JP3413049B2 - Gas combustion equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a gas combustion device,
In particular, the present invention relates to a gas combustion apparatus including a rod-shaped burner and a covering member that covers the predetermined surface so that gas ejected from a plurality of flame holes on the predetermined surface of the burner forms a continuous flame. .

[0002]

2. Description of the Related Art FIG. 14 is an explanatory view of a main part of a conventional pottery apparatus (9), FIG. 15 is an XV-XV sectional view of FIG. 14, and FIG. 16 is an XVI-XVI sectional view of FIG. It is a figure.
The pottery device (9) is a device for grilling fish and meat, and as shown in the figure, a burner pipe (9a) supported in a substantially horizontal position and above the burner pipe (9a). A cover plate (9b) that is supported along the burner pipe (9a) and has an upwardly convex arcuate cross section.

At the top of the burner pipe (9a),
Flame holes (90) (90) are formed at predetermined intervals in the axial direction. The gas ejected from each of these flame holes (90) (90) forms a continuous flame in the axial direction at a substantially intermediate position between the burner pipe (9a) and the cover plate (9b) by the cover plate (9b). . The gas is supplied from one end of the burner pipe (9a). In this case, since the cover plate (9b) is heated to a red heat state by the flame, the radiant heat from the cover plate (9b) in addition to the heat of the flame also heats the object to be heated such as fish and meat. . Therefore, the efficiency of the firing is improved.

Further, the covering plate (9b) prevents the inconvenience that the oil and the dripping material dripping from the object to be heated block the flame holes (90) and (90). In addition, this pottery equipment (9),
Thermocouple for detecting the temperature at the end of the continuous flame
(9c) is provided. When the detected temperature of the thermocouple (9c) becomes equal to or lower than a predetermined temperature, the control circuit (not shown) of the pottery apparatus (9) regards it as the extinguished state and controls the gas supply stop.

[0005]

However, the conventional burner apparatus (9) has the following problems. ． The flame formed between the burner pipe (9a) and the cover plate (9b) is continuous in the axial direction of the burner pipe (9a),
In the middle of the axial direction, the flame is stable even when it receives wind, but at the end portion in the axial direction, when the wind is received, the flame tends to become unstable. In particular, in the case of yakitori, broiled chicken, etc., a strong wind from a puchiwar reaches the flame, so that the state of the flame at the end portion tends to be particularly unstable.

When the state of the flame at the end becomes unstable, the temperature detected by the thermocouple (9c) tends to be lowered. In this case, the above control causes the gas combustion to be stopped because it is regarded as the extinguished state. ． The dripping material dropped from the object to be heated reaches the widthwise end edge of the covering plate (9b) along the upper surface of the covering plate (9b), and then wraps around the inside of the end edge due to its surface tension. , Attached to the inner surface of the edge portion. By continuing this adhesion, as shown by the dotted line in FIG. 15, the dropped substance grows inward from the edge portion. In particular, when the dropped substance is sagging, the growth is remarkable because it easily expands due to the heat during the firing. This growth causes the drips to form flame holes (90).
When reaching, the part of the flame hole (90) is blocked. As a result, the flame from the flame hole (90) tends to lift, incomplete combustion of the flame occurs, and the state of the flame becomes unstable. Furthermore, when the flame hole (90) is completely closed, the flame from the flame hole (90) disappears.

Further, a thermocouple (9c) is provided at the end in the axial direction.
In such a case, if the flame at the end becomes unstable or disappears, the temperature detected by the thermocouple (9c) decreases, and gas combustion is stopped.

It is an object of the present invention to provide a gas combustion device which suppresses the influence of wind on the flame formed in the vicinity of the arrangement of the flame detection sensor. The invention of claim 2 is
An object of the present invention is to provide a gas combustion device that prevents a flame hole portion near a portion where a flame detection sensor is disposed from being blocked by a dropped substance from an object to be heated.

[0009]

[0010]

[0011]

[0012]

According to a first aspect of the present invention, there is provided a burner pipe in which a plurality of flame holes are formed so as to be aligned in the longitudinal direction at the top of the upper surface, and the burner pipe has a predetermined shape. A cover plate that is spaced apart from each other and that faces each of the flame holes and that has an upwardly convex umbrella-shaped cross section; and the end in the longitudinal direction within the gap between the cover plate and the burner pipe. And a flame detection sensor disposed on the both sides of the flame detection sensor, which is directly below the cover plate, and the height of the upper end is equal to or higher than the height of both end edges in the width direction of the cover plate, and A wind shield having a height of a lower end equal to or lower than the height of the flame hole. ”

In this structure, the gas ejected from each of the plurality of flame holes burns in the gap between the burner pipe and the cover plate, and the flame is continuous in the longitudinal direction of the burner pipe. Then, the state of the flame at the end portion in the longitudinal direction in the gap is detected by the flame detection sensor. Further, the wind shield suppresses the inflow of wind from the widthwise outer side into the gap at the end portion in the longitudinal direction (flame forming portion monitored by the flame detection sensor).

[0014]

According to a second aspect of the present invention, there is provided a burner pipe in which a plurality of flame holes are formed so as to be aligned in the longitudinal direction at the top of the upper surface, and the burner pipe is arranged at a predetermined distance from the burner pipe. A cover plate facing each of the flame holes and having an upwardly convex umbrella-shaped cross section, and a flame detector arranged at the end in the longitudinal direction within the gap between the cover plate and the burner pipe. A sensor and a pair of blocking plates for blocking the growth of the droplets from the heated object facing the flame holes from both end portions in the width direction of the coating plate, each of the pair of blocking plates,
Immediately below the cover plate and disposed on both sides of the flame detection sensor, the height of the upper end is equal to or higher than the height of both end edges in the width direction of the cover plate, and the height of the lower end is the flame hole. It is below the height. " In this structure, the gas ejected from each of the plurality of flame holes burns in the gap between the burner pipe and the cover plate, and the flame is continuous in the longitudinal direction of the burner pipe. Then, even if a dripping substance from the object to be heated drips onto the upper surface of the flame detection sensor side end portion in the longitudinal direction of the coating plate, the dripping substance is directed from the both widthwise end portions of the coating plate toward the flame hole. Growth is blocked by the blocking plate.

[0016]

[0017]

[0018]

[0019]

[0020]

According to the first aspect of the present invention, the wind shield suppresses the inflow of wind from the outside in the width direction at the end portion in the longitudinal direction with respect to the gap between the burner pipe and the covering plate. The inconvenience that the flame at the end becomes unstable by the wind is prevented. Further, the stabilization of the flame at the end portion stabilizes the detection output of the flame detection sensor at the end portion. Therefore, various controls based on the detection output are ensured. In particular, in the control for stopping the gas supply based on the detection output, malfunction due to the wind of a prickly wind or the like is prevented.

According to the second aspect of the present invention, even if a drop from the object to be heated drops onto the upper surface of the end of the cover plate on the flame detection sensor side in the longitudinal direction, the drop remains at both ends in the width direction of the cover plate. To the flame holes are prevented by the blocking plate. Therefore, it is possible to prevent the disadvantage that the flame drops near the flame detection sensor are blocked by the grown droplets. Therefore, the detection output of the flame detection sensor that detects the state of the flame at the end is stabilized. Therefore, in the case where various controls are performed based on the detection output, the control becomes reliable. In particular, in the case of stopping the gas supply based on the detection output, the flame holes at the end are not blocked by the dropped substance, and there is no inconvenience that the gas combustion is forcibly extinguished.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
It will be described with reference to the drawings. FIG. 1 is a perspective view of a pottery apparatus (1) according to an embodiment of the present invention, and FIG.
2 is a sectional view taken along line II-II of the pottery apparatus (1) of FIG. 3, and FIG. 3 is a plan view of the burner pipe (2) of FIG.

FIG. 4 is an assembled perspective view of the rear end portion of the gas burner (100) of FIG. 1, and FIG. 5 is a side view of the rear end portion before mounting the cover plate (3). Yes, FIG. 6 is a plan view of the covering plate (3) at the rear end before mounting,
FIG. 7 is a sectional view taken along line VII-VII of FIG. 6 after the covering plate (3) at the rear end is attached, and FIG. 8 is a covering plate (3) at the rear end of FIG. VIII-VI after mounting
It is a II sectional view. Further, FIG. 9 shows the gas burner (10
FIG. 10 is a sectional view taken along line IX-IX of the front end portion of FIG.

Further, FIG. 10 shows the gas burner (100) of FIG.
FIG. 11 is an explanatory view of a main part in the use state of FIG. 11, and FIG. 11 is a sectional view of the gas burner (100) of FIG. 10 taken along line XI-XI. As shown in FIGS. 1 and 2, the calcination device (1) includes a plurality of all-primary air type gas burners (100) (100) (100) (100) (100) (100) arranged in parallel between the front and rear side walls of an open fire bed (1a). ) Is provided. Each of these gas burners (100) (100) has a burner pipe (2)
And a cover plate that covers this burner pipe (2) from above.
(3) and are provided.

The front side wall of the pottery apparatus (1) is
A front box (12) projecting forward from the upper part thereof is provided, and inside the front box (12), a plurality of fans for supplying primary air for gas combustion to each of the gas burners (100) (100). (13) (13)
And an ignition device (not shown) for igniting the front end of each of the gas burners 100, 100. [Regarding the configuration of each part of the gas burner (100)] * Burner pipe (2) * The above burner pipe (2) is as shown in Figs.
This burner pipe is made of straight metal pipe
The rear end of (2) has a flattened flattened state (21).
The front end of the burner pipe (2) is an open part (22) that is open to the front.

The flat part (21) is screwed to a substantially horizontal rear crosspiece (11) provided on the rear side wall of the fire bed (1a), and the open part (22) is a front box. It is fitted on the nozzle (14) provided inside the (12). In this case, the opening (22) is the nozzle (14).
Since it is displaceable in the axial direction, the thermal expansion in the axial direction of the burner pipe (2) during combustion is absorbed. or,
The open part (22) is an air supply chamber (1) provided in the front box (12).
5) has been inserted. The open part (2
An opening (16) is formed in the lower constituent wall of 2), and a guide duct (17) connected to the air supply chamber (15) from below so as to communicate with the opening (16). The primary air from the fan (13) is forced into the air supply chamber (15) via the.

Further, a pair of primary air holes (23) and (23) are formed on the peripheral wall of the opening (22) in the air supply chamber (15). The primary air from the air supply chamber (15) is sent into the burner pipe (2) through these primary air holes (23) (23). Burner pipe
The primary air sent into (2) is mixed with raw gas from the nozzle (14) in the burner pipe (2). The gas burner (100) is of the all-primary air type, and all the combustion air is secured by supplying air from the primary air holes (23) (23).

The burner pipe (2) is formed with a plurality of flame holes (20) (20) arranged in the axial direction at substantially constant intervals over a certain range in the middle of the axial direction. There is. Each of these flame holes (20) (20) is located at the top (ridgeline) of the upper surface of the burner pipe (2).

Gas in the burner pipe (2) is ejected from each of these flame holes (20) (20), and the ejected gas is ignited by the ignition device and burned. * Coating plate (3) * The above coating plate (3) is made of heat-resistant strip metal plate,
As shown in FIG. 1 to FIG. 3 and FIG. 7 to FIG. And this cover plate
(3) is above the burner pipe (2) and the burner pipe (2)
The cover plate (3) is arranged so as to extend along the axial direction and faces the burner portion (2a) in the axial direction. The rear end of this cover plate (3) is
The cover plate (3) is supported by a bracket (4), and the front end of the cover plate (3) is supported by a second bracket (6) described later.

The distance between the cover plate (3) and the burner portion (2a) is set to be substantially constant in the axial direction. Further, the intervals and the ejection speed of the gas are set so that the flame due to the combustion of the gas ejected from each of the flame holes (20) (20) continues in the axial direction of the burner portion (2a). ing.
The flame may or may not be continuous in the axial direction without the cover plate (3).

The covering plate (3) corresponds to the "covering member" described in the claims. In this one, the coated plate
Since (3) has a semi-circular cross section that is convex upward, the flame does not overflow to the outside of the cover plate (3) and the entire cross section of the cover plate (3) is heated uniformly. In addition, the widthwise edge portion (3
1) and (31) are configured to be bent inside.

* First bracket (4) * As shown in FIGS. 4 to 8, the first bracket (4) is attached to the rear crosspiece (11) by screws together with the flat portion (21). A piece (42), an upright piece (41) which stands upright from the front end of the mounting piece (42), a protruding piece (44) which projects forward from the upper end of the upright piece (41), and an upright piece ( And 41) a pair of guide pieces (43) (43) extending forward from each of both side edges of (41).

The upright piece (41) is formed with an insertion hole (41a) through which a heat sensitive portion (71) of a thermocouple (7) described later is inserted. In addition, a certain area on the front side of the projecting piece (44) is formed in an arcuate cross section that coincides with the inner peripheral edge of the cross section of the cover plate (3) and supports the rear end of the cover plate (3). One part (4
4a). This piece (44a) and guide piece (43) (43)
A gap is formed between each of them and for allowing the widthwise end of the covering plate (3) to enter with the covering plate (3) placed on the piece (44a). Further, each of the guide pieces (43) (43) is formed so as to extend below the upright piece (41) and cover the flat portion (21).

* Mounting member (5) * This gas burner (100) has the above-mentioned first bracket (4).
There is a mounting member (5) to be mounted on. As shown in FIGS. 4 to 8, the mounting member (5) includes a top plate (51),
A pair of side plates hanging from both widthwise edges of the top plate (51)
(52) (52), a pair of protruding plates (53) (53) protruding inward from the rear end edges of these side plates (52) (52), and the lower ends of the front end edges of the side plates (52) (52) (54) (54) bent inward from the portion, and a pair of substantially vertical posture extending plates (55) extending forward from the inner edge of these protrusions (54) (54) and parallel to each other. ) (55) and

The top plate (51), the side plates (52) (52), the protruding plate (5)
3) (53) and the protruding pieces (54) and (54) surround the upright piece (41), the guide pieces (43) (43), and the base end side portion of the protruding piece (44). So that the first bracket (4) is covered. That is, the top plate (51) is in contact with the upper surface of the base end side portion of the protruding piece (44), and each of the side plates (52) (52) is substantially in contact with the outer surface of each of the guide pieces (43) (43). Each of the protruding plates (53) (53) is an upright piece.
The protrusions (54) and (54) are substantially in contact with the outer surface (rear end face) of the (41) and the front edges of the guide pieces (43) and (43).

The vertical length of each of the extension plates (55) (55) is such that the upper end of each of the extension plates (55) (55) is the above-mentioned cover plate.
It is set such that it is located above the edge in the vicinity of the inside of the edge in the width direction of (3), and the lower end is located below the flame holes (20) (20). Also, these extension plates (55)
The length of (55) in the front-rear direction (the above-mentioned axial direction) is set so as to extend to the front side with respect to the plurality of flame holes (20) (20) at the rear end of the burner portion (2a). It is set.

The upper edge of each of the protrusions (54) (54) has an extension plate (5
5) It is configured to be lower than the upper edge of (55), and a recessed portion (56) (recessed downward) is provided between the extension plates (55) (55) and the side plates (52) (52). 56) has been formed. With respect to these recesses (56) (56), the edge portion (3) of the cover plate (3) placed on the piece (44a) is
1) The rear end of (31) is inserted. Furthermore,
The heat-sensitive part (71) is provided between the protruding plates (53) and (53), between the side plates (52) and (52), and between the rear ends of the extension plates (55) and (55). It has been inserted.

The extension plates (55) and (55) correspond to the "wind shield plate" and the "blocking plate" described in the claims. * Second bracket (6) * As shown in FIGS. 2 and 9, the second bracket (6) includes a backing plate (61) in a substantially vertical posture, and a front side from a lower edge of the backing plate (61). The extension piece (63) that extends to the side and is fixed to the burner pipe (2), and the support plate (62) that protrudes rearward from the lower part of the contact plate (61) and supports the front end of the cover plate (3). ) And consist of.

The support plate (62) is provided with a pair of upright pieces (62a) (62a) which stand upright from both side edges of the substantially horizontal main plate, and are covered by these upright pieces (62a) (62a). The plate (3) is prevented from falling off in the width direction. Then, the backing plate (6
The distance from 1) to the base end of the piece (44a) is set larger than the length of the covering plate (3) in the longitudinal direction. Therefore,
The thermal expansion in the longitudinal direction of the cover plate (3) during combustion is absorbed.

* Thermocouple (7) * This burner device (1) includes a burner pipe (2) and a cover plate (3).
A thermocouple (7) is provided to detect the temperature of the rear end of the flame that is continuous in the axial direction of the burner (2a) in the gap between the rod and the thermocouple (7). The heat-sensitive part (71) formed in the above is provided. The thermocouple (7) is fixed to the mounting piece (42).

This thermocouple (7) is a pottery device (1)
Is electrically connected to a control circuit (not shown) of the control circuit, which executes various control operations for ensuring the safety of gas combustion based on the temperature detected by the thermocouple (7). For example, if the detected temperature drops below the specified temperature after combustion starts in the gas burner (100),
Assuming combustion at (100) has gone off, nozzle (14)
Cut off the gas circuit to. This prevents gas leakage at the time of the extinction.

[Regarding Gas Combustion in Gas Burner (100)] In the above gas burner (100), gas is ejected from each of the flame holes (20) (20) of the burner portion (2a) as described above.
Then, after the flame hole (20) at the front end of the burner portion (2a) is ignited by the ignition device, the flame holes (20) (2
Go to 0). Further, the gas combustion is performed in a state along the cover plate (3) at a substantially intermediate position between the cover plate (3) and the burner pipe (2). This combustion flame is continuous in the axial direction of the burner part (2a).

In this combustion state, the covering plate (3) is in a red heat state, and the radiant heat also burns the object to be heated such as yakitori. Therefore, the efficiency of the firing is improved. And, by each of the extension plates (55) (55),
Inflow air from the outside in the width direction to at least the rear end is shielded in the gap between the (2a) and the cover plate (3). Therefore, the inconvenience that the flame at the rear end portion becomes unstable due to the inflow air is prevented.

Further, since the detection output of the thermocouple (7) is stabilized by stabilizing the state of the flame at the rear end portion, even if the object to be heated such as a yakitori is covered with a whip, the above extinguishing prevention control is performed. The accidental misfire is prevented. Also, various controls based on the detection output of the thermocouple (7) are reliable. Furthermore, the lower end of each of the extension plates (55) (55) is substantially in contact with the burner portion (2a), and the upper end of each of the extension plates (55) (55) is substantially in contact with the cover plate (3). Therefore, between each of the extension plates (55) (55) and the burner portion (2a), the extension plates (55) (5
The air flowing into the inside of the gap via each of 5) and the cover plate (3) is reduced. Therefore, the flame stabilizing effect at the rear end portion is further improved.

The combustion exhaust gas between the extension plates (55) (55) is
It is ejected by being axially removed from the mutual space. On the other hand, in the combustion state, the sauce drops from the object to be heated such as yakitori, but this sauce flows on the upper surface of the covering plate (3) and flows outward in the width direction, and the edge portion (31) ( 31), and due to its surface tension, it wraps around inward in the width direction. In this state, the sauce adheres to the inner surface of the edge portions (31) (31) by heat. Then, as the combustion continues, the attached sauce grows inside.

However, at the rear end, the extension plate (55)
By each of (55), the growth of the sintered sauce inside the edge portions (31) (31) is prevented. Therefore, the plurality of flame holes (20) (20) at the rear end portion due to the grown sauce
Occlusion of some or all of each is prevented.
Further, the detection output of the thermocouple (7) is stabilized by preventing each of the plurality of flame holes (20) (20) at the rear end from being blocked. Therefore, even if only the rear end flame holes (20) (20) are closed, the accidental misfire is prevented by the above extinguishing prevention control. Further, various controls based on the detection output are reliable.

Furthermore, the upper ends of the extension plates (55) (55) are substantially in contact with the inner edges of the edge portions (31) (31) of the cover plate (3), and the lower ends are the burner portions (2a). They are in close contact. Therefore, the extension plate (5
5) Between each of the (55) and the burner portion (2a), between each of the extension plates (55) (55) and the covering plate (3), the amount of sagging that enters the gap is reduced, The effect of preventing the blockage of the flame holes (20) (20) is further improved. [Other Embodiments]. FIG. 12 shows a gas burner (10 according to another embodiment.
FIG. 13 is a side view of the gas burner (10) of FIG.
10 is a sectional view taken along line XIII-XIII in FIG.

In the above embodiment, the mounting member (5) is provided with the "wind shield" and the "blocking plate" described in the appended claims (extension plates (55) (55)). However, this may be provided on the cover plate (3) as shown in the figure. In this case, a pair of hanging plates (33) (33) can be adopted that hang down from each of the rear end portions of the edge portions (31) (31). The lower end of each of the hanging plates (33) (33) is substantially in contact with the burner portion (2a).

This device also has the same operation and effect as those of the above embodiment. Incidentally, the "wind shield" and "blocking plate" described in the claims may be connected to the burner portion (2a). ． In the above embodiment, the extension plate (55) (5) (5) (5) (5) (5) (5) as described in the claims
Although each of 5) is arranged at the rear end of the burner portion (2a), it may be configured to further extend from the rear end to the front side.

Further, the burner portion (2a) may be extended in the axial direction. In this one, extension plate (55) (55)
The shielding area of the inflowing air by each of the above becomes large, and the flame is further stabilized even in the middle of the flame continuous in the axial direction. In this case, the combustion exhaust gas between the extension plates (55) (55) is axially removed from the mutual space and discharged. And, in the case of burning using secondary air instead of the above all primary air type, a gap for the secondary air to pass between the extension plates (55) (55) and the burner part (2a). It is good to have it.

Then, each of the extension plates (55) (55) is connected to the burner section.
In the case of the above-mentioned configuration extending in the axial direction of (2a), the growth inhibition region of the sag by each of the extension plates (55) (55) becomes large, and the effect of blocking the flame holes (20) (20) is reduced. Further improve.

Instead of the extension plates (55) (55), a non-combustible non-woven fabric or a metal block may be used. ． In the above embodiment, the burner portion (2a) as the "burner" described in the claims is configured to be supported in a substantially horizontal posture. It may be configured to be supported by.

Further, although the burner portion (2a) is arranged to extend straight, it may be curved to extend.

[Brief description of drawings]

FIG. 1 is a perspective view of a pottery apparatus (1) according to an embodiment of the present invention.

2 is a sectional view taken along line II-II of the pottery apparatus (1) of FIG.

FIG. 3 is a plan view of the burner pipe (2) of FIG.

4 is an assembled perspective view of the rear end of the gas burner (100) of FIG.

FIG. 5 is a side view of the rear end portion before mounting the cover plate (3).

FIG. 6 is a plan view of the covering plate (3) at the rear end before being mounted.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 6 with the covering plate (3) at the rear end portion attached.

8 is a sectional view taken along the line VIII-VIII of FIG. 6 after the cover plate (3) at the rear end is attached.

9 is a front end portion IX-I of the gas burner (100) of FIG.
X cross section

FIG. 10 is an explanatory view of the main part of the gas burner (100) of FIG. 1 in use.

11 is a cross-sectional view taken along line XI-XI of the gas burner (100) of FIG.

FIG. 12 is a side view of a gas burner (100) according to another embodiment.

FIG. 13: XIII-XI of the gas burner (100) of FIG.
II cross section

FIG. 14 is an explanatory view of a main part of a conventional pottery apparatus (9).

FIG. 15 is a sectional view taken along line XV-XV in FIG.

16 is a sectional view taken along line XVI-XVI of FIG.

[Explanation of symbols]

(1) ... ware device (2) ・ ・ ・ Burner pipe (2a) ・ ・ ・ Burner section (3) ・ ・ ・ Coating plate (4) ・ ・ ・ First bracket (5) ・ ・ ・ Mounting member (6) ・ ・ ・ Second bracket (55) ・ ・ ・ Extension plate

Claims (2)

(57) [Claims] 1. A burner pipe in which a plurality of flame holes are formed so as to be lined up in the longitudinal direction at the top of the upper surface, and a plurality of flame holes are arranged at a predetermined interval with respect to the burner pipe so as to face each of the flame holes. And a cover plate having an upwardly convex umbrella-shaped cross section, a flame detection sensor disposed at the end in the longitudinal direction within the gap between the cover plate and the burner pipe, and directly below the cover plate. Which is disposed on both sides of the flame detection sensor, the height of the upper end of which is equal to or higher than the height of both edges of the cover plate in the width direction, and the height of the lower end of which is equal to or lower than the height of the flame hole. A gas combustion device including a plate. 2. A burner pipe in which a plurality of flame holes are formed so as to be lined up in the longitudinal direction at the top of the upper surface, and a plurality of flame holes are arranged at a predetermined interval with respect to the burner pipe and face each of the flame holes. And a cover plate having a convex umbrella-shaped cross-section upward, a flame detection sensor arranged at the end in the longitudinal direction within the gap between the cover plate and the burner pipe, and the width direction of the cover plate. The flame detection sensor is provided with a pair of blocking plates for blocking the growth of the droplets from the heated object from both edge portions toward the flame holes, each of the pair of blocking plates being directly under the cover plate. Of the gas combustor, the height of the upper end of which is greater than or equal to the height of both edges of the cover plate in the width direction, and the height of the lower end of which is less than or equal to the height of the flame holes.