JP5182618B2 - Combustion heater - Google Patents

Description

  The present invention relates to a combustion heater for burning a premixed gas of fuel gas and combustion air.

  Conventionally, a radiant tube burner that burns the entire premixed mixture of fuel gas and combustion air in a heat-resistant circular tube (radiation tube) and heats the heat dissipation tube with this flame has been manufactured, It is used for heating furnaces, heating, etc. as an elongated heat source that does not expose the flame. Further, a combustion burner is known in which combustion gas is burned in an inner pipe, a jet of combustion gas is made to collide with an orthogonally installed shielding surface to change the direction of flow, and heat is extracted from a heat radiating pipe.

This type of combustion heater has the disadvantages that combustion ends in the middle of the heat radiating tube, and it is difficult to obtain a uniform temperature distribution along the entire length, and nitrogen oxide (NOx) is often generated. Therefore, Patent Document 1 includes a porous tube whose inside is a supply path for a premixed gas and a heat radiating tube disposed coaxially on the outer periphery of the porous tube, and is ejected radially from the porous tube. The premixed gas in a laminar flow is burned on the cylindrical surface where the flame propagation speed and the premixed gas flow rate are balanced between the heat radiating pipe and the porous pipe. A combustion heater that can increase the temperature, easily generate a large amount of heat, and realize low NOx is disclosed.
JP-A-6-241419

However, the following problems exist in the conventional technology as described above.
It is difficult to keep a balance between the flow velocity and combustion speed of the premixed gas without providing a separate flame holding mechanism, and the premixed gas flowing out of the porous body varies in flow rate and flow rate depending on the position, and is stable. The problem arises that it is difficult to form a tubular flame.
Furthermore, since the above-described technique needs to provide a porous tube in a part of the inner tube, there is a problem that it takes time for manufacturing and increases costs.

  The present invention has been made in consideration of the above points, and an object of the present invention is to provide a combustion heater that can stably form a flame without causing an increase in cost.

In order to achieve the above object, the present invention employs the following configuration.
The combustion heater according to the present invention includes an inner tube having a combustion gas supply passage therein and an outer tube disposed on the outer periphery of the inner tube with a combustion space therebetween, and ejects the combustion gas. A combustion heater in which a hole is formed in a tube wall of the inner pipe, the combustion gas provided in the combustion space so as to face the hole along the axial direction and ejected from the hole It has a stagnation point and a circulation flow forming member for forming a stagnation point and a circulation flow.
Therefore, in the combustion heater of the present invention, the combustion gas around the stagnation point and the stagnation point formed on the surface of the stagnation point and the circulating flow forming member is near (zero), thereby easily (ie, increasing the cost). A stable flame can be formed and held). In addition, since a circulation flow is formed around the stagnation point, stable combustion can be realized. Conventionally, if the gas flow rate is increased, the exhaust path for the combustion gas cannot be secured sufficiently, and the stability of the flame may be impaired. However, in the present invention, the stagnation point and the circulating flow forming member opposed to the hole are provided. As a result, it is possible to stably form and hold a flame on the surface, and to ensure a combustion gas exhaust path in a region where the inner pipe does not face the stagnation point and the circulating flow forming member.

In the present invention, the stagnation point and the circulation flow forming member are arranged on the central axis of the outer pipe, and a plurality of the inner pipes are arranged around the central axis with the hole portion facing the central axis. Such a configuration can also be suitably employed.
Thereby, in the present invention, it becomes possible to stably form and hold the stagnation point and flame of the combustion gas around the central axis of the outer tube, and it is possible to heat the outer tube while suppressing the temperature distribution. .

Further, as the stagnation point and the circulation flow forming member, the combustion gas supply passage is provided inside, and the combustion gas is directed toward each outer peripheral surface of the inner pipe arranged around the central axis. A configuration having each of the hole portions that squirt out to form a stagnation point can also be suitably employed.
As a result, in addition to the stagnation point arranged at the center of the outer pipe and the surface of the circulating flow forming member, the stagnation point and flame of the combustion gas can be stabilized on the surface of the inner pipe arranged around the central axis. It becomes possible to form and hold.

As the stagnation point and the circulation flow forming member, a plurality of the stagnation points and the circulation flow forming member are provided at intervals in the combustion space, each of which is the inner pipe formed with the hole portion facing the outer peripheral surface of the adjacent inner pipe. A configuration can also be suitably employed.
This makes it possible to stably form and hold the combustion gas stagnation point and flame on the outer peripheral surface of the plurality of inner pipes facing the holes of the adjacent inner pipes.

In this configuration, a configuration in which a plurality of the inner pipes are arranged around the central axis of the outer pipe at a distance from each other can be suitably employed.
Thereby, in the present invention, it becomes possible to stably form and hold the stagnation point and flame of the combustion gas around the central axis of the outer tube, and it is possible to heat the outer tube while suppressing the temperature distribution. .

Moreover, in this invention, the structure by which the 2nd hole part which ejects the said gas for combustion is provided in the position spaced apart from the said stagnation point in the said inner pipe | tube can also be employ | adopted suitably.
Thereby, in the present invention, it is possible to cause the flame formed and held at the stagnation point to be transferred to the combustion gas ejected from the second hole. Therefore, in the present invention, it is possible to increase the amount of input heat without causing pressure loss as in the case of using a porous body, and without lengthening the inner tube and the outer tube. It is possible to prevent the equipment from becoming large, as in the case where the length is increased. And in this invention, since a pressure loss can be suppressed, it can be used also in a low-pressure city gas line.

The second hole is preferably arranged on both sides of a region facing the stagnation point and the circulation flow forming member and alternately arranged with the hole in a direction along the facing region. Can be adopted.
Thereby, in this invention, it becomes possible to produce and hold | maintain a flame and to carry out the flame transfer of a flame by equal distribution.

Further, in the present invention, the inner tube and the stagnation point that are cantilevered on the base end side and the distal end side of the circulation flow forming member are supported between the outer tube and the inner tube and the stagnation point and A configuration having a support member that maintains the distance between the outer peripheral surface of the circulating flow forming member and the inner peripheral surface of the outer tube can be suitably employed. The support member may be a plate-like member, or may be a rod-like member suspended between the outer tube and the inner tube.
As a result, in the present invention, the inner pipe, the stagnation point, and the distal end portion of the circulation flow forming member are shaken, and the inner pipe, the stagnation point, the outer peripheral surface of the circulation flow forming member, and the outer pipe are formed on the proximal end side and the distal end side. It is possible to prevent the gap between the inner peripheral surface and the inner peripheral surface from becoming constant, and to maintain a constant distance between the hole and the stagnation point and between the circulating flow forming member and the inner peripheral surface of the outer tube. Can be formed stably and continuously, and as a result, a flame can be formed and held stably and continuously.

As the support member, it is possible to suitably employ a configuration that is provided on the distal end side with respect to the hole portion positioned closest to the distal end side and at a size that at least closes the combustion space facing the hole portion.
As a result, in the present invention, the combustion gas ejected from the hole located closest to the tip side and colliding with the support member collides with the support member and is guided to the wide combustion space. Thus, it is possible to easily ignite the combustion gas in the combustion space.

In the present invention, it is also possible to suitably employ a configuration in which the support member disposed on the distal end side with respect to the hole portion located on the most distal end side is provided with a size that blocks the entire combustion space.
Thereby, in this invention, it becomes possible to avoid the situation where combustion gas stagnates in the tip part of a low-temperature outer pipe, and it becomes an unburned state and CO is produced.

Furthermore, in the present invention, a configuration in which the support plate is provided so as to be relatively movable in the axial direction with respect to the outer tube can be suitably employed.
As a result, in the present invention, even when a large difference in the amount of thermal expansion occurs in the axial direction due to the temperature difference between the outer tube and the inner tube, the support plate moves relative to the outer tube. Without generating, it is possible to maintain the distance between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube.

Moreover, in this invention, the structure by which the said supply path of the said inner pipe is obstruct | occluded by the said front end side can also be employ | adopted suitably.
Thereby, in this invention, while supplying combustion gas from the base end side, the small and low-cost combustion heater which can exhaust exhaust gas is realizable.

  In the present invention, it is possible to stably form a flame without incurring a cost increase.

Hereinafter, an embodiment of a combustion heater of the present invention will be described with reference to FIGS. 1 to 5.
In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

(First embodiment)
Fig.1 (a) is front sectional drawing of the combustion heater 1 which concerns on 1st Embodiment, FIG.1 (b) is side sectional drawing.
The combustion heater 1 is supported in a cantilever manner by an outer tube 10 as a heat-resistant metal heat-dissipating tube having a closed end and a supporting means (not shown) on the base end side (left side of FIG. 1A). 10 is composed of a plurality of heat-resistant metal inner pipes 20 and bluff bodies (stagnation points and circulation flow forming members) 50 which are disposed in a combustion space 30 inside 10 and have a supply passage 21 for combustion gas G therein. Has been.

  As the combustion gas G, a gas in which fuel and air are premixed or a gas in which fuel and oxygen-containing gas are premixed can be used, and methane, propane, or the like is used as the fuel. Further, the liquid fuel can also be used by providing a location for pre-evaporation.

  The outer tube 10 has a bottomed cylindrical shape with a closed end, and an exhaust tube 11 for exhausting the burned gas is connected to the base end side.

Similar to the outer tube 10, the inner tube 20 has a bottomed cylindrical shape with a closed tip, and a premixed gas supply mechanism (not shown) for supplying the combustion gas G described above is provided on the proximal end side. For example, a total premixed gas having an excess air ratio of about 1.0 to 1.6 is supplied.
As shown in FIG. 1B, the inner tube 20 is arranged around the central axis of the outer tube 10 (here, six at an interval of 60 °) spaced apart from each other.

Each inner tube 20 has a plurality of (in this case, five) hole portions 24 in the radial direction, spaced from each other along the axial direction at a position facing the bluff body 50 on the distal end side and facing the central axis of the outer tube 10. Is formed through the tube wall. An ignition device (not shown) is provided in the vicinity of the position facing the hole 24 of the outer tube 10.
The outer peripheral surface 20A on the base end side (left side in FIG. 1A) from the region where the hole 24 is formed is for preheating the combustion gas G in the supply passage 21 with the burned gas (flame). The preheating region P is designated.

  The bluff body 50 is arranged with its axis line aligned with the central axis of the outer tube 10 and surrounded by the inner tube 20. The bluff body 50 is located at a position facing each inner tube 20 (hole 24) at the inner tube 20. A concave curved surface 50A formed around the axis of the tube 20 is formed along the axial direction.

Next, the combustion operation in the combustion heater 1 will be described.
The combustion gas G supplied from the premixed gas supply mechanism to the supply passage 21 of the inner pipe 20 is ejected from the hole 24 toward the concave curved surface 50A of the bluff body 50, as shown in FIG. The
The combustion gas G ejected from the hole 24 collides with the concave curved surface 50A of the opposing bluff body 50 to form a stagnation point S on the concave curved surface 50A for each hole 24, and the stagnation point S is defined as a boundary. And branching along the concave curved surface 50A.

Then, by igniting the combustion gas G in the vicinity of the stagnation point S by the ignition device, a flame is formed and held at the stagnation point S. At this time, since the flow velocity of the gas at the stagnation point S is zero, the flame formed by the circulating flow formed around the jet toward the stagnation point S is stably held at the stagnation point S.
The combustion gas G branched at the stagnation point S burns from the vicinity of the bluff body 50 having a high gas pressure to the inner peripheral surface 10 </ b> A side of the outer pipe 10 that is opposite to the bluff body 50 with respect to the inner pipe 20. It flows into the space 30.

The combustion gas flows through the combustion space 30 and is exhausted from the exhaust pipe 11. In the middle from the combustion space 30 to the exhaust pipe 11, the combustion gas passes through the wall of the inner pipe 20 in the preheating region P of the inner pipe 20. Then, heat exchange with the combustion gas (unburned gas) G is performed.
As a result, the combustion gas G in the supply passage 21 is ejected from the hole 24 in a state of being preheated to a high temperature, and the stability of the flame F is increased. It is possible to burn stably without generating fuel.

  As described above, in the present embodiment, the combustion gas G is ejected from the hole 24 formed in the tube wall of the inner tube 20 toward the concave curved surface 50A of the bluff body 50, and the flame F is held at the stagnation point S. Therefore, a stable flame F can be easily formed and maintained even when the flow rate is changed without causing an increase in cost as in the case of providing a porous tube. In addition, in this embodiment, in order to increase the amount of combustion, it is only necessary to increase the number of holes 24. Therefore, since the number of components and the structure are simple, the manufacturing cost can be suppressed. In addition, unlike the case where a porous tube is used, it is not necessary to greatly increase the supply pressure of the combustion gas G, and even a low-pressure city gas line can be sufficiently applied. Furthermore, in this embodiment, since the flame is formed and held using each of the plurality of inner tubes 20 arranged around the central axis of the outer tube 10, the outer tube 10 that is a heat radiating tube generates a temperature distribution in the circumferential direction. Therefore, it is possible to realize uniform heat treatment.

In addition, if the gas supply pressure is increased using a porous tube, the flame may reach the outer tube and be unable to be held, and the exhaust path for the burned gas may not be sufficiently secured. In the embodiment, a sufficient exhaust system path can be secured in the combustion space 30 in the vicinity of the inner peripheral surface 10A of the outer tube 10 and the space where there is no jet between adjacent holes.
In particular, in the present embodiment, the flow path of the combustion gas G branched at the stagnation point S is along the outer peripheral surface 20A of the inner tube 20, so that it is smoothly in the vicinity of the inner peripheral surface 10A of the outer tube 10. It becomes possible to exhaust into the combustion space 30.
In this embodiment, the shaft-shaped bluff body is used as the stagnation point and the circulating flow forming member. However, the present invention is not limited to this, and a tubular body (for example, a hexagonal square tube) is used. It is good also as a structure to use.

(Second Embodiment)
Next, a second embodiment of the combustion heater 1 will be described with reference to FIG.
In this figure, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.
The difference between the second embodiment and the first embodiment is that a circular tube similar to the inner tube 20 is arranged on the central axis of the outer tube 10.

  That is, as shown in the partially enlarged view of FIG. 2 (c), in this embodiment, the inner pipe (stagnation point and circulating flow) is aligned with the central axis of the outer pipe 10 and spaced from the inner pipe 20. Forming member) 120 is disposed. The inner tube 120 has a bottomed cylindrical shape with a closed end, and a premixed gas supply mechanism (not shown) that supplies the above-described combustion gas G to the internal supply path 121 on the base end side. Is connected.

Further, the inner pipe 120 is formed with holes 124 through which the combustion gas G is ejected at positions facing the pipes 20 arranged around the inner pipe 120. As shown in FIG. 2D, the hole 124 is formed in a position facing the outer peripheral surface 20 </ b> A without facing the hole 24 with respect to each inner tube 20 in the axial direction. That is, the hole 24 of the inner tube 20 is also opposed to the outer peripheral surface 120 </ b> A without facing the hole 124 of the inner tube 120.
Other configurations are the same as those of the first embodiment.

  In the combustion heater 1 configured as described above, the combustion gas G supplied from the premixed gas supply mechanism to the supply passage 21 of the inner tube 20 is ejected from the hole 24 toward the outer peripheral surface 120A of the inner tube 120, respectively. The The stagnation point S of the combustion gas G is formed on the outer peripheral surface 120A, and the combustion gas G branches at the stagnation point S and flows along the outer peripheral surface 120A.

  On the other hand, the combustion gas G supplied to the supply passage 121 of the inner pipe 120 is ejected from the hole portion 124 toward the outer peripheral surface 20A of the inner pipe 20. The stagnation point S of the combustion gas G is formed on the outer peripheral surface 20A, and the combustion gas G branches off at the stagnation point S and flows along the outer peripheral surface 20A. That is, in this embodiment, not only the inner pipe 120 but also the inner pipe 20 acts as a stagnation point and a circulating flow forming member.

Then, by igniting the combustion gas G in the vicinity of the stagnation point S by the ignition device, a flame is formed and held at the stagnation point S. At this time, since the flow velocity of the gas at the stagnation point S is zero, the formed flame is stably held at the stagnation point S.
The combustion gas G branched at the stagnation point S flows into the combustion space 30 on the inner peripheral surface 10A side of the outer tube 10 having a relatively low gas pressure. The burned gas is exhausted from the exhaust pipe 11.

Thus, in this embodiment, in addition to obtaining the same operation and effect as in the first embodiment, the combustion gas G is also ejected from the inner pipe 120, so that heating is more effective. And a stagnation point S is formed on the outer peripheral surface 20A of the inner pipe 20 arranged around it to form and hold a flame, so that a more stable flame can be formed and held in a wider range. Can do.
Note that the hole 24 of the inner tube 20 and the hole 124 of the inner tube 120 may be provided at positions facing each other. However, in order to form the stagnation point S more stably, the outer peripheral surface 120A is mutually formed. , And preferably at a position facing 20A.

(Third embodiment)
Next, a third embodiment of the combustion heater 1 will be described with reference to FIG.
In this figure, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 3B, in this embodiment, the inner tube is not provided on the central axis of the outer tube 1, and a plurality of inner tubes 20 (here, the central tube 20 are spaced apart from each other in the circumferential direction). 6) at intervals of 60 °.
As shown in the partially enlarged view of FIG. 3C, each inner pipe 20 is provided with a hole 24 through which the combustion gas G is ejected at a position facing the adjacent inner pipe 20.
As for the position of the hole 24 in the axial direction, as in the second embodiment, the portion of FIG. 2D is arranged so that the jetted combustion gas G collides with the outer peripheral surface 20A of the adjacent inner pipe 20. As shown in the enlarged view, it is preferable that the adjacent inner pipes 20 are arranged alternately.

  In the combustion heater 1 having the above-described configuration, in addition to obtaining the same operation and effect as those of the second embodiment, the stagnation point S and the flame are formed at a position closer to the outer tube 10 as a heat radiating tube. Therefore, it becomes easier to take out heat through the outer tube 10, and it becomes possible to improve heating efficiency.

(Fourth embodiment)
Next, a fourth embodiment of the combustion heater 1 will be described with reference to FIG.
In this figure, the same components as those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.
The difference between the fourth embodiment and the first embodiment is that a support plate is provided on the distal end side of the inner tube 20 and the bluff body 50.

As shown in FIG. 4A, a support plate (support member) 40 made of a heat-resistant metal or the like is provided along the direction orthogonal to the axial direction on the tip side of the hole portion 24 of the inner tube 20. ing. As shown in FIG. 4B, the support plate 40 is fitted and fixed to the outer peripheral surface 20A of the inner tube 20 and the outer peripheral surface 50A of the bluff body 50, and the outer peripheral surface 40B is attached to the inner peripheral surface 10A of the outer tube 10. It is supported so as to be movable in the axial direction.
That is, the support plate 40 has a size that closes the entire combustion space 30, is integrally formed with the inner tube 20 and the bluff body 50, and is provided so as to be movable in the axial direction with respect to the outer tube 10. Yes.

  In the combustion heater 1 having the above-described configuration, the inner tube 20 and the bluff body 50 that are cantilevered on the base end side are supported by the support plate 40, whereby the outer peripheral surface 20 </ b> A and the bluff of the inner tube 20 are supported. The distance between the outer peripheral surface 50A of the body 50 and the inner peripheral surface 10A of the outer tube 10 is kept constant. Further, even when the inner tube 20 that is at a high temperature is thermally expanded due to a temperature difference between the outer tube 10 and the inner tube 20, the support plate 40 configured integrally with the inner tube 20 and the bluff body 50 is not Since it moves relative to the inner peripheral surface 10A of the tube 10 in the axial direction, deformation and distortion are prevented.

  Moreover, as shown in the partially enlarged view of FIG. 4 (c), the combustion gas G ejected from the hole 24 located on the most distal side collides with the outer peripheral surface 50A of the opposing bluff body 50, and each hole A stagnation point S is formed on the outer peripheral surface 50A for each portion 24 and is branched along the outer peripheral surface 50A with the stagnation point S as a boundary, but the combustion space 30 facing the hole 24 is closed by the support plate 40. Therefore, the combustion gas G branched toward the support plate 40 is guided to the combustion space 30 on the opposite side of the bluff body 50 after colliding with the support plate 40. Therefore, it becomes easy to ignite the surrounding combustion gas G by the flame held at the stagnation point S.

  Furthermore, in this embodiment, since the combustion space 30 is partitioned by the support plate 40, the combustion gas G stays at the distal end portion of the outer tube 10 at a relatively low temperature, resulting in an unburned state and generating CO. It becomes possible to avoid the situation to do.

In the above embodiment, the plate-like support plate 40 is used as the support member. However, the present invention is not limited to this. For example, the support member 40 is supported on the inner peripheral surface 10A of the outer tube 10 so as to be movable in the axial direction. A support member including a ring member and a rod member that connects the ring member and the inner tube 20 and the bluff body 50 may be used.
Moreover, in the said embodiment, although it was set as the structure which provided the support plate 40 in the inner tube 20 and the bluff body 50 which were shown in 1st Embodiment, it is not limited to this, 2nd Embodiment shown in FIG. It is good also as a structure which provides a support plate in the inner tube 20 in 120, and a structure which provides a support plate in the inner tube 20 in 3rd Embodiment shown in FIG.
Thereby, there can exist an effect | action and effect similar to 4th Embodiment.

(Fifth embodiment)
Next, a fifth embodiment of the combustion heater 1 will be described with reference to FIG.
The difference between the fifth embodiment and the first embodiment is that, apart from the hole 24, a second hole for reducing the pressure loss of the gas is provided.

5A is a plan view of the inner tube 20 viewed from the side of the bluff body 50 (the central axis of the outer tube 10; see FIG. 1), and FIG. 5B is a side sectional view.
As shown in FIG. 5A, the tube wall (outer peripheral surface 20 </ b> A) of the inner tube 20 is provided with a hole 24 at an axial position 22 that faces the central axis of the outer tube 10, and extends along the axial position 22. A second hole 25 is provided alternately with the hole 24 in the direction and on both sides of the shaft position 22.
As shown in FIG. 5 (b), the combustion gas G is ejected from these second holes 25 toward a position away from the stagnation point S.
Further, the second hole 25 is provided at a position where the combustion gas G ejected from the second hole 25 stably transfers from the flame S formed at the stagnation point S.
Other configurations are the same as those of the first embodiment.

In the combustion heater 1 configured as described above, the flame formed and held at the stagnation point S can be transferred to the combustion gas G ejected from the second hole 25, and the flow rate is easily increased. Can burn gas. Therefore, in this embodiment, pressure loss is not generated as in the case of using a porous body, and in order to increase the flow rate, the input heat amount is increased without lengthening the inner tube 20, the bluff body 50, and the outer tube 10. As the inner tube 20, the bluff body 50, and the outer tube 10 are lengthened, it is possible to prevent an increase in size of the device and to suppress pressure loss. It can also be used in other city gas lines.
In the present embodiment, the holes 24 and the second holes 25 are alternately arranged along the axial position 22, and the second holes 25 are arranged on both sides of the axial position 22. It is possible to cause formation and maintenance and flame transfer in a stable state with almost equal distribution.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the fifth embodiment, the configuration in which the second hole 25 is provided in addition to the hole 24 in the combustion heater 1 shown in the first embodiment has been described. The inner tube 20 (inner tube 120) shown in the second to fourth embodiments may also have a configuration in which a second hole is provided in addition to the hole 24. Moreover, it is good also as a structure which provides 3rd hole or more and forms a stagnation point and a circulation flow area | region.

  In the first embodiment, the stagnation point concentric with the outer tube 10 and the bluff body 50 as a circulating flow forming member are arranged, and the plurality of inner tubes 20 are arranged around the central axis of the outer tube 10. However, the configuration is not limited thereto, and the inner tube 20 may be disposed concentrically with the outer tube 10, and a plurality of bluff bodies 50 may be disposed around the central axis of the outer tube 10. Even with this configuration, it is possible to obtain the same operations and effects as in the first embodiment.

(A) of the combustion heater 1 which concerns on 1st Embodiment is front sectional drawing, (b) is side sectional drawing, (c) is a principal part enlarged view. (A) of the combustion heater 1 which concerns on 2nd Embodiment is front sectional drawing, (b) is side sectional drawing, (c) And (d) is a principal part enlarged view. (A) of the combustion heater 1 which concerns on 3rd Embodiment is front sectional drawing, (b) is side sectional drawing, (c) is a principal part enlarged view. (A) of the combustion heater 1 which concerns on 4th Embodiment is front sectional drawing, (b) is side sectional drawing, (c) is a principal part enlarged view. (A) of the combustion heater 1 which concerns on 5th Embodiment is a top view of the inner tube | pipe from the bluff body side, (b) is side surface sectional drawing of an inner tube | pipe.

Explanation of symbols

  G: Combustion gas, S: Stagnation point, 1 ... Combustion heater, 10 ... Outer pipe (radiation pipe), 10A ... Inner peripheral surface, 20 ... Inner pipe, 20A ... Outer peripheral surface, 21 ... Supply path, 24 ... Hole , 25 ... second hole, 30 ... combustion space, 40 ... support plate (support member), 50 ... bluff body (stagnation point and circulation flow forming member), 50A ... concave curved surface, 120 ... inner pipe (stagnation point and Circulating flow forming member)

Claims (12)

An inner pipe having a combustion gas supply passage inside, and an outer pipe arranged on the outer periphery of the inner pipe with a combustion space therebetween, and a hole for ejecting the combustion gas is a pipe of the inner pipe A combustion heater formed on the wall,
Wherein along the axial direction in the combustion space is provided to face the hole, have a stagnation point and circulating flow formation member to form a stagnation point and circulating flow of the combustion gas ejected from the hole,
The stagnation point and the circulation flow forming member are disposed on a central axis of the outer pipe,
A plurality of the inner pipes are arranged around the central axis with the hole facing the central axis . The combustion heater according to claim 1 , wherein
The stagnation point and the circulating flow forming member have a concave curved surface formed around the axis of the inner pipe for each of the plurality of inner pipes. The combustion heater according to claim 1 or 2 ,
The stagnation point and the circulation flow forming member have a combustion gas supply passage therein, and jet the combustion gas toward each outer peripheral surface of the inner tube arranged around the central axis. A combustion heater having each of the holes forming stagnation points. The combustion heater according to claim 1, wherein
The stagnation point and the circulating flow forming member are the inner pipe in which a plurality of the stagnation points and the circulation flow forming member are provided at intervals in the combustion space, and each of the holes is formed facing the outer peripheral surface of the adjacent inner pipe. Combustion heater characterized by. The combustion heater according to claim 4 .
A plurality of the inner pipes are arranged around the central axis of the outer pipe at intervals. The combustion heater according to any one of claims 1 to 5 ,
The combustion heater according to claim 1, wherein the inner pipe is provided with a second hole for ejecting the combustion gas at a position spaced from the stagnation point. The combustion heater according to claim 6 , wherein
The second hole is disposed on both sides of a region facing the stagnation point and the circulation flow forming member, and is alternately disposed with the hole in a direction along the facing region. Burning heater. The combustion heater according to any one of claims 1 to 7 ,
The inner pipe, the stagnation point, and the distal end side of the circulation flow forming member that are cantilevered at the base end side are supported between the outer pipe and the outer circumference of the inner pipe, the stagnation point, and the circulation flow formation member. A combustion heater having a support member that maintains a distance between a surface and an inner peripheral surface of the outer tube. The combustion heater according to claim 8 ,
The combustion heater according to claim 1, wherein the support member is provided in a size that closes at least the combustion space opposed to the hole portion on a distal end side with respect to the hole portion located on the most distal end side. The combustion heater according to claim 8 or 9 ,
The combustion heater according to claim 1, wherein the support member disposed closer to the distal end than the hole located closest to the distal end is provided with a size that closes the entire combustion space. The combustion heater according to any one of claims 8 to 10 ,
The combustion heater according to claim 1, wherein the support plate is provided so as to be movable relative to the outer tube in the axial direction. An inner pipe having a combustion gas supply passage inside, and an outer pipe arranged on the outer periphery of the inner pipe with a combustion space therebetween, and a hole for ejecting the combustion gas is a pipe of the inner pipe A combustion heater formed on the wall,
A stagnation point and a circulation flow forming member that are provided in the combustion space along the axial direction so as to face the hole and form a stagnation point and a circulation flow of the combustion gas ejected from the hole;
The inner pipe is provided with a second hole for ejecting the combustion gas at a position spaced from the stagnation point,
The second hole is disposed on both sides of a region facing the stagnation point and the circulation flow forming member, and is alternately disposed with the hole in a direction along the facing region. Burning heater.

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