JP2001021110A - Method and device for combustion of gas burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for combustion of a gas burner wherein even if the orientation of a nozzle of the gas burner and the positional relationship of the burner and an object to be heated cannot be optimized corresponding to the purpose of combustion, the shape and orientation of a combustion flame from the gas burner can be formed. SOLUTION: A member 1, which can function as an electrode plate, is disposed on the side where a combustion flame 9 from a gas burner 2 is formed, and an electrode 4 having one of electric charges is inserted into a combustion flame from the gas burner, and the combustion of the gas burner is carried out in such a condition that the member 1 has the other electric charges. Thus, the combustion flame 9 is fordmed so as to be directed to the member 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for burning a gas burner, and more particularly, to a method for burning a gas burner capable of shaping the shape and direction of a combustion flame from the gas burner and a method for burning a gas burner using the combustion method. It relates to a combustion device.

[0002]

2. Description of the Related Art In the combustion of a gas burner, the shape of a combustion flame formed at the tip of a burner nozzle is basically determined by combustion factors such as nozzle diameter and nozzle angle, combustion gas injection speed, type, and air ratio. When a combustion condition is given, combustion proceeds naturally with one flame shape corresponding to the combustion condition. Therefore, when the shape or direction of the combustion flame is changed for any purpose, any of the above-mentioned various combustion factors is changed according to the purpose to obtain a required flame.

That is, under a certain combustion condition, when a combustion flame corresponding to the combustion is formed at the tip of the burner nozzle, if the object to be heated is to be heated with high heating efficiency by the flame, the gas burner and the heated By adjusting the relative positional relationship with the object to obtain high efficiency, the optimal heating conditions can be obtained from the combustion device or the environment where the object to be heated is placed, and the positional relationship between the gas burner and the object to be heated. If the positional relationship cannot be set, it is inevitable that the heating efficiency decreases.

For example, in the case of a gas burner using city gas as fuel gas, the flame (diffusion flame) tends to lift upward due to buoyancy. Therefore, the object to be heated is placed below and the flame of the gas burner is irradiated from above. It is difficult to obtain high heating efficiencies in a heating manner, so that city gas is not used as frequently as acetylene, for example, as a flame source for metal welding. In metal melting furnaces, special measures such as increasing the flow velocity by adjusting the diameter of the fuel injection nozzle, or adjusting the nozzle angle, so that the flame can be irradiated to the melting surface from above with high heating efficiency. Is required.

Further, in the case of manufacturing various cast articles by casting a molten metal into a mold, a burner flame is applied to the mold surface in order to secure the releasability of the cast article and to protect the mold surface of the mold. Is applied to apply soot as a release agent (for example, JP-A-56-165555,
Japanese Patent Application Laid-Open No. 5-104204), a flame using city gas as a fuel gas generates soot in a normal combustion state and has a tendency to lift upward as described above. If the surface is below or beside the burner nozzle, it will be difficult to deposit a sufficient amount of soot.

For this purpose, for example, in an apparatus for continuously casting a copper wire 21 from molten copper 20 as shown in FIG.
Conventionally, as fuel gas, acetylene which has a high combustion velocity and can blow out a flame at a high flow rate downward or to the side is used, and a large amount of soot is burned by a flame from an acetylene + air (fuel excess condition) premix burner 10. It is common to generate a protective film 13 of soot on the mold surface 12 of the mold 11 as shown in FIG. 8b. In FIG. 8,
Reference numeral 15 denotes a casting opening for pouring molten copper, and reference numeral 16 denotes a metal belt for guiding molten copper. However, acetylene has a self-destructive property, requires careful handling, and is expensive. In addition, not all of the large amount of soot generated adheres, but scatters over a wide area due to convection and buoyancy, so that it cannot be said that the trapping efficiency is high.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances in which a combustion flame from a gas burner is held, and determines the positional relationship between the direction of the nozzle of the gas burner and the object to be heated. It is an object of the present invention to provide a gas burner combustion method that can achieve a higher objective achievement rate than conventional combustion methods even when the optimal positional relationship cannot be set according to the purpose. Another object is to obtain a combustion device using the combustion method.

According to the combustion method and apparatus according to the present invention,
For example, when burning a gas burner for the purpose of heating,
The rate at which the amount of heat of the combustion flame is transferred to the object to be heated can be effectively increased, and when soot is to be attached to the mold surface, for example, when city gas is used as the fuel gas. Even so, it is possible to surely increase the amount of adhering soot.

[0009]

Means for Solving the Problems In order to solve the above problems, the present inventors have inserted an electrode into a combustion flame in the course of performing many observations and experiments on aspects of a combustion flame from a gas burner. Occasionally, they have found that the shape and orientation of the flame change, leading to the present invention.

That is, in the method of burning a gas burner according to the present invention, basically, a member that can be an electrode plate is arranged on the side of the combustion flame from the gas burner, and an electrode having one charge is inserted into the combustion flame from the gas burner. Then, the gas burner is burned in a state in which the member that can become the electrode plate has the other electric charge, whereby the combustion flame is shaped toward the member that can become the electrode plate.

The present invention also provides a gas burner combustion apparatus, a gas burner, an object to be irradiated with a combustion flame from the gas burner, and an electrode inserted into the combustion flame, wherein the object is an electrode. The object to be irradiated and the electrode are connected to electrode terminals having different polarities, respectively.

According to the experiments of the present inventors, when the gas burner is burned in accordance with the combustion method according to the present invention,
Regardless of the type of fuel gas, the combustion flame shapes its shape toward a member (an irradiation target to which the combustion flame is irradiated) that can be the electrode plate having the other charge, and the direction of the burner nozzle is adjusted. Even when the member that could become the electrode plate was slightly deviated from the vertical state, the flame tip could be brought into contact with the member that could become the electrode plate in a substantially vertical state. In addition, city gas is used as fuel gas,
Even if the gas burner is placed above the member that can be the electrode plate and the burner nozzle is burned downward, the flame does not lift upwards, but by adjusting the distance between the nozzle and the member that can be the electrode plate, it becomes the electrode plate. It could be spread out flat along the surface of the member.

[0013] In the method and apparatus for burning a gas burner according to the present invention, the reason why the combustion flame is shaped toward a member (an object to be irradiated with the combustion flame) which can be the electrode plate is not necessarily clear, but is as follows. Can be considered. Originally, cations, anions, and free electrons exist in the flame. When a positive electrode direct current discharge is performed in a flame, free electrons (having a negative charge) in the flame are much lighter in mass and easier to move than other ions, so that they can easily gather at the discharge electrode. The result is that the flame as a whole becomes positively charged, and that flow is likely to be due to the pulling of the mainstream.

The type of the current, the polarity, and the voltage between the electrodes are arbitrary, provided that the dielectric breakdown does not occur. However, in the experiments conducted by the present inventors, it is preferable that the electrode inserted into the flame side be a positive electrode. If the voltage was about 3 kV or more, the intended purpose was sufficiently achieved.

[0015] The method and apparatus for burning a gas burner according to the present invention can be used significantly in many fields. For example, a member that can be the electrode plate (an object to be irradiated with a combustion flame)
Is an object to be heated such as an object to be melted in a melting furnace (for example, metallic lead), even if the positional relationship between the burner nozzle and the object to be heated is not the optimal relationship for heating. Since the combustion flame is shaped toward the object to be heated, the combustion flame can be spread in a plane along the surface of the object to be heated, and the heating efficiency can be reliably increased.

Further, when the member that can be the electrode plate (the object to be irradiated with the combustion flame) is a mold, the method and apparatus for burning a gas burner according to the present invention provide a protective film (release film) on the mold surface. This is effective for adhering soot.
For example, when applying the combustion method of the present invention to a continuous casting apparatus as shown in FIG. 8a, the combustion flame from the gas burner 10 is actively shaped toward the mold 11 and along the mold surface 12 thereof. Spread. Therefore, when the fuel gas is acetylene, almost all of the generated soot is removed from the mold surface 12.
To form a release surface, and the amount scattered to the outside is extremely small. Thereby, the amount of acetylene used can also be minimized.

When city gas is used as the fuel gas, even when the burner nozzle is directed downward, the flame is prevented from floating up and is guided to the mold surface 12.
For this reason, the city gas, which has been extremely difficult to use in the past, can be effectively used as a fuel gas for generating a protective film (release film) in a mold. In addition, in the experiments performed by the present inventors, the amount of soot generated also increased as compared with the case where no electrode was inserted.

Since the city gas is cheaper and safer than acetylene, the combustion method of the present invention is very effectively used in the field of forming a protective film (release film) by soot on a mold. At that time, the city gas may be used alone as the fuel gas, but a mixed gas of the city gas and acetylene may be used to increase the amount of soot generated. Even in this case, the amount of acetylene used is reduced, and the cost is reduced and the safety is improved.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on experiments performed by the present inventors. 1 and 2
FIG. 1 illustrates a case where the present invention is applied when a gas burner is burned for the purpose of heating a metal plate.
2 shows a case where a voltage is applied, and FIG. 2 shows a case where no voltage is applied (conventional combustion method).

In FIG. 1, reference numeral 1 denotes a metal plate (aluminum plate) as an object to be irradiated with a combustion flame from a gas burner.
And is connected to the positive electrode terminal 51. Reference numeral 2 denotes a burner having a nozzle diameter of 3.7 mm.
It is arranged vertically downward toward the side. Reference numeral 4 denotes an electrode rod made of stainless steel connected to the negative electrode terminal 52, and is arranged so that the tip is located in the flame 9. A DC voltage of 0 to 10 kV is applied to the electrode terminals 51 and 52 from the power supply control box 53 at 1 mA or less.

A combustion experiment was performed using the above-described apparatus. Using city gas as fuel gas, flow rate 1.2L / min,
Linear distance 16 from the tip of burner nozzle 3 to aluminum plate 1
0mm, distance 50mm from the aluminum plate 1 to the tip of the electrode rod
When no current was applied, and when a voltage was applied in the range of 3 to 10 kV, the flame shape was observed. As shown in FIG. 2, when no voltage is applied, the combustion flame 9 floats upward, and the flame 9 does not come into contact with the aluminum plate 1. As the applied voltage is increased, the area where the lower end of the flame 9 contacts the aluminum plate 1 is expanded,
In V, as shown in FIG. 1, there was no lift of the flame, and almost all of the flame that came into contact with the aluminum plate 1 spread along the surface of the aluminum plate 1.

FIG. 3 is a schematic view showing a melting furnace 30 employing the above-described combustion method. The melting furnace as an object to be irradiated with a combustion flame from a gas burner and the side of the object to be melted are connected to a negative electrode terminal 52. And the electrode rod 4 connected to the positive electrode terminal 51 is positioned in the combustion flame from the burner 2 positioned above. In such a melting furnace, a metal raw material (a substance to be melted) 3
Thus, the combustion flame 9 can be spread in a plane with respect to the surface of No. 2 and the molten metal 33 can be obtained efficiently with high thermal efficiency.

Next, an experiment was conducted on the generation and adhesion amount of soot due to the combustion flame. The apparatus used is shown in FIGS.
As shown in FIG. 3, an aluminum water-cooled can 40 having a cooling water inlet 41 and a cooling water outlet 42 is provided.
To the negative electrode terminal 52 of FIG. Immediately above the aluminum water-cooled can body 40, a burner 2 having a nozzle diameter of 3.7 mm was disposed almost vertically with the nozzle 3 facing the aluminum water-cooled can body 40 side. On the upper surface of the aluminum water-cooled can 40, as a member corresponding to the mold surface 12 on which the protective film 13 made of soot shown in FIG. 8B is to be formed, an aluminum thin plate 43 (irradiated with combustion flame from a gas burner) is irradiated. (Corresponding to an object). An electrode rod 4 made of stainless steel is placed between the burner nozzle 3 and the aluminum water-cooled can 40 such that the tip is located in the flame 9, and the electrode rod 4 is connected to the positive electrode terminal of the power supply control box 53. 51, so that a DC voltage of about 0 to 10 kV can be applied at 1 mA or less. A soot adhesion experiment was performed using the above apparatus.

[Experiment 1] Using city gas as fuel gas, flow rate 1.2 L / min, linear distance 160 mm from the tip of burner nozzle 3 to aluminum thin plate 43, aluminum thin plate 4
The distance from 3 to the tip of the electrode rod 4 was 30 mm. Under this condition, when no current is applied (FIG. 5), the voltage is 5 kV,
When a positive current of 1 mA was applied, the combustion was continued for one minute for each of the cases (FIG. 4). In each case, the flame shape at the time of combustion was observed, and the surface of the aluminum thin plate 43 after one minute of combustion was visually observed.

As shown in FIG. 5, when no current was applied, the combustion flame 9 floated upward, and the flame 9 did not come into contact with the aluminum thin plate 1. Then, no color change was observed on the surface of the aluminum thin plate 43 after the lapse of one minute of combustion. When a voltage of 5 kV was applied, the flame did not rise as shown in FIG. 4, and almost all of the flame 9 in contact with the aluminum thin plate 43 spread along the surface of the aluminum thin plate 43. Then, the surface of the aluminum thin plate 43 after the lapse of one minute of combustion was uniformly black over the entire surface, and adhesion of soot was confirmed.

From the above results, in the apparatus shown in FIG. 8, even when city gas is used as fuel gas instead of acetylene, according to the combustion method of the present invention, ie, the burner 10 and the mold 11 Alternatively, an electrode rod connected to the positive electrode terminal is arranged between the metal belt 16 and
Since the flame is shaped toward the mold by connecting the mold 11 and the metal belt 16 to the negative electrode terminal side, it is possible to obtain a mold apparatus capable of reliably forming the required soot coating 13 on the mold surface 12 or the like. It is understood that it is possible.

[Experiment 2] Next, an experiment was conducted in a case where a mixed gas of city gas and acetylene was used as a fuel gas. The experimental conditions were the same as above, and the city gas flow rate was constant, and the acetylene flow rate was 0 to 1.1 L / min.
Changed. Aluminum plate 43 after 1 minute of combustion
The amount of soot adhering to the surface was measured by a change in mass before and after combustion. FIG. 6 shows the result. As shown in the figure, when no discharge was caused (when no voltage was applied to the electrode rod 4: ▽), no mass of adsorbed soot was observed even when acetylene was added, but discharge occurred (voltage was applied to the electrode rod 4). Case: ○)
Has an increased amount of adhesion almost in proportion to the acetylene flow rate. By the way, under the same combustion conditions, without discharge, only acetylene combustion, and after burning for 1 minute, the aluminum sheet 13
When 27 mg of soot (the amount of ◎ in FIG. 6, that is, acetylene flow rate 0.7 L / min) was attached to the surface of
A flow rate of acetylene of 1.1 L / min was required. From this, it can be seen that according to the combustion method according to the present invention, a large amount of soot deposition can be obtained with a small acetylene flow rate as compared with the conventional combustion method, and it is possible to obtain an inexpensive and highly safe mold surface. It is shown that the combustion method of the present invention is extremely effective as a method for forming a release surface using soot.

[Experiment 3] Further, in order to confirm the effectiveness of the present invention, the measurement results of the amount of soot deposited on an acetylene-air premix burner, which is a conventional combustion method, and the combustion method of the present invention shown in FIG. Was compared. FIG. 7 shows the measurement results of the soot adhesion amount in the conventional technique (acetylene-air premix burner). Here, the acetylene flow rate was fixed at 1.5 L / min, and the air ratio was adjusted by adjusting the air flow rate. ai
r ratio). As shown in the figure, the lower the air ratio, the higher the soot adhesion amount. Also, in the figure,
8, 12, and 16 mm indicate the distance between the burner outlet (nozzle tip) and the aluminum thin plate.

6 and FIG. 7, it can be seen that the soot adhesion amount at the acetylene flow rate of 0.7 L / min in FIG.
g (◎), whereas, in the conventional technique, a deposition amount corresponding to this condition cannot be obtained under the condition of a distance of 16 mm. At a distance of 12 mm, an air ratio of approximately 0.18, and at a distance of 4 mm, 8 mm, an air ratio of approximately 0.2, an equivalent amount of soot can be obtained. The flow rate is as high as 1.1 L / min, and it is also proved that the acetylene consumption is reduced by 30% or more by using the combustion method according to the present invention. When using the combustion method according to the present invention,
Even if the distance from the burner nozzle is large, a high soot adhesion amount is obtained, and the advantage that the degree of freedom in designing the mold apparatus is increased is also provided.

[0030]

According to the method and apparatus for burning a gas burner of the present invention, the direction of the flame can be actively shaped toward a member that can be an electrode plate. Even if it is not possible to set the positional relationship of (1) to the optimal positional relationship according to the purpose of combustion, a higher objective achievement rate can be obtained as compared with the conventional combustion method.

For example, when a gas burner is burned for the purpose of heating, it is possible to effectively increase the rate at which the amount of heat of the combustion flame is transferred to the object to be heated, and to attach soot to the mold surface. In this case, even if the city gas is used as the fuel gas, the amount of soot attached can be reliably increased.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a case where a combustion method and a device of the present invention are applied for the purpose of heating a metal plate, and FIG. 1 illustrates a case where a voltage is applied.

FIG. 2 is a diagram similar to FIG. 1, showing a case where no voltage is applied.

FIG. 3 is a schematic view showing a melting furnace employing the combustion method of the present invention.

FIG. 4 is a diagram illustrating a case where the combustion method of the present invention is applied for the purpose of generating soot by a combustion flame, and FIG.
This shows a case where a voltage is applied.

FIG. 5 is a view similar to FIG. 4, showing a case where no voltage is applied.

FIG. 6 is a graph showing the amount of soot deposited when the combustion method of the present invention is performed using a mixed gas of city gas and acetylene as a fuel gas.

FIG. 7 is a graph showing a soot deposition amount in a conventional technique (acetylene-air premix burner).

FIG. 8 is a schematic view illustrating an apparatus for continuously casting a copper wire from molten copper according to a conventional method, and FIG.
b shows a cross section of the mold surface.

[Explanation of symbols]

1, 43: members that can be electrode plates (heated object, aluminum plate, aluminum thin plate), 2, 10: gas burner, 3: nozzle, 4: electrode rod, 9: flame, 11: mold, 12: mold surface, 13 ... Soot protection film (peeling film), 51 ... Positive electrode terminal, 52 ... Negative electrode terminal, 53 ... Power supply control box

Claims (8)

[Claims] 1. A member which can be an electrode plate is disposed on a side where a combustion flame from a gas burner is formed, an electrode having one charge is inserted into a combustion flame from a gas burner, and the other charge is transferred to the member which can be an electrode plate. A method of burning a gas burner, comprising: burning a gas burner while holding the gas burner, thereby shaping a combustion flame toward a member that can be the electrode plate. 2. The heating device according to claim 1, wherein the member that can be the electrode plate is an object to be heated, and a combustion flame is shaped toward the object to be heated, thereby increasing the heating efficiency of the object to be heated. Gas burner combustion method. 3. The gas burner combustion method according to claim 2, wherein the object to be heated is an object to be melted in a melting furnace. 4. A member that can be said electrode plate is a mold, and a combustion flame is shaped toward said mold surface to increase the amount of soot as a protective film on the mold surface. 2. The method for burning a gas burner according to claim 1. 5. The gas burner combustion method according to claim 4, wherein a city gas alone or a mixed gas of a city gas and acetylene is used as the fuel gas. 6. A gas burner, an object to be irradiated with a combustion flame from the gas burner, and an electrode inserted into the combustion flame, wherein the object to be irradiated is made of a substance that can be an electrode plate. A gas burner combustion apparatus, wherein the object to be irradiated and the electrode are connected to electrode terminals having different polarities, respectively. 7. The gas burner combustion according to claim 6, wherein the gas burner combustion device is a combustion device constituting a part of a melting furnace, and the irradiation target is a melting target of the melting furnace. apparatus. 8. The gas burner according to claim 6, wherein the gas burner combustion device is a combustion device constituting a part of a device for adhering soot to a mold surface, and the object to be irradiated is a mold. Combustion equipment.