Concentric burner and heating cooker

Abstract

Provided is a concentric burner configured from a slave burner and a master burner surrounding the slave burner, the slave burner being provided with a slave burner inflow pipe (45) that extends in a horizontal direction on a top plate of a heating cooker from a slave burner body (41), and being such that a slave burner nozzle (46) is attached to a burner holder (461) that is exposed on the top plate of the heating cooker at a position below a master burner body (51), making it possible to suppress any excessive increase in the temperature of a nozzle holder (461) and the slave burner inflow pipe (45) resulting from radiant heat from the master burner body (51). A heat-radiating part (57) is provided to the outer surface of the master burner body (51), the heat-radiating part (57) being positioned at a portion separated from a straight upper part of the nozzle holder (461) in the circumferential direction and discharging the heat of the master burner body (51) to the outside.

Description

Parent and child burners and cooking appliances

[0001] The present invention relates to a parent-child burner provided in a cooking appliance and consisting of a child burner and a parent burner surrounding the child burner, and to a cooking appliance equipped with this parent-child burner.

[0002] A known example of this type of parent-child burner is described in Patent Document 1. In this burner, the child burner includes a child burner body exposed on the top plate of a cooking appliance, a child burner cap with multiple child burner flame holes formed therein for ejecting the mixture in the child burner distribution chamber and mounted on the child burner body to define a child burner distribution chamber between the child burner body and the child burner cap, and a child burner inlet pipe extending horizontally from the child burner body above the cooking appliance top plate. A child burner nozzle is provided facing the opening at the upstream end of the child burner inlet pipe, and a mixture of fuel gas ejected from a nozzle hole at the tip of the child burner nozzle and primary air flowing in from the opening at the upstream end of the child burner inlet pipe is supplied to the child burner distribution chamber via the child burner inlet pipe. The parent burner also comprises an annular parent burner body that surrounds the child burner bodies exposed on the top plate of the cooking appliance, an annular parent burner cap that is placed on the parent burner body so as to define a parent burner distribution chamber between the parent burner body and the parent burner cap and that has multiple parent burner flame holes formed therein for spraying the mixture in the parent burner distribution chamber, and a parent burner inlet pipe that extends from the parent burner body below the top plate of the cooking appliance.The parent burner nozzle is provided facing the opening at the upstream end of the parent burner inlet pipe, and the mixture of fuel gas sprayed from the nozzle hole at the tip of the parent burner nozzle and primary air that flows in from the opening at the upstream end of the parent burner inlet pipe is supplied to the parent burner distribution chamber via the parent burner inlet pipe.

[0003] In a typical parent-child burner system, the child burner inlet pipe extends below the cooking appliance top, just like the parent burner inlet pipe. However, if the door of the cabinet with the cooking appliance built in the top is quickly opened when the parent-child burner is at its lowest heat (when only the child burner is burning at low heat), negative pressure will build up inside the cabinet, and this negative pressure will act on the opening at the upstream end of the child burner inlet pipe, causing the child burner flame to be drawn into the child burner distribution chamber, resulting in a fire going out.

[0004] In contrast, in the system described in Patent Document 1, the sub-burner inlet pipe is located on the cooktop. Therefore, even if negative pressure occurs inside the cabinet, this negative pressure does not act on the opening at the upstream end of the sub-burner inlet pipe, preventing misfires in the sub-burners. However, when the sub-burner inlet pipe is located on the cooktop, the sub-burner nozzle is also located on the cooktop. Specifically, a nozzle holder is provided that is exposed on the cooktop, and the sub-burner nozzle is attached to this nozzle holder. However, if the nozzle holder is noticeable when viewed from above, it would detract from the appearance. Therefore, in the system described in Patent Document 1, the nozzle holder is exposed on the cooktop below the main burner body.

[0005] However, with this arrangement, the nozzle holder and the sub-burner inlet pipe are located near the main burner body. This arrangement has been found to cause the following problem: When the main burners are burned for a long period of time, the temperature of the nozzle holder and the sub-burner inlet pipe rises excessively due to radiant heat from the main burner body. This causes the fuel gas to thermally expand within the nozzle holder, and the air-fuel mixture to thermally expand within the sub-burner inlet pipe. This thermal expansion of the fuel gas within the nozzle holder reduces the density of the fuel gas flowing into the sub-burner inlet pipe. This, combined with the thermal expansion of the air-fuel mixture within the sub-burner inlet pipe, reduces the density of the air-fuel mixture ejected from the sub-burner flame holes. This results in a significant reduction in the combustion volume of the sub-burners compared to the initial stage of combustion.

[0006] CN212691761U

[0007] In view of the above, the present invention aims to provide a parent-child burner that can suppress excessive temperature rise in the nozzle holder and the child burner inlet pipe, and a heating cooker equipped with this parent-child burner.

[0008] In order to solve the above problems, the first invention of the present application is a parent-child burner provided in a cooking appliance, which is composed of a child burner and a parent burner surrounding the child burner, the child burner having a child burner body exposed on the cooking appliance top plate, a child burner cap with a plurality of child burner flame holes formed therein for ejecting the mixture in the child burner distribution chamber, which is placed on the child burner body so as to define a child burner distribution chamber between the child burner body and the child burner cap, and a child burner inlet pipe extending horizontally from the child burner body on the cooking appliance top plate, and a mixture of fuel gas ejected from a nozzle hole at the tip of a child burner nozzle provided facing the opening at the upstream end of the child burner inlet pipe and primary air flowing in from the opening at the upstream end of the child burner inlet pipe is supplied to the child burner distribution chamber via the child burner inlet pipe, and the parent burner is an annular parent burner body surrounding the child burner body exposed on the cooking appliance top plate. a parent burner cap mounted on the parent burner body so as to define a parent burner distribution chamber between the parent burner body and the parent burner cap, the parent burner cap having a plurality of parent burner flame holes formed therein for ejecting the mixture in the parent burner distribution chamber, and a parent burner inlet pipe extending from the parent burner body below the top plate of the cooking appliance, wherein a mixture of fuel gas ejected from a nozzle hole at the tip of a parent burner nozzle provided facing the opening at the upstream end of the parent burner inlet pipe and primary air flowing in from the opening at the upstream end of the parent burner inlet pipe is supplied to the parent burner distribution chamber via the parent burner inlet pipe, the child burner nozzles are attached to nozzle holders exposed above the top plate of the cooking appliance below the parent burner body, and a heat radiating portion for radiating heat from the parent burner body to the outside is provided on the outer surface of the parent burner body, located circumferentially away from directly above the nozzle holder.

[0009] According to the present invention (first aspect), the temperature rise of the parent burner body is suppressed by heat radiation from the heat radiation portion. Furthermore, since the heat radiation portion is circumferentially separated from the portion of the parent burner body located in close proximity to the nozzle holder and the sub-burner inlet pipe, i.e., directly above the nozzle holder, heating of the nozzle holder and the sub-burner inlet pipe due to heat radiation from the heat radiation portion is also suppressed. Therefore, even if the parent and sub-burners are burned for a long period of time, excessive temperature rise of the nozzle holder and the sub-burner inlet pipe can be suppressed. As a result, thermal expansion of the fuel gas in the nozzle holder and the thermal expansion of the mixture in the sub-burner inlet pipe are suppressed, and a significant decrease in the combustion amount of the sub-burners compared to the initial stage of combustion can be suppressed.

[0010] It is also possible to construct the heat dissipation section by applying a paint with high heat dissipation properties. However, this increases costs and does not provide sufficient durability. Therefore, in the present invention, it is desirable that the heat dissipation section be constructed by fins protruding from the outer surface of the main burner body. This reduces costs and improves durability.

[0011] 1 is a perspective view of a main part of a cooking device equipped with a parent-child burner according to an embodiment of the present invention; FIG. 2 is a cross-sectional side view taken along line II-II in FIG. 1; FIG. 3 is a cross-sectional plan view taken along line III-III in FIG. 2; FIG. 4 is a perspective view of an exploded state of the parent-child burner according to the embodiment; FIG. 5 is an enlarged perspective view of a parent burner body of the parent-child burner according to the embodiment, viewed obliquely from below;

[0012] 1 and 2 show a cooking appliance equipped with a dual burner A according to an embodiment of the present invention. The cooking appliance has a top plate 2 that covers the top surface of a cooking appliance body 1. The top plate 2 is composed of a main body 21 and a cover plate 22 that prevents overflowing liquid from seeping in through a burner opening 21a that is opened in the main body 21 and faces the dual burner A. A trivet 3 having a plurality of trivet claws 31 is placed on the top plate 2 so as to surround the burner opening 21a.

[0013] The parent-child burner A is composed of a child burner 4 and a parent burner 5 surrounding the child burner 4. The heating power can be changed widely from the minimum heating power that burns only the child burner 4 at low heat to the maximum heating power that burns both the child burner 4 and the parent burner 5 at high heat. The child burner 4 is equipped with a thermocouple 6 for detecting the flame of the child burner 4, and the parent burner 5 is equipped with an ignition electrode 7 for igniting the parent burner 5.

[0014] The sub burner 4 comprises a sub burner body 41 exposed on the top plate 2 of the cooking appliance and a sub burner cap 42 placed on the sub burner body 41. Referring also to Figure 4, the sub burner body 41 has an outer cylinder 411 and an inner cylinder 412 formed as separate members. The sub burner cap 42 has an outer cylinder portion 421 seated on the upper end of the outer cylinder 411 of the sub burner body 41 and an inner cylinder portion 422 fitted into the inner cylinder 412 of the sub burner body 41. An annular sub burner distribution chamber 43 is defined between the sub burner body 41 and the sub burner cap 42. The outer cylinder portion 421 of the sub burner cap 42 has multiple sub burner flame holes 44 formed therein for ejecting the air-fuel mixture from the sub burner distribution chamber 43.

[0015] The secondary burners 4 further include secondary burner inlet pipes 45 that extend horizontally from the secondary burner bodies 41 on the top plate 2 of the cooking appliance. A secondary burner nozzle 46 is provided on the top plate 2, facing the opening at the upstream end of the secondary burner inlet pipe 45. The secondary burner nozzle 46 is attached to a nozzle holder 461 that is fixed to a mounting base 11 fixed to the cooking appliance body 1 so as to be exposed above the top plate 2 through the cover plate 22. Fuel gas is supplied to the secondary burner nozzle 46 via a secondary burner gas pipe 462 and the nozzle holder 461. A mixture of fuel gas ejected from nozzle holes 46a at the tips of the secondary burner nozzles 46 and primary air flowing in from the opening at the upstream end of the secondary burner inlet pipe 45 is supplied to the secondary burner distribution chamber 43 via the secondary burner inlet pipe 45.

[0016] The parent burner 5 includes an annular parent burner body 51 that surrounds the child burner body 41 exposed on the top plate 2 of the cooking appliance, and an annular parent burner cap 52 that is placed on the parent burner body 51. Referring also to FIG. 4 , the parent burner body 51 has an outer cylindrical portion 512 and an inner cylindrical portion 513 that extend from the outer and inner peripheries of an annular bottom wall portion 511. The parent burner cap 52 has an outer cylindrical portion 521 that seats on the upper end of the outer cylindrical portion 512 of the parent burner body 51, and an inner cylindrical portion 522 that fits around the inner cylindrical portion 513 of the parent burner body 51. An annular parent burner distribution chamber 53 is defined between the parent burner body 51 and the parent burner cap 52. The outer cylindrical portion 521 of the parent burner cap 52 has a plurality of parent burner flame holes 54 through which the air-fuel mixture in the parent burner distribution chamber 53 is ejected. In addition, a slit-shaped flame transfer hole 54 a extending in the radial direction is formed on the upper surface of the main burner cap 52 for flame transfer between the sub burner 4 and the main burner 5 .

[0017] The parent burner 5 further includes a parent burner inlet pipe 55 extending from the parent burner body 51 below the top plate 2 of the cooking appliance. A mixture of fuel gas ejected from a nozzle hole (not shown) at the tip of a parent burner nozzle 56 provided facing the opening at the upstream end of the parent burner inlet pipe 55 and primary air flowing in from the opening at the upstream end of the parent burner inlet pipe 55 is supplied to the parent burner distribution chamber 53 via the parent burner inlet pipe 55. The parent burner inlet pipe 55 is made up of a downstream pipe 551 that fits into a port portion 53a that communicates with the parent burner distribution chamber 53 and is provided on the underside of the bottom wall portion 511 of the parent burner body 51 at one circumferential position, and extends below the top plate 2, and an upstream pipe 552 that is connected to the lower end of the downstream pipe 551 via a connecting pipe portion 552a and extends horizontally below the top plate 2. A venturi portion 552b is formed near the upstream end of the upstream pipe 552. When fuel gas is injected from the nozzle hole of the parent burner nozzle 56, negative pressure is generated in the venturi portion 552b, which causes primary air to be sucked in from the upstream end of the upstream pipe 552, i.e., from the opening at the upstream end of the parent burner inlet pipe 55.

[0018] However, when the nozzle holder 461 to which the sub burner nozzle 46 is attached is arranged so as to be exposed on the top plate 2 of the cooking appliance as in this embodiment, it would be unsightly if the nozzle holder 461 were to stand out. Therefore, the nozzle holder 46 is exposed on the top plate 2 of the cooking appliance at a position below the main burner body 51.

[0019] The sub burner body 41 also has an extension 413 that extends downward below the sub burner distribution chamber 43. Referring also to Figure 3, an internal gap 414 that communicates with the sub burner distribution chamber 43 is provided within a predetermined circumferential range of the extension 413. The circumferential central portion of the internal gap 414 is formed as a narrow portion 4141 whose radial width is narrower than the radial width of the other portions of the internal gap 414, while the other portions of the internal gap 414, i.e., the circumferential side portions, are formed as wide portions 4142 whose radial width is greater. The downstream end of the sub burner inlet pipe 45 communicates with the narrow portion 4141 of the internal gap 414, and extends radially outward along a radial line that passes through the circumferential center of this narrow portion 4141. The mixture flows from the narrow portion 4141 to the wide portion 4142 of the internal gap 414 through the sub-burner inlet pipe 45, thereby achieving the effect of drawing in primary air from the opening at the upstream end of the sub-burner inlet pipe 45 (an effect similar to the so-called radial venturi effect).

[0020] A seal portion 412a is formed in the extension 413 of the inner tube 412 of the sub burner body 41, positioned outside the internal gap 414, and contacting the inner circumferential surface of the extension 413 of the outer tube 411 of the sub burner body 41. The internal flow path of the sub burner inlet pipe 45 narrows in diameter toward the downstream side. The sub burner inlet pipe 45 can also have a venturi portion near its upstream end, similar to the main burner inlet pipe 55.

[0021] 4, a base plate portion 416 is integrally formed on the outer cylinder 411 of the sub burner body 41, and is integrated with the bottom wall of the sub burner inlet pipe 45. The base plate portion 416 projects outward from a circumferential location that matches the sub burner inlet pipe 45 at the bottom of the portion that becomes the extension portion 413, and from the opposite location. The nozzle holder 461-side end of the base plate portion 416 is fixed to a nozzle holder 461, which is fixed to the mounting base 11 via legs 461a, thereby ensuring concentricity between the sub burner nozzle 46 and the sub burner inlet pipe 45. A downstream pipe 551 of the main burner inlet pipe 55 is integrally formed on the portion of the base plate portion 416 that projects outward from a location opposite the circumferential location that matches the sub burner inlet pipe 45.

[0022] A skirt portion 514 extends diagonally downward from the outer periphery of the parent burner body 51 to prevent overflow from flowing around the underside of the bottom wall portion 511 of the parent burner body 51. Furthermore, to prevent overflow from falling into the child burner inlet pipe 45, a hood portion 515 extends radially inward from the inner periphery of the circumferential portion of the bottom wall portion 511 of the parent burner body 51 that coincides with the child burner inlet pipe 45, covering the child burner inlet pipe 45 from above. Furthermore, to prevent overflow that has flowed around the underside of the hood portion 515 from falling into the child burner nozzle 46, a second hood portion 451 extends radially outward from the upstream end of the child burner inlet pipe 45 to cover the child burner nozzle 46 from above. Both circumferential side portions 515 a , 451 a of the canopy portions 515 , 451 are bent downward to reach the base plate portion 416 .

[0023] Here, the nozzle holder 461 is located below the parent burner body 51, and the sub burner inlet pipe 45 is disposed near the parent burner body 51. Therefore, if the parent and sub burners A are burned for a long time, the temperatures of the nozzle holder 461 and the sub burner inlet pipe 45 may rise excessively due to radiant heat from the parent burner body 51. In this case, the fuel gas thermally expands in the nozzle holder 461, and the air-fuel mixture thermally expands in the sub burner inlet pipe 45. The thermal expansion of the fuel gas in the nozzle holder 461 reduces the density of the fuel gas flowing into the sub burner inlet pipe 45, and the thermal expansion of the air-fuel mixture in the sub burner inlet pipe 45 reduces the density of the air-fuel mixture ejected from the sub burner flame holes 44. This, combined with the result that the combustion amount of the sub burners 4 is significantly reduced compared to the initial stage of combustion.

[0024] Therefore, in this embodiment, a heat dissipation section that dissipates heat from the parent burner body 41 to the outside is provided on the outer surface of the parent burner body 51, located at a position circumferentially separated from immediately above the nozzle holder 461. More specifically, a plurality of fins 57 that constitute a heat dissipation section are protruded from the lower surface of the parent burner body 51, i.e., the lower surface of the bottom wall portion 511, as clearly shown in Figure 5, and are located between immediately above the nozzle holder 461 and the port portion 53a on the opposite side in the circumferential direction.

[0025] This suppresses the temperature rise of the parent burner body 51 by heat radiation from the fins 57. Furthermore, since the fins 57 are circumferentially separated from the portion of the parent burner body 51 located in close proximity to the nozzle holder 461 and the sub-burner inlet pipe 45, i.e., directly above the nozzle holder 461, heating of the nozzle holder 461 and the sub-burner inlet pipe 45 by heat radiated from the fins 57 is also suppressed. Therefore, even if the parent and sub-burners A are burned for a long period of time, excessive temperature rise of the nozzle holder 461 and the sub-burner inlet pipe 45 can be suppressed. As a result, thermal expansion of the fuel gas in the nozzle holder 461 and the thermal expansion of the mixture in the sub-burner inlet pipe 45 are suppressed, and a significant decrease in the combustion amount of the sub-burners 4 compared to the initial stage of combustion can be suppressed.

[0026] Although the present invention has been described above with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, the heat dissipation portion is formed by fins 57 protruding from the outer surface of the parent burner body 51. However, it is also possible to form the heat dissipation portion by applying a highly heat-dissipating paint. However, this increases costs and does not provide sufficient durability. In contrast, forming the heat dissipation portion with fins 57 as in the above embodiment is advantageous because it is low cost and improves durability. Furthermore, in the above embodiment, the heat dissipation portion is provided on the underside of the parent burner body 51. However, it is also possible to form the heat dissipation portion on an outer surface other than the underside of the parent burner body 51, for example, on the outer peripheral surface.

[0027] A...parent and child burners, 2...top plate, 4...child burner, 41...child burner body, 42...child burner cap, 43...child burner distribution chamber, 44...child burner flame hole, 45...child burner inlet pipe, 46...child burner nozzle, 46a...nozzle hole, 5...parent burner, 51...parent burner body, 52...parent burner cap, 53...parent burner distribution chamber, 54...parent burner flame hole, 55...parent burner inlet pipe, 56...parent burner nozzle, 57...fins (heat dissipation section).

Claims

1. A parent-child burner to be installed in a cooking appliance, comprising a child burner and a parent burner surrounding the child burner, the child burner comprising a child burner body exposed on the cooking appliance top plate, a child burner cap with multiple child burner flame holes formed therein for spraying the mixture in the child burner distribution chamber, which is placed on the child burner body so as to define a child burner distribution chamber between the child burner body and the child burner cap, and a child burner inlet pipe extending horizontally from the child burner body on the cooking appliance top plate, so that the mixture of fuel gas sprayed from the nozzle hole at the tip of the child burner nozzle, which is installed facing the opening at the upstream end of the child burner inlet pipe, and primary air flowing in from the opening at the upstream end of the child burner inlet pipe is supplied to the child burner distribution chamber via the child burner inlet pipe section, The parent burner comprises an annular parent burner body that surrounds the child burner body and is exposed on the top plate of the cooking appliance; an annular parent burner cap that is placed on the parent burner body so as to define a parent burner distribution chamber between the parent burner body and the parent burner cap and that has a plurality of parent burner flame holes formed therein for ejecting the mixture in the parent burner distribution chamber; and a parent burner inlet pipe that extends from the parent burner body to below the top plate of the cooking appliance, so that a mixture of fuel gas ejected from a nozzle hole at the tip of a parent burner nozzle that is provided facing the opening at the upstream end of the parent burner inlet pipe and primary air that flows in from the opening at the upstream end of the parent burner inlet pipe is supplied to the parent burner distribution chamber via the parent burner inlet pipe; and the child burner nozzle is attached to a nozzle holder that is exposed on the top plate of the cooking appliance at a position below the parent burner body, A parent-child burner characterized in that a heat dissipation section is provided on the outer surface of the parent burner body, positioned circumferentially away from the nozzle holder, for dissipating heat from the parent burner body to the outside.

2. A parent-child burner according to claim 1, wherein said heat dissipation portion is composed of fins protruding from the outer surface of said parent burner body.

3. A cooking device comprising the parent and child burner according to claim 1 or 2.

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