JP5625869B2 - Concentration burner - Google Patents

Description

  The present invention relates to a light and dark combustion burner capable of reliably reducing NOx while achieving flame combustion stability.

  Conventionally, a lean mixture having an air ratio larger than 1 is burned in the flare holes in order to reduce NOx, while a concentrated mixture having an air ratio smaller than 1 is used to stabilize the combustion flame. Various types of concentration burners have been proposed in which a concentration flame hole for burning is adjacent to the emission flame hole. (For example, refer to Patent Documents 1 and 2).

JP 7-42917 A JP 2002-48314 A

  By the way, as a method of separately supplying the rich mixture and the light mixture to the rich flame hole and the pale flame hole, in Patent Document 1, the supply port for the rich mixture and the supply port for the light mixture are individually provided. The fuel gas supply port is directly supplied from the rich gas mixture supply port to the rich flame hole, while the light gas mixture supply port is directly supplied to the light flame hole. In addition, the air supply port is provided separately, and the supply passages leading to the rich flame hole and the pale flame hole are respectively provided with branches and lengths to adjust the density of the air-fuel mixture.

  However, in the case of a concentration burning burner in which the concentration flame holes are respectively arranged on both sides of the row of emission flame holes and the emission flame holes are simply sandwiched from both sides, the supply method proposed in each of the above patent documents is used. Although a rich mixture and a light mixture can be supplied, by adding a row of dense flame holes so as to extend further on the center line of the pale flame hole, for example in the short direction (width direction), for example, dark-light-dark-light -If the arrangement is such that the dense flame holes and the pale flame holes are alternately arranged in an arrangement such as the rich, the supply passage structure is used to supply the rich mixture and the pale mixture to the respective dense flame holes and the pale flame holes. This may lead to complications and, as a result, a situation that is contrary to weight reduction.

  The present invention has been made in view of such circumstances, and the object of the present invention is to be able to reliably supply a light mixture and a rich mixture to the light flame hole and the rich flame hole with a simple structure. Thus, it is an object of the present invention to provide a light and dark combustion burner that can supply a required air-fuel mixture reliably and without adversely reducing the weight even when multiple deep flame holes and pale flame holes are combined.

  In order to achieve the above object, in the present invention, two rows of pale flame holes are arranged so as to sandwich the central deep flame holes arranged from both sides so as to extend in the longitudinal direction at the central position, and the pale flames on both sides are arranged. The following specific matters were provided for a light and dark combustion burner in which two rows of outer dense flame holes are arranged so as to sandwich the holes from the outside. That is, the rich gas mixture introduced into one rich gas mixture introduction passage is divided and supplied to the one row of central rich flame holes and the two rows of outer rich flame holes. A first supply passage for supplying a rich mixture to the central rich flame hole; a second and a third supply passage for separately supplying a rich mixture to the two rows of outer rich flame holes; and the rich mixing The air introduction passage is partitioned from each other. A part of a forming member for partitioning the first supply passage is disposed so as to protrude into the rich gas mixture introduction passage, and a communication hole communicating with the first supply passage with respect to the protruding portion is provided. A communication hole communicating with the second supply passage with respect to a forming member for defining the dense mixture introduction passage while being formed so as to open toward the rich mixture introduction passage, and the third supply A communication hole communicating with the passage is formed so as to open toward the rich air mixture introduction passage at a position corresponding to the communication hole position of the projecting portion (Claim 1).

  In the case of the present invention, in the concentration combustion burner in which the concentration flame holes and the emission flame holes are arranged in the order of concentration-light-dense-light-dense, the rich mixture introduced from one rich mixture introduction passage is used. A pair of outer rich flames through the communication holes formed in the central dense flame hole through the communicating hole of the protruding portion projecting into the rich gas mixture introducing passage and the forming member for partitioning the rich gas mixture introducing passage. The holes can be divided and supplied individually. Therefore, even if the burner is arranged in the order of dark-light-dark-light-dark as described above, the rich air-fuel mixture can be supplied smoothly and reliably with a simple structure to each rich flame hole. become. In addition, by setting the opening area of these communication holes, etc., it is possible to easily supply a rich mixture to each rich flame hole at the same flow rate, flow rate and pressure, and to easily supply a rich mixture with the same air ratio. It becomes possible.

  In the present invention, the opening size of the central concentrated flame hole is set smaller than that of the outer concentrated flame hole, or the rich air-fuel mixture supplied to the central concentrated flame hole is set smaller than that of the outer concentrated flame hole. Can also be set to be on the small side (claim 2). By doing so, the rich flame formed in the central rich flame hole is made smaller than the rich flame formed in the outer rich flame hole, or the surface area is increased to come into contact with the surrounding air. It becomes easy to do so, and the possibility of falling short of combustion air due to the absence of secondary air in the vicinity can be suppressed.

  In the present invention, the light mixture introduced into one light mixture introduction passage is divided into two light mixture supply passages and supplied individually to the two rows of light flame holes. Then, by forming a forming member for partitioning the first supply passage so as to bisect the space downstream of the light mixture introduction passage, two light mixture supply passages are partitioned. (Claim 3). By doing so, it becomes possible to partition and form two light mixture supply passages using the forming member for partitioning the first supply passage, resulting in a complicated structure and an increase in the number of constituent members. Without any problem, the light mixture can be individually supplied to the two rows of the light flame holes.

  In the present invention, at a position lower than the rich mixture introduction passage, a light mixture introduction passage into which fuel gas and air are introduced in order to supply the pale mixture to the pale flame hole is provided, The forming member for partitioning the first supply passage may be provided with a protruding piece arranged so as to protrude from the forming member and protrude into the light mixture supply passage. Item 4). By doing so, the fuel gas and air introduced into the lean mixture introduction passage collide with the protruding piece, or the direction of the flow is changed, resulting in a turbulent state. The mixing of air and air is promoted. In addition, such mixing promotion can be realized only by providing the forming member with a protruding piece. Here, the projecting piece may be provided along the introduction flow of the fuel gas in the fresh gas mixture supply passage, and may include a shape changing portion that the introduction flow of the fuel gas collides with. (Claim 5) By disposing the projecting piece along the flow of introduction of the fuel gas in this way, it is possible to reduce the pressure loss as much as possible while reducing the pressure loss as much as possible. It is possible to further promote mixing.

  Further, in the present invention, the light mixture introduction passage extends from one side in the longitudinal direction to the other side, while the pale flame hole is arranged to extend the entire length in the longitudinal direction at a position above the light mixture introduction passage. The baffle plate is provided so as to shield the upper side of the other side in the longitudinal direction of the light mixture introduction passage and guides the flow of the light mixture toward the light flame hole in the one side region in the longitudinal direction. The baffle plate can be formed by cutting up an edge of a forming member for defining the first supply passage (Claim 6). By doing in this way, while it becomes possible to eject the air-fuel mixture in a more uniform state over the longitudinal direction of the light flame hole, the baffle plate is formed by cutting and raising the edge of the forming member, It is possible to reduce the number of components and to omit the mounting work.

  As described above, according to the lean burn burner of the present invention, in the lean burn burner in which the rich flame holes and the pale flame holes are arranged in the order of dark-light-dark-light-dense, Forming member for partitioning the rich mixture introduction passage into the central rich flame hole through the communicating hole of the projecting portion where the rich mixture introduced from the rich mixture introduction passage projects into the rich mixture introduction passage Can be separately supplied to the pair of outer concentrated flame holes through the communication holes formed. For this reason, even if the burner is arranged in the order of dark-light-dark-light-dense as described above, the rich air-fuel mixture is smoothly and reliably divided and supplied to each of the rich flame holes. Will be able to. In addition, by setting the opening area of these communication holes, etc., it is possible to easily supply a rich mixture to each rich flame hole at the same flow rate, flow rate and pressure, and to easily supply a rich mixture with the same air ratio. You can also do that.

  In particular, according to claim 2, the rich flame formed in the central rich flame hole is made smaller than the rich flame formed in the outer rich flame hole, or the surface area is increased to contact the surrounding air. It is possible to easily or easily perform the operation, and it is possible to suppress the risk of falling into the combustion air shortage due to the absence of secondary air in the vicinity.

  According to the third aspect, it is possible to form the two light mixture supply passages by using the forming member for forming the first supply passage, without complicating the structure and increasing the number of constituent members. The light mixture can be individually supplied to the two rows of the light flame holes.

  According to claim 4, by forming the protruding piece on the forming member for forming the first supply passage, the fuel gas introduced into the light mixture introduction passage collides with the protruding piece and the air. Or by changing the direction of the flow and becoming a turbulent state, it is possible to promote mixing of fuel gas and air. In addition, such mixing promotion can be realized simply by providing the forming member with a protruding piece. Furthermore, according to the fifth aspect, the projecting piece is disposed along the flow of the fuel gas, thereby reducing the pressure loss as much as possible while reducing the pressure loss as much as possible. It becomes possible to further promote mixing.

  According to the sixth aspect, the air-fuel mixture can be ejected in a more uniform state over the longitudinal direction of the light flame hole, while at the same time, the number of components is reduced and the mounting operation is omitted. Will be able to.

The example of the combustion apparatus incorporating the light and darkness combustion type burner of this invention is shown, Fig.1 (a) is explanatory drawing shown in a perspective view state, FIG.1 (b) is explanatory drawing shown in sectional drawing state. It is a perspective view of the light and dark combustion burner of the embodiment of the present invention. It is a front view of the burner of FIG. 4A is a plan view of the burner in FIG. 2, FIG. 4B is an enlarged view of the FF portion in FIG. 4A, and FIG. 4C is a left side view of the burner in FIG. FIG. It is a perspective view of the state which decomposed | disassembled the pair of 1st plate member which comprises a 1st burner part with respect to a 3rd burner, a pair of 2nd plate member, and a pair of flame hole member which comprises a pale flame hole row | line | column. . It is a perspective view of the state which decomposed | disassembled a pair of 2nd plate member which comprises a 2nd burner part. It is a fragmentary perspective view of the state cut | disconnected by the cross section in the AA of FIG. FIG. 8B is a partial perspective view of the state cut along the line CC in FIG. 3, and FIG. 8B is a partial perspective view of the state cut along the line DD in FIG. is there. It is a fragmentary perspective view of the state cut | disconnected by the cross section in the BB line of FIG. FIG. 4 is a cross-sectional explanatory view taken along line AA in FIG. 3. FIG. 11A is a diagram corresponding to FIG. 4A of the second embodiment, and FIG. 11B is a diagram corresponding to FIG. 4A of another embodiment belonging to the second embodiment. It is a front view which shows 3rd Embodiment, Comprising: It is a figure corresponding to FIG. 3 of a notch state. FIG. 13A is a perspective view showing a third burner portion used in the third embodiment, and FIG. 13B is a perspective view showing a third burner portion used in the fourth embodiment. The other form of the shape change part formed in the 3rd burner part of 3rd Embodiment is shown, FIG.14 (a) is an example of a bending shape, FIG.14 (b) is an example of a bulging shape, FIG. 14C is an example of a bent shape for saving material collection. It is a front view which shows 4th Embodiment, Comprising: It is a figure corresponding to FIG. 3 of a notch state. FIG. 9 is a view corresponding to FIG. 2, showing a part of the first embodiment for explaining the comparison with the fourth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 shows a combustion apparatus 2 to which a light and dark combustion burner (hereinafter simply referred to as “burner”) according to a first embodiment of the present invention is applied. In this combustion apparatus 2, a burner set in a state where a predetermined number of burners 3, 3,. The upper space of the can 21 is a combustion space 22, and combustion air from the blower fan 24 is supplied to the lower space 23, while the gas manifold 25 (shown only in FIG. 1B) is provided on one side of each burner 3. ) And two gas nozzles 26, 27 project from the gas manifold 25 to one burner 3. One (lower) gas nozzle 26 can eject the fuel gas toward the first supply port 31 of the burner 3, and the other (upper) gas nozzle 27 can eject the fuel gas toward the second supply port 32 of the burner 3. ing. Then, the air from the lower space 23 is pushed in from the surroundings of the gas nozzles 26 and 27 by the discharge pressure of the blower fan 24 so that both the fuel gas and the air can be supplied to the first and second supply ports 31 and 32. It has become. At this time, the first supply port 31 is set to a considerably large diameter so as to push in more air, while the second supply port 32 is set to a relatively small diameter to reduce the amount of air to be pushed in. Has been. In this way, in addition to the fuel gas supplied from the first supply port 31, an amount of air having a predetermined air ratio larger than 1.0 is supplied to the inside, while the same is supplied from the second supply port 32. In addition to the fuel gas supplied to the air, an amount of air having a predetermined air ratio smaller than 1.0 is supplied to the inside. A large number of small holes are formed in the rectifying plate 28 (see FIG. 1B) arranged so as to partition the lower space 23 and the burners 3, 3,... Secondary air is supplied between 3 and 3.

  As shown in FIG. 2, the burner 3 includes three pairs of plate members 4, 4, 5, 5, 6, 6 that are processed into a predetermined shape by pressing and bending using a metal plate material. , Formed by using a pair of flame hole forming members 7 and 7 and connecting each of three types of plate members 4, 4, 5, 5, 6, and 6, with each other facing each other as described later It is. Such a burner 3 is formed in a flat shape as a whole (see FIG. 3). If the left-right direction in FIG. 3 is the longitudinal direction (length direction) and the direction orthogonal to the paper surface in FIG. 3 is the short direction (width direction), it is at the lower position on one side in the longitudinal direction (left side in FIG. 3). The first supply port 31 is opened, the second supply port 32 having a smaller diameter than the first supply port 31 is opened at the upper position (see also FIG. 4C), and a combustion flame is formed on the upper end surface. The flame hole array is formed to extend in the longitudinal direction. As shown in FIG. 2 or FIGS. 4 (a) and 4 (b), as the flame hole row, a narrow flame hole row 33 extends at the entire length in the longitudinal direction at the central position in the short side direction. A relatively wide pale flame hole row 34 extends in the entire length in the longitudinal direction at each of both sides in the short direction, and a narrow deep flame hole row 35 is located at the outer side of the pale flame hole rows 34, 34 on both sides. It extends in the entire direction. Then, the light flame mixture supplied and mixed from the first supply port 31 is guided to each of the light flame holes 341 of the light flame hole rows 34 and 34, and a light flame is formed by this light gas mixture, and the central position is located. Concentrated mixture supplied and mixed from the second supply port 32 to each of the concentrated flame holes 331 of the concentrated flame hole array 33 and each of the concentrated flame holes 351 of the two outer flame positions 35 and 35 at both outer positions. A rich flame is formed by this rich mixture.

  Such a burner 3 can be formed as follows, for example. That is, as shown in FIGS. 5 and 6, each of the three types of paired plate members 4, 4, 5, 5, 6, 6 and the pair of flame hole forming members 7, 7 are used. A pair of third plate members 6 and 6 (refer to FIG. 5) are opposed to each other, and both sides and lower edges thereof are joined to each other, whereby a supply passage for the rich mixture is formed between the inner surfaces, and A central deep burner portion 3a for forming a rich flame is formed in the rich flame hole row 33. Next, with the central dark burner 3a sandwiched therebetween, the pair of first plate members 4 and 4 are opposed to each other from both sides in the short direction, and the both sides and lower edges thereof are joined to each other. At this time, the both ends (front and rear end portions) of the central dark burner 3a in the longitudinal direction are sandwiched by the both ends (front and rear end portions) of the pair of first plate members 4 and 4 in the longitudinal direction. Can be securely fixed in the burner 3. And the pale flame hole forming member 7 is interposed in the two upper end openings between the first plate member 4 and the central dark burner 3a on both sides. As a result, the light burner 3b is formed which surrounds the central dark burner 3a from both sides in the short direction and forms a light flame in the two light flame hole rows 34, 34 on the upper end surface. In this light burner 3b, the light mixture from the first supply port 31 passes through a supply passage formed between the inner surface of the first plate member 4 and the outer surface of the third plate member 6 of the central concentrated burner 3a. It will be supplied to each of the pale flame holes 341 in the hole rows 34 and 34. Then, the second plate member 5 is put on the outer side of each first plate member 4 of the light burner 3b, and both second and lower edge portions are joined to the edge portions of the first plate members 4, thereby each second plate. The rich air-fuel mixture is supplied through a supply passage formed between the inner surface of the member 5 and the outer surface of the first plate member 4 opposite to the inner surface of the first plate member 4, and the rich flame is supplied to the rich flame holes 351 of the outer rich flame hole rows 35, 35. The outer dark burner 3c (see FIG. 2) is formed. In the present embodiment, a pair of plate members 4, 4, 5, 5, 6, 6 which are separate plate members are prepared, and the burner 3 is joined by joining the edges of each pair. However, the present invention is not limited to this. For example, the burner 3 may be formed by bending a single plate member. Further, for example, the end portions of the plate members having different shapes and types such as the second plate member 5 and the third plate member 6 are made continuous with each other to be integrated into one body, and the burner 3 is formed by bending this. It may be. Thus, the formation method of the burner 3 is not limited to what was described in this embodiment.

  Next, characteristic structural portions will be described with reference to FIGS. Due to the formation of the light burner 3b, the light mixture from the first supply port 31 opened to one side is sent to the other side through the cylindrical portion 36 (see the dotted arrows in FIGS. 7 and 8A). The two internal spaces 37, 37 (FIG. 8B), whose direction is changed from the other side to the upper side, and the space between the pair of first plate members 4, 4 is partitioned (divided) by the third plate members 6, 6. ) And FIG. 9), the upper flame train 34 and 34 is supplied. The cylinder portion 36 and the internal spaces 37, 37 constitute a light mixture supply passage for supplying the light mixture to the two rows of pale flame holes 34, 34, and the cylinder portion 36 has a first supply port 31. It also serves as a mixing chamber and an introduction passage (a light mixture introduction passage) for fuel gas and air supplied from the air. The third plate members 6 and 6 constitute a forming member for defining a first supply passage which will be described later, and the third plate members 6 and 6 bisect the downstream side of the light mixture introduction passage ( The two fresh air-fuel mixture supply passages (inner spaces 37, 37) are partitioned and divided.

  Further, after the rich air-fuel mixture from the second supply port 32 is led to the closed end at the back through the cylindrical portion 38 (see FIGS. 7 and 8A), the concentrated rich air is concentrated from the closed end position of the cylindrical portion 38. It is supplied to both the burner 3a and the outer dark burner 3c. That is, at the closed end position of the cylindrical portion 38, the lower end portion 60 (see FIGS. 8A and 10) of the central dark burner 3a is inserted from above and protrudes into the cylindrical portion 38. The inside of the cylindrical portion 38 is substantially bisected in the short direction. And a communicating hole 61 and 61 is formed in each of a pair of 3rd plate members 6 and 6 which comprise this lower end part 60, and each communicating hole 61 is the inside of the cylinder part 38, and the internal space 62 of the central dark burner 3a. Are communicated, and the rich air-fuel mixture in the cylinder portion 38 is supplied to the rich flame hole array 33 through the communication holes 61 and the internal space 62. On the other hand, communication holes 41, 41,... Are formed in both of the pair of first plate members 4, 4 constituting the cylindrical portion 38, and each communication hole of the first plate member on one side (the right side in FIG. 10). 41, the inside of the cylindrical portion 38 communicates with the internal space 51 between the first plate member 4 on one side and the second plate member 5 on the same side, and the first plate member 4 on the other side (left side in FIG. 10). Each communication hole 41 communicates the inside of the cylindrical portion 38 with an internal space 52 between the second plate member 5 on the same side as the first plate member 4 on the other side. Thereby, the rich air-fuel mixture in the cylinder portion 38 is supplied to the one-side rich flame hole array 35 through the communication holes 41 and the internal space 51 on one side, while the rich air-fuel mixture in the cylinder portion 38 is supplied to the other side. It is supplied to the deep flame hole array 35 on the other side through each communication hole 41 and the internal space 52. The internal spaces 51, 52, and 62 constitute a rich gas mixture supply passage together with the cylindrical portion 38, and the cylindrical portion 38 is a mixing chamber for fuel gas and air supplied from the second supply port 32. And it also plays a role of an introduction passage (rich mixture introduction passage). That is, the internal space 51 constitutes the second supply passage, the internal space 52 constitutes the third supply passage, and the internal space 62 constitutes the first supply passage. The lower end portion 60 only has to protrude so as to face the inside of the cylindrical portion 38, and it is not always necessary to extend the inside of the cylindrical portion 38 to the bottom and bisect the inside of the cylindrical portion 38. Further, the communication holes 61, 61 and the communication holes 41, 41,... May be formed so as to open at positions facing each other in the short side direction, or may be shifted from each other with respect to the longitudinal direction as in this embodiment. You may form so that it may open at the position. That is, the communication holes 61, 61 open at the closed end position of the cylindrical portion 38 constituting the rich mixture introduction passage, and correspond to the closed end position of the cylindrical portion 38 where the communication holes 61, 61 are opened. It is sufficient that the communication holes 41, 41,... Are also opened at the closed end position of the cylindrical portion 38, which is the same region.

  Further, the one side rich flame hole row 35 communicating with the internal space 51, the other side rich flame hole row 35 communicating with the internal space 52, and the central rich flame hole row 33 communicating with the internal space 62. The flow rate and pressure of the rich mixture supplied to each are set to be the same. For example, the opening areas of the rich flame hole row 35 on one side, the rich flame hole row 35 on the other side, and the rich flame hole row 33 are formed so as to be the same as each other, and communicated with the cylindrical portion 38. The communication holes 41, 41, ... on one side, 41, 41, ... on the other side, and the communication holes 61, 61, ... may be formed to have the same total opening area. In the embodiment, the opening areas of the communication holes 41 and the communication holes 61 are set to be the same, and the number of formations is set to be the same. In other words, the number of communication holes 61 communicating with the internal space 62 is four, the number of communication holes 41 communicating with the internal space 51 is four, and the number of communication holes 41 communicating with the internal space 52 is four. I have to. As described above, the three rich flame hole rows 35, 33, 35 disposed so as to surround the two pale flame hole rows 34, 34 from both sides are concentrated gas mixtures having the same flow rate, flow velocity, and pressure. Will be able to supply.

  In the case of the above-described embodiment, each of the two pale flame hole rows 34, 34 is sandwiched from both sides by the rich flame hole rows 35, 33 or the rich flame hole rows 33, 35. , 34 can be surrounded by a thick flame from both sides. That is, the flame structure in the short direction can be arranged in the order of rich flame-light flame-rich flame-light flame-rich flame. As a result, even if the number of the light flame hole rows 34 is increased to increase the area of the light flame hole rows, the combustion of the combustion chamber 22 (see FIG. 1) is avoided while avoiding an increase in the flame length of the light flame. The chamber height can be kept low, while the combustion chamber height can be kept low, and the area (ratio) of the flare holes can be increased to further reduce NOx, and combustion can be further stabilized. Can be planned. In addition, compared with a case where one burner hole row is sandwiched between the dense flame hole rows from both sides to form one burner, the burner can be made more lightweight in terms of realizing the same pale flame hole area. become. Further, the rich air-fuel mixture introduced and mixed from one fuel gas and air supply port (second supply port 32) is mixed with the cylindrical portion 38 at the closed end position of the cylindrical portion 38 at the lower end portion 60 of the central concentrated burner 3a. The inside is divided into right and left sides (divided into two equal parts), and each divided space in the cylindrical portion 38 is divided into the inner space 51 or 52 toward the outside, while being divided into the inner space 62 toward the inside. Even when three thick flame hole rows 35, 33, 35 are formed at the center and both outer sides, the rich air-fuel mixture can be smoothly and surely diverted with a simple structure to each rich flame hole. It can be supplied to the rows 35, 33, 35. In addition, by setting the opening areas of the communication holes 41 and 61 and the concentrated flame hole rows 35 and 33, it is possible to supply a rich mixture having the same flow rate, flow rate, and pressure and having the same air ratio. Can do.

Second Embodiment
FIG. 11 shows the flame surface of the burner 3 of the second embodiment. In the second embodiment, the rich flame formed in the central rich flame hole row 33a or 33b is prevented from falling short of combustion air. That is, it is possible to avoid the possibility of a shortage of combustion air due to the absence of secondary air in the vicinity. Since other configurations are the same as those of the first embodiment, a duplicate description is omitted, and only different points will be described below. As a second embodiment for avoiding the possibility of falling into the combustion air shortage, there are the following three forms of form 1 to form 3, which may constitute the embodiment alone or in combination of any two or more. It is good also as a form.

  As shown in FIG. 11A, the inner width N1 of the rich flame hole row 33a of the central rich burner 3a is set smaller than the inner width N2 of the rich flame hole row 35 of the outer rich burner 3c as shown in FIG. is there. As a form 2, as shown in FIG. 11 (b), the number of divisions of the individual rich flame holes of the rich flame hole row 33b of the central rich burner 3a is increased more than that of the rich flame hole row 35 of the outer rich burner 3c. It is a thing. As a result, the length K1 in the longitudinal direction of each of the rich flame holes 331 of the rich flame hole row 33b becomes smaller (for example, half) than the length K2 of the individual rich flame holes 351 of the rich flame hole row 35, and the rich flame The surface area of the rich flame formed in the hole row 33b is larger than that of the rich flame formed in the outer rich flame hole row 35, and the area where the rich flame formed in the rich flame hole row 33b comes into contact with the surrounding air Can be increased. Although the illustration is omitted as the form 3, the flow rate of the rich mixture supplied through the communication hole 61 (see FIG. 10) is made smaller than the flow rate of the rich mixture supplied through the communication hole 41. It is. For this reason, by reducing the inner diameter of the communication hole 61 itself, reducing the number of the communication holes 61, or combining them, the opening area of the communication hole communicating with the central concentrated flame hole array 33 is outside. What is necessary is just to make it smaller than that of the communicating hole connected to the dense flame hole row 35 of the. At this time, it is preferable that the supply flow rate of the rich air-fuel mixture is the same for the central rich flame hole row 33 and the outer rich flame hole row 35.

  As described above, the rich flame formed in the outer dense flame hole row 35 is easily in contact with the secondary air on the outer side, whereas the rich flame formed in the central dense flame hole row 33 is difficult to come in contact with the secondary air. However, in Form 1, by reducing the rich air-fuel mixture ejected from the central concentrated flame hole array 33, in Form 2, the concentrated flame formed in the central concentrated flame hole array 33 is divided into small portions and the surroundings. By making it easier to touch the air, it is possible to avoid the possibility of falling into the combustion air shortage by reducing the rich air-fuel mixture ejected from the central rich flame hole array 33 in the third mode.

<Third Embodiment>
FIG. 12 is a partially cutaway front view of the burner 3 according to the third embodiment. In the third embodiment, the degree of mixing when the fuel gas and air introduced from the first supply port 31 to the cylindrical portion 36 are mixed in the cylindrical portion 36 can be increased. That is, in order to increase the air ratio of the light mixture supplied from the cylindrical portion 36 to the light flame hole rows 34, 34 of the light burner 3b and further reduce NOx, the combustion stability of the light flame is ensured. Therefore, it is necessary to make the degree of mixing of the light mixture more certain. Conventionally, in order to ensure the degree of mixing of the light mixture, the supply passage of the light mixture has been throttled in the middle. However, if the supply passage is restricted, the pressure loss increases and the pressure loss increases. This increases the load on the blower fan 24 (see FIG. 1). Therefore, in the third embodiment, as a smaller passage resistance, the mixing of the light mixture can be further promoted while reducing the pressure loss as much as possible. The first embodiment differs from the first embodiment only in the points relating to the protruding pieces 63 and 64 and the shape changing portions 631 to 633 and 641 described later, and the other configuration is the same as that of the first embodiment, and therefore, the redundant description is omitted. Only different points will be described below.

  In the third embodiment, the lower end portion 60 (see FIG. 10) of the central dark burner 3a arranged in the cylindrical portion 36 is further protruded downward as shown in FIG. A protruding piece 63 that can project into the portion 36 is formed, and a shape changing portion 631 is formed on the protruding piece 63. The protruding piece 63 is arranged at a position that bisects the inside of the cylindrical portion 36, and the shape changing portion 631 is formed so as to be located on the extended line of the nozzle center of the gas nozzle 26 (see FIG. 1B). In the example of FIG. 12, the shape changing portion 631 is configured by providing a lateral V-shaped notch. In this case, the fuel gas ejected from the first supply port 31 into the cylindrical portion 36 collides with the shape changing portion 631 to disturb the flow, thereby promoting the mixing with air. In addition, since the shape changing portion 631 is formed on the protruding piece 63 disposed so as to bisect the inside of the cylindrical portion 36, the passage resistance can be suppressed to a smaller value.

  As another form belonging to the third embodiment, as shown in FIG. 14A, a contact surface on which the fuel gas flow can collide is formed as the shape changing portion 632 formed on the protruding piece 63, or FIG. As shown in FIG. 4B, the shape changing portion 633 formed on the protruding piece 63 may be formed in a bulging shape. Or as shown in FIG.14 (c), the protrusion piece 64 (refer the dashed-dotted line of the same figure) which protruded ahead from the lower end part 60 of the central dark burner 3a rather than the downward direction is formed beforehand, and this is made into 90 The protruding piece 64 is bent downward and protrudes downward (see the solid line in the figure). And the shape change part 641 may be formed in the protrusion piece 64 by bending etc., for example. It should be noted that the projecting pieces 63 and 64 do not have to divide into the inside of the tubular portion 36 by projecting so that the lower ends of the projecting pieces 63 and 64 are located in the vicinity of the bottom position of the tubular portion 36 (for example, see FIG. 12). For example, it may simply project into the fuel gas flow so that it can collide with it, or it may project in an eccentric direction other than the center in the cylindrical portion 36.

<Fourth embodiment>
FIG. 15 is a partially cutaway front view of the burner 3 according to the fourth embodiment. In the fourth embodiment, a light air-fuel mixture is introduced from the first supply port 31 on one side to the other side through the cylindrical portion 36 and then supplied to the light flame hole rows 34 and 34 and ejected from the light flame hole rows 34 and 34. The jetting flow rate can be made uniform over the longitudinal direction. That is, in the case of the first embodiment, as illustrated in FIG. 15, the light air mixture introduced and mixed from the first supply port 31 on one side reaches the other side through the inside of the cylindrical portion 36, and the direction here Is turned upward and the air reaches the flaming hole array 34 through the internal space 37 and is ejected. However, in this case, even if the flow is changed upward at the other side position of the cylindrical portion 36, the ejection flow rate in the range extending over the entire length in the longitudinal direction of the pale flame hole rows 34, 34 is not uniform and is uneven. Is likely to occur. As a countermeasure for this, a portion for restricting the supply passage is interposed at the upper position (downstream position) after the direction has been changed. This results in the need to increase the dimensions accordingly. Therefore, in the fourth embodiment, it is possible to make the ejection flow rate uniform in the longitudinal direction of the thin flame hole rows 34, 34 without increasing the vertical dimension of the entire burner. In addition, since it differs from 1st Embodiment only by the point which concerns on the baffle plate 65 mentioned later, and the other structure is the same as 1st Embodiment, the overlapping description is abbreviate | omitted and only a different point is demonstrated below.

  In the fourth embodiment, the flow of the light mixture is provided by providing the baffle plate 65 so as to shield and extend obliquely from the internal space 37 at the upper position on the other side in the longitudinal direction of the cylindrical portion 36. The conversion guide is provided so that the direction is not upward and is directed obliquely upward toward one side in the longitudinal direction, whereby a pale flame hole located on one side in the longitudinal direction opposite to the other side in the longitudinal direction of the cylindrical portion 36 Even if it goes to the range, a light mixture can be actively supplied. In addition, the baffle plate 65 (see also FIG. 13 (b)) is formed by cutting and raising the lower edge of the central dark burner 3a, thereby reducing the number of components and omitting the mounting work. Trying to get. Further, by forming through holes 651, 651,... Of a predetermined diameter in the baffle plate 65, a light mixture can be supplied also from the other side in the longitudinal direction of the cylindrical portion to the internal space 37 in the upper region. As a result, the flow of the light air-fuel mixture with respect to the light flame hole arrays 34 and 34 can be adjusted more finely.

3 Burner (Tint burning burner)
4 1st plate member (formation member for carrying out compartment formation of rich mixture introduction passage)
6 3rd plate member (formation member for dividing and forming the 1st supply passage)
33 Centered deep flame hole (central rich flame hole)
34 Pale flame hole train (Pale flame hole)
35 Outer deep flame hole train (outer rich flame hole)
36 Tube (light mixture introduction passage)
37 Internal space (light mixture supply passage)
38 cylinder part (rich mixture introduction passage)
41 communication hole (communication hole communicating with the second supply passage, communication hole communicating with the third supply passage)
51 Internal space (second supply passage)
52 Internal space (third supply passage)
61 Communication hole (Communication hole communicating with the first supply passage)
62 Internal space (first supply passage)
63 Projection piece 65 Baffle plate

Claims (6)

Two rows of pale flame holes are arranged so as to sandwich the central deep flame holes arranged so as to extend in the longitudinal direction at the central position from both sides, and two rows of outer flame holes are arranged so as to further sandwich the pale flame holes on both sides from the outside. It is a light and dark combustion burner in which dense flame holes are arranged,
The rich gas mixture introduced into one rich gas mixture introduction passage is divided and supplied to the one row of central rich flame holes and the two rows of outer rich flame holes,
A first supply passage for supplying a rich mixture to the central rich flame hole; a second and a third supply passage for separately supplying a rich mixture to the two rows of outer rich flame holes; and the rich mixing The air introduction passage is partitioned from each other,
A part of a forming member for defining the first supply passage is disposed so as to protrude into the rich gas mixture introduction passage, and a communication hole communicating with the first supply passage with respect to the protruding portion is provided. While formed so as to open facing the rich mixture introduction passage,
A communication hole communicating with the second supply passage and a communication hole communicating with the third supply passage correspond to the communication hole position of the projecting portion with respect to the forming member for forming the dense mixture introduction passage. A concentration burning burner, wherein the burner is formed so as to open toward the rich mixture introduction passage at a position. The light and burner according to claim 1,
The opening size of the central concentrated flame hole is smaller than that of the outer concentrated flame hole, or the rich mixture supplied to the central concentrated flame hole is smaller than that of the outer concentrated flame hole. Concentration burning burner set to be. The light and burner according to claim 1 or 2, wherein
The pale mixture introduced into one pale mixture introduction passage is divided into two pale mixture supply passages and supplied individually to the two rows of pale flame holes,
The formation member for partitioning the first supply passage is interposed so as to bisect the space on the downstream side of the light mixture introduction passage, so that two light mixture supply passages are partitioned. A light and dark burner. The light and dark combustion burner according to any one of claims 1 to 3,
A light mixture introduction passage through which fuel gas and air are introduced in order to supply the light mixture to the pale flame hole at a position below the rich mixture introduction passage;
A concentration combustion burner, wherein a forming member for partitioning the first supply passage includes a projecting piece disposed so as to project into the light mixture supply passage. The light and burner according to claim 4,
In the lean burn burner, the projecting piece is disposed along the fuel gas introduction flow in the light mixture supply passage, and has a shape changing portion with which the fuel gas introduction flow collides. The light and burner according to any one of claims 1 to 5,
The pale mixture introduction passage extends from one side in the longitudinal direction to the other side, while the pale flame hole is disposed so as to extend the entire length in the longitudinal direction at a position above the pale mixture introduction passage,
A baffle plate that is disposed so as to shield the upper side of the other side position in the longitudinal direction of the light mixture introduction passage and guides the flow of the light mixture toward the light flame hole in the one side region in the longitudinal direction,
The baffle plate is a light-and-burn combustion burner formed by cutting up an edge of a forming member for defining the first supply passage.

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