JP2012137219A - Thick and thin fuel combustion burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thick and thin fuel combustion burner certainly achieving NOx reduction by certainly achieving stability in combustion of flame without deteriorating combustibility even if thick flame holes and thin flame holes are combined in a multiple manner.SOLUTION: In sequence, a row of thick flame holes 33 is arranged in the center, rows of thin flame holes 34, 34 are arranged on both sides, and further rows of thick flame holes 35, 35 are arranged on both outer sides. A narrowed part 371 is formed in each of supply passages 37 supplying lean air-fuel mixture to the rows of the thin flame holes 34, 34, and leakage holes 42, 63 are formed in a downstream position in the immediate vicinity of the narrowed part. Some of rich air-fuel mixture supplied to the outer thick flame holes 35 and center thick flame holes 33 is leaked from the leakage holes 42, 63 to the side of the lean air-fuel mixture, and the lean air-fuel mixture mixed with the rich air-fuel mixture is supplied to the outward positions of the thin flame holes 34. On the contrary, the lean air-fuel mixture may be leaked to the side of the center thick flame holes 33.

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, 2, and 3). In particular, in Patent Document 3, the rich flame holes are arranged on both sides of the pale flame hole, and an air-fuel mixture having an intermediate concentration between the pale mixture and the rich mixture is supplied between the pale flame hole and the rich flame hole. It has been proposed to provide a flame hole.

JP 7-42917 A JP 2002-48314 A JP 2003-269705 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 a deep arrangement, the flammability of the dense flame formed in the central dense flame hole sandwiched between the pale flame holes on both sides is the most. It may be worse than the thick flame formed in the outer thick flame hole. Moreover, in the light and dark combustion burner, improving the flame holding property of the light flame is an important issue in improving the performance as the combustion device.

  The present invention has been made in view of such circumstances, and the object of the present invention is to ensure flames without causing deterioration in combustibility even when multiple deep flame holes and pale flame holes are combined. It is an object of the present invention to provide a light and dark combustion burner that can reliably reduce NOx by achieving the combustion stability of NO.

  In order to achieve the above object, according to the first aspect of the present invention, two rows of pale flame holes are arranged so as to sandwich the central concentrated flame holes arranged so as to extend in the longitudinal direction at the central position from both sides, The following specific matters were provided for a burnt burner in which two rows of outer dense flame holes are arranged so that the pale flame holes are further sandwiched from the outside. That is, a first leakage is made to a partition wall that separates an outer rich mixture supply passage for supplying a rich mixture to the outer rich flame hole and a pale mixture supply passage for supplying a pale mixture to the pale flame hole. A hole is formed so that a part of the rich air-fuel mixture can flow from the outer rich air-fuel mixture supply passage into the light air-fuel mixture supply passage through the first leakage hole (Claim 1).

  Further, in the second invention, two rows of flare holes are arranged so as to sandwich the central rich flame holes arranged so as to extend in the longitudinal direction at the center position from both sides, and the flare holes on both sides are further outside. The following specific matters are provided for a light and dark combustion burner in which two rows of outer rich flame holes are arranged so as to be sandwiched between them. That is, a second leak is made to the partition wall separating the central rich mixture supply passage for supplying the rich mixture to the central rich flame hole and the pale mixture supply passage for supplying the pale mixture to the pale flame hole. A hole is formed in a penetrating manner so that a part of the rich air-fuel mixture can flow from the central rich air-fuel mixture supply passage into the light air-fuel mixture supply passage through the second leakage hole (Claim 2).

  In the case of the above invention, a part of the rich mixture can flow into the light mixture supply passage from the outer rich mixture supply passage through the first leakage hole or from the central rich mixture supply passage through the second leakage hole. Therefore, the air-fuel mixture flowing through the part adjacent to the partition wall is mixed with the air-fuel mixture flowing in from the leakage hole, and the air ratio becomes smaller than the original air-fuel mixture and the air-fuel mixture and the air-fuel mixture are concentrated. It is supplied to the outside position of the pale flame hole in a state of intermediate concentration with the air-fuel mixture. For this reason, the flame holding property of the pale flame formed in the pale flame hole can be improved, and the combustion stability of the flame of the entire burner can be surely achieved.

  When each of the thin flame holes in the concentration burner is formed by a flame hole forming member having a plurality of thin plates assembled in layers with a predetermined slit interval and having at least three layers of slits, the leakage hole is While forming at the position opposite to the outer surface of the flame hole forming member, as a thin plate at the outermost position constituting the flame hole forming member, the rich mixture flowing from the leakage hole flows into the slit at the outermost position. It can be set as the structure provided with an opening at least so that it may make it (Claim 3). In this case, the rich mixture flowing in from the leakage hole enters the outermost slit through the opening and is mixed into the light mixture flowing in the slit. The air-fuel mixture is surely supplied to the outermost position of the pale flame hole formed by the flame hole forming member. Thereby, the flame-holding property of the pale flame formed in the pale flame hole can be improved reliably.

  Further, as a third invention, two rows of pale flame holes are arranged so as to sandwich the central dense flame holes arranged so as to extend in the longitudinal direction at the central position from both sides, and the pale flame holes on both sides are further outside. The following specific matters are provided for a light and dark combustion burner in which two rows of outer rich flame holes are arranged so as to be sandwiched between the two. That is, a second leak is made to the partition wall separating the central rich mixture supply passage for supplying the rich mixture to the central rich flame hole and the pale mixture supply passage for supplying the pale mixture to the pale flame hole. A hole is formed so that a part of the light mixture can flow from the light mixture supply passage into the central rich mixture supply passage through the second leakage hole.

  In the case of the present invention, the air-fuel mixture having an air ratio larger than that of the rich air-fuel mixture is supplied to the central rich flame hole by the amount of the inflow of the light air-fuel mixture. For this reason, the rich flame formed in the outer concentrated flame hole can be in sufficient contact with the secondary air, whereas the concentrated flame formed in the central concentrated flame hole is sandwiched between the light flames for combustion air. Since there is a possibility that the combustion air shortage may occur due to insufficient contact with the air, the possibility of falling into the combustion air shortage is avoided by mixing the light mixture through the leakage hole immediately before being supplied to the central concentrated flame hole. Thus, the rich flame formed in the central rich flame hole can be completely burned with good combustion stability.

  In each of the above inventions, it is possible to provide inflow direction setting means for setting the direction of inflow through the leakage hole. In this case, the inflow direction setting means can be constituted by a flow path resistance element formed at a position upstream or downstream of the leakage hole formation position. Alternatively, the inflow direction setting means may be constituted by a collision wall formed in the partition wall so that the flow of the air-fuel mixture on the inflow side collides, and the leakage hole may be formed through the collision wall. Claim 5). By adding such an inflow direction setting means, it is possible to reliably set the direction of inflow through the leakage hole in each invention to an intended one, and the effects of each invention can be obtained with certainty.

  As described above, according to the concentration burner according to any one of claims 1 to 3, the dense flame holes and the pale flame holes are arranged in the order of dark-light-dark-light-dark. In the lean burner, a part of the rich mixture flows into the lean mixture supply passage from the outer rich mixture supply passage through the first leakage hole or from the central lean mixture supply passage through the second leakage hole. As a result, the air-fuel mixture that flows through the leak hole is mixed with the air-fuel mixture that flows through the area adjacent to the partition wall. It becomes possible to supply the air-fuel mixture in an intermediate concentration with the gas to the outer position of the pale flame hole. For this reason, the flame holding property of the light flame formed in the light flame hole can be improved, and the combustion stability of the flame of the entire burner can be achieved with certainty. As a result, it is possible to provide a light and dark combustion burner that can reliably reduce NOx.

  In particular, according to the third aspect, the rich gas mixture flowing in from the leakage hole can be put into the slit at the outermost position through the opening and mixed into the light gas mixture flowing in the slit. Thus, the air-fuel mixture having an intermediate concentration can be reliably supplied to the outermost position of the pale flame hole formed by the flame hole forming member. Thereby, the flame holding property of the pale flame formed in the pale flame hole can be improved more reliably.

  According to the lean burn burner of claim 4, the air-fuel mixture having an air ratio larger than that of the rich air-fuel mixture can be supplied to the central rich flame hole by the amount that the light air-fuel mixture flows. For this reason, the rich flame formed in the central thick flame hole is sandwiched between the light flames for combustion air, compared with the case where the rich flame formed in the outer rich flame hole can sufficiently contact the secondary air. If there is a possibility that the air will not be sufficiently contacted with the fuel, it may cause a shortage of combustion air. can do. Thereby, the rich flame formed in the central rich flame hole can be completely burned with good combustion stability. As a result, even if the deep flame holes and the pale flame holes are arranged in the order of dark-light-deep-light-dense, the flame flames and the pale flame holes are combined in a multiple manner without failing to deteriorate the combustibility. It is possible to provide a light and dark combustion burner that can achieve flame combustion stability and can reliably reduce NOx.

  Further, according to claim 4 or claim 5, by adding an inflow direction setting means constituted by a flow path resistance element or a collision wall, the direction of inflow through the leakage hole is surely set to an intended one. Thus, the effects of each invention can be obtained with certainty.

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. A pair of third plate members constituting the third burner, a flame hole member constituting the pale flame hole array disposed on both sides of the third burner, a second plate member, and a state where the first plate member is disassembled It is a perspective view shown by. It is a perspective view shown in the state which decomposed | disassembled the 3rd burner, the flame hole member and 2nd plate member which are arrange | positioned with respect to the one side of this 3rd burner. It is a perspective view shown in the state cut | disconnected by the AA line of FIG. 8A is a perspective view showing a state cut along the line BB in FIG. 3, and FIG. 8B is a perspective view showing a state cut along the line CC in FIG. FIG. 4 is a cross-sectional explanatory view in a state cut along a cross section taken along line AA of FIG. FIG. 10A is a diagram corresponding to FIG. 9 showing another embodiment, and FIG. 10B is a diagram corresponding to FIG. 9 showing still another embodiment. 11A is a simplified cross-sectional explanatory view showing a first means for setting the leakage direction, and FIG. 11B is a simplified cross-sectional explanatory view showing a second means for setting the leakage direction. (C) It is a simplified cross-section explanatory drawing which shows the 2nd means which sets the leakage direction.

  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. 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. The concentrated flame holes 331 of the concentrated flame hole array 33 at the center position and the concentrated flame holes 351 of the two concentrated flame hole arrays 35, 35 at both outer positions are supplied from the second supply port 32 and mixed. The concentrated gas mixture is guided, and a concentrated flame is formed by the concentrated gas mixture. Further, at both sides in the short direction of the light flame formed in each of the two light flame hole arrays 34, as will be described later, the air ratio is slightly smaller than that of the light mixture and an intermediate between the rich mixture and the light mixture. A gas mixture with a concentration is supplied.

  Such a burner 3 can be formed as follows, for example. That is, as shown in FIG. 5, each pair of plate members 4, 4, 5, 5, 6, 6 and a pair of flame hole forming members 7, 7 are used. A pair of third plate members 6 and 6 (see FIG. 5) are opposed to each other, and both sides and lower edges thereof are joined to each other, whereby a rich mixture supply passage (central rich mixture supply passage) is formed between the inner surfaces. ; (See reference numeral 62 in FIG. 7)) is formed, and a central deep burner portion 3a for forming a rich flame is formed in the deep flame hole array 33 (see FIGS. 4A and 4B) on the upper end surface. 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. In addition, flame hole forming members 7 are interposed in the two upper end openings between the first plate members 4 and the central dark burner 3a on both sides.

  This flame hole forming member 7 includes a plurality of strip-shaped thin plates 71, 72,... (See FIG. 4B) arranged in layers at a predetermined interval, and an extremely thin slit between adjacent thin plates 71, 72, 72, 72. In addition, a plurality of flame holes are defined in the longitudinal direction by bundling and fixing all the thin plates at predetermined intervals in the longitudinal direction. The light flame hole row 34 is configured by a plurality of flame holes arranged in the longitudinal direction. In the illustrated example, the flame hole forming member 7 is composed of five thin plates in total by arranging thin plates 71 and 71 on both outer sides of the three thin plates 72, 72 and 72. And the notch-shaped opening 73 (refer FIG. 6) is formed in the lower edge position of the both outer thin plates 71 and 71 for every predetermined space | interval in the longitudinal direction. As described above, 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, a light mixture supply passage is 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. (Refer to the reference numerals 37 and 37 in FIGS. 7 and 8A), the light is supplied to the respective light flame holes 341 of the light flame 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 mixture is supplied through an outer rich mixture supply passage (see reference numerals 51 and 52 in FIGS. 7 and 8A) formed between the inner surface of the member 5 and the outer surface of the first plate member 4 facing each other. As a result, the outer rich burner 3c for forming a rich flame is formed in each of the rich flame holes 351 of the outer rich flame hole rows 35, 35. For the central dark burner 3a, the light burner 3b, and the outer dark burner 3c, refer to FIGS. 2, 4A and 4B. 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, the supply (flow) of various air-fuel mixtures will be described. 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 arrow in FIGS. 7 and 8B). The two internal spaces 37, 37 (FIG. 8 (a)) are 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 guided to the closed end at the back through the cylindrical portion 38 (see FIGS. 7, 8A, and 8B), the closed end of the cylindrical portion 38 is obtained. From the position, it is supplied to both the central dark burner 3a and the outer dark burner 3c. In other words, the lower end portion 60 (see FIGS. 8A and 9) of the central dark burner 3a is inserted from above at the closed end position of the cylindrical portion 38 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. 9). 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. 9). 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 and 52 together with the cylindrical portion 38 form an outer rich mixture supply passage, and the cylindrical portion 38 is provided with a mixing chamber and introduction of fuel gas and air supplied from the second supply port 32. It also plays the role of a passage (rich mixture introduction passage). Further, the internal space 62 constitutes a central rich mixture 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. What is necessary is just to set so that both may be the same as the flow volume and pressure of the rich gas mixture supplied to each. 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 the same number. In other words, the total number of communication holes 61 communicating with the internal space 62 is four on both sides in the short direction, while the number of communication holes 41 communicating with the internal space 51 is four, and the communication holes communicating with the internal space 52 are provided. The number of 41 is set to four. 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 addition, the rich air-fuel mixture supplied to the internal spaces 51 and 52 and the rich air-fuel mixture supplied to the internal space 62 are leaked through the holes 42, 42,..., 63, 63,. The air mixture leaks to the side of the internal spaces 37 and 37 and is mixed with a light mixture in a predetermined region of the light flame hole row 34 and 34, and an air-fuel mixture having an intermediate concentration slightly smaller than the light gas mixture is a light flame hole row 34. , 34 are supplied to both sides in the short direction. That is, the inner space 51, 52 for supplying a rich mixture to the rich flame hole rows 35, 35 of the outer dense burner 3c, the inner space 51 or 52, and the light burner 3b adjacent to the inner space 51 or 52 with the second plate 4 therebetween. .. Are formed in the second plates 4, 4 so as to communicate with each other at the position on the dense flame hole array 35 side (upper side). Further, the internal flame 62 for supplying the rich air-fuel mixture to the rich flame hole array 33 of the central rich burner 3a and the internal spaces 37, 37 on both sides in the short side direction are the same as the first flame holes 42. Second leakage holes 63, 63,... Communicating with each other at the position on the hole row 33 side (upper side) are formed through the third plates 6, 6.

  The first leakage holes 42, 42, ... and the second leakage holes 63, 63, ... are formed for each flame hole corresponding to each flame hole forming position of the flame hole forming member 7. .. Are opposed to the opening 73 on the lower edge of the thin plate 71 outside the flame hole forming member 7 in the short direction (see also FIG. 6). 51 or 52 passes through the first leakage holes 42, 42,... And the openings 73, 73,... And flows into the slit between the outer thin plate 71 and the adjacent inner thin plate 72. It has become. That is, the leaked rich air-fuel mixture is supplied to the outermost slit in the short direction of the flame hole forming member 7, in other words, to the outer position in the short direction of the light flame hole row 34. As a result, the leaked rich air-fuel mixture is mixed into the light air-fuel mixture with respect to both outer positions in the short direction of the light flames Fp, Fp (see FIG. 9) formed in the light flame hole rows 34, 34 of the burner 3. Accordingly, the air ratio becomes smaller than that of the light mixture, and the air ratio is larger than that of the rich flames Fr and Fr on both sides in the short direction, so that an air-fuel mixture having an intermediate concentration between the light mixture and the rich mixture is supplied. (See Fm in FIG. 9). For this reason, compared with the case where the air-fuel mixture having such an intermediate concentration is not supplied, the flame holding property of the pale flame formed in the pale flame hole rows 34 and 34 can be improved, and the width of the pale flame hole 34 in the short direction. Even if it is made wider, combustion stability can be ensured.

  An inflow that sets an inflow direction so that the rich air-fuel mixture can surely flow from the inner spaces 51, 52, and 62 through the leakage holes 42 and 63 with respect to the light air-fuel mixture on the inner spaces 37 and 37 side. The direction setting means will be described below. The inflow direction setting means can be realized by generating an internal pressure (static pressure) difference between the internal space 37 and the internal spaces 51, 52, 62 at the positions of the leakage holes 42, 63. According to the internal pressure difference, the rich air-fuel mixture can be leaked from one space to the other space through the leakage holes 42 and 63. Such an internal pressure difference can be realized by changing the original supply pressure of the light mixture and the rich mixture, or the original supply pressure is the same but the channel resistance is different. Can be realized. In this embodiment, the inflow direction setting means is constituted by a flow path resistance element formed at the upstream position of each leakage hole 42, 63, preferably at the closest position on the upstream side.

  Specifically, a first bulging portion (or a convex portion) 43 that bulges toward the internal space 37 is formed in the second plate 4 at the closest position upstream of each first leakage hole 42. In the embodiment, a portion partially bulged with respect to the longitudinal direction is illustrated. However, the present invention is not limited thereto, and the bulging portion may be formed continuously or over the entire length in the longitudinal direction. In addition, a second bulging portion (or convex portion) 64 that bulges toward the internal space 37 is formed in the third plate 6 at the closest position upstream of the second leakage hole 63. The second bulging portion is also illustrated as being partially bulged in the longitudinal direction in the embodiment, but is not limited thereto, and bulges continuously or over the entire length in the longitudinal direction. A part may be formed. And it arrange | positions so that the 1st bulging part 43 and the 2nd bulging part 64 may mutually oppose in a transversal direction. As a result, the first bulging portion 43 and the second bulging portion 64 bulge from both sides in the short direction with respect to the flow of the light mixture flowing in the internal space 37, A narrowed portion 371 that sharply decreases the cross-sectional area of the flow path is formed. At the opening positions of the leakage holes 42 and 63, the flow path on the internal space 37 side is immediately reduced after being sharply reduced by the narrowed portion 371 and then immediately expanded, so that the internal space 37 side rather than the internal spaces 51, 52 and 62 is provided. The internal pressure (static pressure) on the one side becomes low, and the rich air-fuel mixture from the internal spaces 51, 52, 62 can surely flow into the internal space 37 through the leak holes 42, 63.

  Further, in the case of the present embodiment, the two pale flame hole rows 34, 34 are sandwiched from both sides by the rich flame hole rows 35, 33 or the rich flame hole rows 33, 35. Each of the light flames formed on 34 and 34 can be surrounded by the rich flame from both sides. In other words, the flame structure in the short direction can be arranged in the order of the arrangement of rich flame Fr-light flame Fp-rich flame Fr-light flame Fp-rich flame Fr. As a result, even if the number of the pale flame hole rows 34 is increased to increase the area of the pale flame hole row, the combustion can be further stabilized. 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.

  In addition, as described above, an air-fuel mixture having an intermediate concentration is formed in the light flame hole rows 34 and 34 by mixing the air-fuel mixture flowing from the leakage holes 42 and 63 toward the light air-fuel mixture side of the internal space 37. Since the light flames Fp and Fp are supplied to both outer positions in the short direction, the flame holding ability of the light flame formed in the light flame hole rows 34 and 34 can be improved. In addition to increasing the area of the pale flame hole row by using two rows, the combustion stability can be ensured even if the width in the short direction of the pale flame hole 34 is formed wider. As a result, it is possible to further reduce NOx.

Second Embodiment
FIG. 10A is a diagram corresponding to FIG. 9 of the burner 3 of the second embodiment. This second embodiment differs from the first embodiment only in the configuration of the inflow direction setting means, and the other configurations are the same as those in the first embodiment. Unless otherwise specified, the configuration described in the first embodiment is the same as the first embodiment. The second embodiment is also provided as it is. Whereas the inflow direction setting means of the first embodiment is configured by the flow path resistance element formed at the nearest position upstream of the position of each leakage hole 42, 63, the inflow direction setting means of the second embodiment is The flow path resistance element is formed at the nearest position downstream of the positions of the leakage holes 42 and 63.

  In other words, the first plate member 4 is partially bulged to the second plate 5 side, that is, the side where the flow path of the internal space 51 or 52 is suddenly reduced at the closest position downstream of each leakage hole 42. The third plate members 6 and 6 at the closest positions downstream of the leakage holes 63 are partially bulged to the opposite sides, thereby rapidly reducing the flow path of the internal space 62. , 65 are formed. In this case, the rich air-fuel mixture flowing through the internal spaces 51, 52, 62 receives resistance due to the presence of the bulging portions 44, 65, and the formation positions of the leakage holes 42, 63 at the upstream positions of the respective bulging portions 44, 65. In this case, the internal pressure becomes higher than the side of the light mixture in the internal space 37. For this reason, as in the first embodiment, the rich air-fuel mixture in the internal spaces 51, 52, 62 can be reliably introduced into the light air-fuel mixture on the internal space 37 side through the leakage holes 42, 63. Become. As a result, the same operation and effect as in the first embodiment can be obtained in the second embodiment.

<Third Embodiment>
FIG. 10B is a diagram corresponding to FIG. 9 of the burner 3 of the third embodiment. This third embodiment is different from the first or second embodiment in that the light air-fuel mixture flows from the inner space 37 into the concentrated air-fuel mixture in the inner space 62 through the leak hole, but the other configuration is the first or the second structure. The same as in the second embodiment.

  In other words, the internal space 37 and the third space are positioned immediately downstream of the bulging portions 65, 65 as inflow direction setting means partially formed in the longitudinal direction in the third plate members 6, 6 that define the internal space 62. Leakage holes 63, 63 communicating with each other are formed through. Thereby, the internal pressure on the side of the internal space 62 is lower than the side of the internal space 37 at the position of the leakage holes 63, 63, and the air-fuel mixture from the internal space passes through each leakage hole 63 and the rich air-fuel mixture in the internal space 62. Can be made to flow in against.

  In the case of this third embodiment, the rich flame formed in the outer rich flame holes 35, 35 can be sufficiently in contact with the secondary air, whereas the rich flame formed in the central rich flame hole 33 is light on both sides. Since the contact with the combustion air is not sufficient due to being sandwiched between the flames, there is a possibility that the combustion air may be insufficient. Therefore, the light mixture is mixed through the leakage hole 63 immediately before being supplied to the central concentrated flame hole 33. Thus, it is possible to avoid the possibility of falling into the combustion air shortage, and the air ratio can be made larger than the rich air-fuel mixture in the outer rich flame holes 35 and 35. As a result, the rich flame Fr ′ formed in the central rich flame hole 33 can be completely burned with good combustion stability.

<Fourth embodiment>
FIG. 11 shows another inflow direction setting means instead of the inflow direction setting means employed in the first to third embodiments, and any one of the inflow direction setting means shown in FIGS. 11 (a) to 11 (c). The first to third embodiments can be configured by applying to the inflow setting means of any of the first to third embodiments. The principle of the inflow direction setting means shown as the fourth embodiment is that one space 8 in which the air-fuel mixture to flow in and the other space 9 in which the air-fuel mixture on the side to flow in flow through are formed through the partition wall 10. When communicating with the leakage hole 11, even if one space 8 and the other space 9 have the same internal pressure (static pressure) at the position of the leakage hole 11, they can be introduced by dynamic pressure. Is. That is, the collision wall 12 that collides with the air-fuel mixture to be introduced is formed in the partition wall 10, and the leakage hole 11 is formed in the collision wall 12.

  In FIG. 11A, a collision wall 12a that is inclined so that the flow of the air-fuel mixture collides with one space 8 so as to intersect the flow direction of the air-fuel mixture flowing from the bottom to the top is formed in the partition wall 10. The leakage hole 11 is formed to penetrate through 12a. FIG. 11 (b) shows an example that does not necessarily cross the flow direction of the air-fuel mixture. A convex collision wall 12b that protrudes toward the other space 9 is formed on the partition wall 10 so that the flow passage cross section of the air-fuel mixture in one space 8 expands, and a leakage hole 11 is formed in the collision wall 12b It is. In FIG. 11C, a collision wall 12c that is perpendicular to the flow direction of the air-fuel mixture in one space 8 is formed in the partition wall 10, and the leakage hole 11 is formed through the collision wall 12c.

<Other embodiments>
Although the example which formed both the 1st leak hole 42 and the 2nd leak hole 63 was shown in 1st, 2nd embodiment, it is not restricted to this but only one leak hole is formed. It may be. Even in this case, the effects of the present invention based on the first and second embodiments can be obtained. In the third embodiment, an example in which a pair of leakage holes 63 and 63 are formed at one place so as to communicate with the internal spaces 37 and 37 on both sides is not limited thereto. It is also possible to form a leakage hole that only communicates. Further, the openings 73, 73,... Of the flame hole forming member 7 shown in the first embodiment do not need to be formed intermittently. What is shorter than the thin plate 72 by the height of the opening 73 may be used.

3 Burner (Tint burning burner)
4 First plate member (partition wall)
6 Third plate member (partition wall)
11 Leakage hole 12, 12a, 12b, 12c Collision wall (inflow direction setting means)
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)
37 Internal space (light mixture supply passage)
42 1st leak holes 43 and 44 bulging part (inflow direction setting means)
51 Internal space (outer rich mixture supply passage)
52 Internal space (outer rich mixture supply passage)
62 Internal space (Central rich mixture supply passage)
63 2nd leak hole 64,65 swelling part (inflow direction setting means)

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,
A first leakage hole is provided for a partition wall separating the outer rich mixture supply passage for supplying the rich mixture to the outer rich flame hole and the pale mixture supply passage for supplying the pale mixture to the pale flame hole. Penetrated,
A lean burner characterized in that a part of the rich mixture is allowed to flow into the light mixture supply passage through the first leakage hole from the outer rich mixture supply passage. 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,
A second leakage hole is formed in the partition wall separating the central rich mixture supply passage for supplying the rich mixture to the central rich flame hole and the pale mixture supply passage for supplying the pale mixture to the pale flame hole. Penetrated,
A lean burner characterized in that a part of the rich mixture is allowed to flow into the lean mixture supply passage through the second leakage hole from the central rich mixture supply passage. The light and burner according to claim 1 or 2, wherein
Each pale flame hole is formed by a flame hole forming member having a plurality of thin plates assembled in layers with a predetermined slit interval and having at least three layers of slits,
The leakage hole is formed at a position opposite to the outer surface of the flame hole forming member, while the outermost thin plate constituting the flame hole forming member allows the rich air-fuel mixture flowing from the leakage hole to reach the outermost position. A light-burning burner having at least an opening for flowing into a slit at an outer position. 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,
A second leakage hole is formed in the partition wall separating the central rich mixture supply passage for supplying the rich mixture to the central rich flame hole and the pale mixture supply passage for supplying the pale mixture to the pale flame hole. Penetrated,
A lean combustion burner characterized in that a part of the lean mixture from the lean mixture supply passage can flow into the central rich mixture supply passage through the second leakage hole. The light and dark combustion burner according to any one of claims 1 to 4,
An inflow direction setting means for setting a direction of inflow through the leakage hole;
The inflow direction setting means is a concentration combustion burner configured by a flow path resistance element formed at a position upstream or downstream of the formation position of the leakage hole. The light and dark combustion burner according to any one of claims 1 to 4,
An inflow direction setting means for setting a direction of inflow through the leakage hole;
The inflow direction setting means is constituted by a collision wall formed in the partition wall so that the flow of the air-fuel mixture on the inflow side collides, and the leak combustion burner in which the leakage hole is formed through the collision wall.

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