-monoxide is supplied. Also disclosed is a device for reducing pollutant emissions of a surface burner.

<CIT> discloses a gas burner established in manner to provide part of the flames of a direction substantially vertical and forming an inner crown, and another part, a crown of outer of converging flames having a direction inclined going from low to high.

<CIT>) discloses a concentric burner for a cooking stove, which is provided with the annular master burner and the slave burner arranged inside the master burner and of which master burner is formed of an inner flame type burner formed with a plurality of burner ports opened inward in the inner peripheral part thereof. The slave burner is structured of an upper flame type burner formed with burner ports opened upward in an upper end thereof. The burner ports of the master burner are tilted in one direction in the circumferential direction inward in the radial direction and while being tilted upward to restrict inward elongation of the flames of the master burner.

<CIT>) discloses systems and methods that include providing a cooking system that comprises a burner assembly and a heat exchanger submerged in a vessel. The burner assembly includes a high velocity burner and a low velocity burner, the high velocity burner configured to provide high velocity, volumetric flowrate through a fluid duct of the heat exchanger that includes a plurality of compactly-arranged, alternatingly-disposed vertical and horizontal tubes passing through the fluid duct, and the low velocity burner configured to reduce and/or eliminate "lift off" that could result from operation of the high velocity burner. The heat exchanger is submerged in the vessel with the tubes of the heat exchanger open to the vessel to allow ingress and egress of a fluid contained within the vessel.

In one embodiment, the invention provides a burner assembly in accordance with claim <NUM>.

In another embodiment, the invention provides a burner assembly in accordance with claim <NUM>.

A further embodiment is directed to a cooking system in accordance with claim <NUM>.

For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description:.

In some cases, it may be desirable to provide a cooking system with a burner assembly having a high velocity burner to force combusted air and fuel through a heat exchanger and a low velocity burner to maintain a continuous combustion process and prevent so-called "lift off" where a flame and/or combustion process may be extinguished by a high velocity combustion process that exceeds the ignition capabilities of the burner. For example, a heat exchanger may comprise a plurality of compactly-arranged tubes comprising a plurality of fluid circuits. Alternatively, a heat exchanger may be submerged in a cooking vessel and comprise a plurality of compactly-arranged, interstitially-spaced vertical and horizontal tubes that are open to the cooking vessel to allow ingress and egress of a cooking fluid. In either of these example heat exchangers, resistance to fluid flow through a fluid duct of the heat exchanger may be excessive, such that traditional burners would fail to pass combusted air and fuel through the heat exchanger and would suffer from "lift off" if the velocity and/or flowrate of combustion was increased.

Accordingly, embodiments of cooking systems are disclosed herein that comprise one or more burner assemblies with a high velocity burner (or sub-burner) configured to provide the necessary high velocity flowrate through the tubes of a heat exchanger (e.g., whether the tubes are arranged in multiple fluid circuits of compactly-arranged tubes disposed perpendicularly and interstitially to one another, or whether the tubes comprise compactly-arranged and interstitially-spaced vertical and horizontal tubes that are open to the cooking vessel to allow ingress and egress of a cooking fluid). In addition, the burner assemblies also include a low velocity burner (or sub-burner) configured to significantly reduce and/or substantially eliminate "lift off" that could result from operation of only the high velocity burner.

Referring now to <FIG>, various views of a burner assembly <NUM> are shown. The burner assembly <NUM> of <FIG> is outside the scope of the appended claims. The burner assembly <NUM> generally comprises a body <NUM>, a manifold <NUM>, a plurality of runners <NUM> joining the body <NUM> to the manifold <NUM>, a plurality of first burners <NUM>, a plurality of second burners <NUM>, a ribbon burner <NUM>, and a plurality of deflectors <NUM>. The body <NUM> comprises a lower portion <NUM> joined to an upper portion <NUM>. In some embodiments, the lower portion <NUM> may be bolted to the upper portion <NUM> using fasteners <NUM> disposed through holes in the lower portion <NUM> and threaded into the upper portion <NUM>. In some embodiments, a gasket <NUM> may be disposed between the lower portion <NUM> and the upper portion <NUM> of the body <NUM> to prevent leakage and/or seepage of any fluid flowing within the cavity <NUM> from escaping between the lower portion <NUM> and the upper portion <NUM>. When assembled, the lower portion <NUM> and the upper portion <NUM> generally form a cavity <NUM> through which fuel and/or an air/fuel mixture may flow.

The burner assembly <NUM> also comprises a manifold <NUM> configured to deliver the fuel and/or the air/fuel mixture into the cavity <NUM> through a plurality of parallel runners <NUM>. Each runner <NUM> comprises a lower threaded portion <NUM>, an upper threaded portion <NUM>, and a butt joint <NUM> that joins the lower threaded portion <NUM> to the upper threaded portion <NUM>. In some embodiments, it will be appreciated that each runner <NUM> may be a solid piece and comprise the lower threaded portion <NUM> and the upper threaded portion <NUM> joined by the butt joint <NUM>. The lower threaded portion <NUM> may generally be threaded into and extend into an inner opening of the manifold <NUM>, such that fuel and/or an air/fuel mixture may flow from an internal volume of the manifold <NUM> through an internal volume of the lower threaded portion <NUM> and into an internal volume of the butt joint <NUM>. The upper threaded portion <NUM> may generally be threaded into the lower portion <NUM> of the body <NUM> and extend into the cavity <NUM> of the body <NUM>. Accordingly, an internal volume of the upper threaded portion <NUM> may receive fuel and/or an air/fuel mixture from the internal volume of the butt joint <NUM>. It will be appreciated that each runner <NUM> thus comprises a fluid flow path that extends through internal volumes of the lower threaded portion <NUM>, the butt joint <NUM>, and the upper threaded portion <NUM>. Furthermore, the upper threaded portion <NUM> comprises a plurality of fuel delivery holes <NUM> that may distribute the fuel and/or the air/fuel mixture received from the manifold <NUM> evenly throughout the cavity <NUM>. Additionally, in some embodiments, an upper distal end of the upper threaded portion <NUM> may be closed and/or substantially abut a substantially flat surface of the upper portion <NUM> of the body <NUM> so that the fuel and/or the air/fuel mixture that passes through the runner <NUM> only escapes the upper threaded portion <NUM> through the fuel delivery holes <NUM>.

The burner assembly <NUM> comprises a plurality of first burners <NUM> arranged adjacently along a length of the upper portion <NUM> of burner assembly <NUM>. Additionally, the plurality of first burners <NUM> are arranged along a centerline of the upper portion <NUM> of the body <NUM>, such that the centerline of the body <NUM> intersects a center axis of each first burner <NUM>. Each first burner <NUM> comprises a cylindrically-shaped first bore <NUM> configured to receive the fuel and/or the air/fuel mixture from the cavity <NUM>. The first bore <NUM> also comprises a plurality of holes <NUM> disposed about the first bore <NUM> that are configured to allow the fuel and/or the air/fuel mixture to flow from the first bore <NUM> to a combustion chamber <NUM> that is formed by a cylindrically-shaped third bore <NUM>. Each first burner <NUM> also comprises a cylindrically-shaped second bore <NUM> that is axially aligned with and disposed downstream from the first bore <NUM> with respect to the flow of the fuel and/or the air/fuel mixture through the burner assembly <NUM> and that comprises a diameter that is smaller than the diameter of the first bore <NUM>. The second bore <NUM> may also receive the fuel and/or the air/fuel mixture from the first bore <NUM>. In some embodiments, the smaller diameter of the second bore <NUM> may be sized to control a pressure drop through the second bore <NUM> and/or the plurality of holes <NUM> disposed about the first bore <NUM>.

Accordingly, the first burner <NUM> may define a first flow path <NUM> from the cavity <NUM> through the first bore <NUM> and the second bore <NUM> into the combustion chamber <NUM> and further define a plurality of second flow paths <NUM> from the cavity <NUM> through the first bore <NUM>, through the plurality of holes <NUM>, and into the combustion chamber <NUM>. Furthermore, as will be discussed herein in further detail, to ignite the fuel and/or the air/fuel mixture in the first burner <NUM>, each first burner <NUM> also comprises a groove <NUM> disposed in the third bore <NUM> that forms the cylindrically-shaped combustion chamber <NUM> on each of an opposing left side and right side of the combustion chamber <NUM> so that fuel through the first flow path <NUM> and the plurality of second flow paths <NUM> of the first burner <NUM> may be ignited by the ribbon burner <NUM>. Thus, the first burner <NUM> may further define a first sub-burner <NUM> in fluid communication with the cavity <NUM> via the first flow path <NUM>, and a second sub-burner <NUM> in fluid communication with the cavity <NUM> via the second flow paths <NUM>. The second sub-burner <NUM> extends circumferentially about the first sub-burner <NUM> with respect to a central axis of burner <NUM> (not shown).

In some embodiments, the flowrate, velocity, and/or volume of the fuel and/or the air/fuel mixture through the first flow path <NUM> of the first burner <NUM> may be greater than the flowrate, volume, and/or volume of the fuel and/or the air/fuel mixture through the plurality of second flow paths <NUM> through the first burner <NUM>. In particular, without being limited to any particular theory, the radial flow of fluids along second flowpaths <NUM> causes impact of the fluids with the inner walls of third bore <NUM>, thereby reducing the kinetic energy for these fluid flows and decreasing their velocity as compared to the fluids flowing through first flow path <NUM>. As a result, the first sub-burner <NUM> (including flow path <NUM>) may be referred to herein as a "high velocity sub-burner" and second sub-burner <NUM> (including flow path <NUM>) may be referred to herein as a "low velocity sub-burner". However, it should be appreciated that in other embodiments, the flowrate and/or volume of the fuel and/or the air/fuel mixture through the first flow path <NUM> of the first burner <NUM> (i.e., through the first sub-burner <NUM> and the second sub-burner <NUM>) may be equal to or less than the flowrate and/or volume of the fuel and/or the air/fuel mixture through the plurality of second flow paths <NUM> through the first burner <NUM>. This adjustment of the relative velocities of flow paths <NUM>, <NUM> may be accomplished by, for example, adjusting the sizes (e.g., diameters) of the first bore <NUM> and holes <NUM>.

The burner assembly <NUM> also comprises a plurality of second burners <NUM> disposed on each of a left side and a right side of the upper portion <NUM> of the body <NUM> of burner assembly <NUM>. Each second burner <NUM> may generally be configured as a low flow-rate ribbon burner <NUM> that comprises a plurality of feeder holes <NUM>, a cavity <NUM>, and a plurality of upper holes <NUM>. The feeder holes <NUM> are configured to receive the fuel and/or the air/fuel mixture from the cavity <NUM> and allow the fuel and/or the air/fuel mixture to flow into a cavity <NUM> that houses the ribbon burner <NUM>. The second burner <NUM> also comprises a plurality of upper holes <NUM> that are disposed on the left and right sides of the cavity <NUM> and the ribbon burner <NUM>. The upper holes <NUM> receive fuel and/or the air/fuel mixture from the cavity <NUM>. Accordingly, the second burner <NUM> may define a first flowpath <NUM> from the cavity <NUM> through a plurality of feeder holes <NUM>, into the cavity <NUM>, and through a plurality of upper holes <NUM>. Furthermore, as will be discussed herein in further detail, the fuel and/or the air/fuel mixture flowing through the upper holes <NUM> may be ignited by the ribbon burner <NUM>.

Additionally, the ribbon burner <NUM> comprises a plurality of small perforations <NUM> that may also allow fuel and/or the air/fuel mixture to pass through a plurality of second flowpaths <NUM> from the cavity <NUM> through the perforations <NUM>, where they may be ignited by the ribbon burner <NUM>. In some embodiments, the flowrate and/or volume of the fuel and/or the air/fuel mixture through the first flowpath <NUM> of the second burner <NUM> may be greater than the flowrate and/or volume of the fuel and/or the air/fuel mixture through the plurality of second flowpaths <NUM> through the second burner <NUM>. However, in other embodiments, the flowrate and/or volume of the fuel and/or the air/fuel mixture through the first flowpath <NUM> of the second burner <NUM> may be equal to or less than the flowrate and/or volume of the fuel and/or the air/fuel mixture through the plurality of second flowpaths <NUM> through the second burner <NUM>. Additionally, in some embodiments, the combined flowrate and/or volume of the fuel and/or the air/fuel mixture through a first burner <NUM> may be greater than the flowrate and/or volume of the fuel and/or the air/fuel mixture through a second burner <NUM>. However, in alternative embodiments, the combined flowrate and/or volume of the fuel and/or the air/fuel mixture through a first burner <NUM> may be equal to or less than the flowrate and/or volume of the fuel and/or the air/fuel mixture through a second burner <NUM>.

In some embodiments, the burner assembly <NUM> may comprise one or more infrared burners. Accordingly, the first burner <NUM>, the second burner <NUM>, and/or the ribbon burner <NUM> may be configured as an infrared burner. Accordingly, first burner <NUM>, the second burner <NUM>, and/or the ribbon burner <NUM> may comprise additional components, including but not limited to, ceramic components and/or other components necessary to configure and/or operate the first burner <NUM>, the second burner <NUM>, and/or the ribbon burner <NUM> as an infrared burner. However, in some embodiments, the first burner <NUM>, the second burner <NUM>, and/or the ribbon burner <NUM> may alternatively be configured as any other suitable burner.

In operation, the burner assembly <NUM> is configured to combust fuel and/or an air/fuel mixture through a plurality of first burners <NUM> and a plurality of second burners <NUM>. In some embodiments, the burner assembly <NUM> may also comprise a separate igniter and/or a plurality of igniters configured to ignite the air/fuel mixture in each of the first burners <NUM> and the second burners <NUM>. In this embodiment, the combined flowrate and/or volume of the fuel and/or air/fuel mixture through the first burners <NUM> is greater than the flowrate and/or volume of the fuel and/or the air/fuel mixture through the plurality of second burners <NUM>. Accordingly, the velocity of the combusted fuel and/or the combusted air/fuel mixture through the first burners <NUM> is higher than the velocity of the combusted fuel and/or the combusted air/fuel mixture through the second burners <NUM>.

Because the velocity of the combusted fuel and/or combusted air/fuel mixture through the first burners <NUM> exits the first burners <NUM> at such a high velocity, traditional burners may experience so-called "lift off" where the flame is extinguished due to the high velocity. As such, the lower velocity of the combusted fuel and/or the combusted air/fuel mixture exiting the second burners <NUM> may prevent this "lift off" by continuously burning fuel at a lower flowrate and/or delivering a combusted air/fuel mixture at the lower velocity. Additionally, the burner assembly <NUM> also comprises a deflector <NUM> on each of a left side and a right side of the upper portion <NUM> of the body <NUM> of burner assembly <NUM> that is secured to the upper portion <NUM> of the body <NUM> by a plurality of fasteners <NUM>. The deflectors <NUM> may be angled towards a center of the upper portion <NUM> and extend over the second burners <NUM> in order to deflect the combusted air/fuel mixture exiting the second burners <NUM> towards the combusted air/fuel mixture exiting the first burners <NUM>. Accordingly, the deflectors <NUM> may also aid in preventing "lift off" by directing the lower velocity combusted air/fuel mixture exiting the second burners <NUM> towards the higher velocity combusted air/fuel mixture exiting the first burners <NUM>.

Further, within the first burner <NUM> itself, the velocity of the combusted fuel and/or the fuel mixture through the first sub-burner <NUM> may be such that the first sub-burner <NUM> may also experience "lift off. " However, the relatively slower velocity of the combusted fluid flow from second sub-burner <NUM> may prevent this "lift off" of the first sub-burner <NUM> by continuously burning fuel at a lower flow rate and/or delivering combusted fuel or fuel/air mixture at a lower velocity.

Referring now to <FIG>, a pair of perspective views and a back view of a burner assembly <NUM> is shown according to an embodiment of the invention. Burner assembly <NUM> comprises a generally cylindrical body <NUM> that includes a central axis <NUM>, a first or upstream end 200a, a second or downstream end 200b opposite upstream end 200a, and a radially outer surface 200c extending axially between ends 200a, 200b. Radially outer surface 200c further includes a first upstream cylindrical surface <NUM> extending from upstream end 200a, a second or downstream cylindrical surface <NUM> extending axially from downstream end 200b, and a frustoconical surface <NUM> between surfaces <NUM>, <NUM>. In this embodiment, downstream cylindrical surface <NUM> has a larger diameter about axis <NUM> than upstream cylindrical surface <NUM> such that frustoconical surface <NUM> extends radially outward moving axially from upstream cylindrical surface <NUM> to downstream cylindrical surface <NUM>. A plurality of mounting bores <NUM> extend axially from frustoconical surface <NUM> to downstream end 200b that are evenly circumferentially spaced about axis <NUM>. As will be described in more detail below, mounting bores <NUM> are configured to receive bolts, screws, rivets, or other suitable mounting members to secure burner assembly <NUM> to another member or structure (e.g., a heat exchanger, vessel, etc.). In addition, a plurality of mounting bores <NUM> also extend into body <NUM> from upstream end 200a. Mounting bores <NUM> may be used to couple piping or other supply conduits to burner assembly <NUM> (e.g., such as to supply fuel or a fuel air mixture to burner assembly <NUM>).

Body <NUM> of burner assembly <NUM> also includes a cylindrical recess or cavity <NUM> extending axially from upstream end 200a and a plurality of burners <NUM> extending axially from cavity <NUM> to downstream end 200b. As shown in <FIG> and <FIG>, each burner <NUM> has a central or longitudinal axis <NUM> that extends parallel to axis <NUM> of burner assembly <NUM>. In this embodiment, burner assembly <NUM> includes a total of seven burners <NUM> with one of the burners (identified as burner <NUM>') coaxially aligned with burner assembly <NUM> and the remaining six burners <NUM> evenly circumferentially spaced about axis <NUM>. In particular, in this embodiment, axis <NUM> of central burner <NUM>' is aligned with axis <NUM> of burner assembly <NUM>, and the axes <NUM> of the remaining burners <NUM> are all parallel to and radially offset from axis <NUM> of burner assembly <NUM>. It should be appreciated that generic references to burners <NUM> is meant to encompass all of the burners <NUM> on burner assembly <NUM> (including central burner <NUM>').

Referring now to <FIG> and <FIG>, cross-sectional views of burner assembly <NUM> and central burner <NUM>' are shown. It should be appreciated that the details described below for burner <NUM>' are also applicable to describe the features of the other burners <NUM>, except that axis <NUM> of the remaining burners <NUM> are not aligned with axis <NUM> as previously described above. Thus, a detailed description of the other burners <NUM> is omitted herein in the interest of brevity.

In this embodiment, burner <NUM>' comprises a bore <NUM> (bore <NUM> may be referred to herein as a "burner bore <NUM>") extending axially from downstream end 200b of body <NUM> to cavity <NUM> and an insert <NUM> disposed within bore <NUM>. Insert <NUM> is coaxially aligned with axis <NUM> and includes a first or upstream end 230a, a second or downstream end 230b opposite upstream end 230a, a recess or cavity <NUM> extending axially from upstream end 230a, a plurality of first bores <NUM> extending axially from cavity <NUM> to downstream end 230b, and a plurality of second bores <NUM> extending radially from cavity <NUM>. As best shown in <FIG>, insert <NUM> is disposed within bore <NUM> such that upstream end 230a engages or abuts with a radially extending annular shoulder <NUM> within bore <NUM> such that cavity <NUM> is in communication with cavity <NUM> of body <NUM>. In addition, bore <NUM> and upstream end 200b of burner assembly <NUM> are in communication with cavity <NUM> (and thus also cavity <NUM>) through each of the plurality of first bores <NUM> and the plurality of second bores <NUM>.

Each burner <NUM>' defines a plurality of first flow paths <NUM> extending from cavity <NUM>, axially through bores <NUM> and into bore <NUM> toward downstream end 200b, and a plurality of second flow paths <NUM> extending from cavity <NUM> radially through bores <NUM> and then axially through bore <NUM> toward downstream end 200b. As will be described in more detail below, bore <NUM> (or the portion of bore <NUM> that is not occupied by insert <NUM>) forms a combustion chamber <NUM> that receives fuel (or an air/fuel mixture) from both the first flow paths <NUM> and the second flow paths <NUM> that may be ignited therein. However, because the fuel (or air/fuel mixture) flowing through the plurality of second flow paths <NUM> first flows radially from cavity <NUM> into bore <NUM> (or combustion chamber <NUM>), the fluids flowing along second flow paths <NUM> flow at a slower velocity (and thus at a lower flow rate) than the fluids flowing along plurality of first flow paths <NUM>. In other words, without being limited to any particular theory, the radial flow of fluids along second flow paths <NUM> causes impact of the fluids with the inner wall of bore <NUM>, thereby reducing the kinetic energy for these fluid flows and decreasing their velocity as compared to the fluids flowing axially through first flow paths <NUM>. Also, the relatively smaller diameter of the bores <NUM> compared with cavity <NUM> causes an increase in velocity of the fluids flowing along flow paths <NUM> upon entering bores <NUM>. As a result, burner <NUM>' defines a first sub-burner <NUM> (or high velocity burner) fed by flow paths <NUM>, and a second sub-burner <NUM> (or low velocity burner) fed by flow paths <NUM> (see <FIG>). In particular, in this embodiment, second sub-burner <NUM> is annularly or circumferentially disposed about first sub-burner <NUM> with respect to axis <NUM>.

In addition, the increased velocity through flow paths <NUM> due to the constrictions created within the relatively smaller diameter first bores <NUM> also allows for higher velocities of combusted fuel (or air/fuel mixture) through the first sub-burner <NUM> from relatively smaller flow rates of fuel (or fuel/air mixture) through cavity <NUM>. This may further enhance the ability of burner assembly <NUM> to deliver a flow of combusted fluids at a sufficiently high velocity to overcome any back pressure imposed by the internal structure of an associated heat exchanger (e.g., heat exchangers <NUM>, <NUM> described below).

Referring back now to <FIG>, a plurality of slots <NUM> extend through burner assembly <NUM> to place the combustion chambers <NUM> of adjacently disposed burners <NUM> in fluid communication with one another. As a result, in this embodiment, the combustion chambers <NUM> of all of the burners <NUM> on burner assembly <NUM> are in fluid communication with one another either directly or indirectly via the slots <NUM>. Further, a pair of spark plugs <NUM> (or other suitable igniter member) are inserted partially into the combustion chambers <NUM> of two of the burners <NUM> (however, more or less than two spark plugs <NUM> may be used in other embodiments) through corresponding angled bores <NUM> extending from frustoconical surface <NUM>. As a result, spark plugs <NUM> may be utilized to ignite fuel (or air/fuel mixture) disposed within combustion chambers <NUM> of burners <NUM>.

Referring now to <FIG>, and <FIG>, in operation, burner assembly <NUM> is configured to combust fuel and/or an air/fuel mixture through the plurality of burners <NUM>. Initial combustion (or ignition) of the fuel and/or air/fuel mixture within burners <NUM> is achieved via one or both of the spark plugs <NUM>, and this initial combustion subsequently spreads to the other burners <NUM> via slots <NUM>. Within each burner <NUM>, the fuel and/or fuel mixture enters chamber <NUM> via sub-burners <NUM>, <NUM> and ignites therein. In at least some operations, the velocity of the combusted fuel and/or combusted air/fuel mixture through the first-sub burners <NUM> is such that they may experience so-called "lift off" where the flame is extinguished due to the high velocity. However, the lower velocity of the combusted fuel and/or fuel/air mixture exiting second sub-burners <NUM> (which have a slower flow rate due to the radially directed bores <NUM> as previously described) may prevent this "lift off" by continuously burning fuel at a lower flowrate and/or delivering a combusted air/fuel mixture at a lower velocity. In addition, if any of the burners <NUM> should experience a total loss of combustion (e.g., due to "lift-off," temporary lack of fuel, or another reason), then the fluid communication between the burners <NUM> via slots <NUM> may allow for re-ignition from an adjacent burner <NUM> that is still combusting fuel therein.

Additionally, while not shown specifically in <FIG>, additional adjacent burners (e.g., ribbon burners <NUM> in <FIG>) or deflectors (e.g., deflectors <NUM> in <FIG>) may also be incorporated onto or adjacent to burner assembly <NUM> in the same or a similar manner to that described above for burner assembly <NUM>, so that additional reliability may be achieved during operations with burner assembly <NUM>. Further, as described above for burner assembly <NUM>, in some embodiments, burner assembly <NUM> may comprise one or more infrared burners. Accordingly, the burners <NUM> (including sub-burners <NUM>, <NUM>) and/or the possible additional adjacent burners discussed above may comprise additional components including but not limited to, ceramic components and/or other components necessary to configured and/or operate burners <NUM> (or the additional adjacent burners) as infrared burners.

Referring now to <FIG>, an oblique side view, an oblique cross-sectional side view, and an oblique end view of a heat exchanger <NUM> are shown, respectively, according to an embodiment of the invention. The heat exchanger <NUM> comprises a first fluid circuit <NUM> having a first inlet <NUM>, a plurality of top headers <NUM>, a plurality of downward tubes <NUM>, a plurality of bottom headers <NUM>, a plurality of upward tubes <NUM>, and a first outlet <NUM>. The first inlet <NUM> is connected in fluid communication with a first top header <NUM>' and is configured to receive a fluid there through and allow the fluid to enter the first top header <NUM>'. The first top header <NUM>' is connected in fluid communication with a first set of downward tubes <NUM>, which is connected in fluid communication with a bottom header <NUM>. Fluid from the first top header <NUM>' may flow through the first set of downward tubes <NUM> into a bottom header <NUM>. The bottom header <NUM> may also be connected in fluid communication with a set of upward tubes <NUM> that may carry fluid from the bottom header <NUM> through the upward tubes <NUM> and into another top header <NUM>. Accordingly, this pattern may continue along the length of the heat exchanger <NUM>, such that each top header <NUM> transfers fluid through a set of downward tubes <NUM> into a bottom header <NUM> and subsequently from the bottom header <NUM> through a set of upward tubes <NUM> into an adjacently downstream located top header <NUM>.

Furthermore, it will be appreciated that downward tubes <NUM> may be associated with carrying a fluid from a top header <NUM> in a downward direction towards and into a bottom header <NUM>, and upward tubes <NUM> may be associated with carrying a fluid from a bottom header <NUM> in an upward direction towards and into a top header <NUM>. This pattern may continue along the length of the heat exchanger <NUM> until a last set of downward tubes <NUM> carries fluid through into a final bottom header <NUM>' and out of the first outlet <NUM>. Accordingly, the first fluid circuit <NUM> comprises passing fluid from the first inlet <NUM> into the first top header <NUM>' through a repetitive serpentine series of downward tubes <NUM>, a bottom header <NUM>, a set of upward tubes <NUM>, and a top header <NUM> until passing through a final set of downward tubes <NUM> into the final bottom header <NUM>' and exiting the heat exchanger <NUM> through the first outlet <NUM>. Furthermore, in other embodiments, it will be appreciated that the first inlet <NUM> and/or the first outlet <NUM> may alternatively be disposed both in a top header <NUM>, both in a bottom header <NUM>, or in opposing top and bottom headers <NUM>, <NUM>.

The heat exchanger <NUM> also comprises a second fluid circuit <NUM> having a second inlet <NUM>, a plurality of left headers <NUM>, a plurality of rightward tubes <NUM>, a plurality of right headers <NUM>, a plurality of leftward tubes <NUM>, and a second outlet <NUM>. The rightward tubes <NUM> and the leftward tubes <NUM> may be oriented substantially perpendicular to the downward tubes <NUM> and the upward tubes <NUM> of the first fluid circuit <NUM>. The second inlet <NUM> is connected in fluid communication with a first left header <NUM>' and is configured to receive a fluid there through and allow the fluid to enter the first left header <NUM>'. The first left header <NUM>' is connected in fluid communication with a first set of rightward tubes <NUM>, which is connected in fluid communication with a right header <NUM>. Fluid from the first left header <NUM>' may flow through the first set of rightward tubes <NUM> into a right header <NUM>. The right header <NUM> may also be connected in fluid communication with a set of leftward tubes <NUM> that may carry fluid from the right header <NUM> through the leftward tubes <NUM> and into another left header <NUM>. Accordingly, this pattern may continue along the length of the heat exchanger <NUM>, such that each left header <NUM> transfers fluid through a set of rightward tubes <NUM> into a right header <NUM> and subsequently from the right header <NUM> through a set of leftward tubes <NUM> into an adjacently downstream located left header <NUM>.

Furthermore, it will be appreciated that rightward tubes <NUM> may be associated with carrying a fluid from a left header <NUM> in a rightward direction towards and into a right header <NUM>, and leftward tubes <NUM> may be associated with carrying a fluid from a right header <NUM> in a leftward direction towards and into a left header <NUM>. This pattern may continue along the length of the heat exchanger <NUM> until a last set of rightward tubes <NUM> carries fluid through into a final right header <NUM>' and out of the second outlet <NUM>. Accordingly, the second fluid circuit <NUM> comprises passing fluid from the second inlet <NUM> into the first left header <NUM>' through a repetitive serpentine series of a set of rightward tubes <NUM>, a right header <NUM>, a set of leftward tubes <NUM>, and a left header <NUM> until passing through a final set of rightward tubes <NUM> into the final right header <NUM>' and exiting the heat exchanger <NUM> through the second outlet <NUM>. Furthermore, in other embodiments, it will be appreciated that the second inlet <NUM> and/or the second outlet <NUM> may alternatively be disposed both in a left header <NUM>, both in a right header <NUM>, or in opposing left and right headers <NUM>, <NUM>. Additionally, it will be appreciated that in some embodiments, the heat exchanger <NUM> may comprise only one of the first fluid circuit <NUM> and the second fluid circuit <NUM>.

First Fluid circuit <NUM> and the second fluid circuit <NUM> may comprise different lengths. Accordingly, the first inlet <NUM> and/or the first outlet <NUM> may be disposed in any of the top headers <NUM> or bottom headers <NUM>, and the second inlet <NUM> and/or the second outlet <NUM> may be disposed in any of the left headers <NUM> and the right headers <NUM> to vary the length of the fluid circuits <NUM>, <NUM>, respectively. By altering the length of the fluid circuits <NUM>, <NUM>, the heat exchanger <NUM> may be configured to maintain a temperature gradient, reduce a pressure drop, and/or otherwise control the temperature and/or pressure of the fluid though each of the fluid circuits <NUM>, <NUM>.

The tubes <NUM>, <NUM>, <NUM>, <NUM> of the heat exchanger <NUM> may generally be arranged to provide a compact, highly resistive flowpath through the fluid duct <NUM>. In order to effectively and/or evenly distribute the heat produced by a coupled burner assembly (which may comprise burner assembly <NUM> or burner assembly <NUM>, each previously described above) through the tubes <NUM>, <NUM>, <NUM>, <NUM>, sets and/or rows of tubes <NUM>, <NUM> may be interstitially and/or alternatively spaced with sets and/or rows of tubes <NUM>, <NUM>. In the shown embodiment, two rows of downward tubes <NUM>, two rows of rightward tubes <NUM>, two rows of upward tubes <NUM>, and two rows of leftward tubes <NUM> are interstitially and/or alternatively spaced, respectively, along the length of the heat exchanger <NUM>. However, in alternative embodiments, a single row of tubes <NUM>, <NUM>, <NUM>, <NUM> may be interstitially and/or alternatively spaced, respectively, along the length of the heat exchanger <NUM>. In other embodiments, however, heat exchanger <NUM> may comprise any number of rows of tubes <NUM>, <NUM>, <NUM>, <NUM> interstitially and/or alternatively spaced along the length of the heat exchanger <NUM>. For example, heat exchanger <NUM> may comprise three rows of downward tubes <NUM>, two rows of rightward tubes <NUM>, three rows of upward tubes <NUM>, and two rows of leftward tubes <NUM> may be interstitially and/or alternatively spaced. Accordingly, it will be appreciated that the number of rows of tubes <NUM>, <NUM>, <NUM>, <NUM> interstitially and/or alternatively spaced may vary, so long as at least one row of vertically-oriented tubes <NUM>, <NUM> is disposed adjacently with at least one row of horizontally-oriented tubes <NUM>, <NUM> along the length of the heat exchanger <NUM>.

Heat exchanger <NUM> also comprises a plurality of mounting holes <NUM> disposed through a mounting flange <NUM> that is disposed at the distal end of the heat exchanger <NUM> located closest to the first inlet <NUM> and the second inlet <NUM>. The mounting holes <NUM> may generally be configured to mount the heat exchanger <NUM> to a burner assembly (e.g., either the burner assembly <NUM> of <FIG> or the burner assembly <NUM> of <FIG>). In some embodiments, the heat exchanger <NUM> may be secured to a burner assembly via fasteners such as bolts, rivets, etc. (e.g., fasteners <NUM>). However, in other embodiments, the heat exchanger <NUM> may be secured to a burner assembly through an alternative mechanical interface (e.g., plate, adapter, etc.). While mounting flange <NUM> is shown as having a rectangular (or square) shape, it should be appreciated that flange <NUM> may be differently shaped or formed (e.g., flange <NUM> may be circular or curved in shape) to accommodate the connection between the chosen burner assembly (e.g., burner assembly <NUM>, <NUM>) and heat exchanger <NUM>. The heat exchanger <NUM> is secured to the chosen burner assembly so that combusted fuel and/or combusted air/fuel mixture is forced through a plurality of inner walls of the heat exchanger <NUM> that form a fluid duct <NUM> through the heat exchanger <NUM>. Accordingly, heat from the combusted fuel and/or the combusted air/fuel mixture may be absorbed by a fluid flowing through the tubes <NUM>, <NUM>, <NUM>, <NUM> of the heat exchanger <NUM>. The heated fluid may exit the heat exchanger <NUM> through the first outlet <NUM> and the second outlet <NUM> of the first fluid circuit <NUM> and the second fluid circuit <NUM>, respectively, and therefore be used to heat and/or cook consumable products (i.e., chips, crackers, frozen foods).

In operation, the configuration of tubes <NUM>, <NUM>, <NUM>, <NUM> provides a compact, highly resistive flow path through the fluid duct <NUM>. Accordingly, to force combusted fuel and/or combusted air/fuel mixture through the fluid duct <NUM> requires high velocity. Accordingly, the velocity of the combusted fuel and/or the combusted air/fuel mixture through the high velocity burners (or sub-burners) of the chosen burner assembly (e.g., first burners <NUM> of the burner assembly <NUM>; first sub-burners <NUM> of burner assembly <NUM>, etc.) is high enough to provide the requisite velocity needed to overcome the resistance to flow through the heat exchanger <NUM>. Furthermore, the lower velocity of the combusted fuel and/or the combusted air/fuel mixture through the low velocity burners of the chosen burner assembly (e.g., second sub-burners <NUM> or second burners <NUM> of the burner assembly <NUM>; second sub-burners <NUM> of burner assembly <NUM>, etc.) prevents "lift off" so that the combustion process remains constant through the burner assembly (i.e., burner assembly <NUM> or <NUM>).

Referring now to <FIG>, a schematic of a cooking system <NUM> is shown according to an embodiment of the invention. Cooking system <NUM> generally comprises at least one burner assembly <NUM>, at least one heat exchanger <NUM>, at least one cooking vessel <NUM> (e.g., a fryer), at least one oil input line <NUM>, and at least one oil output line <NUM>. In this embodiment, cooking system <NUM> utilizes burner assembly <NUM>; however, it should be appreciated that cooking system <NUM> may alternatively or additionally include burner assembly <NUM> as described in more detail below. As previously disclosed, the burner assembly <NUM> may be mounted to at least one heat exchanger <NUM>. However, in this embodiment, the burner assembly <NUM> may be mounted to a plurality of heat exchangers <NUM>. Furthermore, while not shown, in some embodiments, multiple burner assemblies <NUM> may be mounted to multiple heat exchangers <NUM> in the cooking system <NUM>. The burner assembly <NUM> is configured to provide a high velocity flow of combusted fuel and/or combusted air/fuel mixture through the fluid duct <NUM> of the heat exchangers <NUM>.

Fluid, such as a cooking fluid (e.g., oil, water, etc.) may be pumped into the first inlet <NUM> and/or the second inlet <NUM> of the heat exchangers <NUM> (see <FIG>) through a plurality of oil input lines <NUM>, each oil input line <NUM> being associated with a respective inlet <NUM>, <NUM>. Fluid may enter the oil input lines <NUM> from a reservoir and/or may be circulated through the heat exchangers <NUM> from the cooking vessel <NUM>. The fluid may be pumped and/or passed through the tubes <NUM>, <NUM>, <NUM>, <NUM> of the heat exchangers <NUM> (see <FIG>). Heat produced from the combustion of fuel and/or an air/fuel mixture in the burner assembly <NUM> may be transferred to the fluid flowing through the tubes <NUM>, <NUM>, <NUM>, <NUM> of the heat exchangers <NUM> (see <FIG>). The heated fluid may exit the heat exchanger <NUM> through the first outlet <NUM> and the second outlet <NUM> and be carried into the cooking vessel <NUM> through a plurality of oil output lines <NUM>, each oil output line <NUM> being associated with a respective outlet <NUM>, <NUM>. In some embodiments, the heated fluid may be carried into the cooking vessel <NUM> at different locations to maintain a proper temperature, temperature gradient, and/or temperature profile within the cooking vessel <NUM>. As stated, in some embodiments, fluid from the cooking vessel <NUM> may be recirculated through the oil input lines <NUM> and reheated within the heat exchangers <NUM>. Furthermore, it will be appreciated while burner assembly <NUM> is disclosed in the context of food service equipment (e.g., fryer, boiler), the burner assembly <NUM> may be used for any application or industry that requires a fluid to be heated rapidly, consistently, and efficiently.

Additionally, as previously mentioned above, in some embodiments burner assembly <NUM> may be used in place of burner assembly <NUM> within cooking system <NUM>. In these embodiments, fuel and/or air/fuel mixture is forced through burner assembly <NUM> from upstream end 200a to downstream end 200b (i.e., through cavity <NUM> and burners <NUM>) so that the fuel (or mixture) combusts within combustion chambers <NUM> and is emitted through fluid duct <NUM> of heat exchangers <NUM> in the same manner as described above for burner assembly <NUM> (see <FIG>, <FIG>, and <FIG>).

Referring now to <FIG>, a schematic of a cooking system <NUM> is shown according to another embodiment of the invention. Cooking system <NUM> may be substantially similar to cooking system <NUM> of <FIG>. However, cooking system <NUM> comprises a plurality of burner assemblies <NUM> (which may each comprise burner assembly <NUM>, burner assembly <NUM>, or a combination of burner assembles <NUM>, <NUM>), a plurality of heat exchangers <NUM>, at least one cooking vessel <NUM> (i.e., a fryer), at least one oil input line <NUM> per heat exchanger <NUM>, and at least one oil output line <NUM> per heat exchanger <NUM>. As previously disclosed, each burner assembly <NUM> may be associated with at least one heat exchanger <NUM>. However, in this embodiment, each burner assembly <NUM> may be mounted to a single heat exchanger <NUM>. Each burner assembly <NUM> is configured to provide a high velocity flow of combusted fuel and/or combusted air/fuel mixture through the fluid duct <NUM> of the associated heat exchanger <NUM> (see <FIG>).

Fluid, such as a cooking fluid (e.g., oil) may be pumped into the first inlet <NUM> and/or the second inlet <NUM> of the heat exchanger <NUM> through a plurality of oil input lines <NUM>, each oil input line <NUM> being associated with a respective inlet <NUM>, <NUM> (see <FIG>). Fluid may enter the oil input lines <NUM> from a reservoir and/or may be circulated through the heat exchangers <NUM> from the cooking vessel <NUM>. The fluid may be pumped and/or passed through the tubes <NUM>, <NUM>, <NUM>, <NUM> of the heat exchanger <NUM> (see <FIG>). Heat produced from the combustion of fuel and/or an air/fuel mixture in the burner assemblies <NUM> may be transferred to the fluid flowing through the tubes <NUM>, <NUM>, <NUM>, <NUM> of each respective heat exchanger <NUM> (see <FIG>). The heated fluid may exit the heat exchangers <NUM> through the first outlet <NUM> and the second outlet <NUM> of each heat exchanger <NUM> and be carried into the cooking vessel <NUM> through a plurality of oil output lines <NUM>, each oil output line <NUM> being associated with a respective outlet <NUM>, <NUM>.

In some embodiments, the heated fluid may be carried into the cooking vessel <NUM> at different locations to maintain a proper temperature, temperature gradient, and/or temperature profile within the cooking vessel <NUM>. Furthermore, it will be appreciated that each burner assembly <NUM> may be individually controlled by a burner controller (not pictured). As such, in some embodiments, each burner assembly <NUM> may be operated at substantially similar temperatures. However, in other embodiments, each burner assembly <NUM> may be operated at different temperatures to maintain a temperature gradient across the cooking vessel <NUM> and/or to control a cooking process requiring different temperatures. Still further, while multiple burner assemblies <NUM> and multiple heat exchangers <NUM> are pictured, in some embodiments, a single burner assembly <NUM> may be associated with a single heat exchanger <NUM> to provide heated fluid to the cooking vessel <NUM>. As stated, in some embodiments, fluid from the cooking vessel <NUM> may be recirculated through the oil input lines <NUM> and reheated within the heat exchangers <NUM>. Furthermore, it will be appreciated while burner assembly <NUM> is disclosed in the context of food service equipment (e.g., fryer, boiler), the burner assembly <NUM> may be used for any application or industry that requires a fluid to be heated rapidly, consistently, and efficiently.

Referring now to <FIG>, an oblique side view and an oblique cross-sectional side view of a heat exchanger <NUM> are shown, respectively, according to an embodiment of the invention. The heat exchanger <NUM> generally comprises a top wall <NUM>, a bottom wall <NUM>, a left side wall <NUM>, and a right side wall <NUM> that define a fluid duct <NUM> having an inlet <NUM> and an outlet <NUM> through the heat exchanger <NUM>. Heat exchanger <NUM> also comprises a plurality of vertical tubes <NUM> that extend between the top wall <NUM> and the bottom wall <NUM>. The plurality of vertical tubes <NUM> may extend through the top wall <NUM> and the bottom wall <NUM> to allow ingress and egress of fluid into the vertical tubes <NUM> through each of the top wall <NUM> and bottom wall <NUM>. Additionally, heat exchanger <NUM> also comprises a plurality of horizontal tubes <NUM> that extend between the left side wall <NUM> and the right side wall <NUM>. The plurality of horizontal tubes <NUM> may extend through the left side wall <NUM> and the right side wall <NUM> to allow ingress and egress of fluid into the horizontal tubes <NUM> through each of the left side wall <NUM> and the right side wall <NUM>.

The vertical tubes <NUM> and the horizontal tubes <NUM> of the heat exchanger <NUM> may generally be arranged to provide a compact, highly resistive flow path through the fluid duct <NUM>. In order to effectively and/or evenly distribute the heat produced by a burner assembly (e.g., burner assembly <NUM> or <NUM>) through the vertical tubes <NUM> and the horizontal tubes <NUM>, sets and/or rows of vertical tubes <NUM> may be interstitially and/or alternatively spaced with sets and/or rows of horizontal tubes <NUM>. In the shown embodiment, two rows of vertical tubes <NUM> are interstitially and/or alternatively spaced with two rows of horizontal tubes <NUM> along the length of the heat exchanger <NUM>. However, in alternative embodiments, a single row of vertical tubes <NUM> may be interstitially and/or alternatively spaced with a single row of horizontal tubes <NUM> along the length of the heat exchanger <NUM>. In other embodiments, however, heat exchanger <NUM> may comprise any number of rows of vertical tubes <NUM> interstitially and/or alternatively spaced with any number of rows of horizontal tubes <NUM> along the length of the heat exchanger <NUM>. For example, heat exchanger <NUM> may comprise three rows of vertical tubes <NUM> interstitially and/or alternatively spaced with two rows of horizontal tubes <NUM>. Accordingly, it will be appreciated that the number of rows or vertical tubes <NUM> interstitially and/or alternatively spaced with rows of horizontal tubes <NUM> may vary, so long as at least one row of vertical tubes <NUM> is interstitially and/or alternatively spaced with at least one row of horizontal tubes <NUM> along the length of the heat exchanger <NUM>.

The heat exchanger <NUM> also comprises a plurality of mounting holes <NUM> disposed through a mounting flange <NUM> that is disposed at the distal end of the heat exchanger <NUM> located closest to the inlet <NUM>. The mounting holes <NUM> may generally be configured to mount the heat exchanger <NUM> to a burner assembly (e.g., either the burner assembly <NUM> of <FIG> or the burner assembly <NUM> of <FIG>). In some embodiments, the heat exchanger <NUM> may be secured to a burner assembly via fasteners such as bolts, rivets, etc. (e.g., fasteners <NUM>). However, in other embodiments, the heat exchanger <NUM> may be secured to a burner assembly through an alternative mechanical interface (e.g., plate, adapter, etc.). While mounting flange <NUM> is shown as having a rectangular (or square) shape, it should be appreciated that flange <NUM> may be differently shaped or formed (e.g., flange <NUM> may be circular or curved in shape) to accommodate the connection between the chosen burner assembly (e.g., burner assembly <NUM>, <NUM>) and heat exchanger <NUM>. The heat exchanger <NUM> is secured to the chosen burner assembly so that combusted fuel and/or combusted air/fuel mixture is forced through the fluid duct <NUM> of the heat exchanger <NUM>. Accordingly, heat from the combusted fuel and/or combusted air/fuel mixture may be absorbed by a fluid flowing through the tubes <NUM>, <NUM> of the heat exchanger <NUM>. The heated fluid may exit heat exchanger <NUM> through the tubes <NUM>, <NUM> and therefore be used to heat and/or cook consumable products (i.e., chips, crackers, frozen foods).

In operation, the configuration of tubes <NUM>, <NUM> provides a compact, highly resistive flow path through the fluid duct <NUM>. Accordingly, to force combusted fuel and/or combusted air/fuel mixture through the fluid duct <NUM> requires high velocity. Accordingly, the velocity of the combusted fuel and/or the combusted air/fuel mixture through the high velocity burners of the burner assembly (e.g., first burners <NUM> of the burner assembly <NUM>; first sub-burners <NUM> of burner assembly <NUM>, etc.) is high enough to provide the requisite velocity needed to overcome the resistance to flow through the heat exchanger <NUM>. Furthermore, the lower velocity of the combusted fuel and/or the combusted air/fuel mixture through the low velocity burners of the burner assembly (e.g., second sub-burners <NUM> or second burners <NUM> of the burner assembly <NUM>; the second sub-burners <NUM> of burner assembly <NUM>, etc.) prevents "lift off" so that the combustion process remains constant through the burner assembly (i.e., burner assembly <NUM> or <NUM>).

Referring now to <FIG>, a schematic top view and a schematic side view of a cooking system <NUM> are shown, respectively, according to an embodiment of the invention. Cooking system <NUM> generally comprises at least one burner assembly <NUM>, at least one heat exchanger <NUM>, and at least one cooking vessel <NUM> (e.g., a fryer). In this embodiment, cooking system <NUM> utilizes burner assembly <NUM>; however, it should be appreciated that cooking system <NUM> may alternatively or additionally include burner assembly <NUM> as described in more detail below. As previously disclosed, the burner assembly <NUM> may be mounted to at least one heat exchanger <NUM>. However, in this embodiment, the burner assembly <NUM> may be mounted to a plurality of heat exchangers <NUM>. Furthermore, while not shown, in some embodiments, multiple burner assemblies <NUM> may be mounted to multiple heat exchangers <NUM> in the cooking system <NUM>. The burner assembly <NUM> is configured to provide a high velocity flow of combusted fuel and/or combusted air/fuel mixture through the fluid duct <NUM> of the heat exchanger <NUM> (see <FIG>). The heat exchangers <NUM> may generally be submerged in the cooking vessel <NUM>.

Fluid, such as a cooking fluid (e.g., oil) contained within the cooking vessel <NUM>, may be free to flow through the vertical tubes <NUM> and horizontal tubes <NUM> of the heat exchanger <NUM> (see <FIG>). Heat produced from the combustion of fuel and/or an air/fuel mixture in the burner assembly <NUM> may enter the inlet <NUM> of the heat exchanger <NUM> from the burner assembly <NUM> and be transferred to the fluid flowing through and/or contained within the tubes <NUM>, <NUM> of the heat exchanger <NUM>. Accordingly, in embodiments comprising multiple heat exchangers <NUM>, the heat exchangers <NUM> may be disposed throughout the cooking vessel <NUM> at substantially similar intervals and/or uniformly spaced to maintain a substantially uniform temperature within the cooking vessel <NUM>. However, in other embodiments comprising multiple heat exchangers <NUM>, the heat exchangers <NUM> may be disposed to maintain a temperature gradient and/or temperature profile within the cooking vessel <NUM>. The heated fluid may flow through and exit the tubes <NUM>, <NUM> of heat exchanger <NUM> back into cooking vessel <NUM>. In some embodiments, the outlet <NUM> of duct <NUM> (which carries combusted fluids from burner assembly <NUM>) may extend through the cooking vessel <NUM> and be discharged to an outside environment through a collective exhaust header (not shown) and/or any other ductwork to expel the combusted gases. In some embodiments, fluid from the cooking vessel <NUM> may be circulated within the cooking vessel <NUM> by a pump (not shown) to increase and/or promote fluid flow through the tubes <NUM>, <NUM> of the heat exchanger <NUM>. Furthermore, it will be appreciated while burner assembly <NUM> is disclosed in the context of food service equipment (e.g., cooking vessel, fryer, boiler), the burner assembly <NUM> may be used for any application or industry that requires a fluid to be heated rapidly, consistently, and efficiently.

Referring now to <FIG>, a schematic top view of a cooking system <NUM> is shown according to another embodiment of the invention. Cooking system <NUM> may be substantially similar to cooking system <NUM> of <FIG>. However, in this embodiment, cooking system <NUM> comprises a plurality of burner assemblies <NUM>, wherein each burner assembly <NUM> may be mounted to a single heat exchanger <NUM>. As is similarly described above for burner assemblies <NUM> in <FIG>, burner assemblies <NUM> may each comprise burner assembly <NUM>, burner assembly <NUM>, or a combination of burner assemblies <NUM>, <NUM>. The burner assembly <NUM> is configured to provide a high velocity flow of combusted fuel and/or combusted air/fuel mixture through the fluid duct <NUM> of the heat exchanger <NUM> (see <FIG>). The heat exchangers <NUM> may generally be submerged in the cooking vessel <NUM>. Fluid, such as a cooking fluid (e.g., oil) contained within the cooking vessel <NUM>, may be free to flow through the vertical tubes <NUM> and horizontal tubes <NUM> of the heat exchanger <NUM> (see <FIG>). Heat produced from the combustion of fuel and/or an air/fuel mixture in the burner assembly <NUM> may enter the inlet <NUM> of each heat exchanger <NUM> from the burner assembly <NUM> and be transferred to the fluid flowing through and/or contained within the tubes <NUM>, <NUM> of the heat exchanger <NUM>. Additionally, heat may be transferred to the fluid within the cooking vessel <NUM> that contacts any outer surface of the heat exchangers <NUM>.

In this embodiment, the heat exchangers <NUM> may generally be disposed throughout the cooking vessel <NUM> at substantially similar intervals and/or uniformly spaced to maintain a substantially uniform temperature within the cooking vessel <NUM>. However, in other embodiments, the heat exchangers <NUM> may be disposed at any other interval and/or spacing based on a desired temperature profile across the cooking vessel <NUM> and/or the configuration of the cooking vessel <NUM>. Thus, in some embodiments, the burner assemblies <NUM> and heat exchangers <NUM> are disposed to maintain a temperature gradient and/or temperature profile within the cooking vessel <NUM>. In addition, to accomplish control of the burner assemblies <NUM>, each burner assembly <NUM> may be controlled by a burner assembly controller <NUM>. As such, the burner assembly controller <NUM> may control each burner assembly <NUM> to a specified amount of heat in order to maintain a temperature gradient and/or temperature profile of the fluid within the cooking vessel <NUM>. However, in other embodiments, the burner assemblies <NUM> may be controlled to provide a substantially similar amount of heat to maintain a substantially similar temperature of the fluid throughout the cooking vessel <NUM>. In such embodiments, multiple burner assemblies <NUM> may, at least in some instances, be controlled by a single burner assembly controller <NUM>. The heated fluid may flow through and exit the tubes <NUM>, <NUM> of heat exchanger <NUM> back into cooking vessel <NUM>. In some embodiments, the outlet <NUM> of duct <NUM> (which carries combusted fluids from burner assembly <NUM>) may extend through the cooking vessel <NUM> and be discharged to an outside environment through a collective exhaust header (not shown) and/or any other ductwork to expel the combusted gases. In some embodiments, fluid may be circulated within the cooking vessel <NUM> by a pump (not shown) to increase and/or promote fluid flow through the tubes <NUM>, <NUM> of the heat exchanger <NUM>. Furthermore, it will be appreciated while burner assembly <NUM> is disclosed in the context of food service equipment (i.e., cooking vessel, fryer, boiler), the burner assembly <NUM> may be used for any application or industry that requires a fluid to be heated rapidly, consistently, and efficiently.

Referring now to <FIG>, a schematic view of a cooking system <NUM> is shown according to another embodiment of the invention. Cooking system <NUM> generally includes a reservoir <NUM>, a first heat exchanger <NUM>, a plurality of second heat exchangers 708a, 708b, a cooking vessel <NUM>, and a thermal oxidizer <NUM>. In addition, cooking system <NUM> includes a cooking fluid circuit comprising conduits <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, an exhaust system comprising conduits <NUM>, <NUM>, and a fuel system comprising conduits <NUM> and header <NUM>. Each of the conduits <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may comprise any suitable fluid conveyance member capable of channeling fluids there through. For example, conduits <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may comprise pipes, hoses, open channels, or other fluid conveyances.

Cooking vessel <NUM> may comprise any suitable vessel or tub for containing a cooking fluid <NUM> (e.g., oil, water, etc.) at a high temperature. For example, cooking vessel <NUM> may be similar to cooking vessels <NUM>, <NUM> previously described above (see <FIG>, and <FIG>). Reservoir <NUM> may comprise a tank or vessel (or collection of vessels) that is configured to hold or store the cooking fluid <NUM> for use within cooking system <NUM>.

Heat exchangers <NUM>, 708a, 708b may comprise any suitable device for transferring heat between two fluids (e.g., such as heat exchangers <NUM>, <NUM>, previously described). In this embodiment, each of the heat exchangers <NUM>, 708a, 708b is the same (or similar to) heat exchanger <NUM> of <FIG>. As will be described in more detail below, heat exchangers <NUM>, 708a, 708b are utilized within cooking system <NUM> to transfer heat to cooking fluid <NUM> so that cooking fluid <NUM> is at a sufficient temperature to carry out the desired cooking reaction (e.g., frying) within cooking vessel <NUM>. Each of the heat exchangers 708a, 708b include a burner assembly <NUM> that may comprise burner assembly <NUM> or burner assembly <NUM> previously described above (it should be appreciated that heat exchangers 708a, 708b may share a single burner assembly <NUM> in other embodiments). In this embodiment, burner assemblies <NUM> each comprise the burner assembly <NUM> previously described above (see <FIG>). As with cooking systems <NUM>, <NUM>, burner assemblies <NUM> are used to combust fuel (e.g., natural gas) to provide heat to the cooking fluid <NUM> as it flows through heat exchangers 708a, 708b. In addition, as will be described in more detail below, in this embodiment heat exchanger <NUM> does not include a burner assembly <NUM> and instead utilizes heat from thermal oxidizer <NUM> (described below) to increase the temperature of cooking fluid <NUM> flowing therein.

Referring now to <FIG>, a schematic side cross-sectional view of thermal oxidizer <NUM> is shown. Thermal oxidizer <NUM> is a vessel comprising a first or upstream end 740a, a second or downstream end 740b opposite upstream end 740a, and an internal chamber <NUM>. An inlet <NUM> into internal chamber <NUM> is disposed at upstream end 740a, and an outlet <NUM> from internal chamber <NUM> is disposed proximate downstream end 740b. A plurality of burner assemblies <NUM> are disposed at upstream end 740a and extend into chamber <NUM>. In this embodiment, the burner assemblies <NUM> on thermal oxidizer <NUM> are evenly circumferentially disposed about inlet <NUM> (or a central axis of inlet <NUM>). The burner assemblies <NUM> on thermal oxidizer <NUM> may comprise burner assembly <NUM> or burner assembly <NUM> previously described above. In this embodiment, each of the burner assemblies <NUM> on thermal oxidizer <NUM> comprise the burner assembly <NUM> of <FIG>. Fuel (e.g., natural gas, propane, etc.) is provided to burner assemblies <NUM> from fuel header <NUM> (which is shown in <FIG>) via a plurality of fuel supply conduits <NUM>. Fuel header <NUM> may comprise a supply pipe (or other conduit) or tank that provides a flow of fuel to conduits <NUM>. In some embodiments, fuel header <NUM> is a main supply pipe of natural gas provided from a local utility service.

A manifold <NUM> is coupled to thermal oxidizer <NUM> at upstream end 740a. In this embodiment, manifold <NUM> is an annular chamber that surrounds oxidizer <NUM> at upstream end 740a. A supply line <NUM> provides air (or oxygen) to manifold <NUM>, which is then supplied to fuel supply conduits <NUM> upstream of burner assemblies <NUM>. As a result, an air/fuel mixture is supplied to burner assemblies <NUM> via conduits <NUM>, <NUM> during operations. Upon entering the burner assemblies <NUM>, the air/fuel mixture is combusted in the manner described above for burner assemblies <NUM>, <NUM> (depending on whether burner assembly <NUM> or <NUM> is used) such that hot combusted fluids are emitted into thermal oxidizer <NUM> at upstream end 740a.

Referring now to <FIG> and <FIG>, during operations, a food item (e.g., chips, crackers, frozen foods, etc.) may be placed into cooking vessel <NUM> to perform a cooking operation (e.g., frying, boiling, etc.). To facilitate the cooking operation, hot cooking fluid <NUM> is flowed into cooking vessel <NUM> via conduits <NUM>, <NUM>. Subsequently, the cooking fluid <NUM> exits cooking vessel <NUM> via conduit <NUM> and flows to heat exchanger <NUM>. In addition, cooking fluid <NUM> may be flowed to heat exchanger <NUM> from reservoir <NUM> via conduit <NUM> as shown in <FIG>. As a result of the interaction between the hot cooking fluid <NUM> and the food item within vessel <NUM>, hot exhaust gases are emitted from vessel <NUM> that are captured by vent hood <NUM> and transferred to inlet <NUM> of thermal oxidizer <NUM> via conduit <NUM> (a blower or other suitable compressing or pumping assembly may be included along conduit <NUM> to facilitate the flow of fluids from vessel <NUM> into chamber <NUM> of thermal oxidizer <NUM>). Upon entering internal chamber <NUM>, the exhaust fluids from cooking vessel <NUM> are heated by the hot combusted gases also emitted into chamber <NUM> by burner assemblies <NUM>. In some embodiments, at least some of the exhaust fluids entering chamber <NUM> at inlet <NUM> are also ignited by the combustion within burner assemblies <NUM>. The heated gases are flowed through chamber <NUM> from upstream end 740a to downstream end 740b where they are emitted from chamber <NUM> at outlet <NUM> and communicated to heat exchanger <NUM> via conduit <NUM>.

Within heat exchanger <NUM>, heat is transferred from the exhaust fluids entering exchanger <NUM> via conduit <NUM> to the cooking fluid <NUM> entering heat exchanger <NUM> via conduits <NUM>, <NUM>. As previously described, in this embodiment, heat exchanger <NUM> (as well as heat exchangers 708a, 708b) is configured the same as heat exchanger <NUM> previously described above. Accordingly, in this embodiment, the hot fluids emitted from outlet <NUM> of thermal oxidizer <NUM> flow through duct <NUM> of exchanger <NUM>, while the cooking fluid <NUM> flows through the tubes <NUM>, <NUM>, <NUM>, <NUM> (see <FIG>). As a result, the temperature of cooking fluid <NUM> is increased as it flows within exchanger <NUM>, and the hot exhaust fluids from thermal oxidizer <NUM> are eventually emitted from duct <NUM> either into the atmosphere or to another tank, vessel, or process.

Referring now to <FIG>, upon exiting exchanger <NUM>, the heated cooking fluid <NUM> then flows in parallel to each of the heat exchangers 708a, 708b, via conduits <NUM>. Fuel (e.g., natural gas, propane, etc.) is provided to burner assemblies <NUM> within heat exchangers via conduits <NUM> and is combusted therein in the same manner described above for burner assemblies <NUM>, <NUM> (depending on whether burner assembly <NUM> or <NUM> is used) to provide hot combusted fluids (e.g., gases) that are flowed through heat exchangers 708a, 708b to further increase the temperature of cooking fluid <NUM> also flowing there through. In particular, the hot combusted fluids from burner assemblies <NUM> are flowed through ducts <NUM> of heat exchanger 708a, 708b, while the heated cooking fluid <NUM> is flowed through tubes <NUM>, <NUM>, <NUM>, <NUM> of heat exchangers 708a, 708b (see <FIG>). As a result, additional heat is transferred to the cooking fluid <NUM> from the combusted fluids emitted from burner assemblies <NUM> within heat exchangers 708a, 708b such that the cooking fluid <NUM> is eventually emitted from heat exchangers via conduits <NUM>, <NUM> at a final cooking temperature. Conduits <NUM>, <NUM> thereafter provide this heated cooking fluid <NUM> to vessel <NUM> to perform the cooking operation as previously described. In some embodiments, air or oxygen may be mixed with the fuel flowing to burner assemblies <NUM> within exchangers 708a, 708b to facilitate the combustion of the fuel therein.

Claim 1:
A burner assembly (<NUM>), comprising:
a body (<NUM>) that defines a first cavity (<NUM>), wherein the body (<NUM>) comprises:
an upstream end (200a); and
a downstream end (200b);
a burner (<NUM>) coupled to the body (<NUM>) that is configured to combust an air/fuel mixture, wherein the burner (<NUM>) has a central axis, wherein the first cavity (<NUM>) extends from the upstream end (200a), and the burner (<NUM>) extends from the first cavity (<NUM>) to the downstream end (200b), and wherein the burner (<NUM>) comprises:
a combustion chamber (<NUM>);
a first sub-burner (<NUM>) comprising a plurality of axially extending first bores (<NUM>), wherein the first sub-burner (<NUM>) is configured to communicate the air/fuel mixture from the first cavity (<NUM>) into the combustion chamber (<NUM>) through the plurality of axially extending first bores (<NUM>) at a first flowrate; and
a second sub-burner (<NUM>) comprising a plurality of radially extending second bores (<NUM>), wherein the second sub-burner (<NUM>) is configured to communicate the air/fuel mixture from the first cavity (<NUM>) into the combustion chamber (<NUM>) through the plurality of radially extending second bores (<NUM>) at a second flowrate;
a burner bore (<NUM>) extending through the body (<NUM>) from the downstream end to the first cavity (<NUM>); and
an insert (<NUM>) disposed within the burner bore (<NUM>), wherein the insert (<NUM>) comprises each of the plurality of first bores (<NUM>) and the plurality of second bores (<NUM>);
wherein the second flowrate is lower than the first flowrate; and
an igniter (<NUM>) configured to ignite the air/fuel mixture.