HK1150068A - Open loop gas burner - Google Patents

Description

Open-loop gas burner

Technical Field

The present invention relates to a gas burner with an open-loop geometry, achieving uniform or distributed flame characteristics, uniform or distributed heating conditions and uniform/smooth pressure distribution throughout the burner.

Background

Conventional gas burners are used in grill and tray (griddle) assemblies to heat cooking surfaces. There are two commonly used gas burners, including atmospheric burners and power burners. Atmospheric burners rely solely on the static pressure of the gas supply to provide an air-gas mixture at different burner ports where it can be ignited to produce a flame. The power burner uses a fan or blower and is connected to a gas supply before the burner inlet to enhance mixing of the air and gas and further to provide an air-gas mixture to the burner at a pressure typically above atmospheric pressure.

Conventional gas burners exhibit performance deficiencies due to the non-uniform flame characteristics, non-uniform heating conditions and non-uniform pressure distribution inherent in the design of these burners. The uneven flame characteristics of conventional gas burners typically produce uneven heating conditions on the cooking surface. These non-uniform heating states manifest themselves as localized hot or cold spots along the cooking surface, which results in unpredictable and inconsistent cooking.

The uneven flame characteristics are mainly due to the geometry of the gas burner. The closed loop geometry has a flue at the back end of the burner which causes all of the flue gas to move to that particular zone. The movement of the flue gases to the rear end results in an excessive heat build-up in this region and therefore an uneven flame characteristic and an uneven heating state.

The inconsistent pressure distribution in conventional gas burners is primarily a result of the diffuser being positioned directly below the burner port. Because of the ten-tap proximity port, this configuration does not provide space for the gas to stabilize the pressure above the diffuser. Because of the uneven distribution of the gas throughout the distribution section of the gas burner, the inconsistent pressure distribution resulting from the positioning of the diffuser can also lead to popping, flashback, or excessive flame emptions. Furthermore, the location of the diffuser and inlet in conventional gas burners makes the overall front to back size of the burner difficult to package. It would be further advantageous to have a final assembly of gas burners that is shorter in front-to-back dimension.

Accordingly, there is a need for a gas burner that achieves the desired uniform or distributed flame characteristics, uniform or distributed heating conditions, and uniform pressure distribution throughout the burner. Further, there is a need for a gas burner having a geometry that provides stable combustion, eliminates popping and flashback, and improves overall energy efficiency.

Disclosure of Invention

The present invention provides a gas burner with an open-loop geometry that achieves uniform flame characteristics distributed from multiple burner ports. The plurality of burner ports are distributed to achieve a uniform temperature distribution over the surface heated by the burner.

The invention further provides a gas burner with an air-gas mixture distribution section having a uniform or distributed heating state and a uniform pressure distribution throughout the burner. The air-gas mixture distribution section provides well-mixed air and gas that is delivered to the burner ports.

The present invention still further provides an inlet to the air-gas mixture distribution section, the inlet being coupled to a supply of combustible gas.

The present invention also provides a gas burner having a fan coupled to an inlet of the burner that mixes air with a combustible gas and provides it to the gas burner at an elevated pressure.

The invention still further provides that the burner port has a number of slots formed in the substantially flat upper surface of the air-gas mixture distribution section and arranged to balance the thermal characteristics of the burner. The ports are configured to form a pattern designed to provide a desired temperature profile for the surface to be heated. In one embodiment, the ports are arranged in an array with rows of port sequences interleaved with columns of port sequences.

The invention also provides a gas burner having a distribution diffuser located near the inlet to the air-gas distribution section. The distribution diffuser is located between the inlet to the air-gas mixture distribution section and the top heating surface and extends along the side of the burner to a distance such that the pressure of the air-gas mixture within the burner is balanced. This geometry provides for bottom fuel introduction rather than conventional front fuel introduction, although the present invention contemplates the use of conventional front introduction.

These and other advantages and benefits of the present invention are obtained by a gas burner having an air-gas mixture distribution section formed in an open-loop geometry. The gas burner may have any number of sides designed to provide an open-loop geometry. In one embodiment, the gas burner has a first side, a second side, and a third side. The air-gas mixture distribution section has a top heating surface. A plurality of ports are disposed on the top heating surface. The air-gas mixture distribution section has an inlet disposed thereon and a distribution diffuser mounted therein.

The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.

Drawings

Fig. 1 is a right side perspective view of a first embodiment of the gas burner of the present invention having an open-loop geometry.

Fig. 2 is a left side perspective view of the gas burner of fig. 1.

FIG. 3 is a perspective view of the gas burner of FIG. 1, showing the gas burner in a burner tray assembly.

Fig. 4 is an upper plan view of the gas burner of fig. 1, mounted in the burner tray assembly of fig. 3.

Fig. 5 is a perspective view of the dispensing diffuser of fig. 1.

Fig. 6 is a right side perspective view of a second embodiment of an air-gas distribution section for use in the gas burner of fig. 1.

Fig. 7 is a right side perspective view of a third embodiment of an air-gas distribution section for use in the gas burner of fig. 1.

Detailed Description

Referring to the drawings, and in particular to FIG. 1, there is shown a gas burner generally designated by the reference numeral 100. In one embodiment, the gas burner 100 has an air-gas mixture distribution section 105. The air-gas mixture distribution section 105 has an open-loop, or U-shaped, geometry with multiple sides (sides). In one embodiment, the air-gas mixture distribution section 105 has two long sides 110 and 115, and one short side 120. A plurality of apertures or ports 125 are provided on a top heating surface 130 of the air-gas mixture distribution section 105, which heating surface 130 is substantially flat in the present configuration. The gas burner 100 further comprises an inlet 135 at the end of the air-gas mixture distribution section 105. A distribution diffuser 140 is disposed adjacent the inlet 135.

The gas burner 100 of the present invention advantageously utilizes heat more efficiently because there are no burner ports provided at the rear end of the burner and therefore there is an outlet for flue gas to escape. The open-loop geometry of the gas burner 100 provides natural heat convection through the aft end of the burner as it eliminates unwanted heat there. The hot flue gases in the rear end provide the residual heat for that part of the burner area. Furthermore, the gas burner 100 is more energy efficient because it requires less gas volume to achieve the same thermal characteristics. Flame stability is improved because it requires less input to achieve the desired temperature profile. In addition, the gas burner 100 has improved control and accuracy, and it is easier to package the burner because of design flexibility.

The distribution diffuser 140 provides a uniform pressure distribution to the air-gas mixture distribution section 105. This uniform pressure distribution further helps to provide uniform or distributed flame characteristics for the ports 125. In one embodiment, the distribution diffuser 140 is disposed between the inlet 135 and the top heating surface 130 in such a way as to equalize the pressure of the air-gas mixture within the combustor 100. The distribution diffuser 140 may also extend along the long sides 110, 115 to a distance sufficient to equalize the pressure of the air-gas mixture within the combustor 100.

With particular reference to FIG. 5, a distribution diffuser 140 having a top surface 200, two bottom surfaces 205, 210, and two side surfaces 215, 220 is shown. The sides 215, 220 have a plurality of holes 225 therein. The top surface 200 may be made of a fine mesh screen. The configuration of the distribution diffuser 140 is advantageous because it creates a lower chamber 230 below the top surface 200 and between the side surfaces 215 and 220. The gas pressure may stabilize within the lower chamber 230 and then be more uniformly distributed throughout the air-gas mixture distribution section 105.

This configuration is also advantageous because it provides a bottom fuel intake that replaces the conventional front fuel intake. Moreover, this configuration provides additional unexpected results, including uniform or distributed flame characteristics, uniform or distributed heating conditions, and consistent pressure distribution throughout the combustor 100. Another advantage of a distribution diffuser 140 having this configuration is that it makes manufacturing easier because there is flexibility in where fuel can enter the air-gas mixture distribution section 105. Furthermore, in the design of the distribution diffuser 140 described above, popping and flashback are eliminated. The present invention also contemplates the introduction of forward fuel to the air-gas mixture distribution section 105.

The diffuser 140 may have a screen 240 attached to the top surface 220. The spacers 240 may extend along the short sides 120, and at least partially along the long sides 110 and 115. The baffle 240 thus further helps to equalize the pressure of the air-gas mixture within the distribution section 105. The baffle 240 may be made of a mesh material so that the air-gas mixture may pass through it and out the port 125.

Referring to fig. 3, the gas burner 100 may be mounted within a burner tray assembly 145. Burner tray assembly 145 includes a front wall 150, a rear wall 155, and a bottom wall 160. In one embodiment, burner tray assembly 145 has an insulating layer 165 disposed therein. An insulating layer 165 is disposed along the interior of the front wall 150, rear wall 155, and bottom wall 160. The insulating layer 165 may include an insulating material. Alternatively, an air layer may be provided along the interior of the front wall 150, the rear wall 155, and the bottom wall 160 to provide insulation. In another embodiment, combustor tray assembly 145 has a temperature sensor 170. The temperature sensor 170 extends through the bottom wall 160 and through an open area generally centered in the burner heating zone of the gas burner 100.

The gas burner 100 is controlled by a valving device (valving) including an intake valve 177, a blower 175 and an air supply pipe 180. The air intake valve 177 and the blower 180 are in fluid communication with the air supply duct 180 and provide air and fuel gas to the air supply duct 180. A gas supply pipe 180 extends through the front wall 150 and is in fluid communication with the distribution section 105 to provide an air-gas mixture to the gas burner 100. The blower 175 facilitates mixing of the air and gas and further provides the gas burner 100 with an air-gas mixture at a pressure above atmospheric pressure. The igniter 185 also extends through the front wall 150 to ignite the fuel stream at the top heating surface 130 of the gas burner 100. In one embodiment, a controller (not shown) may automatically operate the intake valve 177, the blower 175, and the igniter 185. In another embodiment, the intake valve 177, the blower 175, and the igniter 185 may be manually operated.

Referring now to fig. 4, a top view of the gas burner 100 is shown. In one embodiment, ports 125 may be an array of rows of port sequences 190 interleaved with columns of port sequences 195. In one embodiment, the ports 125 have an elongated rectangular or trough shape to achieve uniform or distributed flame characteristics throughout the top heating surface 130. The array has a smaller number of ports 125 in the portions of the long sides 110 and 115 adjacent to the temperature sensor 170 than in all other portions of the gas burner 100. In another embodiment, the ports 125 may have any other arrangement that provides uniform or distributed flame characteristics and uniform or distributed heating conditions to the surface above the gas burner 100. For example, the ports 125 may be oriented substantially transverse or parallel to the longitudinal axis of the long sides 110 and 115 and the short side 120 of the gas burner 100. The ports 125 may be holes, slots, or any other shape effective to release the combustible gas. The port array provides a substantially uniform heat distribution and optimal thermal characteristics for the gas burner 100.

In the illustrated embodiment, the long sides 110 and 115, and the short sides 120 of the air-gas distribution section 105 are a series of rectangular or square shapes. However, other shapes of the sides of the air-gas distribution section 105 are also contemplated by the present invention, such as circular, oblong (obround), triangular, and other shapes suitable for providing a flame to a surface to be heated.

Referring to fig. 6 and 7, additional alternative configurations of the air-gas distribution section of the present invention are shown. As shown in fig. 6, the air-gas distribution section 205 has a bottom edge 220, a left side edge 210, and a right side edge 215. The left and right sides 210 and 215 further have end burner sections 212 and 217, respectively, attached thereto. The end burner sections 212 and 217 project towards each other in a direction away from the left side 210 and the right side 215, respectively, and thus provide increased coverage for heating the surface above the air-gas distribution section 205 when the burner 100 is in use. The dispensing section 205 thus resembles a square or rectangle with an opening at one end. The open loop geometry, and all of the same advantages discussed above, are maintained in this arrangement.

As shown in fig. 7, the air-gas distribution section 305 has a bottom edge 320, a left side edge 310, and a right side edge 315. The left side 310 and the right side 315 further have end burner sections 312 and 317, respectively, attached thereto. The end burner sections 312 and 317 project toward each other in a direction away from the left side 310 and the right side 315, respectively. Further, the left side 310 and the right side 315 have intermediate burner sections 314 and 319, respectively. The left and right middle burner sections 314, 319 are connected to the left and right sides 310, 315 at approximately mid-point along the length of these sides and project towards the middle of the air-gas distribution section 305. As such, this arrangement provides increased coverage of the heated surface while still maintaining an open-loop geometry. Either of the distribution sections 205 or 305 may be used in the combustor 100.

While the invention has been described with reference to one or more embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (20)

1. A gas burner for uniformly distributing the pressure of an air-gas mixture within the gas burner, comprising:

an air-gas mixture distribution section having an open-loop geometry with a plurality of edges;

a top heating surface on the air-gas mixture distribution section, the top heating surface having a plurality of ports disposed thereon; and

an inlet disposed on one of the plurality of sides of the air-gas mixture distribution section for receiving an air-gas mixture.

2. The gas burner of claim 1, further comprising a distribution diffuser mounted in one of said plurality of sides of said air-gas mixture distribution section.

3. The gas burner of claim 1, wherein said plurality of sides are a first side, a second side, and a third side, wherein said first side is shorter than said second side and said third side.

4. The gas burner of claim 1, wherein said top heating surface is substantially flat.

5. The gas burner of claim 2, wherein said distribution diffuser is located within said air-gas mixture distribution section between said inlet and said top heating surface to provide an equilibrium pressure of the air-gas mixture.

6. The gas burner of claim 5, wherein a chamber is provided in said first edge of said distribution section between said distribution diffuser and said inlet.

7. The gas burner of claim 1, wherein said inlet enters said air-gas mixture distribution section through a bottom of said first edge of said air-gas mixture distribution section.

8. The gas burner of claim 1, wherein the gas burner is mounted in a burner tray assembly.

9. The gas burner of claim 1, further comprising an air intake valve and a blower in fluid communication with a gas supply tube, wherein the gas supply tube is in fluid communication with the inlet.

10. The gas burner of claim 1, wherein said plurality of ports are arranged in a sequence of ports parallel and transverse to a longitudinal axis of said edge.

11. The gas burner of claim 10, wherein said port pattern outputs a uniform or distributed heat pattern to uniformly heat the surface above said distribution section.

12. A burner tray assembly, comprising:

a front wall, a rear wall, and a bottom wall in which a gas burner is mounted, the gas burner having an open-loop geometry;

an insulating layer disposed along an interior of the front wall, the rear wall, and the bottom wall; and

a temperature sensor extending through the bottom wall.

13. The burner tray assembly of claim 12, wherein said gas burner has an air-gas mixture distribution section with a plurality of sides.

14. The burner tray assembly of claim 13, wherein each of said plurality of sides has a top heating surface.

15. The burner tray assembly of claim 13, wherein said plurality of sides are a first side, a second side, and a third side.

16. The burner tray assembly of claim 14, wherein said top heating surface has a plurality of ports disposed thereon.

17. The burner tray assembly of claim 15, wherein said first edge of said air-gas mixture distribution section is provided with an inlet.

18. The burner tray assembly of claim 15, wherein a distribution diffuser is mounted in said first edge of said air-gas mixture distribution section.

19. The burner tray assembly of claim 18, wherein said distribution diffuser is located within said air-gas mixture distribution section between said inlet and said top heating surface to provide a balanced pressure throughout said gas burner.

20. The burner tray assembly of claim 18, wherein said distribution diffuser extends along said plurality of edges to a distance sufficient to balance pressure within said gas burner and provide uniform or distributed flame characteristics for said top heating surface.