JP2970632B2 - Premix burner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a premix burner in which a premixed gas is blown out from a large number of flame holes formed in a flame holding body to form a flame.

[0002]

2. Description of the Related Art In recent years, due to environmental problems such as air pollution, gas fuels such as city gas and LPG, which have extremely small amounts of harmful components in combustion gas, tend to be used extensively in industry, and gas burners are also used in industrial machines such as boilers. Things are increasing. A so-called surface combustion burner of a type in which a premixed gas flows out through a flame holding body having a large number of fine holes (flame holes) formed in one of these gas burners to form a large number of minute flames on the surface of the flame holding body. There are premix burners that are used. When it is necessary to change the capacity of the premixing burner depending on the equipment to be used, generally, a small flame stabilizer is used as a unit unit, and a predetermined frame-shaped frame is formed in a state where a predetermined number of the flame stabilizer units are combined. To accommodate various types of burners.

[0003]

In the premixed burner described above, when the supply pressure of the premixed gas is increased in order to achieve high load combustion, the minute flame from the surface of the flame holder gradually increases in size. Increase. As is well known, the combustion reaction is performed in a region where the ejection speed of the premixed gas and the combustion speed are balanced, and in the above-described conventional premixed burner, as the supply pressure of the premixed gas is increased, a flame is generated. Unite,
Eventually, the combustion reaction region becomes flat. In this state, the combustion reaction region is narrow with respect to the supply premixed air amount, the flame stability is poor, and the combustion involves vibration. In particular, when a change in the supply pressure of the premixed gas causes a change in the ejection speed of the premixed gas, the above-described equilibrium state is easily broken, and a lift or blowout occurs in the flame. Further, at the time of ignition in this kind of premixed burner, the flame spreads instantaneously over the entire flame holding body, so that there is a problem that the impact at the time of ignition is large.

In order to solve this problem, a frame-shaped frame holder member having a predetermined number of window holes is provided on the surface of the flame holding body, or the like, so that a group of small holes for each predetermined number is formed. There is a premix burner in which a region contributing to the above-mentioned combustion reaction is enlarged by forming a compartment on the flame holding body surface. In this premixed burner, the noise level at the time of combustion is significantly reduced as compared with a conventional burner, but there is a need for further improvement in flammability and noise.

[0005] Furthermore, a premixed burner of small size and high load combustion type, which has high versatility for applied thermal equipment and is capable of stable combustion, has not been technically achieved, and there is also a demand from the market for such a burner. Is growing. Therefore, the applicant has further studied and tried to set conditions for stable combustion in this kind of burner, and in such a series of studies, learned such a relationship and completed the present invention.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the invention according to the first aspect of the present invention ejects premixed gas from a large number of flame holes formed in a flame holding body. Then, in the premix burner of the type that forms a flame, the large number of flame holes are a main flame hole group for forming a main flame having the same flame hole configuration as each other, and a smaller number of the main flame hole groups than each of the main flame hole groups. A large number of rows are arranged on the flame holding body as sleeve fire row groups for forming a sleeve fire row composed of fire holes, respectively, in a direction along an axial direction of a heat transfer tube of a heat appliance to which each of the main flame fire holes is applied. 3. The method according to claim 2, further comprising: arranging the sleeve flame row groups in tandem along the direction in which the main flame flame groups are arranged between the rows of the main flame flame groups. The invention described in the above, between each of the main flame flame hole group between each row of each sleeve flame line hole group, Than ¥¥ hole group is characterized in that a sleeve flame hole groups for sleeve fire formed consisting of a small number of burner ports.

[0007]

According to the premix burner of the present invention, the flames formed on the surface of the flame holding body have the same flame hole configuration as each other,
A large number of main flames divided and formed by a large number of main flame hole groups arranged in tandem in a plurality of rows at a predetermined interval from each other, and in the arrangement direction of each main flame hole group between each row of each main flame hole group. Is formed independently of the sleeve flames formed by the sleeve flame rows for forming the sleeve flames arranged in tandem along the line, and the arrangement direction of the main flame holes and the sleeve flame rows is applied. By setting the direction along the axial direction of the heat transfer tube of the heat equipment, the flame easily flows into the heat transfer tube gap, and the inconveniences such as noise and increase in flow path resistance can be eliminated. In addition, the main flame is large and long, and the sleeve flame is small and short, so that even if the premixed gas ejection speed changes, the state of balance with the combustion speed is maintained, and stable combustion with high flame holding properties is performed. As a result, the combustion reaction area expands. Further, since the size (length) of the flame is different between the main flame and the sleeve flame, combustion resonance is reduced and noise is reduced. Further, a sleeve flame hole group for forming a sleeve fire composed of a smaller number of flame holes than the main flame flame hole groups is arranged between the main flame flame hole groups between the respective rows of the sleeve flame row flame hole groups. Thereby, the oscillation frequency of the flame is further dispersed, and the occurrence of combustion resonance can be more effectively prevented.

[0008]

1 to 4 show a first embodiment of a surface combustion burner as a premix burner according to the present invention. In these drawings, the flame stabilizing body 10 has a large number of flame holes 11 penetrating the front and back sides thereof and ejecting a premixed gas. The basic structure of the flame holding body 10 in the first embodiment is that the ceramic particles are molded into a flat plate shape by molding, such as sintering or binding, after clamping. The large number of flame holes 11 are simultaneously formed at the time of mold clamping,
Alternatively, it is formed by piercing thereafter.

In the flame holder 10, the plurality of flame holes 11 are formed by a main flame flame hole group A forming a main flame and a sleeve flame hole group B forming a small sleeve flame group around the main flame. And a sleeve fire line group C forming a sleeve fire line surrounding the main flame hole group A and the sleeve fire hole group B, and a sleeve fire formed by the sleeve fire line group C The columns are set so that they are arranged in columns. Here, as shown in the figure, the main flame flame hole groups A have the same flame hole structure as each other, that is, the number and arrangement of the flame holes 10 are the same, and they are regularly arranged up and down, left and right at predetermined intervals. I have. Then, when a large number of main flame flame hole groups A arranged in the vertical direction are defined as a vertical main flame flame hole group A row,
Adjacent longitudinal main flame flame hole groups A have a staggered relationship. Further, the major axis direction (maximum width direction) of the main flame flame hole group A is set to the direction along the arrangement direction of the sleeve flame row flame hole group C. Further, when a plurality of rows of sleeve flames are formed by the sleeve flame row holes C, they are arranged so as to be parallel to each other.

Further, the number of the flame holes 11 in the main flame hole group A, the sleeve flame hole group B, and the sleeve flame line hole group C is appropriately changed, so that each flame hole group A, B, In addition to being densely arranged for each C, the flame holes A, B, and C are arranged on the flame holding body 10 at a predetermined interval. That is, a non-flame region N where no flame is formed is formed between each of the flame hole groups A, B and C where a flame is formed.

The first embodiment will be described in more detail. The main flame hole group A has 36 flame holes 11 arranged in a substantially hexagonal shape. The sleeve flame hole group B includes three flame holes 11 arranged in a triangular shape and four flame holes 11 arranged in a substantially rhombic shape. A sleeve flame row group B forming a sleeve fire row surrounding the main flame hole group A and the sleeve flame hole group B is a group in which eight flame holes 11 are collectively arranged in a substantially trapezoidal shape. A plurality of sleeve fire lines formed by the sleeve fire line flame hole group B are provided substantially in a straight line while alternately reversing their directions. Further, the main flame flame hole group A having the hexagonal shape has a maximum outer diameter dimension direction (an axial direction passing between the most distant portions, so-called,
(Long axis direction) is defined as the direction along the arrangement direction of the sleeve flame row holes C.

Further, when the premix burner in the first embodiment is used in a vertically installed state such that the surface of the flame holding plate 10 is vertically oriented, at least the sleeve flame row hole group C is used.
So that the arrangement direction of a series of sleeved fire rows formed along the vertical direction of the flame holding body 10 (about 3
Incline up to about 0 degrees is acceptable. ) Is set,
Considering the convenience of mounting on a thermal device having a large number of vertical heat transfer tubes as described above, the direction in which the sleeve fire rows are formed by the sleeve fire row flame hole group C is a rectangular flat plate-shaped flame holding member 10. Is preferably formed in a state where an appropriate angle within the above-described range is provided with respect to one side.

Regarding the function of the premix burner having the above-mentioned structure,
This will be described below. First, at the time of ignition, a part of the premixed burner is ignited by a pilot burner or the like. This flame is formed so that the flame propagates sequentially for each of the flame hole groups A, B, and C. So that the flame is instantaneous flame holder 1
Since it does not spread over the entire surface of 0, the ignition sound and the impact can be suppressed to be small. Further, since the flame holding property and stability of the flame are significantly improved, a predetermined flame shape can be formed immediately after ignition.

Further, in the premix burner according to the present invention, the flame formed for each of the flame hole groups A, B, C on the flame holding body 10 includes a plurality of flames of each of the flame hole groups A, B, C. This is due to the premixed gas ejected from the holes 11, and each of these flame holes 11
When the supply pressure of the premixed gas is increased, the flame due to is integrated with the flame from the adjacent flame hole 11 and becomes a larger flame. However, in the premix burner according to the present invention, the flame hole groups A, B, and C are formed at a predetermined distance from each other, and the non-flame region N is provided between the flame hole groups A, B, and C. Therefore, the integration of the flame for each of the flame hole groups A, B, and C is prevented (see FIG. 3). Therefore, even if the supply pressure of the premixed gas is high and the combustion load is high, each of the flame hole groups A, B, C
Each time a flame is formed independently, the area contributing to the combustion reaction expands more than the conventional one, and even if the injection speed of the premixed gas changes due to the fluctuation of the supply pressure of the premixed gas, the combustion speed is balanced. Even if the condition is maintained and the balance is broken,
It recovers easily and stable combustion is performed.

Further, since the size (length) of the flame of each of the flame hole groups A, B and C depends on the bottom area, that is, the size and the number of the flame holes 11, the flame of the main flame hole group A is long. The flames of the sleeve flame hole group B and the sleeve fire row flame hole group C are shorter. Therefore, when the load is increased, the flame shape of the burner as a whole is appropriately lengthened and shortened, so that the flame holding property is enhanced and the vibration frequency of the flame by each of the flame hole groups A, B, and C is different from each other. Therefore, the vibration frequency is dispersed throughout the burner, and the generation of combustion resonance noise can be effectively prevented. Therefore, noise during combustion, particularly during high load combustion, is reduced, and stable combustion can be performed.

Further, the second sleeve fire row flame hole group C is arranged so as to form a sleeve fire row in a tandem arrangement, and the flame by this sleeve fire row is appropriately divided by the non-flame area N described above. As a result, while exhibiting the above-described flame holding effect, the whole extends in a thin wall shape in the orthogonal direction from the surface of the flame holding body 10, and the flames formed by the main flame hole group A and the sleeve flame hole group B therebetween have the same direction. A flame is formed which is divided into strips.

As described above, the direction of the flame divided in a narrow direction is easily changed by the influence of the flow path shape, gravity, air flow, and the like in the narrow direction, and the flame direction is changed in the wide direction. Are less susceptible to the aforementioned effects. Therefore, when this burner is applied to a combustion apparatus having the heat transfer tubes 20 arranged in parallel, combustion can be stabilized by arranging the state of flame formation in association with the direction of the heat transfer tube gap.

That is, in order to apply the premix burner having the above-described configuration to a heat appliance, particularly to a boiler having vertical heat transfer tubes arranged in parallel with each other, the following settings are made (see FIG. 4). As shown in the figure, a premixed burner composed of the flame holding body 10 having the above-described configuration is used to transfer a set of parallel sleeved fire rows of the group C of fired sleeves of the sleeve to the direction of transmission of the thermal equipment to be applied. The heat pipes 20 are arranged parallel to the axial direction or at an appropriate inclination angle (acute angle), and substantially have a flat cross section that is long and thin in the axial direction of the heat transfer pipes over the entire flame hole group of each flame hole or the entire premixing burner. Set to form a flame.

According to such an arrangement method, the flame from the flame holder 10 is divided into thin-walled flames extending in the axial direction of the heat transfer tube 20 by the non-flame regions N on both sides of the above-mentioned sleeve flame train. Since a series of flames along the arrangement direction of the sleeve fire rows flutter integrally, each flame flows along the surface of the heat transfer tube 20.

Therefore, the main flame and the surrounding sleeve fire are sandwiched by the thin-walled sleeve fire row of the sleeve fire row flame hole group C, and a flame is formed in a state where the flame groups are connected in series. Thereby, the direction of the flame holding state of the flame can be made different on the surface of the flame holding body 10, and the flame can be easily circulated through the gaps of the heat transfer tubes 20 of the applicable combustion equipment.

The reason for this is that, in the conventional premix burner, the direction of the flame holding property of the flame is not given, so that when the flame flows into the gap between the heat transfer tubes, the individual flames are divided by the heat transfer tubes. The resistance at this time is large, and the heat transfer tube 2
Although the vortex is easily generated on the downstream side of the flame, the noise and the increase of the flow path resistance are caused. However, in the premix burner according to the present invention, the flame formed on the surface of the flame holding body 10 as described above is used. This is because the direction of the flame holding direction has a direction, and the flame easily flows into the gap between the heat transfer tubes 20 by matching this direction with the arrangement direction of the heat transfer tubes 20. In other words, since the flame has a flame shape having a spread substantially similar to the spread direction of the gap formed between the plurality of heat transfer tubes 20, after flowing along the surface of the heat transfer tube 20, This easily flows into the gap between the heat transfer tubes 20.

When the flame stabilizing body is arranged so as to jet a premixed gas horizontally or obliquely, the flame formed on the flame stabilizing body is generally affected by gravity and air current (ascending air current). As a result, the flame spreads radially from the surface of the flame holder toward the periphery, and the tip of the flame tends to be deflected upward. The smaller the size of the flame, the easier it is to hold the flame, but the flame tends to be deviated due to the influence of the flow path, gravity, air flow and the like. However, as in the premix burner according to the present invention, the direction of the flame holding condition of the flame is made different on the surface of the flame holding body 10, so that the premixed gas is injected regardless of the influence of gravity, airflow, etc. as described above. A flame can be formed along the direction, that is, the axial direction of the flame hole 11.

In the case where the combustion equipment to which the premix burner is applied has a structure in which the heat transfer tubes 20 are vertically arranged, the above-described operation and effect and the direction of the flame holding state of the flame are maintained as described above. By making it different on the surface of body 10,
By associating the flame holding direction with the arrangement direction of the heat transfer tubes 20, the flame easily flows into the gap between the heat transfer tubes 20, so that the above-described inconveniences such as noise and an increase in flow path resistance can be solved.

In the above, the case where the premix burner is arranged vertically (in the direction in which the flame extends horizontally) has been described. In the present invention, however, the premix burner is arranged horizontally (in the direction in which the flame extends in the vertical direction). ).

In the above-described first embodiment, the shape of the flame holes forming the main flame holes is substantially hexagonal. However, the shape of the flame holes is not limited to the first embodiment, but may be square, rhombus, or the like. Further, as shown in FIG. 5, an appropriate number of sleeve flame holes are gathered and interposed between the main flame holes, and as shown in FIG. It is also possible to make the number of rows of flame holes different for each set, as shown in FIG. 7, the number of rows of flame holes of each sleeve flame row hole group is minimized (one row), and so on. The shape can be appropriately changed without departing from the gist of the present invention.

Further, the flame holding body 10 is formed by sintering ceramic particles and forming flame holes so as to be grouped into this formed body. As the burner, a porous material such as foamed ceramics or a ceramic grain sintered block can be used, and a porous block in which flat and corrugated ribbons are laminated can also be used.

Further, the flame holes of the premix burner may be formed directly on a plate-like material of such a material, or may be formed on the front surface or the back surface of the premix burner in a frame shape for appropriately dividing the flame holes. A configuration in which a body is provided may be employed. For example, by disposing a frame 30 as shown in FIG. 8 on the combustion surface side or the back surface of a premix burner in which a large number of flame holes are formed uniformly, the flame holes substantially as shown in FIG. To form a group of flame holes.

In addition, the basic shape of the premix burner is a flat plate in each of the above embodiments. However, the present invention is not limited to the flat plate, but may be a curved surface or a cylindrical shape. Therefore, it can be appropriately changed according to the purpose of use of the premixing burner or the furnace shape of the thermal equipment to be applied.

[0029]

As described above, in the premixing burner according to the present invention, the flames formed on the surface of the flame holding body have the same flame hole configuration, and are tandemly arranged in multiple rows at a predetermined interval. A large number of main flames divided and formed by a large number of main flame flame holes arranged, and a sleeve fire line formation which is arranged in tandem along the arrangement direction of each main flame flame hole group between each row of each main flame flame hole group. The direction in which the main flame holes and the sleeve flame holes are arranged independently of the sleeve flames formed by the sleeve flame holes and the direction along the axial direction of the heat transfer tube of the thermal equipment to which the heat flame is applied. By doing so, it becomes easier for the flame to flow into the heat transfer tube gap, and problems such as noise and an increase in flow path resistance can be eliminated.

In addition, the main flame is large and long, and the sleeve flame is small and short. The flame is divided and formed over the entire flame holding body, and the combustion reaction region is enlarged. Therefore, the flame holding body has a large area and a high combustion load burner. However, even if there is a change in the injection speed of the premixed gas due to fluctuations in the supply pressure of the premixed gas, etc., a stable flame can be obtained, and the flame lift and blowout that have been a problem in the past can be obtained. Can be prevented. Furthermore, since the combustion load can be increased compared to conventional ones,
If the amount of combustion is the same, a significantly smaller burner can be obtained.

Further, since the numbers of the flame holes constituting the main flame hole group and the sleeve flame line group are different, the vibration frequencies of the main flame and the sleeve flame line are different from each other. Since the oscillation frequency of the flame is dispersed and the occurrence of combustion resonance can be more effectively prevented, combustion resonance noise, ignition shock and the like can be eliminated.

Further, a sleeve flame hole group for forming a sleeve fire, comprising a smaller number of flame holes than the main flame hole groups, between the main flame hole groups between the respective rows of the sleeve flame hole groups. Is arranged, the oscillation frequency of the flame is further dispersed, and the occurrence of combustion resonance can be more effectively prevented.

Therefore, according to the present invention, it is possible to obtain a low-noise, high-commercial-value premix burner capable of high load combustion.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of a premix burner according to the present invention.

FIG. 2 is a longitudinal sectional view taken along line II of FIG.

FIG. 3 is a diagram for explaining the function of the premix burner shown in FIG. 1, and is a schematic perspective view schematically showing each flame hole group.

FIG. 4 is a schematic diagram for explaining a function when a premix burner according to the present invention is applied to a thermal device.

FIG. 5 is a plan view of a main part of a second embodiment of the premix burner according to the present invention.

FIG. 6 is a plan view of a main part showing a third embodiment of the premix burner according to the present invention.

FIG. 7 is a plan view of a main part showing a fourth embodiment of a premix burner according to the present invention.

FIG. 8 is a plan view of a main part showing a fifth embodiment of the premix burner according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Flame holding body 11 Flame hole 20 Heat transfer tube A Main flame flame hole group B Sleeve flame flame hole group C Sleeve flame flame hole group

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-51-46265 (JP, A) JP-A-2-306007 (JP, A) JP-A-3-213904 (JP, A) 134221 (JP, U) Japanese Utility Model Hei 5-96722 (JP, U) Japanese Utility Model Utility Model 3-64317 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23D 14/14 F23D 14 / 16

Claims (2)

(57) [Claims] 1. A premix burner of the type in which a premixed gas is blown out from a large number of flame holes 11 formed in a flame holding body 10 to form a flame. The same flame holding member as a main flame forming hole group A for forming the same main flame and a sleeve flame forming hole group C for forming a sleeve fire line formed of a smaller number of flame holes 11 than each of the main flame forming hole groups A. 10, a plurality of the main flame flame hole groups A are arranged in tandem in a direction along the axial direction of the heat transfer tube 20 of the heat equipment to which the main flame flame hole groups A are applied. A premix burner characterized in that said main flame burner group A is arranged in tandem between each row of said flame burner group A along the arrangement direction of said main flame burner group A. 2. Between the main flame flame hole groups A between the respective rows of the sleeve flame flame hole groups C, there are formed a smaller number of flame holes 11 than the main flame flame hole groups A. The premix burner according to claim 1, wherein a sleeve flame hole group (B) is arranged.