Burner heater

Abstract

To provide a burner heat generator capable of obtaining sufficient radiation heat on a lateral side even when annular coils are caused to become red hot by using a single burner in the burner heat generator having at least the two stages of annular coils.SOLUTION: A burner heat generator 10 includes: a first annular coil 11; a second annular coil 12 of which ring is smaller than that of the first annular coil 11 and disposed immediately below the first annular coil 11; an accommodation case 20 that accommodates each of the annular coils 11, 12 on the inner side of a transparent cylinder 23 extending downwardly from a top plate 21 and in which an opening 15 for heating the second annular coil 12 by using a burner is formed on a bottom part; and a fixation part 30 for fixing each of the annular coils 11, 12 to the top plate 21. The fixation part 30 includes a fastening tool 55 covering a central part of the second annular coil 12 from the lower side to support the second annular coil 12. A lower surface of the fastening tool 55 has a shape expanding upwardly.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a heater for a burner, etc., which has a heating element that emits radiant heat when heated by a burner flame. [Background technology]

[0002] Burner heaters having the above-mentioned heating element have been known for some time. Burner heaters are used when camping, etc., and can heat the surrounding area with radiant heat emitted from the heating element. This type of burner heater is called a "heater attachment."

[0003] Patent Document 1 discloses a heater for a camping burner. In this heater, a ring-shaped metal coil is disposed as a secondary combustion heating element in the center of the inside of a body formed by providing a glass cylinder between a top plate and a bottom plate.

[0004] Furthermore, Non-Patent Document 1 and Non-Patent Document 2 disclose a burner heater with two annular coils, one above the other. The heater described in Non-Patent Document 1 is manufactured by a company known among campers as "Takei Burner." This company is also the applicant for Patent Document 1. Furthermore, the heater described in Non-Patent Document 2 was manufactured with reference to the heater described in Non-Patent Document 1, as Non-Patent Document 2 states, "As for the difference with the heater part of the Takei Burner," [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Unexamined Utility Model No. 59-123214 [Non-patent literature]

[0006] [Non-Patent Document 1] "Takei Burner Purple Stove Parts 301 Heater #SV-2A (for 301)", YAHOO! Shopping [online], [Searched April 21, 2022], Internet <URL:https: / / store.shopping.yahoo.co.jp / yokohama-marine-and-supply / takei-parts-sv2a.html> [Non-patent document 2] "Karin Heater Attachment," CAMP on PARADE [online], [searched April 21, 2022], Internet<URL:https: / / www.camponparade.com / product-page / %E7%81%AB%E8%BC%AA-%E5%A4%A7> Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the conventional burner heaters disclosed in Non-Patent Documents 1 and 2 are used with a single burner commonly used at camp, it is difficult to sufficiently heat the upper coil, which is farther from the burner than the upper coil, to a red-hot state. As a result, there is a risk that sufficient radiant heat will not be obtained on the sides of the burner heater.

[0008] The present invention was made in consideration of the above circumstances, and aims to realize a burner heater having at least two stages of annular coils, which can obtain sufficient radiant heat from the sides even when the annular coil is heated to red heat by a single burner. [Means for solving the problem]

[0009] The first invention is a heater for a burner having a heating element that emits radiant heat when heated to red-hot by a burner flame, comprising a first annular coil that functions as a heating element, a second annular coil that is smaller in ring size than the first annular coil and is positioned directly below the first annular coil and functions as a heating element, a top plate, and a transparent tube extending downward from the top plate, a storage case that houses the first annular coil and the second annular coil inside the transparent tube and has an opening formed at the bottom for heating the second annular coil with a burner, and a covering member that is arranged to cover the central portion of the second annular coil from below, and the lower surface of the covering member has a shape that widens toward the upper side.

[0010] In a second invention, in the first invention, the covering member is provided as a fastener that constitutes part of a fixing portion for fixing the first annular coil and the second annular coil to the top plate, and supports the second annular coil from below.

[0011] In a third aspect of the present invention, in the first aspect, a plurality of downwardly projecting projections are formed at intervals in the circumferential direction on the underside of the top plate in an area facing the upper end surface of the transparent cylinder.

[0012] In a fourth aspect of the present invention, in the first aspect, the occupation density of the wire material in the second toroidal coil is 30% or more at a midpoint between the outer periphery and the inner periphery of the second toroidal coil in plan view.

[0013] According to a fifth aspect of the present invention, in the first aspect of the present invention, when the heat generating device for a burner is viewed from the side, a lower end of the first annular coil overlaps an upper end of the second annular coil.

[0014] According to a sixth aspect of the present invention, in the first aspect of the present invention, when the burner heat generating device is viewed from directly below, the entire outer periphery of the first toroidal coil is visible through the opening. [Effects of the Invention]

[0015] In the present invention, the lower surface of the covering member that covers the center of the second annular coil has a shape that widens upward. Therefore, when a burner is placed directly below the covering member, the burner flame hits the lower surface of the covering member and is guided outward along the shape of the lower surface.

[0016] In a conventional burner heater, the burner flame strikes a tub-shaped member, which corresponds to the member designated by the symbol 52b in Figure 5. The bottom surface of the tub-shaped member is recessed upward. In this case, with a normal burner, which has a relatively wide flame, much of the flame passes over the outer periphery of the tub-shaped member and reaches the first annular coil above. However, with a single burner, the flame has difficulty passing over the outer periphery of the tub-shaped member and reaching the first annular coil. This makes it difficult to sufficiently heat the first annular coil.

[0017] In contrast, in the present invention, as described above, the burner flame strikes the center of the underside of the covering member and is guided outward, so even if the burner is a single burner, much of the flame passes beyond the outer periphery of the covering member. Therefore, more flame reaches the first annular coil, allowing not only the lower second annular coil but also the upper first annular coil to be sufficiently heated to red-hot. This invention makes it possible to realize a burner heater that can obtain sufficient radiant heat from the sides, even when the annular coil is heated to red-hot by a single burner. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of a heat generating device for a burner according to an embodiment, seen obliquely from above. [Figure 2] FIG. 2 is a side view of the burner heat generating device according to the embodiment. [Figure 3] FIG. 3 is a view of the burner heat generating device according to the embodiment as viewed from below. [Figure 4] FIG. 4 is a perspective view of the burner heater according to the embodiment, with the annular bottom, transparent cylinder, and connecting portion removed and turned upside down. [Figure 5]FIG. 5 is a schematic diagram showing a cross section of the heat generating device for a burner according to the embodiment in the state of FIG. [Figure 6] FIG. 6 is a schematic diagram for explaining the effect of the fasteners of the heat generating device for a burner according to the embodiment. [Figure 7] FIG. 7 is a schematic diagram showing the fastener of the heat generating device for a burner according to the embodiment, seen from the side. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following embodiments are merely examples of the present invention and are not intended to limit the scope of the present invention, its applications, or its uses.

[0020] This embodiment is a burner heater 10 having at least two heating elements that emit radiant heat when heated by the flame of a burner such as a gas burner for camping. The burner heater 10 can be used as a heater when camping or when evacuating after a disaster.

[0021] 1 to 3, the burner heater 10 comprises a first annular coil 11, a second annular coil 12 having a smaller ring than the first annular coil 11 and positioned directly below the first annular coil 11, a storage case 20 that stores the first annular coil 11 and the second annular coil 12 inside a transparent cylinder 23 extending downward from near the underside of a top plate 21 and has an opening 15 formed in the bottom for heating the second annular coil 12 with a burner, and a fixing part 30 for fixing the first annular coil 11 and the second annular coil 12 to the top plate 21 of the storage case 20. The first annular coil 11 and the second annular coil 12 function as the heating elements described above.

[0022] Each of the first annular coil 11 and the second annular coil 12 is a metal coil. Each of the annular coils 11, 12 is formed by bending a normal coil into a ring shape and connecting one end to the other end with a connecting member 5 (see Figures 3 and 4). The connecting member 5 is a coiled wire. However, the connecting member 5 may be made of a material other than a coiled wire. Furthermore, the inner periphery of each of the annular coils 11, 12 is bound together by a wire 6 inserted inside.

[0023] In this embodiment, the first annular coil 11 and the second annular coil 12 have the same winding diameter, but may have different winding diameters. Also, the first annular coil 11 and the second annular coil 12 have the same wire material, but may have different wire materials.

[0024] Each of the toroidal coils 11, 12 uses a wire having a thickness of 0.8 mm to 1.2 mm. The thickness of the wire used in conventional burner heaters is approximately 0.7 mm. Each of the toroidal coils 11, 12 in this embodiment uses a wire that is thicker than that used in conventional burner heaters. In this embodiment, the first toroidal coil 11 and the second toroidal coil 12 use wire of the same thickness, but wires of different thicknesses may also be used.

[0025] As shown in Fig. 2, when the burner heater 10 is viewed from the side, the lower end of the first annular coil 11 overlaps the upper end of the second annular coil 12. However, the first annular coil 11 and the second annular coil 12 do not contact each other, and the upper end of the second annular coil 12 is arranged so as to fit inside the lower end of the first annular coil 11 with a gap therebetween (see Fig. 5).

[0026] As shown in Fig. 3, the first annular coil 11 and the second annular coil 12 are arranged so that their centers are substantially aligned in a plan view. The outer diameter D1 of the first annular coil 11 is larger than the outer diameter D2 of the second annular coil 12. When the burner heater 10 is viewed from directly below, the outer peripheral portion of the second annular coil 12 overlaps with the inner peripheral portion of the first annular coil 11. When the burner heater 10 is viewed from directly below, the entire outer periphery of the first annular coil 11 is visible through the opening 15.

[0027] In this embodiment, the occupation density Dc of the wire in the second toroidal coil 12 is 30% or more at a midpoint C between the outer and inner circumferences of the second toroidal coil 12 in a plan view. In a conventional heat generator for a burner, the occupation density of the wire in the lower toroidal coil is about 20% at the same position. In this embodiment, the occupation density Dc of the wire in the second toroidal coil 12 is higher than that of a conventional heat generator for a burner.

[0028] The "wire occupation density Dc" refers to the proportion of the wire to the circumferential length L (diameter x pi) at the intermediate position C when the number of wires equal to the number of turns N of the second toroidal coil 12 are lined up circumferentially at the intermediate position C with gaps between them. The wire occupation density Dc can be calculated using Equation 1. In Equation 1, T represents the thickness of the wire of the second toroidal coil 12. For example, the second toroidal coil 12 has an outer diameter D1 of 60 mm, an inner diameter of 30 mm, and a diameter of 45 mm at the intermediate position C. The number of turns of the second toroidal coil 12 is 60, and the thickness of the wire of the second toroidal coil 12 is 0.9 mm. In this case, the wire occupation density Dc is approximately 38%. In this embodiment, the wire occupation density Dc of the first toroidal coil 11 is also 30% or more. [Formula 1] Dc=T×N / L×100

[0029] 2, the storage case 20 is a substantially cylindrical case and includes a top plate 21, an annular bottom portion 22, a transparent tube 23 sandwiched between the top plate 21 and the annular bottom portion 22, and a connecting portion 24 connecting the top plate 21 and the annular bottom portion 22.

[0030] The top plate 21 includes a substantially circular plate portion 16 and an upper wall surface portion 17 extending downward from the outer periphery of the plate portion 16. The upper wall surface portion 17 is integrally formed with the plate portion 16. The upper wall surface portion 17 is provided around the entire periphery of the plate portion 16. In this embodiment, the height H1 of the upper wall surface portion 17 is 6 mm or less (for example, 5 mm). This height H1 does not include the height of the bent portion (rounded corner) at the boundary with the plate portion 16 (see FIG. 2). Here, in a conventional burner heater, the height of the same portion is slightly greater than 7 mm. In this embodiment, the height H1 of the upper wall surface portion 17 is lower than that of a conventional burner heater.

[0031] A central through-hole (not shown) is formed in the center of the top plate 21, through which the long screw 50 constituting the fixing portion 30 is inserted. As shown in FIG. 4, a plurality of upper through-holes 46 (five upper through-holes 46 in this embodiment) are formed in the outer periphery of the top plate 21, through which the upper screws 41 constituting the connecting portion 24 are inserted. The plurality of upper through-holes 46 are arranged at intervals in the circumferential direction of the top plate 21. In addition, the top plate 21 is formed with an annular groove 21a recessed downward, and a plurality of through-holes are formed in the annular groove 21a and inside thereof. These through-holes are for exhausting air upward from the accommodation case 20.

[0032] As shown in FIG. 4 (a view inverted upside down), a plurality of downwardly protruding protrusions 25 are formed on the underside of the top plate 21 at intervals in the circumferential direction of the top plate 21. The above-mentioned upper insertion hole 46 is formed in each of the protrusions 25. In a plan view, each of the protrusions 25 extends radially from the outer periphery of the top plate 21 to just before the annular groove portion 21a. Each of the protrusions 25 is formed in an area facing the upper end surface of the transparent tube 23.

[0033] The annular bottom portion 22 is a substantially annular member having an outer diameter approximately the same as that of the top plate 21. The annular bottom portion 22 includes a ring-shaped portion 26 and a lower wall surface portion 27 extending downward from the outer periphery of the ring-shaped portion 26. The lower wall surface portion 27 is formed integrally with the ring-shaped portion 26.

[0034] The ring plate portion 26 is formed with a plurality of lower insertion holes (five lower insertion holes in this embodiment, not shown) through which the lower screws 42 that constitute the connecting portion 24 are inserted. The ring plate portion 26 also has the above-mentioned opening 15 formed therein. The diameter of the opening 15 is larger than the outer diameter D1 of the first annular coil 11. As shown in FIG. 3 , when the burner heater 10 is viewed from directly below, the entire outer periphery of the first annular coil 11 is located inside the edge of the opening 15.

[0035] The lower wall portion 27 has a plurality of notches 28 cut out from the bottom end. The plurality of notches 28 are provided so that the burner heater 10 can be fitted into the trivet when it is installed on the trivet. This increases the stability of the burner heater 10 when installed on the trivet.

[0036] The transparent tube 23 is formed in a cylindrical shape. The transparent tube 23 is made of a highly heat-resistant, transparent material such as glass. The inner diameter of the transparent tube 23 is larger than the outer diameter of the first annular coil 11. The outer diameter of the transparent tube 23 is smaller than the outer diameters of the top plate 21 and the annular bottom portion 22, and is sized so as not to interfere with the connecting rod 40 (described below) that forms the connecting portion 24. The transparent tube 23 is placed on the edge portion 26a of the opening 15 in the ring-shaped plate portion 26 (see Figure 6). The edge portion 26a of the ring-shaped plate portion 26 is slightly recessed downward, so that the transparent tube 23 is held in a fixed position.

[0037] The connecting portion 24 includes a plurality of connecting rods 40 (five connecting rods in this embodiment) each having a female thread formed on the inner circumferential surface of each end thereof, a plurality of upper screws 41 that are threaded into the female threads at the upper ends of the connecting rods 40, and a plurality of lower screws 42 that are threaded into the female threads at the lower ends of the connecting rods 40. In the connecting portion 24, the upper screws 41 that pass through the upper through-holes 46 are threaded into the female threads at the upper ends of the connecting rods 40, thereby sandwiching the top plate 21 between the heads of the upper screws 41 and the upper end surface of the connecting rods 40, and thereby fixing the connecting rods 40 to the top plate 21. In addition, the lower screws 42 that pass through the lower through-holes are threaded into the female threads at the lower ends of the connecting rods 40, thereby sandwiching the ring plate portion 26 between the heads of the lower screws 42 and the lower end surface of the connecting rods 40, and thereby fixing the connecting rods 40 to the annular bottom portion 22. The connecting rod 40 is fixed to the top plate 21 and the annular bottom portion 22, thereby connecting the top plate 21 and the annular bottom portion 22 together.

[0038] As shown in FIG. 5 (upside down), the fixing unit 30 includes the long screw 50, a pair of first holding members 51a, 51b that hold the first annular coil 11 in an annular shape, a pair of second holding members 52a, 52b that hold the second annular coil 12 in an annular shape, first to fourth spacers 61-64 that are inserted onto the shank 50a of the long screw 50, and a fastener 55 that is threaded onto the tip of the shank 50a of the long screw 50. Note that the configuration of the fixing unit 30 in this embodiment is merely one example of the present invention, and other configurations may be adopted. Also, in FIG. 5, the plate portion 16 of the top plate 21 is depicted as a flat plate for convenience, and the annular groove 21a and the like are omitted.

[0039] Each of the holding members 51a, 51b, 52a, and 52b is formed in a generally tub-like shape with a through-hole formed in the center. Each of the holding members 51a, 51b, 52a, and 52b has a circular bottom portion with the through-hole formed therein and a tapered side portion rising from the outer periphery. Each of the second holding members 52a and 52b has a ring-shaped edge portion extending outward from the end of the side portion (the end opposite the bottom portion). An outer peripheral portion 55a of the fastener 55 is pressed against this edge portion. Each of the spacers 61 to 64 is formed in a cylindrical shape. The fastener 55 is a disc-shaped member with a bulging center and corresponds to a covering member. A through-hole 55b with a female thread formed on the inner peripheral surface is formed in the center of the fastener 55.

[0040] When fixing the annular coils 11 and 12 to the top plate 21, the first spacer 61, one of the first holding members 51a, the second spacer 62, the other of the first holding members 51b, the third spacer 63, one of the second holding members 52a, the fourth spacer 64, and the other of the second holding members 52b are inserted in this order onto the shank 50a of the long screw 50 inserted into the central insertion hole of the top plate 21, and then a fastener 55 is screwed onto the tip of the shank 50a. This fixes the annular coils 11 and 12 in the state shown in FIGS. 4 and 5. As shown in FIG. 6, the tip of the shank 50a of the long screw 50 is positioned below the height of the lower end of the second annular coil 12.

[0041] When the fastener 55 is turned upside down from the state shown in FIGS. 4 and 5 , the fastener 55 is disposed so as to cover the central portion of the second annular coil 12 from below. The fastener 55 supports the second annular coil 12 from below via the second holding member 52b. The fastener 55 bulges or protrudes downward below the height of the lower end of the second annular coil 12. The lower surface of the fastener 55 has a shape that widens from the central portion, which is the lower end, toward the upper side. The lower surface of the fastener 55 has a relatively gentle tapered slope. In this embodiment, the average inclination angle θ (see FIG. 7 ) of the lower surface of the fastener 55 is 45 degrees or less. Here, the average inclination angle θ is the angle in the range X excluding the horizontal portion (near the outer periphery 55a and the through hole 55b) when the fastener 55 is viewed from the side. Since increasing the angle θ requires increasing the height of the container case 20, it is preferable to reduce the angle θ while still achieving the effect of guiding the flame F, which will be described later. The angle θ can be set to, for example, 25 degrees or more and 35 degrees or less. The diameter of the fastener 55 can be set to, for example, 3 cm or more and 5 cm or less.

[0042] The pair of first holding members 51a, 51b are provided so as to press the inner circumferential portion of the first annular coil 11 outward from above and below, thereby holding the first annular coil 11 in an annular shape. The pair of second holding members 52a, 52b are provided so as to press the inner circumferential portion of the second annular coil 12 outward from above and below, thereby holding the second annular coil 12 in an annular shape.

[0043] [Effects of the embodiment] In this embodiment, as described above, the underside of the fastener 55 has a shape that widens upward. Therefore, when the burner B is placed directly below the fastener 55, the flame F of the burner B strikes the underside of the fastener 55 and is guided outward along the shape of the underside, as shown by the thick solid line in FIG. 6 . Even if the burner B is a single burner, much of the flame F extends beyond the outer periphery of the fastener 55. Therefore, more of the flame F reaches the first annular coil 11, and not only the lower second annular coil 12 but also the upper first annular coil 11 can be sufficiently heated to red-hot. This embodiment achieves a burner heater 10 that can generate sufficient radiant heat on the sides even when the annular coils 11 and 12 are heated to red-hot using a single burner. Furthermore, because sufficient radiant heat can be obtained on the sides of the burner heater 10 even with a single burner, there is no need to use a conventional burner to generate sufficient radiant heat, thereby contributing to energy savings.

[0044] 6, when wind blows from the left side, the flame F of burner B is blown to the right by the wind, and the amount of flame F striking the upwind side of second annular coil 12 is reduced. However, in this embodiment, even in such a case, the flame F of burner B is also guided to the upwind side along the shape of the underside of fastener 55, as shown by the thick dashed line in FIG. 6, so that the amount of flame F striking the upwind side of second annular coil 12 can be reduced. Note that the connecting portion 24 is not shown in FIG. 6.

[0045] In this embodiment, multiple protrusions 25 are formed on the underside of the top plate 21 in an area facing the upper end surface of the transparent tube 23. The multiple protrusions 25 ensure a gap G between the underside of the top plate 21 and the upper end surface of the transparent tube 23 between adjacent protrusions 25 in the circumferential direction. It is possible to ensure the size of the gap G without providing multiple protrusions 25. However, the transparent tube 23 is not fixed and has a small amount of play in the vertical direction. Therefore, without providing multiple protrusions 25, the transparent tube 23's play in the vertical direction would be large, raising the risk of damage to the transparent tube 23 when carrying the burner heater 10. In contrast, in this embodiment, by forming multiple protrusions 25, it is possible to increase the gap G while maintaining an appropriate amount of play in the vertical direction of the transparent tube 23. The increased gap G increases the amount of exhaust air from the transparent tube 23 during use of the burner heater 10, and accordingly increases the amount of air introduced through the opening 15. Furthermore, the amount of exhaust from the transparent cylinder 23 and the amount of air introduced from the opening 15 are increased by lowering the height H1 of the upper wall surface portion 17, as the exhaust flow indicated by arrow A in Fig. 7 becomes smoother. This therefore promotes combustion within the transparent cylinder 23, and increases the radiant heat emitted from each of the annular coils 11 and 12.

[0046] In this embodiment, as described above, the occupied density Dc of the wire in the second toroidal coil 12 is increased, which increases the amount of heat generated per unit volume in the space occupied by the second toroidal coil 12. This increases the temperature around the second toroidal coil 12. This promotes the combustion reaction around the second toroidal coil 12, and this effect also allows the first toroidal coil 11 to be sufficiently heated to red-hot.

[0047] In this embodiment, when the burner heater 10 is viewed from the side, the lower end of the first annular coil 11 overlaps the upper end of the second annular coil 12. In other words, the first annular coil 11 and the second annular coil 12 are arranged close to each other, shortening the distance from the burner B to the first annular coil 11. This makes it easier for the flame F of the burner B to reach the first annular coil 11, and this effect also allows the first annular coil 11 to be sufficiently heated to red-hot.

[0048] In this embodiment, when the burner heater 10 is viewed from directly below, the entire outer periphery of the first annular coil 11 is visible through the opening 15. This increases the amount of radiant heat radiated downward from each of the annular coils 11 and 12.

[0049] In this embodiment, the height of the cylindrical head of each upper screw 41 is increased. Here, when placing a pot on the five upper screws 41 to boil water, if the height of the head of each upper screw 41 is small, exhaust from the through-holes of the top plate 21 will be insufficient, and the annular coils 11 and 12 will become dark. In contrast, in this embodiment, the height of the head of each upper screw 41 is increased, so insufficient exhaust from the through-holes of the top plate 21 and the annular coils 11 and 12 will not become dark. The height H2 (see FIG. 2 ) of the head of each upper screw 41 from the top surface of the top plate 21 (the edge of the annular groove portion 22a) can be set to, for example, 4 mm or more (preferably 6 mm or more). Height H2 corresponds to the height of the gap between the bottom of a flat-bottomed pot and the top plate 21 when the pot is placed on the pot.

[0050] [Other embodiments] In the above embodiment, the fastener 55 is attached to the casing 20 using a screw structure, but it may also be attached using other structures such as welding.

[0051] In the above embodiment, the covering member 55 is used as a fastener that screws onto the shank 50b of the long screw 50, but it is also possible to form a female thread on the inner circumferential surface of the through hole of the second holding member 52b, use the second holding member 52b as a fastener, and further fix the covering member 55 to the second holding member 52b by welding, etc. In this case, the through hole in the center of the covering member 55 is not necessary.

[0052] In the above-described embodiment, opening 15 is enlarged to increase the amount of radiant heat downward, but opening 15 may be made smaller to increase the amount of heat transferred to top plate 21. This allows water to be boiled on top plate 21 in the above-described embodiment, but makes it possible to boil water in a shorter time. [Industrial Applicability]

[0053] The present invention is applicable to a heater for a burner, etc., which has a heating element that emits radiant heat when heated by the flame of a burner. [Explanation of symbols]

[0054] 10 Burner heater 11 First toroidal coil 12 Second toroidal coil 20 Storage Case 21 Top plate 23 Transparent tube 30 Fixed part 55 Fasteners (covering components)

Claims

1. A burner heater having a heating element that emits radiant heat when heated by a burner flame, a first annular coil that functions as the heating element; a second annular coil having a smaller ring than the first annular coil, disposed directly below the first annular coil, and functioning as the heating element; a container case having a top plate and a transparent cylinder extending downward from the top plate, the container case containing the first annular coil and the second annular coil inside the transparent cylinder, and an opening formed in a bottom portion for heating the second annular coil with a burner; a covering member provided to cover a central portion of the second toroidal coil from below, The lower surface of the covering member has a shape that widens upward.

2. The burner heater according to claim 1, wherein the covering member is provided as a fastener that constitutes part of a fixing portion for fixing the first annular coil and the second annular coil to the top plate, and supports the second annular coil from below.

3. The burner heater according to claim 1, wherein the underside of the top plate has a plurality of downwardly protruding convex portions formed at intervals in the circumferential direction in the area facing the upper end surface of the transparent cylinder.

4. 2. The heat generator for a burner according to claim 1, wherein an occupation density of the wire material of the second annular coil is 30% or more at a midpoint between an outer periphery and an inner periphery of the second annular coil in a plan view.

5. 2. The heat generating device for a burner according to claim 1, wherein a lower end of the first annular coil overlaps an upper end of the second annular coil when the heat generating device for a burner is viewed from the side.

6. 2. The heat generating device for a burner according to claim 1, wherein when the heat generating device for a burner is viewed from directly below, the entire outer periphery of the first annular coil is visible through the opening.

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