JPH0777314A - Gas burner - Google Patents

Abstract

PURPOSE:To raise a combustion efficiency at a high combustion time, and suppress a generation of CO gas quantity at a low combustion time by interposing and setting, on a burner head arranged in a combustion cylinder to which an immersion tube for heating a liquid is connected, a flame holding screen between it and its large diameter cyrindrical section. CONSTITUTION:A gas burner 10 suitable for a package burner of an immersion tube heating system for heating a fleon eliminating trichloroethane cleaning liquid and the like has a burner head 14 arranged in a combustion cylinder 12 connected by an immersion tube for heating a liquid. A burner head 14 is composed of a large diameter cylindrical section 16 and a small diameter cylindrical section 18 built in a row at its base center and to the small diameter cylindrical section 18 a tip edge of a gas feeding tube 20 is inserted and mounted. At cylindrical walls of respective cylindrical sections 16, 18, air introducing holes 24a, 24b, ... to introduce in a cylindrical section a combustion air passing through in a combustion cylinder 12 are formed. This burner head 14 has a flame holding screen 26 interposed at a boundary of both cylindrical sections 16 and 18 and contrives to suppress a generation of a large quantity of CO gas by preserving a flame at a low combustion time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas burner, and more particularly to a gas burner suitable as a package burner of an immersion tube heating type for heating a cleaning liquid such as a dechlorofluorocarbon / trichloroethane cleaning liquid.

[0002]

2. Description of the Related Art FIG. 7 shows the structure of a gas burner as a package burner of the seed immersion tube heating system which has been generally used. The gas burner 7 of the conventional structure shown in FIG.
0 is, for example, a burner head 74 composed of a large-diameter cylinder portion 74a and a small-diameter cylinder portion 74b provided in a combustion cylinder 72 to which an immersion pipe (not shown) for heating the dechlorofluorocarbon / trichloroethane cleaning liquid is connected. The small-diameter cylindrical portion 7 of the burner head 74
A gas supply pipe 76 is connected to 4b. On the other hand, the combustion cylinder 72
A blower fan (not shown) is connected to the air conditioning unit, and a fixed amount of combustion air is supplied. The large-diameter cylinder portion 74a and the small-diameter cylinder portion 74b of the burner head 74 are provided with air introduction holes 78a, 78b, ...
Combustion air is transferred to the burner head 74 via a, 78b.
It is adapted to be supplied into the large-diameter cylindrical portion 74a and the small-diameter cylindrical portion 74b.

The gas burner 70 shown in FIG. 7 has gas nozzle holes 77, 77 provided at the tip of a gas supply pipe 76.
The combustion gas supplied into the small-diameter cylinder portion 74b of the burner head 74 via the ... Is mixed with the combustion air supplied from the air introduction hole 78a of the small-diameter cylinder portion 74b, and the mixture is not shown. Ignition by the spark rod.
Then, the combustion gas is the large-diameter cylindrical portion 74 of the burner head 74.
Combustion air is further promoted by the combustion air introduced from the air introduction holes 78b, 78c ... Provided in a, and the combustion exhaust gas is sent to an immersion pipe (not shown) connected to the tip of the combustion cylinder. As a result, the cleaning liquid in the liquid tank in which this immersion pipe is installed is heated. In this case, the combustion gas in the burner head 74 continues to be burned by the air introduced through the air introduction holes 78a, 78b ... Of the large diameter cylinder portion 74a and the small diameter cylinder portion 74b, and mainly the large diameter cylinder portion 74a. The flame retaining state is maintained by the wall surface of the cylinder.

Thus, this type of gas burner adopts a so-called low combustion ignition direct ignition system, but generally does not have a mechanism for controlling the flow rate of combustion air in order to reduce the cost. Therefore, since the flow rate of the combustion air is set to a value required for high combustion, an excessive air ratio state occurs in low combustion during ignition, and CO gas of about 400 ppm is generated. However, even with this specification, ON-OF
When used in F control, the low combustion state continued for a few seconds at the time of ignition, and there was no problem in actual use.

[0005]

However, in such a gas burner of the immersion tube heating system, there is also a great need to use this package burner under Hi-Lo control in order to keep the liquid temperature at a constant temperature. In this case, a large amount of CO gas is generated at an excessive air ratio at the time of low combustion, and there is a problem that the cost of the device increases if a flow rate control mechanism for combustion air is provided in order to suppress the generation of this CO gas.

On the other hand, as a means for solving such a problem, a gas burner having the structure shown in FIG. 8 is also known. The gas burner 80 shown in FIG. 8 has a baffle plate 82 for holding a flame during low combustion and a burner head 74.
It is provided inside the large diameter cylindrical portion 74a so as to face the opening of the small diameter cylindrical portion 74b. However, according to this, although the baffle plate 82 holds the flame during low combustion and suppresses the generation of CO gas, the baffle plate 82 itself is always exposed to a high temperature flame, and the baffle plate 8
The back surface of 2 (upstream side of the combustion flame) is also heated by the back flame, and burning of the baffle plate 82 due to these heatings becomes a problem.

The present invention has been made in view of such problems, and an object thereof is to improve a combustion state at an excess air ratio during low combustion. The present invention aims to provide a gas burner excellent in combustion efficiency, particularly a gas burner suitable as a package burner for an immersion pipe heating system, at a relatively low cost without increasing the cost of the apparatus.

[0008]

In order to achieve this object, a gas burner according to the present invention is connected to a large-diameter cylindrical portion having an immersion pipe side open in a combustion cylinder to which an immersion pipe for liquid heating is connected, and a base portion thereof. A burner head composed of a small-diameter cylindrical portion provided is arranged, a combustion gas supply pipe is connected to the base of the small-diameter cylindrical portion of the burner head, and a blower fan is connected to the combustion cylinder. The burner head has a large-diameter cylindrical portion and a small-diameter cylindrical portion provided with an introduction hole for combustion air sent by the blower fan, respectively on the cylindrical walls of the large-diameter cylindrical portion of the burner head. The gist of the present invention is that a flame holding screen for holding a flame at the time of low combustion is provided at the boundary with the small-diameter cylindrical portion.

In a second aspect of the present invention, a burner head comprising a large-diameter cylindrical portion having an open tip and a small-diameter cylindrical portion connected to the base of the large-diameter cylindrical portion is arranged in the combustion cylinder through which combustion air flows. A combustion gas supply pipe is connected to the base portion of the small-diameter cylinder portion of the burner head, and combustion air introduction holes are provided in the cylinder walls of the large-diameter cylinder portion and the small-diameter cylinder portion of the burner head, respectively. The gist of the present invention is that a flame holding screen for holding a flame during low combustion is provided at the boundary between the large diameter cylindrical portion and the small diameter cylindrical portion of the burner head.

In these two inventions, the flame-holding screen is preferably provided with a large number of pores formed on the bottom plate surface of the large-diameter cylinder portion that separates the large-diameter cylinder portion and the small-diameter cylinder portion of the burner head. . As a result, the flame is prevented from backing up to the upstream side of the flame holding screen and the flame holding screen is not overheated.

[0011]

According to the gas burner of the present invention having such a configuration, the combustion gas introduced into the small diameter cylinder portion of the burner head through the gas supply pipe is introduced from the air introduction hole of the small diameter cylinder portion. The mixture is mixed with combustion air and the mixture is burned in the process of passing through the flame holding screen. Then, the combustion gas is further promoted for combustion by the air introduced from the air introduction hole of the large-diameter cylindrical portion of the burner head, the combustion exhaust gas is sent to the immersion pipe from the combustion cylinder, and the liquid heating is performed by the heat of the combustion exhaust gas. It is done.

At that time, the combustion flame of the burner head is retained on the wall surface of the large-diameter tubular portion during high combustion, while it is retained on the flame retention screen during low combustion. The flame on the flame holding screen is continuously burned by the combustion air introduced from the air introduction hole of the small diameter cylinder of the burner head, and is introduced from the air introduction hole provided in the large diameter cylinder. It is hardly affected by the lean burn phenomenon due to the blowing of the combustion air, and therefore the generation of CO gas due to the excess air ratio state due to the lean burn phenomenon of the combustion flame and the accompanying decrease in the combustion temperature is suppressed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a schematic structure of a head structure of an immersion pipe heating type gas burner according to an embodiment of the present invention. Further, FIG. 2 shows a cross section taken along the line AA of FIG. As shown in FIGS. 1 and 2, the gas burner 10 has a burner head 14 arranged in a combustion cylinder 12 to which a liquid heating immersion pipe (not shown here) is connected.

The burner head 14 is composed of a large-diameter cylindrical portion 16 having an open tip and a small-diameter cylindrical portion 18 connected to the center of the base of the burner head 14. Combustion air flows through the open end side of the large-diameter cylindrical portion 16. The small-diameter cylindrical portion 18 is arranged on the downstream side in the cylinder 12, and is arranged on the upstream side. The tip of the gas supply pipe 20 is inserted into the small-diameter cylinder portion 18 of the burner head 14, and the combustion gas sent by the gas supply pipe 20 is passed through the gas nozzle holes 22, 22 ... It is adapted to be supplied into the small-diameter cylindrical portion 18. On the other hand, in the cylinder wall of the large-diameter cylinder portion 16 and the cylinder wall of the small-diameter cylinder portion 18 of the burner head 14, the air introduction hole 24 for introducing the combustion air flowing through the combustion cylinder 12 into the cylinder portion.
a, 24b, ... Are provided.

Thus, in the present invention, the flame holding screen 26 is provided at the boundary between the large-diameter cylindrical portion 16 and the small-diameter cylindrical portion 18 of the burner head 14 (the open surface of the small-diameter cylindrical portion 18). The flame holding screen 26 is the burner head 1 in this embodiment.
The large-diameter cylindrical portion 16 and the small-diameter cylindrical portion 18 of No. 4 are each made of a stainless steel plate. Therefore, a large number of screen holes 28 are formed by punching the bottom plate surface of the large-diameter cylindrical portion 16 made of a stainless steel plate and having a bottom. , 28 ... Are formed by drilling. And burner head 14
The stainless steel small-diameter tubular portion 18 is integrally assembled by welding or bolting the flange portion at the open end to the outer bottom wall surface of the large-diameter tubular portion 16.

In the burner head 14, the small-diameter cylindrical portion 1 is provided.
The spark rod 30 for igniting the mixture of the combustion gas and the combustion air introduced into the flame holding screen 2
6, a frame rod 32 for detecting combustion flame after ignition is provided.

FIG. 3 shows the entire structure of a package burner of the immersion tube heating type for heating the cleaning liquid, to which the gas burner shown in FIGS. 1 and 2 is applied. In the gas burner shown in FIG. 3, a gas supply source (not shown) is connected to the base end of the gas supply pipe 20, and a first gas cutoff valve 34 for stopping the gas and a gas flow rate adjusting valve are connected to the pipe line. And a second gas cutoff valve 36 of. Further, a blower fan 38 is connected to the base end of the combustion cylinder 12, and this blower fan is ON-O.
The FF control is used but the air volume cannot be adjusted.

Further, in the control box 40 of this gas burner, the above-mentioned first and second gas cutoff valves 34, 3 are provided.
6. The blower fan 38 is connected, the spark rod 30 is connected through the ignition transformer 42, and the frame rod 32 is connected. On the other hand, the base end of the immersion pipe 46 arranged in a meandering manner in the cleaning liquid bath 44 is fitted to the outer periphery of the combustion cylinder 12 of the gas burner 10. A liquid temperature sensor 48 for detecting the liquid temperature of the cleaning liquid is provided in the bath 44, and a detection signal from the liquid temperature sensor 48 is sent to the control box 40, and the second gas cutoff valve 36 is sent based on the detection signal. The opening degree of is adjusted.

However, according to the gas burner thus constructed, as shown in the timing chart of FIG. 4, when the power of the control box 40 is turned on, the blower fan 38 is turned on by the signal and the combustion air is generated. It is forcibly supplied to the combustion cylinder 12 to which the burner head 14 is attached. This blower fan 38, as described above,
The amount of air blow cannot be adjusted.

Next, a signal from the control box 40 opens the first gas shutoff valve 34 for stopping the gas source,
At about the same time, the second gas cutoff valve 36 for adjusting the gas flow rate is opened, but since the ignition operation at the time of low combustion is initially performed, the opening degree of the second gas cutoff valve 36 is small, and in that state. The combustion gas is the gas nozzle hole 22 of the gas supply pipe 20.
Then, it is ejected into the small-diameter cylindrical portion 18 of the burner head 14.
Combustion air is also introduced into the small-diameter cylindrical portion 18 through the air introduction hole 24a, so that the spark rod 30 is turned on by a signal from the control box 40 so that sparks are continuously emitted and maintained. The mixture of combustion gas and combustion air that has passed through the screen holes 28 of the flame screen 26 is ignited.

Next, when the flame rod 32 senses the combustion of the air-fuel mixture, the second gas cutoff valve 36 is fully opened by a command from the control box 40 again, and the combustion of the gas shifts to a high combustion state. When the combustion in the burner head 14 shifts to a high combustion state, the air introduction holes 24b, 24c, ...
Combustion air introduced from is also used for gas combustion, and high temperature combustion exhaust gas is obtained.

In such a combustion state, the combustion exhaust gas from the gas burner 10 is sent to the immersion pipe 46, and the cleaning liquid in the bath 44 is heated by the heat of the combustion exhaust gas. The heating temperature of the cleaning liquid is detected by the liquid temperature sensor 48, and the detection signal is sent to the control box 40. In the control box 40, the opening degree of the second gas cutoff valve 36 for adjusting the gas flow rate is adjusted in two steps of full open and half open by the signal from the liquid temperature sensor 48, and the combustion state of the gas burner 10 is controlled in two steps of Hi-Lo. Is to do.

However, in the high combustion state, the combustion flame in the burner head 14 is held along the inner wall surface of the large-diameter cylindrical portion 16, and the air introduction hole 24b provided in the large-diameter cylindrical portion 16 is provided. Combustion is further promoted by the combustion air introduced from 24c. Therefore, the amount of CO gas and unburned gas in the combustion exhaust gas is small, and the combustion exhaust gas is used for heating and heating the cleaning liquid in a state close to complete combustion. Therefore, the thermal energy of the exhaust gas is sufficiently supplied to the liquid heating.

On the other hand, in the low combustion state, the combustion flame in the burner head 14 does not reach the inner wall surface of the large-diameter cylindrical portion 16, and the flame holding state is maintained on the flame holding screen 26 as shown in FIG. The combustion is maintained in the maintained state. At this time, the lean burn phenomenon due to the blowing of the combustion air introduced from the air introduction holes 24b, 24c of the large-diameter cylindrical portion 16 is avoided, and the flame temperature does not drop more than necessary.
Emission of O 2 gas and unburned gas to the atmosphere is avoided.

By the way, the rated input is 100,000 kcal /
When the burner of h was burned with low combustion in a state where the residual air amount of exhaust gas was 16.5%, the conventional gas burner produced 400 ppm of CO gas, but according to the gas burner of the present invention, the CO gas It was also obtained the result that the generation amount of was able to be reduced to 120 ppm.

Further, the flame holding screen 26 is the burner head 1.
The premix burner is formed in the small-diameter tubular portion 18 by being interposed between the large-diameter tubular portion 16 and the small-diameter tubular portion 18 of FIG.
Mixing of the combustion gas and the combustion air in the inside is promptly and sufficiently performed. Therefore, by extending the spark rod 30 onto the flame holding screen 26, it is possible to quickly ignite the air-fuel mixture that has passed through the flame holding screen 26. Further, since the air-fuel mixture is promptly obtained as described above, the ignition sound at the time of ignition of the air-fuel mixture by the spark rod 30 is suppressed.

Further, since the gas burner is ignited quickly, the propagation of the ignition sound to the immersion pipe is suppressed. Furthermore, since the flame holding screen is provided at the boundary between the large diameter tubular portion and the small diameter tubular portion of the burner head, the flame on the flame holding screen does not back to the back side (small diameter tubular portion side). The heating of the flame holding screen is also avoided. Burnout of the flame holding screen is thus avoided and permanent use is achieved.

In the above embodiment, the example in which the supply amount of the combustion gas is controlled in two stages has been described, but the control may be performed in three stages or in multiple stages. In the case of performing this multi-step control, the flame is retained by the flame retaining screen 26 at the time of the minimum combustion, and the flame becomes larger as the burnup increases, but the air close to the base end side of the large-diameter tubular portion 16 is provided. Combustion air is provided for combustion in order from the introduction hole 24b to the air introduction hole 24f near the open end side of the large-diameter cylindrical portion 16, so that combustion is efficiently enhanced. At the time of maximum combustion, the combustion air passing between the combustion cylinder 12 and the open end of the large-diameter cylinder portion 16 of the burner head 14 is also used for combustion.

FIG. 6 shows an embodiment for further increasing the combustion efficiency during high combustion. In the embodiment shown in FIG. 6, the combustion cylinder 12 and the attachment portion 4 of the immersion pipe 46.
A flow path 50 for combustion air is provided between the combustion cylinder 12 and
Is formed with an air introduction hole 52 communicating with the air flow passage 50, and after the combustion air flowing in the combustion cylinder 12 is sent to the air flow passage 50 through the air introduction hole 52, the combustion cylinder 12 is opened. It wraps around from the end side and is supplied to the combustion flame. With such a configuration, it is of course possible to suppress the generation of CO gas and the like by the flame holding screen 26 at the time of low combustion and to further improve the combustion efficiency at the time of high combustion.

As described in the above embodiments, according to the gas burner of the present invention, generation of CO gas and discharge of unburned gas are suppressed, but the present invention is not limited to the above embodiments. However, various modifications are possible without departing from the spirit of the present invention. For example, in the above embodiment, the flame holding screen was formed by punching a stainless steel plate to simplify the production and reduce the production cost, but a porous ceramic plate or the like may be provided. . In addition, the screen holes of the flame-holding screen are not limited to circular holes, and various shapes such as a lattice shape or a honeycomb shape can be considered. Further, although the cylindrical gas burner is shown in the above embodiment, it is needless to say that the invention is not limited to this and can be applied to a rectangular cylinder or a polygonal cylinder.

[0031]

As described above, in the gas burner of the present invention, the burner head arranged in the combustion cylinder to which the liquid heating immersion pipe is connected is kept between the large diameter cylinder portion and the small diameter cylinder portion. Since the flame screen is provided, not only the combustion efficiency at the time of high combustion is high, but also the generation of CO gas amount at the time of low combustion can be suppressed, and efficient combustion is achieved. Applying this gas burner to a package burner of an immersion pipe heating system for liquid heating, etc., allows thorough control of the liquid temperature by Hi-Lo control of combustion by suppressing the generation of CO gas amount during low combustion. It is extremely useful in industry because it can contribute to a cleaner working environment and also has the effect of suppressing ignition noise.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a gas burner according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of the gas burner shown in FIG.

3 is an overall configuration diagram of an example in which the gas burner shown in FIG. 1 is applied to an immersion pipe heating type gas burner for heating a cleaning liquid.

FIG. 4 is a timing chart of combustion sequence control of this gas burner.

5 is a diagram illustrating a low combustion state of the gas burner shown in FIG.

FIG. 6 is a schematic configuration diagram of a gas burner according to another embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a gas burner generally used conventionally.

FIG. 8 is a schematic configuration diagram showing another example of a conventional gas burner.

[Explanation of symbols]

 10 Gas Burner 12 Combustion Cylinder 14 Burner Head 16 Large Diameter Cylinder 18 Small Diameter Cylinder 20 Gas Supply Pipe 22 Gas Nozzle Hole 24a-24f Gas Introducing Hole 26 Flame Retaining Screen 28 Screen Hole 38 Blower Fan 44 Bathtub 46 Immersion Pipe

 ─────────────────────────────────────────────────── (72) Inventor Hiroshi Asai 19-18 Sakurada-cho, Atsuta-ku, Nagoya-shi Toho Gas Co., Ltd. (72) Inventor Hiroaki Marubayashi 19-18 Sakurada-cho, Atsuta-ku, Nagoya Toho Gas Co., Ltd. (72) Inventor Nao Kobayashi 1-177 Miyamachi, Ginan-cho, Hashima-gun, Gifu Kato Iron Works Co., Ltd. (72) Inventor Akihiko Iwata 1-177 Miyamachi, Ginan-cho, Hashima-gun, Gifu Kato Iron Works Co., Ltd. Inside the burner factory

Claims (4)

[Claims] 1. A burner head comprising a large-diameter cylindrical portion having an opened immersion pipe side and a small-diameter cylindrical portion connected to the base thereof is arranged in a combustion cylinder to which a liquid heating immersion pipe is connected. A combustion gas supply pipe is connected to the base portion of the small-diameter cylinder portion of the burner head, and a blower fan is connected to the combustion cylinder, and a cylinder wall of the large-diameter cylinder portion and the small-diameter cylinder portion of the burner head is connected. Each of them is provided with an introduction hole for combustion air sent by the blower fan, and holds a flame at the time of low combustion at a boundary between the large diameter cylinder portion and the small diameter cylinder portion of the burner head. A gas burner characterized by being provided with a flame holding screen. 2. The flame-holding screen has a large number of pores formed on the bottom plate surface of the large-diameter cylinder portion that separates the large-diameter cylinder portion and the small-diameter cylinder portion of the burner head from each other. The gas burner according to claim 1, wherein the gas burner is a gas burner. 3. A burner head comprising a large-diameter tubular portion having an open tip and a small-diameter tubular portion connected to the base thereof is disposed in a combustion cylinder through which combustion air flows, and the small-diameter cylinder of the burner head. A combustion gas supply pipe is connected to the base of the burner head, and combustion air introduction holes are provided in the cylinder walls of the large-diameter cylinder portion and the small-diameter cylinder portion of the burner head, respectively. A gas burner characterized in that a flame holding screen for holding a flame during low combustion is provided at a boundary between a large diameter cylinder portion and a small diameter cylinder portion of a burner head. 4. The flame-holding screen has a large number of pores formed on the bottom plate surface of the large-diameter cylinder section that separates the large-diameter cylinder section and the small-diameter cylinder section of the burner head. The gas burner according to claim 3, wherein the gas burner is a gas burner.