WO2024136678A1 - Grill burner assembly - Google Patents

Abstract

A radiant burner includes at least one burner body defining a flow channel extending in a longitudinal direction from a first end to a second end of the or each burner body and having an inlet port arranged at the second end to receive an air and gas mixture. The height of the flow channel increases from the first end to the second end. The radiant burner further includes a plenum chamber arranged at the second end of the at least one burner body and fluidly coupled to the inlet port to supply the air and gas mixture to the flow channel via the inlet port. Furthermore, the radiant burner includes a tube extending in the longitudinal direction from or near the first end and connected to the plenum chamber to supply the air and gas mixture to the plenum chamber.

Description

GRILL BURNER ASSEMBLY

TECHNICAL FIELD

[0001] The present disclosure relates, generally, to a burner and more particularly, though not solely, relates to a radiant burner that provides improved flame characteristics.

BACKGROUND INFORMATION

[0002] Radiant burners, for example, infra-red burners (also known as ‘sear burners’) using perforated ceramic tiles, are well known burners for cooking food items. Infra-red burners are so- called because of the wavelength of the radiative energy emitted by the burner. A common problem with the current ‘natural draught’ radiant burners is the low ratio of radiative to convective heat transfer delivered by the burner. This is generally due to the lack of primary air coming through the venturi tube. A potential solution is the use of carefully designed venturi tubes but most often, the resulting venturi tubes are relatively short, when compared to overall dimensions of the burner head, and generally do not promote a thorough mixing of combustible gas and air. Moreover, the gases discharge velocity at the outlet of such venturis can be relatively high with respect to the burner’s flame front velocity, which is undesirable. Also, this particular construction often leads to uneven temperature distribution over the burner due to an unbalanced, uneven velocity distribution inside flow channels of the burner, which is also undesirable.

SUMMARY OF DISCLOSURE

[0003] One aspect of this disclosure relates to a radiant burner. The radiant burner includes at least one burner body defining a flow channel extending in a longitudinal direction from a first end to a second end of the or each burner body and having an inlet port arranged at the second end to receive an air and gas mixture. Moreover, a height of the flow channel increases from the first end to the second end. The radiant burner further includes a plenum chamber arranged at the second end of the at least one burner body, fluidly coupled to the inlet port to supply the air and gas mixture to the flow channel via the inlet port. Furthermore, the radiant burner includes a tube extending in the longitudinal direction from or near the first end and connected to the plenum chamber to supply the air and gas mixture to the plenum chamber. [0004] In some additional, alternative, or selectively cumulative embodiments, the radiant burner further comprises a porous cover covering at least some of the flow channel and configured to allow the air and gas mixture to escape therethrough.

[0005] In some additional, alternative, or selectively cumulative embodiments, the porous cover comprises one or more of: one or more ceramic plates, one or more perforated metal plates, metal wool, metal mesh, and ceramic foam or sponge.

[0006] In some additional, alternative, or selectively cumulative embodiments, the at least one burner body includes a plurality of burner bodies arranged with their flow channels extending substantially parallel to each other, and the plenum chamber extends in a lateral direction, connecting the plurality of burner bodies.

[0007] In some additional, alternative, or selectively cumulative embodiments, the tube is a venturi tube and is connected substantially centrally to the plenum chamber in the lateral direction.

[0008] In some additional, alternative, or selectively cumulative embodiments, the plenum chamber includes a deflection plate to deflect or constrain movement of the air and gas mixture in the lateral direction towards at least one of the plurality of burner bodies.

[0009] In some additional, alternative, or selectively cumulative embodiments, the air and gas mixture entering the plenum chamber is deflected or constrained to change direction in at least two substantially orthogonal planes, within the plenum chamber, before entering an inlet port of a burner body.

[0010] In some additional, alternative, or selectively cumulative embodiments, the radiant burner further includes a cross-piece arranged above the plenum chamber and extending in the lateral direction, connecting at least two of the plurality of burner bodies. The cross-piece defines a crossflow channel connecting the flow channels of the connected burner bodies.

[0011] In some additional, alternative, or selectively cumulative embodiments, the cross-piece includes a porous cover covering the crossflow channel.

[0012] In accordance with another example embodiment, a grill is disclosed. The grill includes one or more radiant burners. Each radiant burner has at least one burner body defining a flow channel extending in a longitudinal direction from a first end to a second end of the or each burner body and having an inlet port arranged at the second end to receive an air and gas mixture. A height of the flow channel increases from the first end to the second end. Further, each radiant burner includes a plenum chamber arranged at the second end of the at least one burner body and fluidly coupled to the inlet port to supply the air and gas mixture to the flow channel via the inlet port. Moreover, each radiant burner comprises a tube extending in the longitudinal direction from or near the first end and connected to the plenum chamber to supply the air and gas mixture to the plenum chamber.

[0013] In some additional, alternative, or selectively cumulative embodiments, each radiant burner further includes a porous cover covering at least some of the flow channel and configured to allow the air and gas mixture to escape therethrough.

[0014] In some additional, alternative, or selectively cumulative embodiments, the porous cover comprises one or more of: one or more ceramic plates, one or more perforated metal plates, metal wool, metal mesh, and ceramic foam or sponge.

[0015] In some additional, alternative, or selectively cumulative embodiments, the at least one burner body includes a plurality of burner bodies arranged with their flow channels extending substantially parallel to each other, and the plenum chamber extends in a lateral direction, connecting the plurality of burner bodies.

[0016] In some additional, alternative, or selectively cumulative embodiments, the tube is a venturi tube and is connected substantially centrally to the plenum chamber in the lateral direction.

[0017] In some additional, alternative, or selectively cumulative embodiments, the plenum chamber includes a deflection plate to deflect or constrain movement of the air and gas mixture in the lateral direction towards the at least one burner body.

[0018] In some additional, alternative, or selectively cumulative embodiments, the air and gas mixture entering the plenum chamber is deflected or constrained to change direction in at least two substantially orthogonal planes, within the plenum chamber, before entering an inlet port of a burner body.

[0019] In some additional, alternative, or selectively cumulative embodiments, each radiant burner further includes a cross-piece arranged above the plenum chamber and extending in the lateral direction connecting at least two of the plurality of burner bodies. The cross-piece defines a crossflow channel connecting the flow channels of the connected burner bodies. [0020] In some additional, alternative, or selectively cumulative embodiments, the cross-piece includes a porous cover covering the crossflow channel.

[0021] Additional aspects and advantages will be apparent from the following detailed description of example embodiments, which proceeds with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 illustrates a front perspective view of an example grill, in accordance with an embodiment of the disclosure;

[0023] FIG. 2 illustrates a front perspective view of the grill of FIG. 1 with a grate removed and depicting an example radiant burner, in accordance with an embodiment of the disclosure;

[0024] FIG. 3 illustrates a top front perspective view of the radiant burner of FIG. 2, in accordance with an embodiment of the disclosure;

[0025] FIG. 4 illustrates a top front perspective view of the radiant burner of FIG. 3 with a protective mesh cover removed from the radiant burner, in accordance with an embodiment of the disclosure;

[0026] FIG. 5 illustrates a top front perspective view of the radiant burner of FIG. 4 without porous covers, in accordance with an embodiment of the disclosure;

[0027] FIG. 6 illustrates a sectional side perspective view of the radiant burner of FIG. 4, in accordance with an embodiment of the disclosure;

[0028] FIG. 7 illustrates a rear bottom perspective view of the radiant burner of FIG. 4, in accordance with an embodiment of the disclosure; and

[0029] FIG. 8 illustrates a sectional rear perspective view of the radiant burner of FIG. 7, in accordance with an embodiment of the disclosure.

DETAILED DESCRIPTION

[0030] Example embodiments are described below with reference to the accompanying drawings. Unless otherwise expressly stated in the drawings, the sizes, positions, etc., of components, features, elements, etc., as well as any distances therebetween, are not necessarily to scale, and may be disproportionate and/or exaggerated for clarity. [0031] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should be recognized that the terms “comprise,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Unless otherwise specified, a range of values, when recited, includes both the upper and lower limits of the range, as well as any sub-ranges therebetween. Unless indicated otherwise, terms such as “first,” “second,” etc., are only used to distinguish one element from another. For example, one element could be termed a “first element” and similarly, another element could be termed a “second element,” or vice versa. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0032] Unless indicated otherwise, the terms “about,” “thereabout,” “substantially,” etc. mean that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art.

[0033] Spatially relative terms, such as “right,” left,” “below,” “beneath,” “lower,” “above,” and “upper,” and the like, may be used herein for ease of description to describe one element's or feature's relationship to another element or feature, as illustrated in the drawings. It should be recognized that the spatially relative terms are intended to encompass different orientations in addition to the orientation depicted in the figures. For example, if an object in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can, for example, encompass both an orientation of above and below. An object may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly. [0034] Unless clearly indicated otherwise, all connections and all operative connections may be direct or indirect. Similarly, unless clearly indicated otherwise, all connections and all operative connections may be rigid or non-rigid.

[0035] Like numbers refer to like elements throughout. Thus, the same or similar numbers may be described with reference to other drawings even if they are neither mentioned nor described in the corresponding drawing. Also, even elements that are not denoted by reference numbers may be described with reference to other drawings.

[0036] Many different forms and embodiments are possible without deviating from the spirit and teachings of this disclosure and so this disclosure should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the disclosure to those skilled in the art.

[0037] Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. The appearance of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

[0038] Referring to FIGS. 1 and 2, a gas-fired grill or barbeque (or ‘BBQ’) 100 suitable for cooking/grilling one or more food items, according to an example embodiment, is shown. The grill 100 includes a base structure 102 including a firebox and defining a cooking area or surface 104, and a cover (or hood or lid) 106 pivotally/movably connected to the base structure 102 and configured to selectively cover the cooking area 104 from top. Further, the grill 100, as shown, includes at least one radiant or ‘sear’ burner 110 (preferably a ‘natural draft’ radiant burner) arranged inside the cooking area 104 and configured to facilitate ignition of an air and gas mixture to enable the cooking/grilling of the food items. In the embodiment shown, there are four parallel burner locations, each of which may be provided with a radiant burner 110, although, for example, only one radiant burner 110 may be provided while the other burner locations are provided with conventional gas flame burners. To facilitate a positioning of one or more food items inside the cooking area 104 and above the one or more burners 110, the grill 100 includes a plurality of grates 112 supported on the base structure 102 and each arranged above a corresponding burner. Although a grill 100 having four burner locations is shown and contemplated, it may be envisioned that the grill 100 could include only one burner location or more than four burner locations. Additionally, the grill 100 includes a plurality of knobs 114, one for radiant burner 110 and one for each other burner that is provided, each knob controlling a flow of the air and gas mixture to its associated burner 110.

[0039] Referring to FIG. 3, a radiant burner 110 is shown according to an example embodiment. The radiant burner 110 includes at least one burner body, for example, a first burner body 120 and a second burner body 122 arranged spaced apart and extending substantially parallel to the first burner body 120. Although the radiant burner 110 having two separate burner bodies 120, 122 is shown and contemplated, it may be appreciated that the radiant burner 110 may include more than two burner bodies, or a single burner body. The burner bodies 120, 122 facilitate and control the release of the air and gas mixture over their upper surfaces, which mixture is ignited via an ignition system (not shown), and maintain a flame surface or front on the upper surfaces to enable heating/cooking/grilling/searing of the food positioned on the grate(s). Preferably, the burner bodies are formed using sheet metal.

[0040] Further, the radiant burner 110 includes a plenum or expansion chamber 126 connected to the burner bodies 120, 122, and a tube 128 extending in a longitudinal direction of the radiant burner 110 to supply an air and gas mixture to the plenum chamber 126. The air and gas mixture received by the plenum chamber 126 is efficiently mixed therein under turbulent conditions and flows to the burner bodies 120, 122. The plenum chamber also converts the dynamic pressure of the air and gas mixture, in the form of velocity, into static pressure. Moreover, a plurality of detachable protective mesh covers 146 are shown covering the burner bodies 120, 122, retained by plural tabs projecting from side surfaces of the burner bodies. The mesh covers are provided to protect fragile components within the assembly (such as the ceramic tiles described below) from falling debris, such as dripping fats, and also from sharp objects/cooking utensils that may fall onto them. The mesh covers may, for example, be formed from stainless steel mesh.

[0041] Referring to FIGS. 3 to 5, the first burner body 120 includes a first end 130 (i.e., front end 130) and a second end 132 (i.e., rear end 132) and defines a flow channel 134 (i.e., first flow channel 134), as shown in FIG. 5 extending from the first end 130 to the second end 132. In an embodiment, the first burner body 120 includes a base 136, a pair of sidewalls 138, and a front wall 140 closing the flow channel at the first end 130, while base 136 defines an inlet port 142 (i.e., first inlet port 142), shown in FIG. 5 and FIG. 8 of the first flow channel 134. As shown, the first inlet port 142 is arranged proximate to the rear end 132 of the first burner body 120. Also, the base 136 of the burner body 120 is inclined relative to a horizontal such that a height ‘h’ of the first flow channel 134 increases from the front end 130 to the rear end 132. Accordingly, a cross- sectional area of the first flow channel 134 at the inlet port 142 is largest, and decreases towards the front wall 140. Preferably, the decrease in height, and cross-sectional area, is regular and steady, rather than abruptly changing For example, with a constant burner body width, base 136 may be planar but inclined at an angle (for example, between about 5 degrees and about 15 degrees) to the horizontal, or may be curved. Base 136 may also be made up of plural planar segments, extending from a lower height at rear end 132 to a higher end at front end 130. The connected planar segments could be at different angles to horizontal or could all be in horizontal planes forming a plurality of steps in between, wherein the step height is relatively small and so the stepped base approximates a planar/inclined surface.

[0042] Moreover, the radiant burner 110 includes a porous cover 150 (i.e., a first porous cover) covering an open top of the first flow channel 136. It should be noted that, simply to improve clarity, the first porous cover 150 illustrated in FIGS. 3, 4, 6 and 8 is shown to only include limited regions of pores, however in reality, substantially all of the first porous cover is porous. Accordingly, the openings or holes of the first porous cover 150 define a plurality of outlet openings to enable an exit of the air and gas mixture flowing inside the first flow channel 136. Also, a continuous/steady/gradual decrease of the cross-sectional area of the first flow channel 136 in a direction away from the inlet port 142 enables the air and gas mixture to be ejected with a uniform speed along a length of the first porous cover 150. In some embodiments, the first porous cover 150 includes one or more ceramic plates or tiles 152, perforated metal plates, metal wool, metal mesh, and ceramic foam or sponge, or a combination thereof. Further, an upper surface 154 of the first porous cover 150 acts as a flame surface at which the flame front is present when the air and gas mixture, escaping through the outlet openings of the first porous cover 150, is ignited. Each burner body is preferably formed to include a (substantially horizontally arranged in use) supporting lip for the ceramic tiles to seat in, around the perimeter of the burner body, an insulating foam or tape or a ceramic tape being applied to the upper surface of the lip, and between ceramic tiles, to provide sealing and to cope with inevitable thermal expansion. Due to the decrease in the cross-sectional area of the first flow channel 134 in a direction away from the first inlet port 142, and the steady removal of gases from the flow channel (via the first porous cover) along the flow channel, gases pressure is maintained relatively constant along the length of the flow channel, and across its width, so that the velocity of the air and gas mixture exiting via the porous cover is relatively constant along the length of the burner body. This ensures a uniform exit flow rate of the air and gas mixture through the first porous cover 150 along the entire length of the first burner body 120, helping in achieving uniform/even temperature along the length of the first porous cover 150. The second burner body 122 is similar to the first burner body 120 and includes a first end 160, a second end 162, a base 164, a front wall 166, a pair of sidewalls 168, a flow channel 170 (i.e., second flow channel 170), a porous cover 172 (i.e., second porous cover 172), an inlet port 174 (i.e., second inlet port 174), and one or more ceramic plates 176.

[0043] Further, as illustrated FIGS. 3 to 8, the plenum chamber 126 is arranged at the second ends 132, 162 of the burner bodies 120, 122, and extends in a lateral direction relative to the burner bodies 120, 122, connecting the burner bodies 120, 122 together. Accordingly, at least a portion of the plenum chamber 126 is arranged between the first burner body 120 and the second burner body 122. As shown in FIGS. 6 to 8, at least a portion of the plenum chamber 126 extends downwardly of the base 136, 164 of each burner body 120, 122, and includes a first wall 178 extending obliquely (i.e., at an angle, for example between about 10-20 degrees, to horizontal) from a central portion 180 of the plenum chamber 126 and then upwardly (i.e., substantially vertically) to the first burner body 120, and a second wall 182 extending obliquely from the central portion 180 of the plenum chamber 126 and then upwardly to the second burner body 122. Moreover, the plenum chamber 126 includes a deflection plate 184 (best shown in FIG. 5 and FIG. 8) arranged spaced apart from and above the central portion 180 and defining two outlets, for example, a first outlet 186 arranged proximate to the first burner body 120 and a second outlet 188 arranged proximate to the second burner body 122, on opposite sides of the deflection plate 184. Accordingly, the deflection plate 184 is disposed substantially centrally in the lateral direction, of the plenum chamber 126. It may be appreciated that the air and gas mixture flows to the first inlet port 142 and the second inlet port 174 from the plenum chamber 126 via the first outlet 186 and the second outlet 188, respectively. [0044] Deflection plate 184 forces the air and gas mixture exiting tube 128 to move laterally, effectively changing direction by substantially 90 degrees in a substantially horizontal plane and by a further substantially 90 degrees into a substantially vertical plane. Subsequently, in order to enter the flow channels of the burner bodies, the air and gas mixture must essentially change direction again by a further substantially 90 degrees to then flow in a horizontal plane. Accordingly, the air and gas mixture flowing into the plenum chamber from tube 128 essentially changes direction in two orthogonal planes, within the plenum chamber, before passing into a flow channel via an outlet 186, 188. The illustrated embodiment shows the air and gas mixture flowing upwardly into the flow channel(s), although it would also be possible for the air and gas mixture within the plenum chamber to undergo a further orthogonal change in direction prior to entering a burner body, so that the air and gas mixture exiting the plenum chamber does so in a substantially horizontal plane, in which case the air and gas mixture would essentially go through three substantially orthogonal changes in direction before exiting. Thus, the plenum chamber promotes very efficient gas and air mixing under a turbulent regime, thereby promoting combustion evenness and Carbon Monoxide emission reduction, as well as both increasing temperature of the produced flames and reducing temperature variation across the flame surfaces of the burner bodies.

[0045] Additionally, to supply an air and gas mixture to the plenum chamber 126 from a source, the radiant burner 110 includes the tube 128 (best shown in FIGS. 6 and 7) extending in the longitudinal direction of the radiant burner 110, from or near the first end(s) 130, 160 and connected at its distal end to the plenum chamber 126. As shown, an inlet 192 of the tube 128 may be arranged outwardly of the first ends 130, 160 of the burner bodies 120, 122 in the longitudinal direction and an outlet 194 is connected to the plenum chamber 126. In some embodiments, the tube 128 may be arranged substantially centrally to the radiant burner 110 in the lateral direction, extending substantially in parallel with burner bodies 120, 122, and may be connected substantially centrally to the plenum chamber 126. A central location of the outlet 194 of the tube 128 relative to the plenum chamber 126 enables a substantially equal distribution of air and gas mixture in the two laterally-opposed portions of the plenum chamber 126, ensuring substantially equal flow rate of the air and gas mixture to the two burner bodies 120, 122 via the two outlets 186, 188 and inlet ports 142, 174. In some embodiments, the tube 128 is a venturi tube 196 having a tapered convergent portion 198, a throat 200, and a tapered divergent portion 202. As shown, the convergent portion 198 extends from or near the inlet 192 to the throat 200, while the divergent portion 202 extends from the throat portion 200 to or near the outlet 194. It may be appreciated that a cross-sectional area of the convergent portion 198 decreases from the inlet 192 to the throat 200, while a cross-sectional area of the divergent portion 202 increases from the throat 200 to, or towards, the outlet 194. Also, a cross-sectional area (or diameter) of the throat 200 matches the cross-sectional area (or diameter) of both the adjacent end of the convergent portion 198 and the adjacent end of the divergent portion 202. In some embodiments, as best shown in FIGS. 6 and 7, a length of the divergent portion 202 is greater, preferably much greater (for example, 15-25 times greater), than that of the convergent portion 198.

[0046] Additionally, or optionally, the radiant burner 110 includes a cross-piece 210 (best shown in FIGS. 5, 7, and 8) extending, in the lateral direction, between the first burner body 120 and the second burner body 122, connecting the two burner bodies 120, 122. As shown, the cross-piece 210 is arranged above the plenum chamber 126. In an embodiment, the cross-piece 210 may be arranged directly above the plenum chamber 126 (or could be considered to be a very top portion of the plenum chamber) and defines a cross-flow channel 212 (best shown in FIG. 5) extending in the lateral direction, substantially perpendicular to the first/second burner bodies and/or first/second flow channels, and connecting the first flow channel 134 and the second flow channel 170. Accordingly, the first flow channel 134, the second flow channel 170, and the cross-flow channel 212 may define a substantially U-shaped configuration. The cross-flow channel 212 facilitates equalisation of pressure and flow rate of the air and gas mixture inside the two burner bodies 120, 122. Moreover, as illustrated in FIG. 4, the cross-piece 210 includes a porous cover 230 (i.e., third porous cover 230) covering the cross-flow channel 212 from above. Similar to the first and second porous cover 150, 172, the third porous cover 230 includes a plurality of openings or holes defining a plurality of outlet openings to enable an exit of the air and gas mixture flowing inside the cross-flow channel 212. In some embodiments, the third porous cover 230 includes one or more ceramic plates 232, perforated metal plates, metal wool, metal mesh, and ceramic foam or sponge, or a combination thereof. Further, an upper surface 234 of the third porous cover 230 acts as a flame surface at which the flame front is present when the air and gas mixture escaping through the outlet openings of the third porous cover 230 is ignited. Thus, the flame surface on the crossflow channel 212 enables gas and air escaping via pores in the first and second porous covers to be ignited using only a single ignition source. [0047] Thus, at least in some embodiments, the present invention enables the temperature of the flame produced from a gas burner to be increased by the action of the plenum chamber and redistributing the air and gas mixture to the full surface area of the ceramic tiles. Because the plenum chamber is fed via a long venturi, improved gas and air mixing and combustion results, and the resultant generated heat is increased across the individually- fed burner bodies. ‘Turndown’

(via knobs 114) of the gas/air supply to a burner body, over a range from high to low flow rate, is increased giving flexibility from high intensity heat to low intensity heat, within the same burner body. Rapid heat-up is also achieved from the plenum to the ceramic tiles. The disclosed burner is also capable of cross-lighting the separate burners with only a single ignition source and without any additional cross-lighting members.

[0048] Many modifications and other embodiments of the disclosures set forth herein will come to mind to one skilled in the art to which these disclosures pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims.

Claims

1. A radiant burner, comprising: at least one burner body defining a flow channel extending in a longitudinal direction from a first end to a second end of the or each burner body and having an inlet port arranged at the second end to receive an air and gas mixture, wherein a height of the flow channel increases from the first end to the second end; a plenum chamber arranged at the second end of the at least one burner body and fluidly coupled to the inlet port to supply the air and gas mixture to the flow channel via the inlet port; and a tube extending in the longitudinal direction from or near the first end and connected to the plenum chamber to supply the air and gas mixture to the plenum chamber.

2. The radiant burner of claim 1, further comprising a porous cover covering at least some of the flow channel and configured to allow the air and gas mixture to escape therethrough.

3. The radiant burner of claim 2, wherein the porous cover comprises one or more of: one or more ceramic plates, one or more perforated metal plates, metal wool, metal mesh, and ceramic foam or sponge.

4. The radiant burner of any one of the preceding claims, wherein the at least one burner body includes a plurality of burner bodies arranged with their flow channels extending substantially parallel to each other, and the plenum chamber extends in a lateral direction, connecting the plurality of burner bodies.

5. The radiant burner of claim 4, wherein the tube is a venturi tube and is connected substantially centrally to the plenum chamber in the lateral direction.

6. The radiant burner of claim 4 or claim 5, wherein the plenum chamber includes a deflection plate to deflect or constrain movement of the air and gas mixture in the lateral direction towards at least one of the plurality of burner bodies.

7. The radiant burner of claim 6, wherein the air and gas mixture entering the plenum chamber is deflected or constrained to change direction in at least two substantially orthogonal planes, within the plenum chamber, before entering an inlet port of a burner body.

8. The radiant burner of any one of claims 4 to 7, further including a cross-piece arranged above the plenum chamber and extending in the lateral direction, connecting at least two of the plurality of burner bodies, wherein the cross-piece defines a cross-flow channel connecting the flow channels of the connected burner bodies.

9. The radiant burner of claim 8, wherein the cross-piece includes a porous cover covering the cross-flow channel.

10. The radiant cover of claim 9, wherein the porous cover comprises one or more of: one or more ceramic plates, one or more perforated metal plates, metal wool, metal mesh, and ceramic foam or sponge.

11. A grill, comprising: one or more radiant burners, each radiant burner having at least one burner body defining a flow channel extending in a longitudinal direction from a first end to a second end of the or each burner body and having an inlet port arranged at the second end to receive an air and gas mixture, wherein a height of the flow channel increases from the first end to the second end, a plenum chamber arranged at the second end of the at least one burner body and fluidly coupled to the inlet port to supply the air and gas mixture to the flow channel via the inlet port, and a tube extending in the longitudinal direction from or near the first end and connected to the plenum chamber to supply the air and gas mixture to the plenum chamber.

12. The grill of claim 10, wherein each radiant burner further includes a porous cover covering at least some of the flow channel and configured to allow the air and gas mixture to escape therethrough.

13. The grill of claim 11, wherein the porous cover comprises one or more of: one or more ceramic plates, one or more perforated metal plates, metal wool, metal mesh, and ceramic foam or sponge.

14. The grill of any one of claims 10 to 133, wherein the at least one burner body includes a plurality of burner bodies arranged with their flow channels extending substantially parallel to each other, and the plenum chamber extends in a lateral direction, connecting the plurality of burner bodies.

15. The grill of claim 14, wherein the tube is a venturi tube and is connected substantially centrally to the plenum chamber in the lateral direction.

16. The grill of claim 14 or claim 15, wherein the plenum chamber includes a deflection plate to deflect or constrain movement of the air and gas mixture in the lateral direction towards the at least one burner body.

17. The grill of claim 16, wherein the air and gas mixture entering the plenum chamber is deflected or constrained to change direction in at least two substantially orthogonal planes, within the plenum chamber, before entering an inlet port of a burner body.

18. The grill of any one of claims 14 to 17, wherein each radiant burner further includes a cross-piece arranged above the plenum chamber and extending in the lateral direction connecting at least two of the plurality of burner bodies, wherein the cross-piece defines a cross-flow channel connecting the flow channels of the connected burner bodies.

19. The grill of claim 18, wherein the cross-piece includes a porous cover covering the crossflow channel.

20. The grill of claim 19, wherein the porous cover comprises one or more of: one or more ceramic plates, one or more perforated metal plates, metal wool, metal mesh, and ceramic foam or sponge.