JP2000081205A - Bunsen burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate detection of flame by increasing a flame current value so as to enhance safety by providing the same number of secondary air suction slits as that of auxiliary flame ports on a distal end of a tubular flame stabilizing cover. SOLUTION: A flame retention burner 1 is formed integrally with a tubular body capable of being connected to a mixing pipe, a primary flame port 2, a truncated cone shaped burner head 1a having a plurality of auxiliary flame ports 3 in an inclined peripheral face and a tubular flame stabilizing cover 4 having a folded part 4a folded inside respectively on a lower part, a top center part and an end part. The same number of secondary air suction slits 5 as that of plural auxiliary flame ports 3 provided in a burner head 1a of the flame retention burner 1 are provided in an end part of a peripheral face of the tubular flame stabilizing cover 4. Therefore, a flow jetted from the primary flame port 2 causes secondary air to be sucked to a center part through the secondary air suction slits 5. Width and depth of the slits 5 can be changed according to applications of the burner so as to vary quantity of the secondary air sucked through the slits.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention increases the flame current of a flame detecting flame rod used for improving flame holding capacity and electrically detecting a flame when low pressure gas such as city gas 13A is burned. To a Bunsen gas burner that can be used.

[0002]

2. Description of the Related Art Although it has been possible to burn a specified amount of low-pressure gas of city gas 13A with a conventional Bunsen-type flame retention burner, it is necessary to electrically detect a flame with a frame rod, and particularly, it is necessary to reduce the turndown. If it is necessary to increase the value, the flame current value is large to some extent during high combustion, but extremely lower during low combustion, so that the protection relay determines that a misfire has occurred even if there is a flame. Therefore, a commercially available protection relay that requires a somewhat large frame current value cannot detect a flame, and it is very inconvenient to design a protection relay that can detect even a low frame current value. Was. Further, there are prior arts of a gas burner disclosed in Japanese Utility Model Publication No. 58-12008 and a burner cap with a slit disclosed in Japanese Utility Model Publication No. 4-19306, but in the gas burner disclosed in Japanese Utility Model Publication No. 58-12008,
The secondary air hole provided on the side surface of the outer cylinder is located rearward of the mixing tube side of the flame holding gas ejection slit of the burner inner cylinder, and is not configured to supply secondary air to the main flame. 4-19
The burner cap with a slit of No. 306 has a structure in which a frame retention portion and a slit are provided, and the appearance is similar to that of the present invention, but the slit is used to alleviate the generation of thermal stress to prevent deformation and prevent the deformation. It is completely different from the purpose of the invention. Therefore, in the current situation where 13A has become popular as a city gas for home use and at the present time a safety device is required to shut off the gas immediately when the fire goes out,
A Bunsen-type gas burner that can obtain a large flame current value has been required, but there has been no one that can cope with it.

[0003]

A conventional Bunsen gas burner having no slit in the flame holding tube of the burner head,
When the LPG medium pressure is burned, or when the city gas 13A is at medium pressure, a sufficient flame current can be obtained. Main Flame Hole 16
Pressure of LPG medium pressure and city gas 13A low pressure, calorific value, gas nozzle diameter, primary air ratio (ratio of primary air to be sucked) when burning 10000 kcal / H with a Bunsen type burner using a frame retention burner of φ (mm) ) Are shown in Table 1.

[0004]

[Table 1]

More specifically, comparing the LPG medium pressure shown in FIG. 8A with the low pressure of the city gas 13A shown in FIG. 8B, as shown in Table 1, in the case of the LPG medium pressure, a large amount of heat is generated and the gas pressure is low. So the required gas nozzle diameter is 0.8φ,
The ratio of the primary air sucked at this time is 80% theoretically
And the secondary air from around the burner head is 20%
Can be completely burned. On the other hand, in the case of 13 A low pressure, the gas heat generation amount is small and the gas pressure is low, so that the gas nozzle diameter is 2.3φ. Therefore, the ratio of the primary air to be sucked is only 40% in theoretical calculation, and the remaining 60% of the secondary air from around the flame is required, resulting in slow combustion. As a result, it was found that the combustion at a low pressure of 13 A compared with the LPG medium pressure combustion draws less primary air, so that it is difficult for the flame to settle in the main flame hole, so that a small value can be obtained by measuring the flame current value. did. However, in order to increase the primary air ratio, it is necessary to increase the size of the main flame hole. However, if the diameter of the main flame hole is large, there is a problem that a backfire is likely to occur during low combustion, which has been a problem.

The present invention solves the above-mentioned problems of the prior art. In the case of the low-pressure city gas 13A, the ratio of the primary air sucked into the burner is reduced to the LPG medium pressure or the city gas 13A.
Since it was found that the flame current value was small because it was smaller than the medium pressure, the auxiliary flame hole was formed at the tip of the tubular flame holding cover without changing the main flame hole diameter of the burner (with the primary air ratio unchanged). By providing the same number of secondary air suction slits as described above, secondary air is introduced into the flame to compensate for the lack of primary air, and the flame current is increased by making the flame current value easier to detect. It is an object of the present invention to provide a gas burner.

[0007]

According to a first aspect of the present invention, there is provided a Bunsen-type gas burner including a burner head having a main flame hole and an auxiliary flame hole, and a tubular flame holding cover surrounding the burner head. In a Bunsen-type gas burner including a burner 1, a gas nozzle 10, a primary air hole 11, and a mixing pipe 14, a flame is used so that the secondary air is effectively brought into contact with the flame and brought into the same state as when the primary air is large. The secondary air suction slits 5 of the same number as the auxiliary flame holes 3 are provided in order to make it easy for the secondary air to be sucked not only to the periphery of the flame but also to the center of the flame and to increase the area in contact with the air of the flame. It is characterized in that it is provided at the tip of the tubular flame holding cover 4.

The operation of the first aspect of the present invention is not limited to the contact of the secondary air around the flame of the main flame hole, but also the secondary air suction slits 5 as many as the auxiliary flame holes 3 are provided with the flame holding cover 4. By providing the secondary air at the tip of the flame, the secondary air is easily sucked into the center of the flame, the amount of the secondary air that contacts the flame is increased, and the area where the flame contacts the secondary air can be increased.
Therefore, the flame can be fixed to the main flame hole so that the base of the flame becomes excessive air combustion, and the flame current value can be increased from the value measured by the conventional burner.

The invention of claim 2 is characterized in that the position of the secondary air suction slit 5 provided in the cylindrical flame holding cover 4 is a position facing the auxiliary flame hole 3 of the frame retention burner 6. Things.

The operation of the second aspect of the invention is as follows. The position of the secondary air suction slit 5 and the position of the auxiliary flame hole 3 are set to be the same, so that the auxiliary flame of the auxiliary flame hole is subjected to the secondary flame from the slit. By bringing the air into direct contact, the contact between the flame and the secondary air is increased more than before, and the contact area between the flame and the secondary air can be increased. Therefore, even when applied to a heating furnace such as a pottery kiln where the secondary air is forcibly sucked by the draft effect of the chimney, the area where the flame comes into contact with the air is expanded, and the base of the flame becomes excessive air combustion. In this manner, the flame can be fixed to the main flame hole, and the flame current value can be increased from the value measured by the conventional burner.

[0011]

An embodiment of the present invention will be described with reference to the drawings. 1 is a perspective view showing a frame retention burner of the present invention, FIG. 2 is a plan view of the same, and FIG.
4 and FIG. 5 show another embodiment of the frame retention burner, FIG. 4 is a plan view thereof, FIG. 5 is a sectional view taken along line YY of FIG. FIG. 7 is a sectional view showing a Bunsen-type gas burner provided with a frame retention burner of the present invention, FIG. 7 is an explanatory view showing a state of suction of primary air and secondary air of the Bunsen-type gas burner of the present invention, and FIG. It is explanatory drawing which shows the suction state of the primary air and the secondary air in the case of (2) conventional city gas 13A low pressure in the case of LPG medium pressure.

In FIG. 6, the Bunsen type gas burner includes a gas nozzle 10, a primary air hole 11, a primary air damper 12, a cock 13, a mixing pipe 14, and a frame retention burner 1. The frame retention burner 1 is fixed to the tip of the mixing tube 14 by screwing or the like.

1 to 3, a flame retention burner 1 provided at the tip of a mixing pipe 14 of a Bunsen type gas burner according to the present invention has a cylindrical body which can be connected to the mixing pipe 14 at the lower part, and a main flame hole at the center of the top part. 2, a frusto-conical burner head 1a provided with a plurality of auxiliary flame holes 3 on an inclined surface of a peripheral surface thereof, and a bent portion 4 which is bent inward at an end portion.
a and the cylindrical flame holding cover 4 having a. According to the present invention, a plurality of auxiliary air holes 3 provided in the burner head 1a of the frame retention burner 1 and the same number of secondary air suction slits 5 are formed at the end of the peripheral surface of the cylindrical flame holding cover 4. It is. That is, the secondary air suction slit 5 is formed at a depth from the upper end to near the upper part of the auxiliary flame hole 3 at a constant interval around the cylindrical flame holding cover 4. Therefore, the secondary air is sucked into the central portion from the secondary air suction slit 5 by the flow of the air-fuel mixture ejected from the main flame hole 2. In addition, the secondary air suction slit 5 can change the width and depth of the secondary air suction burner in accordance with the application of the Bunsen gas burner to change the amount of secondary air sucked from the slit. For example, with a 1-inch burner, the slit width for secondary air suction is 1 mm and the depth is 13 m.
If the slit width is narrowed as m, the suction amount of the secondary air can be reduced, or if the slit width is widened, such as a slit width of 4 mm and a depth of 13 mm, the suction amount of the secondary air can be increased.

The fuel gas supplied to the Bunsen-type gas burner having the above structure is a city gas 13A supplied at a low pressure, and the gas supplied from the gas supply pipe blows out from the gas nozzle 10 and enters the mixing pipe 14. The primary air for combustion is sucked from the primary air hole 11 by the jetting power of the gas from the gas nozzle 10, and the primary air ratio at this time is determined by the nozzle area of the gas nozzle 10 and the area ratio of the main flame hole 2 of the flame retention burner 1. . Then, the mixture of the gas and the primary air passes through the mixing pipe 14 and reaches the main flame hole 2 and the auxiliary flame hole 3 of the burner head 1a, and the air-fuel mixture is ejected from the main flame hole 2 to suck the secondary air from the surroundings. At the same time, the secondary air is sucked into the flame through the secondary air suction slit 5 of the flame holding cover 4 provided around the burner head 1a and burns.

According to the structure of the present invention, the same number of secondary air suction slits 5 as the auxiliary flame holes 3 of the burner head are provided in the flame holding cover 4, so that as shown in FIG. Assuming that, for example, 20% of the secondary air is sucked from the secondary air suction slit 5 to the center of the burner 1 by the ejected air-fuel mixture, the primary air is relatively 60% (40% + 2).
0%), and the secondary air can be sucked not only to the outside of the flame, but also to the center of the flame. The area that comes into contact with air can be expanded, and LPG medium pressure and 13
A: Since it was possible to burn at the same primary air ratio as in the medium pressure combustion, the flame was fixed to the main flame hole so that the base of the flame became excessive air combustion, and the flame was stably burned. The current value can be increased. The position of the secondary air suction slit 5 is not limited to this position, but may be provided at an appropriate position between the auxiliary flame holes 3 depending on the application.

If the position of the secondary air suction slit 5 provided on the cylindrical flame holding cover 4 is provided at the same position as that of the auxiliary flame hole 3 of the frame retention burner, the auxiliary flame and the secondary air come into direct contact. As a result, the auxiliary flame can be strengthened and the flame of the main flame hole can be strengthened. Thus, when applied to a heating furnace such as a pottery kiln, the slit 5 for secondary air suction is used.
The auxiliary flame and the auxiliary flame hole 3 are opposed to each other to make them the same, whereby the auxiliary flame and the secondary air come into direct contact, and stable combustion and a large flame current value can be obtained.

4 and 5, another embodiment of the frame retention burner is shown. In this embodiment, a plurality of slits 5 for suctioning secondary air are formed at a depth from the upper end to near the upper part of the auxiliary flame hole 3 with the tip of the cylindrical flame holding cover 4 being straight. The positions of the plurality of secondary air suction slits 5 provided in the cylindrical flame holding cover 4 are engraved at intermediate positions of the auxiliary flame holes 3 of the frame retention burner. The position at which the secondary air suction slit 5 to be engraved on the flame holding cover 4 is provided in the middle of the auxiliary flame hole, but is not limited to this. Is the position corresponding to the slit as described above, the width,
The depth can be changed.

[0018]

[Table 2]

Table 2 shows the measured flame current (μA) with respect to the gas pressure (mmH 2 O) of the Bunsen gas burner of the present invention.

The gas pressure is set at 150 m from 1.5 mmH2O.
When mH2O is used, the flame current value of the conventional burner can be increased from about 0.2 μA to 1.6 μA to 3.0 μA as shown in Table 2 in the burner of the present invention. Therefore, a commercially available industrial protection relay (the minimum required frame current value is 1.0 μA to 1.2 μA)
However, a burner which is in a range where detection can be sufficiently performed and which enables stable combustion is made.

Although the above embodiment has been described, the present invention is not limited to this embodiment, and various embodiments can be implemented without departing from the gist of the present invention.

[0022]

According to the first aspect of the present invention, in addition to the contact of the secondary air around the burner with the main flame, the same number of secondary air suction slits as auxiliary flame holes are formed in the cylindrical flame holding cover. This also sucks secondary air into the center of the flame,
The area where the flame comes into contact with the air can be increased. Therefore, the flame can be fixed to the main flame hole so that the base of the flame becomes excessive air combustion, the flame can be stably burned, the flame current value can be increased from the measured value of the conventional burner, and the safe and easy-to-use Bunsen gas A burner can be provided. When this frame retention burner with slit is applied to LPG medium pressure instead of 13A low pressure, the ratio of the relative primary air to be sucked can be increased, so the gas nozzle diameter is increased and the combustion amount is doubled compared to the conventional one. Nevertheless, there is no misfire because the flame holding capacity is improved. In other words, even with burners of the same size, the amount of combustion can be improved over conventional products.

According to the second aspect of the present invention, the position of the secondary air suction slit and the position of the auxiliary flame hole are set to be the same, so that the auxiliary flame of the auxiliary flame hole and the secondary air from the slit come into direct contact. To make the area of contact with the air of the flame in combination with the secondary air around the flame in the main flame hole, strengthen the auxiliary flame and strengthen the flame in the main flame hole Therefore, even when applied to a heating furnace such as a pottery kiln, stable combustion and a large flame current value can be obtained. Therefore, a burner which is in a range that can be sufficiently detected even by a commercially available industrial protection relay and that enables stable combustion can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a frame retention burner according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is a plan view of another embodiment of a frame retention burner.

FIG. 5 is a sectional view taken along the line YY of FIG. 4;

FIG. 6 is a sectional view showing a Bunsen-type gas burner provided with the frame retention burner of the present invention.

FIG. 7 is an explanatory diagram showing a suction state of primary air and secondary air of the Bunsen gas burner of the present invention.

FIG. 8 is an explanatory diagram showing a suction state of primary air and secondary air when (a) conventional LPG medium pressure and (b) conventional city gas 13A low pressure.

[Explanation of symbols]

 Reference Signs List 1 burner 2 main flame hole 3 auxiliary flame hole 4 flame holding cover 5 slit for secondary air suction

Claims (2)

[Claims] 1. A Bunsen type gas burner comprising a burner head comprising a main flame hole and an auxiliary flame hole, a frame retention burner comprising a cylindrical flame holding cover surrounding the burner head, a gas nozzle, a primary air hole, and a mixing pipe. 3. The Bunsen gas burner according to claim 1, wherein the same number of auxiliary air holes as secondary air suction slits are provided at the end of the cylindrical flame holding cover. 2. The position of a slit for secondary air suction provided in a cylindrical flame holding cover is a position facing an auxiliary flame hole of a frame retention burner.
The described Bunsen gas burner.