JPWO2007086146A1 - Combustion device - Google Patents

Abstract

An object of the present invention is to improve a combustion apparatus that performs two-stage combustion, and to develop a combustion apparatus that generates a primary flame and a secondary flame in a well-balanced manner and spreads uniformly over the entire combustion site. The combustion apparatus 1 has an intermediate member 6 composed of a premixing member 2 and a flame hole member 3 and an air flow path member 6. The intermediate member 6 is sandwiched between two air flow path members 5. ing. The fuel gas flows into the opening row portion 10. In the opening row portion 10, since a large number of openings 8 are arranged in a straight line, the fuel gas that has entered the opening row portion 10 is evenly discharged from each opening 8. The fuel gas discharged from the opening 8 of the opening row portion 10 collides with air at a portion of the mixing space 39. The fuel gas discharged from the slit is uniform and the discharge speed is uniform. The fuel gas generates a primary flame in the first combustion unit 46, and primary combustion is performed. The unburned component is released to the outside through the opening of the first combustion unit 46, and air is supplied from the tip of the air flow path member 5 to generate a secondary flame.

Description

  The present invention relates to a combustion apparatus, and more particularly to a combustion apparatus recommended for use in a water heater or a bath apparatus.

Combustion devices are main components of water heaters and bath devices, and are widely used not only in factories but also in general households.
In recent years, environmental destruction caused by acid rain has become a serious social problem, and there is an urgent need to reduce the total amount of NOx (nitrogen oxide) emissions.
There is a combustion apparatus that employs a combustion method called a concentration combustion method as a configuration that can be employed in a small device such as a hot water supply device and that can suppress the amount of NOx generated.
In the lean combustion method, the main flame is generated from a dilute gas mixture that is premixed with about 1.6 times the theoretical air volume in the fuel gas, and there is little air mixing in the vicinity of the main flame. A flame holder generated from a mixed gas having a high concentration is arranged.
For example, Patent Documents 1 and 2 disclose a combustion apparatus that uses light and shade combustion.

In addition, there is another combustion method called a two-stage combustion method as a combustion method that generates little NOx. The two-stage combustion method is a combustion type in which fuel gas is injected in a state where oxygen is insufficient, the gas is ignited to generate a primary flame, and secondary air is supplied to unburned gas to generate a secondary flame. is there.
A combustion apparatus employing a two-stage combustion method is disclosed in Patent Document 3.
Japanese Patent Laid-Open No. 5-118516 JP-A-6-126788 JP-A-52-143524

A combustion apparatus that employs the lean combustion method has a small amount of NOx generated and is well-received in the market, but has a drawback of a small turn-down ratio (Turn Down Ratio TDR). In particular, a combustion apparatus that employs the light and dark combustion method has a drawback that it is difficult to burn in a region where the calorific value is small.
That is, in the lean combustion method, as described above, the main flame is generated from a lean mixed gas obtained by premixing the fuel gas with about 1.6 times the theoretical air amount. Although this mixed gas is lean, its combustion speed is slow.

  By the way, the combustion apparatus which employs the light and dark combustion method includes a blower for generating a lean mixed gas. However, the blower has been used for many years, and the amount of blown air gradually decreases as the blower ages. The amount of air flow may be reduced due to clogging of the filter. Thus, when the amount of blast decreases due to secular change, the amount of air of the mixed gas that forms the main flame tends to decrease, and the amount of air to be mixed approaches the theoretical amount of air. As a result, the combustion speed of the main flame tends to be accelerated by secular change, and the base end portion of the flame gradually approaches the flame hole due to secular change. Therefore, when burning in a region where the heat generation amount is small, the base end portion of the flame approaches the flame hole and damages the flame hole. Therefore, a combustion apparatus that employs the light and dark combustion method must limit combustion in a region where the calorific value is small in anticipation of secular change.

In addition, the lean combustion method is unsatisfactory because the range of usable gases is narrow. That is, the fuel gas supplied by the gas manufacturer may be composed of only a single component, but in many cases, a fuel gas of a plurality of components is mixed. For this reason, even if the amount of heat generated (the amount of heat per unit volume) is the same, the combustion rate differs for each fuel gas manufacturer.
On the other hand, in the light / dark combustion method, the main flame is burned in an excess air state, so that the fuel gas having a low combustion speed is burned out and cannot be burned stably.

  On the other hand, when the two-stage combustion method is employed, the turndown ratio can be increased as compared with the case where the concentration combustion method is employed. There are also a wide variety of applicable fuel gases. However, in the two-stage combustion method, the combustion state is unstable because the fuel gas is burned in a state where oxygen is insufficient. For this reason, there are no commercially available hot water heaters that employ the two-stage combustion method.

That is, in order to put it into practical use as a combustion apparatus, it is necessary to generate a flame that spreads uniformly over a certain area. For this purpose, the primary flame and the secondary flame must be generated in a well-balanced manner and be uniform over the entire combustion site.
However, it is difficult to generate a primary flame and a secondary flame in a well-balanced manner and distribute them uniformly over the entire combustion site. That is, the primary flame partially disappears and the downstream secondary flame becomes excessive, or all the fuel burns at the site where the primary flame should be generated, and the downstream secondary flame disappears. May end up. Therefore, none of the water heaters that have been put to practical use employ a two-stage combustion method.

  Therefore, the present invention focuses on the above-mentioned problems of the prior art, improves the combustion apparatus that performs the two-stage combustion, and the primary flame and the secondary flame are generated in a well-balanced manner and spread uniformly over the entire combustion site. Development of a combustion device is an issue.

  The invention for solving the above-described problems includes a premixing member for premixing fuel gas and air therein, a flame hole member, and an air flow path member, and the premixing member has openings arranged in a row. The air flow path member has a wall shape and has a front air discharge opening on the front end side, and the flame hole member is located between the two air flow path members or the air flow member. There is a flame hole upstream flow channel between the flow path member and the other wall surface, and between the opening row portion and the flame hole member, the first is defined by the space surrounded by the flame hole member and the air flow channel member. A combustion section is formed, air is supplied to the air flow path member, the flame hole upstream flow path, and the premixing member, fuel gas is supplied to the premixing member, and the fuel gas is mixed with air in the premixing member. After being supplied from the opening in the opening row to the flame hole upstream flow path and further mixed with air, the state of oxygen deficiency Burns from burner port member is released in the first combustion unit, which further combustion apparatus characterized by burning supplied with air from the tip air discharge opening of the air passage member.

  The present invention has a premixing member, and fuel gas and air are premixed in the premixing member. The premixing member has an opening row portion having openings arranged in a row, and fuel gas is distributed and supplied from the opening of the opening row portion to the flame hole upstream flow path. The fuel gas is also mixed with air in the flame hole upstream side flow path. Therefore, according to the structure of this invention, the fuel gas and air are well mixed and the mixed gas which flows through a flame-hole upstream flow path is homogeneous. Therefore, the fuel gas adjusted uniformly is discharged from the entire area of the wall of the flame hole member. Therefore, the primary flame and the secondary flame are generated in a well-balanced manner and spread uniformly over the entire combustion site.

  It is desirable that there is a certain amount of space in the vicinity of the opening row portion, which is a part of the above-described flame hole upstream side flow path. This space is a mixing space for mixing fuel and air, and it is preferable that the opening of the opening row portion opens toward the mixing space.

  Further, it is desirable that the mixing space described above communicates over substantially the entire area of the opening row portion.

  When the mixing spaces are communicated in this way, the pressure is promoted to be uniform.

  It is desirable that the openings in the opening row part be opened in a direction crossing the flow direction of the airflow flowing through the flame hole upstream side flow path.

  Since the fuel gas is discharged from the opening of the opening row portion in a direction intersecting the air flow, there are many opportunities for collision with air. Therefore, mixing of fuel gas and air is promoted.

  Various types of flame hole members may be considered. For example, the flame hole member has a flame hole forming portion and two side wall portions, and is a portion between the two side wall portions and facing the flame hole forming portion. The opening row portion of the premixing member is disposed at a position surrounded by the side wall portion, and air can be introduced from the opening portion.

  In addition, a configuration in which an air discharge opening for the combustion portion that discharges air from the air flow path member toward the first combustion portion is also recommended. At this time, it is desirable to arrange the air discharge opening for the combustion part between the flame hole group of the flame hole member.

  The first combustion part is a part that generates a primary flame, and a secondary flame is generated outside the first combustion part by the air supplied from the tip air discharge opening. An air discharge opening for the combustion part is arranged between the flame hole group of the flame hole member so as to release air from the side, and the primary flame is caused by flowing air from around the flame hole group. It is possible to reliably hold the flame. Further, since air is supplied from below the primary flame, the secondary flame can be generated from an early stage, and the fuel gas is completely burned in a space close to the primary flame. Thereby, a combustion space becomes compact and the total length of a primary flame and a secondary flame can be shortened. In addition, the base end of the secondary flame is stabilized.

  A configuration in which an inclined surface is provided in the air flow path member and an air discharge opening for the combustion section is provided on the inclined surface is also recommended.

According to this structure, air is injected toward the diagonal direction, and does not obstruct the flow of the main primary flame and the flow of combustion gas.
Further, according to this configuration, air is mixed along the flow of the main primary flame and the flow of the combustion gas, so that it does not stay near the wall surface of the air flow path member.
That is, the combustion gas flows in a direction substantially parallel to the wall surface in the first combustion portion. For this reason, when air is introduced from the air flow path member in the direction perpendicular to the first combustion section, the air may collide with the primary flame or the combustion gas to cause retention. When air stays in the vicinity of the wall surface of the air flow path member, the surrounding unburned gas burns with the remaining air, and a flame is generated in the vicinity of the wall surface of the air flow path member. Therefore, there is a problem that the wall surface is excessively heated and red hot.
On the other hand, if the air is injected in an oblique direction, the air is mixed along the flow of the primary flame and the flow of the combustion gas, and the secondary flame can be generated at a position away from the air flow path member. Therefore, the wall surface of the air flow path member does not become red hot.

  In another recommended configuration, an upstream air discharge opening is provided on the upstream side of the portion constituting the first combustion portion of the air flow path member, and the air released from the upstream air discharge opening is supplied to the flame hole member. It is the structure which flows to the side surface side.

  According to the configuration described above, since the air released from the upstream air discharge opening flows to the side surface side of the flame hole member, oxygen is supplied to the side surface side of the flame hole member. Therefore, a stable flame is generated on the side surface portion of the flame hole member, and the base end portion of the primary flame is held. As a result, the primary flame is stabilized.

  In another recommended configuration, the flame hole member has a center side opening and a side opening, and the flow rate of the fuel gas discharged from the side opening is higher than the flow rate of the fuel gas discharged from the center opening. Slowly, the air flows in the vicinity of the side opening of the flame hole member.

This configuration clearly divides a flame hole that generates a main primary flame and a flame hole that generates a flame for the purpose of flame holding.
That is, in the above-described configuration, the flow rate of the fuel gas discharged from the side opening is slower than the flow rate of the fuel gas discharged from the center opening, so that the flame generated in the side opening has less fire. Further, since air is supplied in the vicinity of the side opening, the fuel gas discharged from the side opening is stably combusted in a relatively stable state and holds the base end of the primary flame. As a result, the primary flame is stabilized.

  As the structure of the side opening, for example, the flame hole member is constituted by a main body part and a decompression wall provided on the side surface of the main body part, and a gap is provided between the side surface of the main body part and the decompression wall so that the side opening is provided. A structure in which an opening is provided in the main body and a part of the fuel gas flowing through the main body flows into the gap is conceivable.

  In the above configuration, the fuel gas flows into the gap formed by the decompression wall from the opening provided in the main body, but the amount of the fuel gas (precisely, the fuel gas premixed with air) is limited by the opening. Therefore, the flow rate of the fuel gas released from the side opening is slower than the flow rate of the fuel gas released from other portions.

  The shape of the opening provided in the opening row portion may be a slit shape.

  Moreover, the structure which the opening row | line | column part has an inclined surface and the opening was provided in the said inclined surface may be sufficient. At this time, it is desirable that the inner angle of the opening row portion is 180 ° or less.

  By providing the opening on the inclined surface, the fuel gas is discharged in an oblique direction. This increases the chance of contact with the air flow and promotes mixing of the fuel gas and air.

  A configuration in which the tip of the air flow path member has an acute ridgeline shape is also recommended.

  There is an air discharge opening on the front end side of the air flow path member to supply secondary air. However, in the above configuration, the air flow path member has a sharp ridge line, so that air wraps around the air flow path member. Less is. Therefore, the air discharge direction is stabilized.

  The combustion apparatus of the present invention is practical because the primary flame and the secondary flame are generated in a well-balanced manner and uniformly spread over the entire combustion site. In addition, the combustion apparatus of the present invention generates less nitrogen oxide and can set a high turndown ratio. Furthermore, the combustion apparatus of the present invention is widely applicable to the combustion rate of the combustion gas, and does not select the type of gas.

The cross-sectional perspective view of the combustion apparatus which demonstrated the structure of the combustion apparatus of this invention typically. The perspective view of the combustion apparatus in the practical Example of this invention. The top view at the time of accommodating the combustion apparatus of FIG. 2 in a case. AA sectional drawing of FIG. Sectional drawing of the combustion apparatus of FIG. The perspective view which fractured | ruptured the combustion apparatus of FIG. 2 in steps, and showed the internal structure. The disassembled perspective view of the combustion apparatus of FIG. FIG. 3 is an exploded cross-sectional view of the combustion apparatus of FIG. 2. FIG. 3 is a perspective view of a premixing member of the combustion apparatus of FIG. 2. AA sectional drawing of FIG. BB sectional drawing of FIG. The perspective view of the air flow path member of the combustion apparatus of FIG. The enlarged view of the concave change part of the air flow path member of FIG. The perspective view of the flame hole member of the combustion apparatus of FIG. FIG. 15 is an enlarged front view of the fitting groove portion of the flame hole member of FIG. 14. The side view of the state which combined the flame hole member and the premixing member. The enlarged view of the base end part vicinity of the flame hole member of FIG. Explanatory drawing which shows the positional relationship of the opening of a premixing member, and the protruding item | line of an air flow path member. Explanatory drawing which shows the positional relationship of the opening of the premixing member in another Example, and the protrusion of an air flow path member. Explanatory drawing which shows the flow of the air in the air flow path member in a present Example. Explanatory drawing which shows the flow of the air in the air flow-path member in another Example. The disassembled perspective view of the combustion apparatus in another Example. The disassembled perspective view of the combustion device in other examples. The partial enlarged plan view which shows the positional relationship of the flame hole group of a flame hole member, and the combustion part air discharge | release opening of an air flow path member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Combustion apparatus 2 Premixing member 3 Flame hole member 5 Air flow path member 6 Intermediate member 8 Opening 10 Opening line part 13 Air flow path 15 Air introduction opening 20 21 Tip part opening 23 Combustion part air discharge opening 25 Main body member 26 Pressure reduction Wall 27 Side opening 29 Gap 31, 32 Side wall 35 Opening 39 Mixing space 46 First combustion section 48 Air discharge opening (upstream air discharge opening)
49 Flame-hole upstream flow path 66, 67 Inclined surface 68 Slit-shaped opening 69 Slit-shaped opening

Examples of the present invention will be described below. First, the schematic configuration and basic functions of the present invention will be described with reference to the schematic diagram of FIG. The embodiment of FIG. 1 conceptually illustrates the present invention.
In the following description, the vertical relationship is based on the posture in which the combustion apparatus 1 is placed vertically and a flame is generated on the upper side. The expressions on the upstream side and the downstream side are based on the flow of air or fuel gas. The width direction is a direction (in the direction of arrow W in the drawing) corresponding to the left-right direction with the largest area of the combustion device as the front.

  The combustion apparatus 1 of a present Example is used in parallel with a case, or is used independently. The combustion apparatus 1 of the present embodiment includes a premixing member 2, a flame hole member 3, and two air flow path members 5. In the combustion apparatus 1 of the present embodiment, the premixing member 2 and the flame hole member 3 are fitted together to form one intermediate member 6, and the intermediate member 6 is interposed between the two air flow path members 5. Although the structure is sandwiched, when actually used, the air flow path member 5, the intermediate member 6, the air flow path member 5, the intermediate member 6, the air flow path member 5. The premixing members 2 and the intermediate members 6 are alternately arranged to form a surface.

  The premixing member 2 that is a constituent member of the combustion apparatus 1 is a member that performs a function of premixing fuel gas and air inside. The premixing member 2 includes a mixing portion 7 having a curved path and an opening row portion 10 in which openings 8 are provided in a row. The opening row portion 10 is a portion in which a cavity having a substantially square cross section extends long and linearly.

The air flow path member 5 is a member having a thin wall shape. The air flow path member 5 is made of thin plates on the front and back surfaces 11 and 12, the front and back surfaces 11 and 12 are joined with a slight gap therebetween, and three sides other than the lower surface side are joined. A gap serving as an air flow path 13 is provided.
The air flow path member 5 folds a single plate to constitute the front and back surfaces 11 and 12, and has a bent portion 14 having an acute angle at the tip portion, and the bent portion 14 forms a top portion 9. The top portion 9 extends in a ridgeline shape.
On the other hand, on the base end side of the air flow path member 5, the space between the front and back surfaces 11 and 12 is opened, and an air introduction opening 15 is formed.

The air flow path member 5 has air discharge openings in three regions. As described above, since the premixing members 2 and the intermediate members 6 are alternately arranged to form a plane, the same number of plates are provided in the same portion on the front and back surfaces 11 and 12 of the air flow path member 5. An opening is provided.
The region where the air discharge opening is provided is roughly divided into a front end portion, a position facing the first combustion portion, and a position facing the intermediate member 6.

  That is, most of the plates of the front and back surfaces 11 and 12 of the air flow path member 5 are arranged in parallel, but only the tip portion is bent in a mountain shape, and the inclined surfaces 16 and 17 are formed on the front side and the back side. Is formed. A tip opening 20 is provided in the inclined surfaces 16 and 17. Further, a tip end opening 21 is also provided at the most distal portion (ridge line portion). The front end openings 20 and 21 are provided for supplying secondary air to the secondary flame.

  Further, the front and back surfaces 11 and 12 of the air flow path member 5 are formed such that the front-side air flow path 13 is narrower than the base end side as shown in FIG. There is a step in the part corresponding to. This step portion is also an inclined surface 22. The step portion is provided with an air discharge opening 23 for the combustion portion. The air discharge opening 23 for the combustion part supplies secondary air to the primary flame of the first combustion part 46 and burns a part of the primary flame to generate a secondary flame in a part of the first combustion part 46 It is.

  Further, an air discharge opening (upstream air discharge opening) 48 is also provided at a position facing the intermediate member 6. The air discharge opening (upstream air discharge opening) 48 supplies air to the side surface portion of the flame hole member 3 to stabilize flame holding.

The flame hole member 3 includes a main body member 25 and a decompression wall 26. The main body member 25 of the flame hole member 3 is made by bending a single metal plate, and includes a top surface 30 functioning as a flame hole and two side wall portions bent about 90 ° from both ends. 31 and 32. Further, the left and right sides of the flame hole member 3 are closed, and only the surface located on the lower side of the drawing is opened. The top surface 30 of the flame hole member 3 has a long shape and is elongated. On the top surface 30 of the main body member 25, slits to be the flame holes 33 are regularly arranged. The flame hole 33 provided in the main body member 25 functions as a “center opening”.
A bulging portion 34 bulging outward (in the thickness direction) is provided at an intermediate portion between the side wall portions 31 and 32. The bulging portion 34 is provided over the entire width of the flame hole member 3.

  The open end sides of the side walls 31 and 32 are folded back by about 90 ° twice as shown in the figure, and a fitting concave groove 38 is formed on the outside. The bottom wall 36 of the fitting groove 38 is perpendicular to the side walls 31, 32, and the outer wall 37 of the fitting groove 38 is parallel to the side walls 31, 32.

As described above, the decompression wall 26 is attached to the main body member 25. The decompression wall 26 is fixed to the side wall portions 31 and 32 of the main body member 25, and there is a gap 29 between the side wall portions 31 and 32 of the main body member 25. The gap 29 is open on the upper side of the drawing. This opening functions as the side opening 27.
An opening 35 is provided in the side wall portions 31 and 32 of the main body member 25 facing the decompression wall 26, and the inner surface of the main body member 25 and the gap 29 are communicated with each other.

Next, the relationship between the members will be described.
In the present embodiment, as described above, the premixing member 2 and the flame hole member 3 are fitted together to constitute one intermediate member 6. More specifically, the opening row portion 10 of the premixing member 2 is inserted between the side wall portions 31 and 32 of the flame hole member 3. In the actual manufacturing process, the premixing member 2 is inserted through the opening (lower part of the drawing) between the side wall portions 31 and 32 of the flame hole member 3 to join them together.

The side wall portions 31 and 32 and the opening row portion 10 are partially in contact with each other by an uneven shape (not shown), and both are integrated. Since the side wall portions 31 and 32 and the opening row portion 10 are partially in contact with each other due to the concavo-convex shape as described above, in other words, the two are partially separated. The cross section of FIG. 1 illustrates a cross section at a portion where the side wall portions 31 and 32 and the opening row portion 10 are separated.
About the site | part corresponded to the bulging part 34 of the side wall parts 31 and 32, it is separated from the opening row | line | column part 10 included. The portion of the bulging portion 34 corresponds to the row portion of the opening 8 of the opening row portion 10. Therefore, the outside of the opening 8 of the opening row portion 10 is separated from the side wall portions 31 and 32, and there is a wider space (mixing space) 39 than others. This space communicates over a portion corresponding to all the openings 8.
There is a relatively large space 47 between the side wall portions 31 and 32 and between the top portion of the opening row portion 10 and the top surface 30 portion of the flame hole member 3. In the present embodiment, the flame hole upstream flow path 49 is formed by the mixing space 39 and the space 47 downstream of the opening row portion 10.

  Air flow path members 5 are mounted on both sides of the intermediate member 6. The air flow path member 5 is coupled to the intermediate member 6 by fitting the fitting concave groove 38 of the flame hole member 3 into the air introduction opening 15 on the proximal end side. That is, the outer wall 37 of the fitting groove 38 is inserted into the air introduction opening 15, and the projecting end of the air flow path member 5 is inserted into the fitting groove 38 and brought into contact with the bottom wall 36 of the fitting groove 38. .

  The air flow path member 5 and the intermediate member 6 (flame hole member 3) are partially in contact with each other by an uneven shape (not shown), and both are integrated. Since they are partially in contact with each other by the uneven shape as described above, in other words, they are partially apart. The cross section of FIG. 1 illustrates a portion where the air flow path member 5 and the intermediate member 6 (flame hole member 3) are separated so that the function can be easily understood. However, the gap 40 between the air flow path member 5 and the intermediate member 6 is blocked by the bottom wall 36 of the fitting concave groove 38 at the upstream end (the lower end in the drawing) of the combustion device 1. Therefore, the gap 40 between the air flow path member 5 and the intermediate member 6 does not directly communicate with the outside world on the base end side.

  As described above, the flame hole member 3 is located between the two air flow path members 5, but the top surface 30 of the flame hole member 3 is on the lower side of the drawing relative to the air flow path member 5. It is in a position buried between the flow path members 5. Therefore, the space on the tip side of the top surface 30 of the flame hole member 3 is partitioned by the walls of the two air flow path members 5. In the present embodiment, the space surrounded by the top surface 30 of the flame hole member 3 and the two air flow path members 5 functions as the first combustion portion 46.

Next, the function of the combustion apparatus 1 will be described.
Many combustion apparatuses 1 are arranged in a box (not shown) and are blown by a blower 41 from the lower side of the drawing. Further, the fuel gas is introduced from the gas inlet 43 of the premixing member 2 by the nozzle 42.
First, the flow of air will be described. The flow of the blast is indicated by a thin line in the drawing.
The blown air generated by the blower 41 is rectified by the opening 45 of the rectifying plate 44 and enters the inside of the combustion device 1 from the base end (lower side of the drawing) of the combustion device 1.
There are three routes of blowing into the combustion device 1. That is, the first route is a route that passes through the air flow path member 5, and the air flow enters the air flow path member 5 from the air introduction opening 15 provided at the base end portion of the air flow path member 5, and the internal air flow path 13 flows directly upward toward the tip side. And most of the air is discharged to the outside through the tip openings 20 and 21.

A part of the air flowing through the air flow path member 5 is also discharged from the air discharge opening 23 for the combustion section and the air discharge opening (upstream air discharge opening) 48.
The air discharged from the air discharge opening 23 for the combustion part is discharged obliquely forward from the inclined surface 22 of the step part with respect to the axis of the combustion apparatus 1.
Further, the air discharged from the air discharge opening (upstream air discharge opening) 48 flows through the gap 40 between the air flow path member 5 and the intermediate member 6 and reaches the side surface portion of the flame hole member 3.

The second route is a route that flows through the intermediate member 6. That is, the intermediate member 6 is configured such that the opening row portion 10 of the premixing member 2 is sandwiched between the side wall portions 31 and 32 of the flame hole member 3, but between the opening row portion 10 and the flame hole member 3. There is a gap, and a part of this gap is open to the lower side of the intermediate member 6.
Therefore, air enters between the premixing member 2 and the side wall portions 31 and 32 of the flame hole member 3 from the opening 28.
This air flows through the gap between the side wall portions 31 and 32 and the opening row portion 10 and enters the mixing space 39. Subsequently, it flows into the space 47 between the opening row portion 10 and the top surface 30 portion of the flame hole member 3. That is, the above-described air flows through the flame hole upstream flow path 49. Then, it is discharged from the slit as the flame hole 33 to the first combustion section 46. Part of the air that has entered the space 47 enters the space 29 between the main body member 25 and the side wall portions 31 and 32 from the opening 35 provided in the side wall portion of the main body member 25, and the first side through the side surface side opening 27. It is discharged to the combustion unit 46.

  Next, the third route of air will be described. The third route is a route for primary air, and is introduced from the gas introduction port 43 of the premixing member 2 together with the fuel gas. Since the third route is the same as the route through which the fuel gas flows, the following description will be given as the flow of the fuel gas. The flow of fuel gas is illustrated by solid arrows.

Fuel gas is introduced from the gas inlet 43 of the premixing member 2 together with the primary air. The fuel gas is mixed with air in the mixing unit 7 or the like and flows into the opening row unit 10. In the opening row portion 10, since a large number of openings 8 are arranged in a straight line, the fuel gas that has entered the opening row portion 10 is evenly discharged from each opening 8. The fuel gas discharged from the opening 8 of the opening row portion 10 enters the mixing space 39 formed between the side wall portions 31 and 32 of the flame hole member 3 and the opening 8 of the opening row portion 10 and flows upstream of the flame hole. It is mixed with the air flowing through the passage (including the mixing space 39) 49.
Here, the air flowing through the flame hole upstream flow path (including the mixing space 39) 49 flows in the height direction (from the bottom to the top) of the combustion apparatus 1 whereas it is discharged from the openings 8 of the opening row portion 10. The injected fuel gas flows in a direction perpendicular to the air flow. Therefore, the fuel gas discharged from the opening 8 of the opening row portion 10 collides violently with the air even at the portion of the mixing space 39, and the mixing with the air is promoted. Further, since the mixing space 39 communicates over the entire longitudinal direction of the opening row portion 10, the pressure is also smoothed.

The fuel gas passes through the mixing space 39 and flows into the space 47, and the mixing of the fuel gas and air is also promoted during this period. After that, the flow is the same as the flow of the flame hole upstream flow path 49 described above, and enters the space 47 between the opening row portion 10 and the top surface 30 portion of the flame hole member 3, and many portions are the flame holes 33. It is discharged from the slit to the first combustion section 46. Part of the air that has entered the space 47 enters the gap 29 between the decompression wall 26 and the side walls 31, 32 from the opening 35 provided in the side walls 31, 32 of the main body member 25, and the side opening 27. To the first combustion section 46.
The fuel gas discharged from the flame hole 33 is mixed with air in the premixing member 2 and further mixed with air in the mixing space 39, so that the fuel gas is homogeneous and the speed at which the fuel gas is discharged from the flame hole 33. Is even.
However, although the fuel gas discharged from the flame hole 33 is mixed with air, the amount of air is less than the theoretical amount of air. The fuel gas released from the flame hole 33 is in an air-deficient state and cannot be burned completely.

When the fuel gas is ignited, the fuel gas generates a primary flame in the first combustion unit 46, and primary combustion is performed. However, since the fuel gas is in an air-deficient state as described above, it cannot be burned completely, and many unburned components are generated.
Unburned components are discharged to the outside from the opening of the first combustion section 46. Here, air is supplied to the outside of the first combustion unit 46 from the tip of the air flow path member 5. For this reason, the unburned components are supplied with oxygen and undergo secondary combustion. That is, the area outside the first combustion part 46 functions as a second combustion part, and a secondary flame is generated.

In this embodiment, air is supplied to the base end portion of the primary flame described above, and flame holding occurs at the base end portion of the primary flame.
In this embodiment, the fuel gas is not only released from the flame hole 33 which is the “center opening”, but also released from the side opening 27 to the first combustion part 46. However, the flow rate of the fuel gas discharged from the side opening 27 is slower than that of the fuel gas discharged from the flame hole 33 which is the “center opening”. That is, the fuel gas enters the gap 29 between the decompression wall 26 and the side walls 31, 32 from the opening 35 provided in the side walls 31, 32 of the main body member 25, and enters the first combustion unit 46 from the side opening 27. Released. Therefore, the amount of fuel gas entering the gap 29 is limited, and the amount released from the side opening 27 is small. On the other hand, since the side opening 27 has a large opening area, the fuel gas discharged from the side opening 27 has a low flow velocity.

Further, as described above, a part of the air passing through the air flow path member 5 enters the gap 40 between the air flow path member 5 and the intermediate member 6 from the air discharge opening (upstream air discharge opening) 48. It is discharged and reaches the side surface portion of the flame hole member 3 through the gap 40. For this reason, the side surface portion of the flame hole member 3 is rich in oxygen compared to other portions, and the fuel gas discharged from the side surface side opening 27 is supplied with air and burns relatively stably.
As described above, stable flame holding is generated in the vicinity of the side opening 27 in combination with the low flow rate of the fuel gas. Therefore, the base end portion of the primary flame is held by a small flame generated in the vicinity of the side opening 27.

In the present embodiment, the secondary flame is stabilized by the air discharged from the combustion part air discharge opening 23. That is, in this embodiment, there is an inclined surface 22 on the front and back surfaces 11 and 12 of the air flow path member 5 and corresponding to the base end portion of the first combustion portion. Since 23 is provided, air is supplied from the base end portion of the first combustion section in an oblique direction with respect to the air traveling direction. Therefore, the supplied air is supplied into the first combustion unit 46 without disturbing the flow of the primary flame and unburned gas. As a result, part of the unburned gas in the first combustion section 46 starts to burn, and a secondary flame is generated in part. And since this secondary flame is connected with the external secondary flame, the secondary flame generated outside is also stable.
Further, in this embodiment, the air discharge opening 23 for the combustion part opens in an oblique direction and does not hinder the flow of the primary flame and unburned gas as described above, so that the secondary flame is separated from the air flow path member 5. The air flow path member 5 is not excessively heated.
Therefore, the combustion apparatus of the present embodiment is practical because both the primary flame and the secondary flame are stable.

Next, a more practical configuration example of the present invention will be described with reference to FIG. The embodiments described below are practically designed to implement the present invention and are the most recommended configurations.
The basic configuration and basic functions of the combustion apparatus shown in the drawings after FIG. 2 are the same as those of the above-described embodiment, but practical details are applied to the details. The members having the same functions as those of the previous embodiment are denoted by the same reference numerals, and the description of the overlapping functions will be simplified.

  The combustion apparatus 1 shown in FIG. 2 is used in parallel with a case 54 as shown in FIGS. The combustion apparatus 1 of the present embodiment also has a premixing member 2, a flame hole member 3, and an air flow path member 5. The premixing member 2 and the flame hole member 3 are fitted together to constitute one intermediate member 6, and the intermediate member 6 is sandwiched between the two air flow path members 5.

  The shape of the premixing member 2 is as shown in FIGS. The premixing member 2 is formed by pressing a single steel plate to form a developed figure having irregularities on the surface, bending it, and then joining the periphery by spot welding. Spot welding is performed at the surrounding flange portion 51.

The shape of the premixing member 2 after assembling is such that a front plate 52 as shown in FIGS. 8 and 9 and a symmetrical back plate 53 are superimposed on this. The external appearance of the premixing member 2 has a sharp shape, has a flat top 50, and is closed so that gas does not leak out.
A series of gas passages are formed between the front plate 52 and the back plate 53 inside. That is, in the part where the unevenness of the front plate 52 and the back plate 53 coincides, the metal plates are arranged in a gap, and a gas flow path is formed by this gap.

In the premixing member 2 employed in the present embodiment, the gas flow path is largely divided into upper and lower parts as shown in FIG. Specifically, the gas flow path is roughly composed of a mixing flow path 19 and an opening row portion 10.
As shown in FIG. 9, the mixing channel 19 is on the lower side of the premixing member 2 and is a channel from the inlet of the gas channel to the opening row portion 10. If it demonstrates from the inlet_port | entrance of a gas flow path, the gas inlet 43 will open at the lower side corner of the combustion apparatus 1 like FIG. Inside the gas introduction port 43, there is a constricted part 55 whose sectional area is temporarily constricted, and further on the downstream side there is a diameter-enlarging part 56 whose sectional area gradually increases. After that, the uniform cross section 57 has a uniform cross section. The flow path is linear from the gas introduction port 43 to the uniform cross section 57 through the throttle portion 55 and the enlarged diameter portion 56.
The end of the uniform cross section 57 is connected to the opening row portion 10 with the flow path bent vertically.
In the present embodiment, there is no portion that becomes a stop immediately before the opening row portion 10.

The opening row | line | column part 10 is located in the upper end part of the premixing member 2, and is extended over the whole longitudinal direction like FIG. The cross-sectional area of the opening row 10, in other words, the gap between the front plate 52 and the back plate 53 at that portion is large as shown in FIGS.
The cross-sectional shape of the opening row portion 10 is a two-stage shape as shown in FIGS. 10 and 11, and the top side is a narrow area portion 58, and the cross-sectional area is slightly narrow.
That is, the cross-sectional shape of the opening row portion 10 will be described. The top portion 50 is flat, and the upper side vertical wall 81 is perpendicular to both sides of the top portion 50. The end of the vertical wall 81 is connected to the inclined wall and extends slightly outward. Further, the end of the inclined wall is a lower side vertical wall 82.

A large number of openings 8 are provided on both the front plate 52 and the back plate 53 in the narrow area 58 described above, which is the outer surface of the opening row portion 10. The openings 8 are provided in a line along a straight line with a certain interval.
In the present embodiment, the opening 8 is provided only on the front side and the back side of the opening row portion 10, and the top portion 50 has no opening.

Next, the air flow path member 5 will be described with reference to FIGS. The air flow path member 5 is also formed by pressing a single steel plate to form a developed figure having irregularities on the surface, bending it, and then joining it by spot welding. In the air flow path member 5, the front and back surfaces 11 and 12 are joined with a slight gap as shown in FIG. 8, and a gap serving as the air flow path 13 is provided inside.
There is an acute bent portion at the tip of the air flow path member 5, and the apex portion 9 is constituted by the bent portion. The top portion 9 extends in a ridgeline shape.
As shown in FIG. 12, the air flow path member 5 is provided with flange portions 83 on two sides in contact with the bent portion, and the flange portions 83 are spot-welded.
On the proximal end side of the air flow path member 5, the space between the front and back surfaces 11 and 12 is opened as shown in FIG. 8, and an air introduction opening 15 is formed.

The appearance of the air flow path member 5 is a thin wall as shown in FIG. The air flow path member 5 is roughly divided into three regions with respect to the height direction on the basis of the vertically placed state as shown in FIG.
That is, the introduction portion 60 extends from the base end portion to a height of about 1/3. Furthermore, the region of about ３ in the height direction is the intermediate portion 61. The approximately 1/3 region on the front end side is the first combustion portion constituting portion 62.

The air flow path member 5 constitutes a flow path from the air introduction opening 15 toward the front end side, but the cross-sectional area of the flow path becomes narrower toward the front end side.
That is, the cross-sectional area of the portion (introduction portion 60) from the air introduction opening 15 to about 1/3 of the total height is substantially constant as shown in FIG. In other words, the introduction part 60 has the front and back surfaces 11 and 12 parallel to each other as shown in the cross-sectional view of FIG.

The intermediate part 61 is generally tapered.
That is, the intermediate portion 61 has a tapered shape in which the lower portion is wide as shown in the drawing and the interval is narrowed toward the upper portion. However, a bulging portion 84 is provided at a boundary portion between the distal end side end portion of the taper and the first combustion portion constituting portion 62. As for the outer wall part which comprises the bulging part 84, the front and back part is parallel.

Although the cross-sectional area of the first combusting part constituting part 62 is substantially constant (excluding the top part 9), the cross-sectional area per unit length during this period is about 1/3 of that of the introducing part 60.
There is a step portion formed of the inclined surface 22 between the first combustion portion constituting portion 62 and the intermediate portion 61.

The air flow path member 5 is provided with air discharge openings in three regions.
The positions where the air discharge openings are provided are roughly divided into a front end portion, a position facing the first combustion portion, and a position facing the intermediate member 6.

That is, the front end portions of the front and back surfaces 11 and 12 of the air flow path member 5 are bent in a mountain shape, and inclined surfaces 16 and 17 are formed on the front surface side and the back surface side. The inclined surfaces 16 and 17 are provided with a circular tip opening 20 as shown in FIG. In addition, a circular tip opening 21 is also provided at the most distal portion (ridge line portion).
Further, in the present embodiment, slit-shaped tip openings 63 and 64 are provided on the top and the inclined surfaces 16 and 17. There are two types of slit lengths: the smaller slit-shaped tip opening 63 is a slit that connects all the inclined surfaces 16, 17 and the top 9. The larger slit (front end opening) 64 is longer and extends from the portion where the front and back surfaces 11 and 12 are parallel to the top portion 9.

The large slits (tip opening) 64 have a larger number than the small slits (tip opening) 63, and the large slits 64 are continuously provided in two or three rows, and then the small slits 63 are provided. Subsequently, two or three rows of large slits 64 are continuously provided, and these are continuous over the entire length direction of the air flow path member 5.
The circular tip openings 20 and 21 are provided between the slits (tip openings) 63 and 64.

  The front end openings 20 and 21 are provided to supply secondary air to the secondary flame, as in the previous embodiment.

  An air discharge opening 23 for the combustion part is provided on the inclined surface 22 between the first combustion part constituting part 62 and the intermediate part 61 described above. The air discharge opening 23 for the combustion part supplies secondary air to the primary flame of the first combustion part 46 and burns a part of the primary flame to generate a secondary flame in part.

  Further, an air discharge opening (upstream air discharge opening) 48 is also provided in the vicinity of the boundary between the introduction portion 60 and the intermediate portion 61. The air discharge opening (upstream air discharge opening) 48 supplies air to the side surface portion of the flame hole member 3 to stabilize flame holding.

The front and back surfaces 11 and 12 of the air flow path member 5 are provided with uneven shapes in each part for the purpose of providing a gap between them or for providing a gap between other members.
To explain sequentially, a plurality of concave grooves 70 and 71 extending in the height direction are provided on the wall surface constituting the first combustion portion constituting portion 62 on the front end side. The concave grooves 70 and 71 are both concave when viewed from the surface side, and extend in the height direction. The concave groove 70 is shorter than the concave groove 71. The concave grooves 70 and 71 are both arranged in parallel. The concave grooves 70 and 71 are provided mainly for reinforcing the plate.
In this embodiment, a plurality of short grooves 70 are provided, followed by a long groove 71, and a plurality of short grooves 70 are provided, and the grooves 70 are formed over the entire width of the air flow path member 5. , 71 are arranged.

Further, the distance between the long grooves 71 is wider than the distance between the other grooves.
A streamlined recess 72 as shown in FIGS. 12 and 13 is provided between the long recesses 71 and in the vicinity of the base end of the recess 71. The concave deformation portion 72 is also a concave shape when viewed from the front side. Specifically, the shape of the concave change portion 72 is such that a large circle and a small circle are arranged apart from each other and connected by a common tangent line, and the large circle side is located upstream of the air flow path. However, the small circle side is located downstream of the air flow path. A line connecting the centers of the two circles is parallel to the air flow direction. A common tangent line connecting two circles has an inclination of 30 ° or less with respect to a line connecting the centers of the circles.

  The middle portion 61 of the air flow path member 5 is provided with six ridges 73 as shown in FIG. The direction of the ridges 73 is parallel to the air flow direction. As will be described later, the ridge 73 is in contact with the outer surface of the intermediate member 6 to provide a gap therebetween, and the position of the protrusion (ridgeline) of the ridge 73 (from the center line of the air flow path member 5). (Distance) is the same in any part. That is, as described above, in the intermediate portion 61, the cross-sectional shape of the flow path is tapered, but the height of the ridge 73 (the size of the bulge) changes to a reverse tapered shape, and the positions of the protruding end portions are aligned. .

  A plurality of concave grooves 75 are also provided in parallel in the introduction portion 60 of the air flow path member 5. Each of the concave grooves 75 extends from the proximal end side to the distal end side of the air flow path member 5. The concave groove 75 has a concave shape when viewed from the surface side.

A concave groove 77 extending in the lateral direction (perpendicular to the air flow) is provided in the vicinity of the introduction portion 60 of the air flow path member 5.
The concave groove 77 is provided mainly for positioning.

  Further, when the eyes are moved to the side surface portion of the air flow path member 5, a substantially triangular protrusion 80 is provided at the center portion of both side surfaces.

Next, the flame hole member 3 will be described. The flame hole member 3 is formed by welding a decompression wall 26 to the side surface of the main body member 25 as shown in FIGS.
The main body member 25 of the flame hole member 3 is also formed by pressing a single steel plate to form a developed figure having irregularities on the surface, bending it, and spot welding. As shown in FIG. 14, the main body member 25 also has flanges 85 on two sides connected to the top surface 30, joined by the flange 85, and the surface facing the top surface 30 is released.

The main body member 25 of the flame hole member 3 has a top surface 30 functioning as a flame hole as shown in FIGS. 8 and 14, and two side wall portions 31 and 32 bent about 90 ° from both ends. The top surface 30 of the flame hole member 3 has a long shape and is elongated. Moreover, the top part 30 is roof-like, the center ridgeline part 86 is the highest, and the both sides become the gentle inclined wall 87. FIG.
The flame hole member 3 is formed by bending a steel plate as described above, but the steel plate is folded at the ridge line portion 86 of the top portion 30. Therefore, as shown in the drawing, the folded portion hangs down as a vertical wall 88 in the internal cavity.

  The top surface 30 of the main body member 25 is provided with a slit-like opening serving as a flame hole (center side opening) 33. The slit (flame hole 33) extends in the width direction of the top 30. A plurality of slit-shaped openings are arranged in parallel, and are provided in the entire region of the top portion 30 in the longitudinal direction. Then, as shown in FIG. 14, a flame hole group 89 is configured with a plurality of slit-shaped openings as a set, and the flame hole group 89 is arranged on the top surface 30 at regular intervals.

Paying attention to the cross-sectional shape of the main body member 25, the main body member 25 has two narrowed portions 78 and 79 as shown in FIG. In other words, there are two bulging portions 90 and 91 except for the base end portion.
In other words, there are a tip-side bulged portion 90 including the portion of the top surface 30 and an intermediate bulged portion 91 provided in the intermediate portion. A front end side narrowed portion 78 is provided between the intermediate bulging portion 91 and the front end side bulging portion 90. Further, a proximal end side throttle portion 79 is provided on the proximal end side of the intermediate bulging portion 91.

Of the bulging portions 90 and 91 and the narrowed portions 78 and 79 described above, the tip-side bulging portion 90 and the intermediate bulging portion 90 are both provided over the entire width of the flame hole member 3.
Further, openings 35 are provided in a row on the side surface of the distal side bulging portion 91 as shown in FIG. The opening 35 is a small hole.
The proximal end side narrowed portion 79 is provided with a plurality of ridges 92 as shown in FIG. The ridge 92 protrudes outward as viewed from the surface side, and a groove 93 is formed inside as shown in FIG. The ridge 92 extends in the height direction of the flame hole member 3. The ridge 92 extends in parallel with the width direction of the flame hole member 3.

The open end sides of the side wall portions 31 and 32 are folded back by about 90 ° twice as shown in FIGS. 6, 8, 16, and 17, and a fitting groove 38 is formed on the outside. The bottom wall 36 of the fitting groove 38 is perpendicular to the side walls 31, 32, and the outer wall 37 of the fitting groove 38 is parallel to the side walls 31, 32.
The outer wall 37 constituting the fitting groove 38 has a substantially trapezoidal front shape. That is, the sides on both sides of the outer wall 37 are inclined as shown in the enlarged view of FIG. 15, and the tip side is tapered in a tapered shape. Further, as shown in FIGS. 16 and 17, projections 95 are provided on the side wall portions 31 and 32 in the fitting concave groove 38. The positions of the protrusions 95 are at both ends of the fitting concave groove 38, and one protrusion 95 is provided at each end.

  The decompression wall 26 is fixed to the upper end portions of the side wall portions 31 and 32 of the main body member 25. The decompression wall 26 has a long plate shape as shown in FIG. 14 and covers the distal end side bulging portion 90 of the main body member 25 over the entire area. There is a gap 29 between the side wall portions 31, 32 of the main body member 25 and the decompression wall 26. The gap 29 is open on the upper side of the drawing. This opening functions as the side opening 27. Note that a small protrusion 97 is provided on the inner surface of the decompression wall 26 as shown in FIG. 8, and the protrusion 97 abuts the main body member 25 to regulate the interval between the side opening 27.

  As described above, the distal-side bulged portion 90 has the openings 35 (FIG. 14) in a row, and the openings 35 communicate the inner surface of the main body member 25 with the gap 29.

  Both end portions of the main body member 25 are overlapped with the side wall portions 31 and 32 to form a flange 85 and are joined by spot welding, but the side wall portion extends from the proximal end side to the vicinity of the intermediate bulge portion. There is a slit 98 between 31 and 32.

Next, the relationship between the members will be described with reference to FIGS.
Also in the combustion apparatus of the present embodiment, the premixing member 2 and the flame hole member 3 are fitted together to constitute the intermediate member 6.
Although the flame hole member 3 (intermediate member 6) is located between the two air flow path members 5 as described above, the top surface 30 of the flame hole member 3 is more than the upper end of the air flow path member 5. It is on the lower side of the drawing and is in a position buried between the air flow path members 5. Therefore, the space on the tip side of the top surface 30 of the flame hole member 3 is partitioned by the walls of the two air flow path members 5. In the present embodiment, the space surrounded by the top surface 30 of the flame hole member 3 and the two air flow path members 5 functions as the first combustion portion 46.

The intermediate member 6 is obtained by mounting the premixing member 2 on the flame hole member 3, and the top 50 side of the premixing member 2 is inserted into a hollow portion of the flame hole member 3. At this time, the flange portions 51 at both ends of the premixing member 2 are fitted into the slits 98 formed at both ends of the flame hole member 3. Then, the protruding end of the premixing member 2 and the back end of the slit 98 come into contact with each other and positioning in the insertion direction is performed.
Further, the vertical wall 82 provided on the lower side of the opening row portion 10 of the premixing member 2 is brought into contact with the inner wall of the base end side restricting portion 79 of the flame hole member 3 so as to be positioned in the thickness direction.
The narrow area portion 58 of the opening row portion 10 of the premixing member 2 is the position of the intermediate bulging portion 91 of the flame hole member 3.

  When attention is paid to the gap between the opening row portion 10 of the premixing member 2 and the flame hole member 3, the narrowness of the opening row portion 10 is narrowed to the intermediate bulging portion 91 of the side wall portions 31 and 32 of the flame hole member 3 as described above. There is an area 58. That is, the portion of the intermediate bulging portion 91 corresponds to the row portion of the openings 8 of the opening row portion 10. Therefore, the outer side of the opening 8 of the opening row part 10 is separated from the side wall parts 31 and 32, and there is a wider space (mixing space) 39 than the other on the outer side of the opening 8. The mixing space 39 communicates over a portion corresponding to all the openings 8.

  On the other hand, as described above, the lower side of the opening row portion 10 of the premixing member 2 is in contact with the inner wall of the base end side throttle portion 79 of the flame hole member 3. Therefore, the outer wall of the opening row portion 10 and the inner wall of the flame hole member 3 are in contact with each other at almost all positions in the width direction, and there is no gap. However, as described above, the base end side restricting portion 79 is provided with a plurality of protruding ridges 92, and the inner surface side of the protruding ridges 92 is a concave groove 93 (FIG. 6). Therefore, in the portion of the ridge 92, the outer wall of the opening row portion 10 and the inner wall of the flame hole member 3 are separated. Further, since the ridge 92 extends in the height direction of the flame hole member 3, the mixed space 39 communicates with the base end side of the flame hole member 3.

  Here, paying attention to the positional relationship between the position of the ridge 92 and the opening 8 provided in the opening row portion 10 of the premixing member 2, the opening 8 is at a position directly above the ridge 92 as shown in FIG. That is, when the ridge 92 is extended, it intersects with the position of the opening 8. In the present embodiment, the ridge 92 and the opening 8 correspond one-to-one as shown in FIG. However, as shown in FIG. 19, the openings 8 do not necessarily correspond one-to-one, such that the number of the openings 8 is large, or the number of the protrusions 92 is large.

There is a gap between the base end portion of the flame hole member 3 and the premixing member 2. Therefore, the mixing space 39 described above communicates with the outside through the protrusions 92 (concave grooves 93) and the gaps at the base end portions.
On the other hand, when attention is paid to the further front end side of the mixing space 39, a relatively large space 47 between the side wall portions 31 and 32 and between the top portion 50 of the opening row portion 10 and the top surface 30 portion of the flame hole member 3. There is. In the present embodiment, the flame hole upstream flow path 49 is formed by the mixing space 39 and the space 47 downstream of the opening row portion 10.

Air flow path members 5 are mounted on both sides of the intermediate member 6 as shown in FIGS. The air flow path member 5 is fixed to the intermediate member 6 by fitting the fitting concave groove 38 of the flame hole member 3 into the air introduction opening 15 on the proximal end side. That is, the outer wall 37 of the fitting groove 38 is inserted into the air introduction opening 15, and the projecting end of the air flow path member 5 is inserted into the fitting groove 38 and brought into contact with the bottom wall 36 of the fitting groove 38.
As described above, the outer wall 37 of the concave groove for fitting 38 is trapezoidal when viewed from the front, and the sides on both sides are tapered. Therefore, when the air flow path member 5 is mounted, The inner wall follows the taper of the outer wall 37 of the fitting concave groove 38, and positioning in the width direction is performed.
When the air flow path member 5 is housed in a normal position with respect to the flame hole member 3, as shown in FIG. 17, the fitting concave groove 38 is formed on the outer upper end of the concave groove 77 provided near the opening of the air flow path member 5. The protrusion 95 provided inside engages and a feeling of moderation is obtained.
Further, when the air flow path member 5 is mounted at a proper position, as shown in FIG. 24, the air discharge opening 23 for the combustion section is formed in the flame hole group 89 and the flame hole group 89 of the flame hole member 3 in the width direction. Will be located between.
At the upstream end (the lower end in the drawing) of the combustion device 1, the gap 40 between the air flow path member 5 and the intermediate member 6 is sealed by the bottom wall 36 of the fitting groove 38. Therefore, the gap 40 between the air flow path member 5 and the intermediate member 6 does not directly communicate with the outside world on the base end side.

When attention is paid to the gap 40 between the air flow path member 5 and the intermediate member 6 (flame hole member 3), the side surface side of the upstream air discharge opening 48 of the air flow path member 5 as shown in FIGS. The leading end side throttle portion 78 of the flame hole member 3 is located. Since the front-side throttle portion 78 is a portion where the surface of the flame hole member 3 is recessed, there is a gap between the air flow path member 5 and the flame hole member 3 in the vicinity of the upstream air discharge opening 48.
Further, this gap communicates with the first combustion portion 46. That is, the air flow path is tapered on the front end side of the air flow path member 5 from the upstream air discharge opening 48, and the outer wall of the air flow path member 5 is located inside the air flow path as it goes downstream. A gap is formed between the flame hole member 3 and the flame hole member 3. The outer wall of the air flow path member 5 and the flame hole member 3 are partially in contact with each other by a ridge 73 provided on the air flow path member 5.

Next, the function of the combustion apparatus 1 will be described.
A large number of combustion apparatuses 1 are arranged in a case 54 as shown in FIG. 3, and are blown by a blower 41 from the lower side of the drawing as shown in FIG. Further, the fuel gas is introduced from the gas introduction port 43 of the premixing member 2 by a nozzle (not shown).
The flow of the blast is substantially the same as that of the above-described embodiment, and the blast generated by the blower 41 is rectified by the opening of the rectifying plate 44 (FIG. 4), and from the base end (lower side of the drawing) of the combustion device 1. It enters the inside of the combustion apparatus 1.
The route of the air entering into the combustion apparatus 1 is the same as that in the previous embodiment, and there are three routes. That is, the first route is a route passing through the air flow path member 5 as shown in FIG. 6, and the air flow enters the air flow path member 5 from the air introduction opening 15 provided at the base end portion of the air flow path member 5. , Flows through the internal air flow path 13 toward the tip side. And most of the air is discharged to the outside through the tip openings 20 and 21.

Here, in this embodiment, as shown in FIG. 20, the tip shape of the air flow path member 5 is an acute angle, and the tip opening 63, 64 of the tip opening is formed on the inclined surfaces 16, 17 and the top. Since the slits are provided across the air, it is difficult for air to stay at the tip portion or to cause turbulence.
For example, as shown in FIG. 21, if the tip shape of the air flow path member 5 is circular, the air introduced from the air introduction opening 15 collides with the arcuate surface that is the ceiling surface, and moves toward the base end side along the arcuate surface. Wrap around. Then, the sneak-in air collides with the newly supplied air flow as shown by an arrow, and inhibits the discharge of the newly supplied air to distort the discharge direction. In this way, when the tip shape of the air flow path member 5 is circular, the direction of the air flow becomes unstable due to the generation of turbulence and vortices. For this reason, a problem that the secondary flame fluctuates occurs. Further, according to the experiments by the present inventors, there is a problem that the noise is high.

  On the other hand, in this embodiment, since the tip portion has an acute angle as shown in FIG. 20, there are few portions where the supplied air collides, and the air does not wrap around. Further, since the slit-shaped opening is provided on the inclined surface, most of the air that collides with the inclined surface is discharged to the outside from the slit-shaped opening. For this reason, the air discharge direction is stabilized, and the fluctuation of the secondary flame is reduced. Noise is also reduced. However, the present invention does not limit the tip shape of the air flow path member, and the tip shape as shown in FIG. 21 may be circular.

Returning to the description of the embodiment, in the combustion apparatus 1 of this embodiment, a part of the air flowing through the air flow path member 5 flows from the air discharge opening 23 for the combustion section and the air discharge opening (upstream air discharge opening) 48. Are also released.
The air discharged from the air discharge opening 23 for the combustion part is directed from the inclined surface 22 of the step part between the flame hole group 89 and the flame hole group 89 of the flame hole member 3 with respect to the axis of the combustion device 1. Is released diagonally forward.
Further, the air discharged from the air discharge opening (upstream air discharge opening) 48 flows through the gap 40 between the air flow path member 5 and the intermediate member 6 and reaches the side surface portion of the flame hole member 3. Specifically, the air discharged from the air discharge opening (upstream air discharge opening) 48 is discharged into a gap formed by the front end side throttle portion 78 of the flame hole member 3. This air flows through a gap formed by the tapered wall surface of the air flow path member 5 and is released to the side surface portion of the flame hole member 3.

The second route is a route that flows through the intermediate member 6, and air enters between the premixing member 2 and the side wall portions 31 and 32 of the flame hole member 3 from the opening 28.
This air passes through a concave groove 93 formed on the inner surface of the flame hole member 3 (the back side of the ridge 92) and enters the mixing space 39. And it enters the space 47 between the opening row | line | column part 10 and the top face 30 part of the flame hole member 3. FIG. That is, the above-described air flows through the flame hole upstream flow path 49. Then, the gas is discharged from the slit serving as the flame hole (center side opening) 33 to the first combustion unit 46. Part of the air that has entered the space 47 enters the space 29 between the main body member 25 and the side wall portions 31 and 32 from the opening 35 provided in the side wall portion of the main body member 25, and the first side through the side surface side opening 27. It is discharged to the combustion unit 46.

  Next, the third route of air will be described. The third route is a route for primary air, and is introduced from the gas introduction port 43 of the premixing member 2 together with the fuel gas. Since the third route is the same as the route through which the fuel gas flows, the following description will be given as the flow of the fuel gas. The flow of fuel gas is illustrated by solid arrows.

The fuel gas is introduced together with the primary air from the gas introduction port 43 of the premixing member 2, mixed with air by the mixing unit 7 and the like, and flows into the opening row unit 10. Here, in the present embodiment, there is no portion that becomes a diaphragm between the uniform section 57 of the mixing portion 7 and the opening row portion 10. Therefore, the fuel gas protrudes into the opening row portion 10 without any portion where the flow velocity is different.
The fuel gas that has entered the opening row 10 is evenly discharged from each opening 8. That is, since the opening row portion 10 has a considerable internal volume, minute vortices generated in the curved path of the premixing member 2 are converged. Further, as described above, there is no portion to be throttled immediately before the opening row portion 10, and the fuel gas introduced into the opening row portion 10 has a small variation in flow velocity in the cross section of the flow path. Therefore, there is little pressure variation in the inside of the opening row | line | column part 10, and fuel gas is discharge | released from each opening 8 equally. The diameter of the opening 8 may be sequentially reduced so that the amount of ejected gas is uniform.

  The fuel gas discharged from the opening 8 of the opening row portion 10 enters the mixing space 39 constituted by the intermediate bulging portion 91 of the flame hole member 3, and passes through the flame hole upstream flow path (including the mixing space 39) 49. Mixed with flowing air.

On the other hand, the air flowing through the mixing space 39 flows upward from the lower side of the drawing and is rectified.
That is, the air flowing into the mixing space 39 is introduced from the opening 28 between the premixing member 2 and the side wall portions 31 and 32 of the flame hole member 3, but before reaching the mixing space 39, the flame hole member Since it passes through the concave groove 93 (the back side of the ridge 92) formed in the inner surface of No. 3, it is a laminar flow.
More specifically, in this embodiment, most of the portion of the base end side throttle portion 79 of the flame hole member 3 is in contact with the outer wall of the premixing member 2. A large number of concave grooves 93 are formed on the inner surface, and there are gaps in the concave groove 93 portions. Each groove 93 communicates with the mixing space 39. Therefore, the air introduced from the opening 28 between the side walls 31 and 32 passes through the plurality of concave grooves 93 and reaches the mixing space 39. And since the ditch | groove 93 is an elongate flow path and is provided in parallel at equal intervals, the introduce | transduced air is rectified by flowing through the some ditch | groove 93. FIG.

The air flowing through the flame hole upstream side flow path (including the mixing space 39) 49 flows in the height direction of the combustion apparatus 1, whereas the fuel gas discharged from the opening 8 of the opening row portion 10 becomes the flow of air. In contrast, it flows vertically. Therefore, the fuel gas discharged from the opening 8 of the opening row portion 10 collides violently with the air even at the portion of the mixing space 39, and the mixing with the air is promoted.
In addition, in the present embodiment, since the opening 8 of the opening row portion 10 is on the extension line of the concave groove 93 (the back side of the ridge 92), the air that has exited the concave groove 93 is more reliably released from the opening 8. Collide with gas.
Further, since the mixing space 39 communicates over the entire longitudinal direction of the opening row portion 10, the pressure is also smoothed.

The fuel gas rises through the mixing space 39 and flows into the space formed by the tip-side bulging portion 90, but the mixing of the fuel gas and air is also promoted during this time. Most of the fuel gas is discharged from the slit that is the flame hole 33 to the first combustion section 46.
The fuel gas discharged from the slit is mixed with air in the premixing member 2 and further mixed with air in the mixing space 39, so that the fuel gas is uniform and the speed when discharged from the slit is also uniform. .
Part of the air that has entered the space 47 enters the gap 29 between the main body member 25 and the side wall portions 31 and 32 from the opening 35 provided in the side wall portion of the main body member 25, and first combustion from the side surface side opening 27. Released to the part 46.

  When the fuel gas is ignited, the fuel gas generates a primary flame in the first combustion unit 46, and primary combustion is performed. The unburned component is discharged to the outside from the opening of the first combustion unit 46, and air is supplied from the tip of the air flow path member 5 to perform secondary combustion.

In this embodiment, air is supplied to the base end portion of the primary flame described above, and flame holding occurs at the base end portion of the primary flame.
That is, in this embodiment, part of the fuel gas is discharged from the side opening 27 to the first combustion unit 46. However, the fuel gas discharged from the side opening 27 has a slower flow rate than the fuel gas discharged from the slit. That is, the fuel gas enters the gap 29 between the main body member 25 and the side wall portions 31 and 32 from the opening 35 provided in the side wall portion of the main body member 25, and is released from the side surface side opening 27 to the first combustion portion 46. . Therefore, the amount of fuel gas entering the gap 29 is limited, and the amount released from the side opening 27 is small. On the other hand, since the side opening 27 has a large opening area, the fuel gas discharged from the side opening 27 has a low flow velocity.

Further, as described above, a part of the air passing through the air flow path member 5 is supplied to the fuel gas discharged from the side opening 27 and is completely burned.
That is, the air discharged from the air discharge opening (upstream air discharge opening) 48 is formed by the tapered wall surface of the air flow path member 5 from the gap formed by the tip side narrowed portion 78 of the flame hole member 3. It flows along the gap and reaches the side surface of the flame hole member 3.

  As described above, stable flame holding is generated in the vicinity of the side opening 27 in combination with the low flow rate of the fuel gas. Therefore, the base end portion of the primary flame is held by a small flame generated in the vicinity of the side opening 27.

Also in this embodiment, air is supplied in an oblique direction from the combustion part air discharge opening 23 provided on the inclined surface 22, and a part of the unburned gas in the first combustion part 46 starts to burn, A secondary flame is generated in part. This secondary flame is connected to an external secondary flame.
Further, in the present embodiment, since air is released between the flame hole group 89 and the flame hole group 89 of the flame hole member 3, the air is sufficiently supplied around the flame hole group 89, and the primary flame. The flame can be reliably held.
Also in the present embodiment, the air supplied from the air discharge opening 23 for the combustion section does not interfere with the flow of the primary flame and unburned gas, and the secondary flame is generated at a position away from the air flow path member 5. The air flow path member 5 is not heated excessively.
Therefore, the combustion apparatus of the present embodiment is practical because both the primary flame and the secondary flame are stable.

In the above-described embodiment, the configuration in which the opening for discharging the fuel gas is provided on the side surface as an example of the premixing member. According to this configuration, since the fuel gas is released in a direction perpendicular to the air flow, there are many opportunities for collision between the fuel gas and air, and mixing is promoted.
A configuration that emits fuel gas in an oblique direction is conceivable as a configuration that exhibits the same action. For example, as shown in FIG. 22, roof-like inclined surfaces 66 and 67 are provided on the top of the premixing member 2, and slit-like openings 68 are provided on the two inclined surfaces 66 and 67. In this embodiment, the fuel gas is discharged from the slit-shaped opening 68 in a diagonally forward direction. As a result, the fuel gas collides with air and mixing is promoted. Further, according to the present embodiment, the concentration of the fuel gas is stabilized because the fuel gas and air are unlikely to form a vortex.
The combustion apparatus shown in FIG. 23 is provided with a slit-like opening 69 at the top of the premixing member.
Although it is recommended that the fuel gas be discharged in a direction crossing the air flow, the present invention does not exclude a structure that discharges along the air flow as shown in FIG.

  In the embodiment shown in FIG. 2 and subsequent figures, a number of uneven shapes are provided on the surface of each member. The uneven shape fulfills the function of improving the rigidity of the plate body in addition to the function of constituting the flow path. Further, the uneven shape that does not constitute the flow path only fulfills the function of improving the rigidity of the plate.

  In each of the above-described embodiments, a series of flow paths is formed by the gaps between the metal plates. That is, one or both plates are provided with a recess, and a gap is formed between the other plate. Here, it is one of the design matters to determine which plate is provided with the groove when forming the flow path, and the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, a part of the second route of the air has a flow path that passes between the inner surface of the flame hole member 3 and the outer peripheral surface of the premixing member. 93 was provided to secure the flow path. However, conversely, the flow path may be configured by providing a groove or the like on the premixing member side.

Claims (15)

  A premixing member for premixing fuel gas and air therein, a flame hole member, and an air flow path member, wherein the premixing member includes an opening row portion in which openings are provided in a row, and the air The flow path member has a wall-like outer shape and has a front end air discharge opening on the front end side, and the flame hole member is between the two air flow path members or between the air flow path member and another wall surface. Disposed between the opening row portion and the flame hole member, and a first combustion portion is formed by a space surrounded by the flame hole member and the air flow channel member. The fuel gas is supplied to the premixing member, the fuel gas is supplied to the premixing member, and the fuel gas is mixed with air in the premixing member, and then the upstream of the flamehole from the opening of the opening row portion. Supplied to the side flow path and further mixed with air, released from the flame hole member to the first combustion section in a state of lack of oxygen. Baked, and further combustion apparatus characterized by burning supplied with air from the tip air discharge opening of the air passage member.   2. The combustion apparatus according to claim 1, wherein there is a mixing space in the vicinity of the opening row portion in a part of the flame hole upstream side flow passage, and the opening of the opening row portion opens toward the mixing space. .   The combustion apparatus according to claim 1, wherein the mixing space communicates over substantially the entire area of the opening row portion.   The combustion apparatus according to any one of claims 1 to 3, wherein the opening of the opening row portion opens in a direction intersecting with a flow direction of the airflow flowing through the flame hole upstream side flow path.   The flame hole member has a flame hole forming portion and two side wall portions, and has an opening portion between the two side wall portions and opposed to the flame hole forming portion, and the opening row portion of the premixing member is the side wall portion. The combustion apparatus according to any one of claims 1 to 4, wherein the combustion apparatus is disposed at a position surrounded by a portion, and air is introduced from the opening.   The combustion apparatus according to any one of claims 1 to 5, further comprising an air discharge opening for a combustion section that discharges air from the air flow path member toward the first combustion section.   The combustion apparatus according to claim 6, wherein the air flow path member has an inclined surface, and an air discharge opening for a combustion unit is provided on the inclined surface.   The flame hole member has a plurality of flame hole groups, and the combustion part air discharge opening is arranged between the flame hole groups of the flame hole member. 8. The combustion apparatus according to 7.   An upstream air discharge opening is provided on the upstream side of the portion constituting the first combustion part of the air flow path member, and the air discharged from the upstream air discharge opening flows to the side surface side of the flame hole member. The combustion apparatus according to any one of claims 1 to 8, wherein:   The flame hole member has a center side opening and a side side opening, and the flow rate of the fuel gas released from the side side opening is slower than the flow rate of the fuel gas released from the center side opening. The combustion apparatus according to any one of claims 1 to 9, wherein the combustion apparatus flows in the vicinity of the side opening.   The flame hole member is constituted by a main body part and a decompression wall provided on a side surface of the main body part, a gap is provided between the side surface of the main body part and the decompression wall to constitute a side opening, and the main body part has an opening. The combustion apparatus according to any one of claims 1 to 10, wherein a part of the fuel gas that is provided and flows through the main body flows into the gap.   The combustion apparatus according to any one of claims 1 to 11, wherein a shape of the opening provided in the opening row portion is a slit shape.   The combustion apparatus according to claim 1, wherein the opening row portion has an inclined surface, and an opening is provided in the inclined surface.   The combustion apparatus according to any one of claims 1 to 13, wherein an inner angle of the opening row portion is 180 ° or less.   The combustion apparatus according to any one of claims 1 to 14, wherein a tip of the air flow path member has an acute ridge shape.

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