Gas burner and heating cooker

Abstract

In a gas burner for burning hydrogen gas by a diffusion combustion system, a plurality of flame holes 2 are formed in a tubular burner body 21 side by side in the longitudinal direction of the burner body 21, a distribution passage 6 for distributing hydrogen gas to the plurality of flame holes 2 is provided inside the burner body 21, and a gas supply passage 61 for supplying hydrogen gas is connected to the distribution passage 6.SOLUTION: The gas supply passage 61 is connected to the distribution passage 62 from a direction crossing the longitudinal direction of the burner body 21. The distribution passage 26 is provided with a suppressing member 27 which is positioned in a predetermined range Xa including the connecting part 61a of the gas supplying passage 61 in the longitudinal direction of the burner body 21 and suppresses the hydrogen gas from flowing from the connecting part 61a toward the flame hole 22 existing in the predetermined range Xa.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a gas burner that burns hydrogen gas by a diffusion combustion method and a cooking appliance equipped with this gas burner. [Background technology]

[0002] Conventionally, this type of gas burner has been known to have a tubular burner body that is longitudinal in one direction, with multiple flame holes formed in the burner body and aligned in the longitudinal direction of the burner body, and a distribution passage that extends longitudinally of the burner body inside the burner body and distributes hydrogen gas to the multiple flame holes, with a gas supply passage that supplies hydrogen gas connected to the distribution passage (see, for example, Patent Document 1).

[0003] In the above-described conventional example, the gas supply passage is connected to the distribution passage at one longitudinal end of the burner body. In this case, hydrogen gas flows straight through the distribution passage from the gas supply passage connection located at the one longitudinal end of the burner body toward the other longitudinal end of the burner body. The gas pressure in the distribution passage increases at the other longitudinal end of the burner body. Therefore, to uniformly distribute the gas ejection rate from the flame holes throughout the entire longitudinal length of the burner body, it is necessary to make the diameter of the flame holes smaller at the other longitudinal end of the burner body and larger at the one longitudinal end. However, to prevent flashback, which is a problem specific to hydrogen gas, the diameter of the flame holes must be smaller than the quenching distance (e.g., 0.6 mm or less). Therefore, there is a limit to how large the diameter of the flame holes at the one longitudinal end of the burner body can be, making it difficult to uniformly distribute the gas ejection rate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-42068 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above, the present invention aims to provide a gas burner that can equalize the amount of gas ejected from the flame holes over the entire longitudinal direction of the burner body, and a heating cooker equipped with this gas burner. [Means for solving the problem]

[0006] In order to solve the above problems, the first invention of the present application is a gas burner that burns hydrogen gas using a diffusion combustion method, and is equipped with a tubular burner body that is longitudinal in one direction, and the burner body has a plurality of flame holes lined up in the longitudinal direction of the burner body, and a distribution passage that extends longitudinally of the burner body inside the burner body and distributes hydrogen gas to the plurality of flame holes, and a gas supply passage that supplies hydrogen gas is connected to the distribution passage, and the gas supply passage is connected to the distribution passage from a direction intersecting the longitudinal direction of the burner body, and the distribution passage is equipped with a suppression member that is positioned in a predetermined range in the longitudinal direction of the burner body including the connection part of the gas supply passage and suppresses the hydrogen gas from moving from the connection part toward the flame holes located in the predetermined range. A second invention of the present application is a cooking device characterized by including the gas burner of the first invention.

[0007] According to the present invention (first invention), the gas supply passage is connected to the distribution passage from a direction intersecting the longitudinal direction of the burner body. This prevents the gas pressure in the distribution passage from increasing at one longitudinal end of the burner body, as opposed to the conventional arrangement in which the gas supply passage is connected to the distribution passage from the longitudinal direction of the burner body. However, hydrogen gas tends to flow from the connection of the gas supply passage toward the burner holes located within the predetermined range. However, in the present invention, the suppression member prevents hydrogen gas from flowing from the connection of the gas supply passage toward the burner holes located within the predetermined range, so that hydrogen gas is distributed to the distribution passage almost evenly throughout the entire longitudinal direction of the burner body. Therefore, even if all the burner holes have a diameter less than the quenching distance, the amount of gas ejected from the burner holes can be made uniform throughout the entire longitudinal direction of the burner body.

[0008] However, if the amount of hydrogen gas ejected exceeds the appropriate amount, it is likely to produce a loud noise upon ignition. Here, the flow of hydrogen gas toward the burner holes within the predetermined range is directly suppressed by the suppression member, so the amount of gas ejected from these burner holes is controlled to an appropriate amount. Therefore, in the present invention, it is desirable to provide an ignition means for igniting hydrogen gas ejected from the burner holes within the predetermined range. This can prevent the amount of gas ejected from becoming excessive and producing a loud noise upon ignition.

[0009] In this case, it is also desirable to position the connection part of the gas supply passage closer to one end of the burner body in the longitudinal direction, so that the flame holes located within the predetermined range, i.e., the flame holes ignited by the ignition means, are less susceptible to disturbances such as dripping of grease, and deterioration of ignition performance due to disturbances can be suppressed.

[0010] Furthermore, in the present invention, when the connection portion of the gas supply passage is provided in a portion of the burner body facing the portion where the burner holes are formed via the distribution passage, it is desirable that the suppression member be composed of a plate-shaped member extending over the predetermined range between the connection portion and the burner holes, and that a gap be provided between the side edge of this plate-shaped member and the side wall surface of the distribution passage facing the side edge. In this way, a portion of the hydrogen gas from the connection portion is distributed to the burner holes located within the predetermined range via the gap between the side edge of the plate-shaped member and the side wall surface of the distribution passage, and the remaining hydrogen gas is distributed to the burner holes located outside the predetermined range via the distribution passage after contacting the plate-shaped member. Furthermore, because the suppression member can be constructed from a plate-shaped member, costs can be reduced.

[0011] The suppressing member may also be made of a porous material made of metal or ceramic, which is advantageous in that the porous material can prevent backfire into the gas supply pipe upstream of the gas burner. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of a cooking device equipped with a gas burner according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional side view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional front view taken along line III-III in FIG. 2. [Figure 4] 1 is a perspective view of a burner unit including a gas burner according to an embodiment; [Figure 5] 5 is a cross-sectional side view taken along line VV in FIG. 4. [Figure 6] Cross-sectional view taken along line VI-VI in Figure 5. [Figure 7] FIG. 6 is a cross-sectional side view of a main part of a gas burner according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] 1 to 3, in a cooking appliance according to an embodiment of the present invention, two orthogonal horizontal directions are defined as X-axis and Y-axis directions. A plurality of (specifically, four) burner units B are arranged in parallel in the Y-axis direction at the top of a body 1 having an open top. The burner units B each include a gas burner 2 elongated in the X-axis direction and a metal hot plate 3 having an upwardly convex cross section (specifically, an upwardly convex arc shape) arranged above the gas burner 2. The hot plate 3 has a plurality of vent holes 31 formed by cutting and raising processing, through which combustion gas generated by combustion in the gas burners 2 passes. The hot plate 3 is heated to red heat by the combustion in the gas burners 2, and food to be cooked on a grill 4 arranged above the body 1 is heated by far infrared rays radiated from the hot plate 3 and the combustion gas passing through the vent holes 31.

[0014] Grill 4 is placed on a rectangular support frame 42 connected to the upper ends of vertically movable support posts 41 provided on both sides of the body 1 in the Y-axis direction. Support posts 41 are raised and lowered by the vertical swing of an operating lever 43 protruding in one direction of the body 1 in the X-axis direction. A lock lever 44 is attached to operating lever 43, which locks it in any swing position. Pulling lock lever 44 upward releases the lock, allowing the operating lever 43 to swing. A drip tray 5 is also located at the bottom of body 1 so that it can be freely moved in and out in one direction of the X-axis.

[0015] The gas burner 2 comprises a tubular burner body 21 elongated in the X-axis direction, with a plurality of upwardly opening burner holes 22 formed along the X-axis direction at the top of the burner body 21. In this embodiment, two adjacent rows of burner holes, each consisting of a plurality of burner holes 22 along the X-axis direction, are provided in the Y-axis direction. Referring to FIGS. 4 and 5, both ends of the burner body 21 in the X-axis direction are closed by plugs 23, 23. Each plug 23 has a protrusion 231 protruding outward in the X-axis direction. The protrusion 231 of each plug 23 is fastened to support brackets 12 for the burner unit B, which are fixed to frames 11 on both sides of the upper portion of the body 1 in the X-axis direction, thereby fixing and supporting the gas burner 2. Each support bracket 12 also supports each end of the hot plate 3 in the X-axis direction. In addition, the gas burner 2 is provided with an ignition electrode 24 serving as ignition means located above one end in the X-axis direction, and a thermocouple 25 serving as flame detection means located above the other end in the X-axis direction.

[0016] Each gas burner 2 is supplied with hydrogen gas as fuel gas via a gas supply path 61 extending from each valve unit 6 inside a box 13 attached to one surface of the body 1 in the X-axis direction, and this hydrogen gas is ejected from flame holes 22 of the gas burner 2 and diffuses and burns. On one outer surface of the box 13 in the X-axis direction, there are arranged an operation knob 62 for each valve unit 6 and a power switch 63 for starting a controller (not shown) for each valve unit 6. When the operation knob 62 is pressed and turned from its stopped position to perform the ignition operation, hydrogen gas is supplied to the gas burner 2 and a spark is generated at the ignition electrode 24, igniting the gas burner 2.

[0017] Furthermore, a partition plate 7 is erected between adjacent burner units B, B in the Y-axis direction. Even if oil or grease dripping from the food being cooked splashes onto the hot plate 3 of each burner unit B or falls along the hot plate 3, the partition plate 7 prevents the oil or grease from adhering to the flame holes 22 of the gas burner 2 of the adjacent burner unit B. The partition plate 7 is supported by inserting the lower ends of both ends in the X-axis direction into slits (not shown) formed in each frame 11 on both sides in the X-axis direction at the top of the appliance body 1. Another partition plate 7 is erected outside the Y-axis direction of the outermost burner unit B in the Y-axis direction.

[0018] Next, the gas burner 2 will be described in detail with reference to Figures 5 and 6. A distribution passage 26 is provided inside the burner body 21, extending in the X-axis direction, which is the longitudinal direction of the burner body 21, to distribute hydrogen gas to the multiple flame holes 22. A gas supply passage 61 is connected to the distribution passage 26 from below, which is a direction intersecting the X-axis direction. This prevents the gas pressure in the distribution passage 26 from becoming high at the other longitudinal end of the burner body 21, unlike in the case where the gas supply passage 61 is connected to the distribution passage 26 from the longitudinal direction of the burner body 21 at one longitudinal end of the burner body 21.

[0019] However, hydrogen gas is likely to flow from the connection 61a of the gas supply path 61 to the flame holes 22 located within a predetermined range Xa in the X-axis direction that includes the connection 61a of the gas supply path 61 (for example, a range within 50 mm in the X-axis direction from the connection 61a). Therefore, a suppression member 27 is provided in the distribution path 26, positioned within the predetermined range Xa, to suppress the hydrogen gas from flowing from the connection 61a to the flame holes 22 located within the predetermined range Xa. This ensures that hydrogen gas is distributed almost evenly throughout the distribution path 26 in the X-axis direction. Therefore, even if all the flame holes 22 have a hole diameter (for example, 0.6 mm) that is equal to or smaller than the quenching distance, the amount of gas ejected from the flame holes 22 can be made uniform throughout the X-axis direction.

[0020] Furthermore, the connection portion 61a of the gas supply passage 61 is located near one end in the X-axis direction of the burner body 21. An ignition electrode 24, which serves as ignition means, is disposed facing the flame holes 22 located within a predetermined range Xa including the connection portion 61a, specifically, the flame holes 22 located at one end in the X-axis direction, in order to ignite the hydrogen gas ejected from the flame holes 22.

[0021] Here, the flow of hydrogen gas toward the burner holes 22 located within the predetermined range Xa is directly suppressed by the suppression member 27, so the amount of gas emitted from these burner holes 22 is appropriately controlled. Therefore, as in this embodiment, by positioning the ignition electrode 24 so as to ignite the hydrogen gas emitted from the burner holes 22 located within the predetermined range Xa, it is possible to prevent excessive gas emission and the generation of loud noises at ignition. Furthermore, by positioning the connection portion 61a of the gas supply passage 61 near one end of the burner body 21 in the X-axis direction, the burner holes 22 located within the predetermined range Xa are less susceptible to external disturbances such as dripping oil. As a result, it is possible to prevent a decrease in ignition performance due to external disturbances.

[0022] In this embodiment, the connection portion 61a of the gas supply passage 61 is provided in the lower portion of the burner body 21, which is the portion of the burner body 21 that faces, via the distribution passage 26, the upper portion of the burner body 21 where the burner holes 22 are formed. The suppression member 27 is composed of a plate-shaped member 271 that extends over the predetermined range Xa between the connection portion 61a and the burner holes 22. A gap 271a is provided between the side edge of this plate-shaped member 271 and the side wall surface of the distribution passage 26 that faces the side edge. As a result, a portion of the hydrogen gas from the connection portion 61a is distributed to the burner holes 22 located within the predetermined range Xa via the gap 271a between the side edge of the plate-shaped member 271 and the side wall surface of the distribution passage 26, and the remaining hydrogen gas hits the plate-shaped member 271 and is distributed via the distribution passage 26 to the burner holes 22 located outside the predetermined range Xa. Since the suppression member 27 can be constructed using the plate-shaped member 271, costs can be reduced.

[0023] 7, the suppression member 27 can also be made of a porous body 272 made of metal or ceramic. Specifically, the suppression member 27 is made of a porous body 272 having numerous minute gaps equal to or smaller than the quenching distance, such as a sintered body made of a laminate of metal fibers or metal beads, a knitted body made of knitted metal fibers, or porous ceramic. This is advantageous because the porous body 272 can prevent backfire into the gas supply pipe 61 upstream of the gas burner 2. When the suppression member 27 is made of a porous body 272, the connection portion 61a of the gas supply path 61 may be located in a portion of the burner body 21 that does not face the upper portion of the burner body 21, where the flame holes 22 are formed, across the distribution path 26, i.e., on the side of the burner body 21 in the Y-axis direction.

[0024] Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, the burner body 21 is tubular with a circular cross section, but it may have a cross section other than circular. Furthermore, in the above embodiment, the longitudinal direction of the burner body 21 is the X-axis direction, i.e., a horizontal direction, but the present invention can also be applied to a gas burner in which the longitudinal direction of the burner body 21 is other than horizontal, for example, the up-down direction. [Explanation of symbols]

[0025] 2...gas burner, 21...burner body, 22...flame hole, 24...ignition electrode (ignition means), 26...distribution path, 27...suppression member, 271...plate-shaped member, 271a...gap, 272...porous body, 61...gas supply path, 61a...connection portion, Xa...predetermined range.

Claims

1. A gas burner that burns hydrogen gas using a diffusion combustion method, comprising a tubular burner body that is longitudinal in one direction, in which a plurality of flame holes are formed in the burner body and aligned in the longitudinal direction of the burner body, and a distribution channel that extends in the longitudinal direction of the burner body and distributes hydrogen gas to the plurality of flame holes is provided inside the burner body, and a gas supply channel that supplies hydrogen gas is connected to the distribution channel, The gas supply passage is connected to the distribution passage in a direction intersecting the longitudinal direction of the burner body, A gas burner characterized in that a suppression member is provided in the distribution path, positioned in a predetermined range in the longitudinal direction of the burner body, including the connection part of the gas supply path, to suppress hydrogen gas from flowing from the connection part toward the flame holes located in the predetermined range.

2. 2. A gas burner according to claim 1, further comprising ignition means for igniting hydrogen gas ejected from the flame holes located within said predetermined range.

3. 3. The gas burner according to claim 2, wherein the connecting portion is located near one end of the burner body in the longitudinal direction.

4. 4. A gas burner according to claim 1, wherein the connection portion is provided in a portion of the burner body that faces the portion where the flame hole is formed via the distribution path, and the suppression member is composed of a plate-shaped member that extends over the specified range between the connection portion and the flame hole, and a gap is provided between the side edge of this plate-shaped member and the side wall surface of the distribution path that faces the side edge.

5. 4. The gas burner according to claim 1, wherein the suppressing member is made of a porous material made of metal or ceramic.

6. A cooking device comprising the gas burner according to any one of claims 1 to 3.

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