JP3194081B2 - Heat storage type burner and radiant tube burner using the heat storage type burner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative burner installed in heat equipment such as an industrial heating furnace and an indirect heating furnace, and a radiant tube burner using the regenerative burner.

[0002]

2. Description of the Related Art FIG. 10 shows an example of a heating furnace using a conventional direct-fired regenerative burner provided with a regenerator in association with the burner. In FIG. 10, 2 is a heating furnace, 5a, 5
b is a burner 17a, 17b opposed to the heating furnace 2.
Is a heat storage element installed in a pipe for supplying combustion air in the burners 5a and 5b, and 25a and 25b are fuel shutoff valves,
Reference numeral 1 denotes a switching valve for switching a flow path between combustion air and combustion exhaust gas, reference numeral 42 denotes a combustion exhaust gas outlet, and reference numeral 8 denotes an object to be heated which is charged into the heating furnace 2.

In the heating furnace 2 configured as described above, the burners 5a and 5b disposed opposite to each other burn alternately to heat the object 8 and the heat storage bodies 17a and 17b. That is, for a certain period of time, the heat storage body arranged on one side is heated by the combustion exhaust gas of the burner arranged on the other side, and for the next predetermined time period, the combustion air is preheated by the one heat storage body already heated. The burner disposed on one side is burned, and this operation is performed alternately. This point will be specifically described with reference to FIG. 10. FIG. 10 shows that the burner 5a is in a combustion state, and at this time, the heat storage body 17a has the combustion exhaust gas of the burner 5b during the previous combustion of the burner 5b. Is heated to a high temperature. Switching valve 41
The combustion air at normal temperature (30 ° C.) sucked through the heater is heated by the regenerator 17a to be preheated air at about 1250 ° C. and supplied to the burner 5a. In addition, a part of the flue gas generated by the combustion of the burner 5a passes through the burner 5b to about 1350.
The heat storage element 17b enters the heat storage element 17b at
Evacuated at 0 ° C. The burner 5a and the burner 5b are switched by interlockingly switching the fuel cutoff valves 25a and 25b and the switching valve 41 at predetermined time intervals.

Conventionally, the heat storage bodies 17a and 17b are made of ceramics that do not melt even when high-temperature combustion exhaust gas of, for example, 1300 ° C. or more passes, and have a ball-like or lump-like shape. However, since a heat storage element having a large heat exchange area per unit volume, a large gas passage area, and a small pressure loss at the time of fluid passage is preferable, a heat storage element having a honeycomb structure has recently been used. ing. And a regenerative burner using a ceramic honeycomb as a regenerator, such as the invention disclosed in Japanese Patent Publication No. 23950/1990, is provided.

The honeycomb-shaped heat storage body made of ceramics is manufactured by sintering an extruded ceramic material. Therefore, the cross-sectional shape is constant in the flow direction of the passing fluid (the longitudinal direction of the heat storage body). Further, the passing fluid does not diffuse into other cells when it flows into one cell of the honeycomb-shaped heat storage body.

[0006] The direct-fire-type regenerative burner shown in Fig. 10 can be separately heated to control the atmosphere in the furnace to a desired state (temperature) by indirectly heating the heating furnace. As a suitable heating source, for example, there is a radiant tube burner disclosed in Japanese Utility Model Publication No. 2-3950. As shown in FIG. 11, a radiant tube burner disclosed in the publication includes a burner 5 and a heat storage body 1 at both ends of a radiant tube 3.
7 are arranged, and the burners 5 at both ends are alternately switched to perform alternating combustion. Such a so-called regenerative radiant tube burner (regenerative radiant tube burner) has the effects of improving thermal efficiency and extending the radiant tube life and reducing repair costs by making the radiant tube temperature distribution uniform.

[0007]

However, when the heat storage body of the heat storage burner is formed by using the ceramic honeycomb, as described above, the cross-sectional shape of the ceramic honeycomb heat storage body depends on the flow direction of the passing fluid (the heat storage). (The longitudinal direction of the body), and the passing fluid flows into one cell of the honeycomb-shaped regenerator and does not diffuse to other cells. Therefore, the combustion exhaust gas flows into the honeycomb-shaped regenerator. In the case where the current is deviated in the previous flow channel, there are the following problems. That is, when the combustion exhaust gas drifts, a difference occurs in the inflow amount of the honeycomb-shaped heat storage body in the honeycomb cross section. And in the grid where a lot of combustion exhaust gas flowed,
Because it is not possible to store more heat than the heat storage capacity of the honeycomb lattice,
Insufficient exhaust heat recovery is not possible, and the temperature of the honeycomb grid rises, the temperature difference with the grid of the grid that only flows in a small amount increases, thermal stress occurs in the honeycomb cross section, and the honeycomb-shaped heat storage material breaks and is stable for a long time There was a problem that it could not be used. That is, as the cracks in the honeycomb heat storage body progress,
The miniaturized honeycomb fragments block the grids, the flow of fluid in the honeycomb is disturbed, the pressure loss increases, and the broken honeycomb is scattered and blown out of the burner into the furnace to lower the heat storage capacity.

In addition, when the drift of the high-temperature combustion exhaust gas is matched with the drift of the low-temperature combustion air, that is, when there is an equivalent drift in which a large amount of combustion air flows in a cell into which a large amount of combustion exhaust gas flows. Although the heat recovery efficiency does not significantly decrease compared to the case where the gas flows evenly, the uneven flow of the high-temperature combustion exhaust gas and the uneven flow of the low-temperature combustion air are unmatched, that is, a large amount of the combustion exhaust gas flows. If a small amount of combustion air flows into the cell, and a large amount of combustion air flows into the square where a small amount of combustion gas flows, a high-temperature combustion exhaust gas is discharged from the regenerator and only low-temperature preheated air is discharged. There has been a problem that a heat storage burner with low thermal efficiency that cannot be obtained is obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and prevents the occurrence of heat deviation in the heat storage body even when the fluid that is going to pass through the heat storage body is drifting. It is an object of the present invention to provide a regenerative burner that prevents cracks in a heat storage body due to stress or the like, prolongs the life of the heat storage body, and enables stable operation for a long time.

[0010]

SUMMARY OF THE INVENTION In a regenerative burner according to the present invention, an air passage serving as a passage for combustion air and combustion exhaust gas, a heat storage body provided in the air passage, and one end of the air passage are provided. A combustion air injection port provided on the side of the fuel cell, and preheats combustion air in the regenerator during main combustion, and passes combustion exhaust gas through the regenerator to recover heat in the regenerator other than in main combustion. In the structure, at least one rectifying plate is provided between the heat storage body and the combustion air injection port in the ventilation path to diffuse and rectify a fluid passing through the ventilation path.

[0011] The straightening plate is formed of a perforated plate provided with a plurality of holes, and the total cross-sectional area of the holes provided in the perforated plate is set to be larger than the cross-sectional area of the combustion air injection port. .

Further, in a radiant tube burner according to the present invention, at least one or more of the above-mentioned regenerative burners are arranged at the end of the radiant tube.

[0013] The regenerative burner in the radiant tube burner has a combustion air injection port provided eccentrically in the radial direction of the radiant tube.

[0014]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1 FIG. FIG. 1 is an explanatory view illustrating an embodiment of a radiant tube burner to which the present invention is applied. In the figure, reference numeral 1 denotes a radiant tube burner, which includes a radiant tube 3 curved in a substantially U-shape, and a pair of burners 5 disposed at both ends of the radiant tube 3. The radiant tube burner 1 heats the outside surface of the radiant tube 3 by passing the combustion exhaust gas of the burners 5 disposed at both ends of the radiant tube 3 through the inside of the radiant tube 3. It heats the inside of a furnace or the like.

Each of the burners 5 disposed at both ends of the radiant tube 3 has the same configuration, and includes a burner body 9, a burner gun 11 disposed inside the burner body 9, and a burner body 9 through which fuel gas passes. Combustion air passage 13 formed between the burner gun 11 and the combustion air passage 13
, A baffle 15 provided at the tip of the burner gun 11, and a perforated plate 1 provided between the baffle 15 and the heat storage 17 in the combustion air passage 13.
2 and the like.

The burner gun 11 includes a pilot combustion air passage 21 formed in a cylindrical shape, a fuel passage 19 also formed in the pilot combustion air passage 21 in a cylindrical shape, a spark plug (not shown), and the like. I have. Thus, the burner gun 11 has a simple structure in which the fuel passage 19 is disposed concentrically in the pilot combustion air passage 21, and the burner gun 11 can be formed relatively thin.

FIG. 2 is a piping diagram of a fuel supply pipe for supplying fuel to the fuel passage 19 of the burner gun 11. The piping system of the fuel supply piping will be described based on FIG.
A fuel supply source (not shown) is connected to one end of the fuel supply passage 23, and a fuel passage 19 of the burner gun 11 is connected to the other end. In the middle of the fuel supply passage 23, a control valve 25 for controlling the supply of fuel to the burner gun 11 is provided, and a bypass passage 27 bypassing the control valve 25 is provided. In the middle of the bypass passage 27, fuel supplied to the burner gun 11 is supplied.
Is provided with a flow control valve 29 and a control valve 31 for adjusting the amount to the minimum necessary for performing pilot combustion. In the piping system configured as described above, when the burner performs main combustion, the control valve 25 of the fuel supply passage 23 is opened and the control valve 31 of the bypass passage 27 is closed. On the other hand, when the burner performs pilot combustion, the control valve 25 of the fuel supply passage 23 is closed and the control valve 31 of the bypass passage 27 is opened.

Referring again to FIG. 1, the configuration of the burner gun 11 will be described. The space around the burner gun 11 is a combustion air passage 13. However, when one of the burners 5 is in a standby state in which the combustion air passage 13 is not operated, the combustion air passage 1 is turned off.
Reference numeral 3 denotes an exhaust passage through which high-temperature combustion exhaust gas from the other burner 5 flows. However, a pilot combustion air passage 21 is formed in the space around the fuel passage 19, and the combustion air at a low temperature (normal temperature) is always supplied into the pilot combustion air passage 21 before combustion. The fuel in the fuel passage 19 is not heated by the heat of the combustion exhaust gas in the combustion air passage 13 to a high temperature.

The heat storage body 17 is formed of a highly durable material (for example, ceramics) in a honeycomb shape with a relatively large heat capacity in spite of a relatively low pressure loss, and is configured such that air can pass through the inside thereof. Have been. When the high-temperature combustion exhaust gas passes through the heat accumulator 17, the heat accumulator 1
Heat is recovered by collecting heat from the combustion exhaust gas, and when the combustion air passes through the heated regenerator 17, the passing air deprives the regenerator 17 of heat and raises the temperature.

The perforated plate 12 has a function of diffusing and rectifying the combustion exhaust gas which is drawn in from the combustion air injection port 33 formed in the baffle 15 at a high temperature and drifts. If the perforated plate 12 is not provided, the flue gas flowing in a deviated manner flows into the heat storage body 17 in a deflected state, and as described in the section of the problem to be solved by the invention of this specification, Although the problem of breakage of the heat storage body 17 occurs, the occurrence of such a problem can be suppressed by the diffusion / rectification action of the perforated plate 12.

When the perforated plate 12 is not provided, the space between the combustion air injection port 33 and the regenerator 17 is lengthened, and the combustion exhaust gas flowing at a high speed is diffused in a radiant tube circular cross section. It is necessary to grow the flow until the flow becomes almost rectified in the cross section, but this requires a linear interval of several meters, and the burner becomes huge and the equipment cost rises. Therefore, by providing the perforated plate 12, a diffusion / rectification effect can be obtained with a simple configuration, and a rise in equipment costs can be suppressed. In addition,
As the material of the perforated plate 12, any material can be used as long as it can physically withstand high-temperature combustion exhaust gas, for example, a heat-resistant metal, ceramics, or the like. In the present embodiment, the same material as the radiant tube 3 is used. Uses heat-resistant metal. Other details of the perforated plate 12 will be described later.

The other burner 5 has the same structure as the above-described one burner 5. One end of each burner body 9 of each burner 5 is connected to the combustion air supply source and Connected to the atmosphere side. The air passage mechanism 10 is provided with a four-way valve 41 shown in FIG.
The connection between each burner 5 and the combustion air supply source or the atmosphere side can be switched. When the four-way valve 41 is in the position shown in the figure, the combustion air passage 13 of the burner 5 arranged on the lower side in the figure is connected to the combustion air supply source, and the burner 5 arranged on the upper side in the figure is also arranged. Is connected to the atmosphere side.
When the four-way valve 41 is switched, the connection relationship is reversed.

Here, the relationship between the combustion air and the operation of the burner 5 is shown in FIG. 3, the horizontal axis indicates the operation mode of the burner 5, and the vertical axis indicates the combustion amount and the air supply amount. In the combustion mode in which the burner 5 operates, main combustion air is supplied to the burner 5 by pressure in addition to pilot combustion air. On the other hand, in the exhaust mode in which the burner 5 is in a standby state in which the burner 5 is not operated, only pilot combustion air is supplied under pressure, and the burner 5 is supplied with an amount of combustion air suitable for the burner gun 11 to perform pilot combustion. Is done. In this case, the combustion amount of the burner 5 is only 500. In this embodiment, the burner gun 11 only performs pilot combustion.
The combustion amount is about 0 Kcal / H. As can be seen from the above description, the pilot combustion air passage 2 of the burner gun 11
1 is always supplied with pilot combustion air irrespective of the operating state of the burner 5.

FIG. 4 is a sectional view showing the vicinity of the burner 5 of the radiant tube burner 1 shown in FIG. 1. Hereinafter, the structure near the burner 5 will be described in detail with reference to FIG. As shown in FIG. 4, the radiant tube 3 has an intermediate portion supported by a mounting hole 7a provided in a furnace wall 7 and an end portion located outside the furnace, and a flange provided at the end portion. 3a
Is fixed to a mounting portion 7b provided on the outer surface of the furnace wall 7. The gap between both ends of the radiant tube 3 and the furnace wall 7 is hermetically closed by a sealing member (not shown).

The burner body 9 has a substantially cylindrical shape whose one end is bent substantially at a right angle, and has a flange 9c at the bent end.
However, a flange 9 b is provided on the other end side, and the flange 9 c is provided on the flange 3 of the radiant tube 3.
a is attached to the attachment portion 7b of the furnace wall 7 together with a. A hole 9a for inserting the burner gun 11 is formed in the bent portion of the burner body 9.

The baffle 15 is arranged at a position substantially corresponding to the inner surface of the furnace wall 7 in the radiant tube 3. FIG. 5 is a front view of the baffle 15. The details of the baffle 15 will be described with reference to FIGS. Baffle 15
Is composed of a disk portion 15a and a peripheral wall 15b extending from the entire periphery of the disk portion 15a toward the burner gun 11, and an inner tube 15f is continuously formed on the peripheral wall 15b. A flange 35a overlapping the flange 3a is formed at the end of the pipe 15f. The diameter of the disk portion 15a is set substantially equal to the inner wall of the radiant tube 3, and the disk portion 15a closes the inside of the radiant tube 3. Further, the peripheral wall 15b of the baffle 15 is substantially fixed to the inner peripheral surface of the radiant tube 3.

As shown in FIG. 5, the disk portion 15a of the baffle 15 is provided with a notch 15d at the peripheral edge thereof, and a small-diameter hole 15c is provided at a position slightly deviated from the center toward the outer periphery.
Is provided. The notch 15d is formed by cutting out the lower end portion of the disk portion 15a in a half-moon shape, and forms a combustion air injection port 33 together with the radiant tube 3. That is, the combustion air injection port 33 is provided eccentrically with respect to the transverse section of the radiant tube 3,
The combustion air is ejected at a high speed to an eccentric position in the space inside the radiant tube 3 to form a self-exhaust gas circulating flow in the radiant tube 3. On the other hand, the fuel gas is ejected from the small-diameter hole 15c located at a position away from the combustion air injection port 33, and burns while being involved in the self-exhaust gas circulating flow of the combustion air. Thus, to achieve a combustion which does not form a local high temperature region, thereby realizing a low-NO _x combustion preventing the outbreak of regenerative radiant tube burner biggest drawback is a nitrogen oxide.

The position of the small-diameter hole 15c corresponds to the hole 9 for inserting the burner gun 11 provided in the burner body 9.
a. The diameter of the small-diameter hole 15c is set to be substantially the same as the outer diameter of the tip of the burner gun 11. Further, the peripheral edge of the small-diameter hole 15c extends toward the burner body 9 to form a cylindrical portion 15e, and a guide pipe that houses the burner gun 11 is arranged and supported on the cylindrical portion 15e. And Burnagan 11
Is inserted into the radiant tube 3 from the hole 9a of the burner body 9 as described above, is disposed substantially parallel to the radiant tube 3, and has a distal end supported by a baffle 15 in a guide pipe (not shown). Has been inserted. Thus, the tip of the burner gun 11 is
The small-diameter hole 15c is disposed at a certain distance from the combustion air injection port 33.

The perforated plate 12 comprises a heat storage body 17 and a baffle 15
Between the combustion air injection ports 33
It is better to arrange them at a predetermined distance in the direction of the heat storage body. By keeping the predetermined distance in this manner, it is possible to secure a space that acts as a header before the combustion air injection port 33 when the combustion air passes when the burner 5 is operating, and the air jet is There is an effect of being formed by a uniform flow. Note that the predetermined distance is preferably a distance larger than the shortest side if the combustion air injection port is an ellipse including a circle or a polygon.

FIG. 6 shows a perforated plate 12 used in the present embodiment.
The front view of was shown. The perforated plate 12 has a combustion air injection port 3
3, a large number of round holes 12a having a smaller area than the cross-sectional area of the combustion air injection port 3 are provided.
3 is set larger than the fluid passage cross-sectional area. Round hole 1
The reason why the area of 2a is smaller than the cross-sectional area of the combustion air injection port 33 is that when the cross-sectional area of the round hole 12a is larger than the cross-sectional area of the combustion air injection port, the flow of combustion exhaust gas flowing in a non-uniform manner does not change. The diffusion and rectification effects cannot be obtained, and the total opening cross-sectional area of the round hole 12a is set to be larger than the fluid passage cross-sectional area of the combustion air injection port 33 because the perforated plate 12 This is to reduce as much as possible the pressure loss caused when the combustion air passes through. The shape and number of the holes of the perforated plate 12 are not particularly limited, and any shape such as a lattice as shown in FIG. 7 is applicable. In addition, by arranging a plurality of perforated plates 12, the diffusion / rectification effect is further increased.

One burner 5 configured as described above
Operates as follows. First, when performing pilot combustion, the control valve 25 of the fuel supply passage 23 is closed,
Fuel is supplied to the burner gun 11 only through the bypass passage 27. The combustion air supply source constantly feeds the pilot combustion air to the burner gun 11, so that the fuel and the pilot combustion air become a mixed gas having an air ratio suitable for the pilot combustion. Then, the mixed gas is ignited by an ignition plug to perform pilot combustion (the state of the upper burner 5 shown in FIG. 1).

When the control valve 25 of the fuel supply passage 23 is opened and the supply of the main combustion air from the combustion air supply source is started while the burner gun 11 is performing the pilot combustion, a large amount of fuel is supplied from the fuel supply source. Is pumped into the fuel passage 19 of the burner gun 11, and the burner gun 11 performs main combustion. And in this main combustion state,
When the control valve 25 of the fuel supply passage 23 is closed and the supply of combustion air from the combustion air supply source is stopped, the burner gun 11 returns to the pilot combustion state. Even in this state, a small amount of fuel is supplied to the burner gun 11 through the bypass passage 27 of the fuel supply passage 23, and the combustion air supply source always supplies combustion air. Perform pilot combustion.

The radiant tube burner 1 provided with each burner 5 operating in this manner performs so-called alternating combustion in which each burner 5 is operated alternately. First, one burner 5 (hereinafter, the symbol of the component related to one burner 5 is denoted by A) is activated, and the other burner 5 (hereinafter, the symbol of the component related to the other burner 5 includes: B will be described). In this case, the control valve 25A of the fuel supply passage 23A
Is opened, the control valve 25B of the combustion air passage 23B is closed, and the four-way valve 41 of the air passage mechanism 10 is switched to the position shown in FIG. Thus, the fuel, the main combustion air, and the pilot combustion air required for the main combustion are supplied to the burner 5A, and the main combustion described above is performed. On the other hand, the burner gun 11B of the burner 5B is supplied with fuel and pilot combustion air in an amount suitable for pilot combustion, and the pilot combustion is continued.

The combustion exhaust gas generated by the main combustion of the burner 5A flows toward the burner 5B while heating the inside of the radiant tube 3. Then, the combustion exhaust gas flows into the combustion air passage 13B from the combustion air injection port 33B of the baffle 15B, and is discharged to the atmosphere via the air passage mechanism 10. At this time, since the combustion air injection port 33B is arranged eccentrically in the radiant tube, the combustion exhaust gas having a circular cross section of the radiant tube flows in the combustion air passage 13B as a deflected flow. Then, the inflowing combustion exhaust gas is diffused and rectified by the perforated plate 12B, and the heat is recovered by the heat storage body 17B in the burner body 9B. Therefore, the temperature of each heat storage body 17B rises.

When a predetermined time T (for example, about 20 seconds) has elapsed after the start of the main combustion of the burner 5A, the control valve 25A of the fuel supply passage 23A shown in FIG. 23B, the four-way valve 41 of the air passage mechanism 10 is switched, the burners 5A and 5B on the operating side and the standby side are switched, and the burner 5B is opened.
, The main combustion is performed, and the pilot combustion is performed by the burner 5A.

FIG. 8 is a view showing the state of the alternating combustion of the above-described burners 5A and 5B. The horizontal axis shows time, and the vertical axis shows the combustion state of each of the burners 5A and 5B. Based on FIG. 8, the state of the alternating combustion of the burners 5A and 5B will be described. At time t1, the burner 5A starts main combustion, and the burner 5B starts pilot combustion.
Then, at time t2 when the time T has elapsed, the burner 5A performing the main combustion switches to the pilot combustion, and the burner 5B performing the pilot combustion starts the main combustion. Thereafter, similarly, every time the time T elapses, the burners 5A and 5B on the operating side and the standby side are switched, and the radiant tube burner 1 performs alternating combustion.

Embodiment 2 FIG. 9 is a sectional view of a burner according to another embodiment of the present invention. In the first embodiment, an example in which the heat storage bodies 17 are arranged in the main combustion air passage 13 has been described. However, in the present embodiment, the heat storage bodies 17 are arranged and housed below the burner body 9. It was made. Further, a perforated plate 120 is additionally provided above the newly installed heat storage body 17. The perforated plate 120 is arranged for the purpose of diffusing and rectifying the drift generated when the combustion exhaust gas flowing in when the burner 5 is not operating changes its flow into an L shape at the bent portion of the burner body 9. In addition, the installation position of each heat storage body 17 is the same as in the first and second embodiments.
The position is not limited to 2, and may be any position within the main combustion air passage 13 or in the middle of the passage of the air passage mechanism 10 connected thereto.

Although the above-described first and second embodiments are one of preferred embodiments of the present invention, the present invention is not limited to this, and various modifications may be made without departing from the spirit of the present invention. It is feasible. For example, in the above embodiment, the switching of the operation standby state of each burner 5 is performed by
Although it is configured to be repeated every T hours, each heat storage body 17A, 1
A configuration may be adopted in which the temperature of 7B is monitored, and when the temperature reaches or exceeds the set temperature, the operation and standby of each of the burners 5A and 5B are switched.

Furthermore, the burner of the present invention may be applied to a type independent of the radiant tube, that is, to a furnace that directly fills the object to be heated by filling the combustion exhaust gas atmosphere. Further, for example, the present invention can also be applied to a heat storage type radiant tube system using a three-pronged radiant tube as disclosed in Japanese Utility Model Application Laid-Open No. 6-65705. Further, the heat storage body of the burner is not limited to the honeycomb-shaped heat storage body, but may be applied to any shape and material such as ceramics and metals such as balls and blocks.

[0040]

As described above, in the present invention, at least one rectifying plate for diffusing and rectifying the fluid passing through the ventilation path between the heat storage body and the combustion air injection port in the ventilation path. Since it is installed, even if the fluid that is going to pass through the heat storage body is deflected, it is possible to rectify the deflected flow by diffusing the fluid, prevent the heat departure in the heat storage body, and store heat due to thermal stress etc. Preventing the body from cracking, extending the life of the heat storage body, and enabling a heat storage type burner that can be operated stably for a long period of time. As a result, various effects can be obtained, such as a reduction in repair costs for thermal equipment, a reduction in the amount of heat input to the furnace generated when the combustion of the burner is stopped as an emergency measure due to burner damage, a reduction in work efficiency, and a reduction in opportunity loss.

Further, the current plate is constituted by a perforated plate provided with a plurality of holes, and the total cross-sectional area of the holes provided in the perforated plate is set larger than the cross-sectional area of the combustion air injection port.
A straightening plate can be realized with a simple configuration, and the influence of the resistance of the perforated plate on the air injection port for combustion can be suppressed to a small value.

Further, by arranging at least one regenerative burner provided with a rectifying plate or a perforated plate at the end of the radiant tube, the effect of the radiant tube burner in addition to the above effect can be obtained.

Further, since the combustion air injection port of the regenerative burner of the radiant tube burner is provided eccentrically in the radial direction of the radiant tube, in addition to the above-mentioned effects, the combustion air injected into the radiant tube can be provided. closed-loop flow is generated, it is not the air for combustion with fuel gas contacts immediately combustion gradually slow combustion can be realized to proceed, it is possible to suppress the generation of NO _X.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is a system diagram of a fuel supply passage according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a relationship between a combustion state of a radiant tube burner and an amount of supplied air according to the first embodiment of the present invention.

FIG. 4 is a sectional view near a burner according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of a baffle according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of the perforated plate applied to the first embodiment of the present invention.

FIG. 7 is a sectional view of another example of the perforated plate applied to the first embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating a state of alternating combustion of the radiant tube burner according to the first embodiment of the present invention.

FIG. 9 is a sectional view near a burner according to a second embodiment of the present invention.

FIG. 10 is a schematic diagram of a heating furnace in a combustion exhaust gas atmosphere using a conventional regenerative burner.

FIG. 11 is an explanatory diagram of a configuration of a conventional radiant tube burner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radiant tube burner 3 Radiant tube 5 Burner 11 Burner gun 12 Perforated plate 13 Combustion air passage 15 Baffle 19 Fuel passage 21 Pilot combustion air passage 33 Combustion air injection port

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeo Kurioka 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Tatsuya Shimada 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan (72) Inventor Suga Politics 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Ryoichi Tanaka 2-1-1, Shirite, Tsurumi-ku, Yokohama, Kanagawa Japan Nippon Furnace Industries Co., Ltd. In-company (72) Inventor Takuya Igarashi 2-1-153 Shirite, Tsurumi-ku, Yokohama-shi, Kanagawa Japan Furnace Industries Co., Ltd. (56) References JP-A-8-247421 (JP, A) JP-A-48-36753 (JP, A) JP-A-3-195806 (JP, A) JP-A-63-179408 (JP, U) JP-A-57-160533 (JP, U) JP-A-62-1189 25 (JP, U) Japanese Utility Model Hei 6-65705 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23D 14/12 F23C 3/00 301 F23D 14/66 F23L 15/00 -15/02

Claims (4)

(57) [Claims] An air passage that serves as a passage for combustion air and combustion exhaust gas, a heat storage body disposed in the air passage, and a combustion air injection port provided at one end of the air passage. In a regenerative burner having a structure in which combustion air is preheated by the regenerator during main combustion and combustion exhaust gas is passed through the regenerator and heat is recovered by the regenerator other than in main combustion, the regenerator in the ventilation path A regenerative burner, wherein at least one rectifying plate for diffusing and rectifying a fluid passing through the ventilation path is provided between the burner and the combustion air injection port. 2. The rectifying plate comprises a perforated plate provided with a plurality of holes, and a total cross-sectional area of the holes provided in the perforated plate is set to be larger than a cross-sectional area of the combustion air injection port. The regenerative burner according to claim 1. 3. A radiant tube burner, wherein at least one of the regenerative burners according to claim 1 or 2 is arranged at an end of the radiant tube. 4. The radiant tube burner according to claim 3, wherein the regenerative burner in the radiant tube burner has a combustion air injection port provided eccentrically in a radial direction of the radiant tube.