JPH10176810A - Regenerative burner and radiant tube burner using the same regenerative burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerative burner capable of preventing the generation of localized heating at a heat storage body and protecting the heat storage body from being broken by thermal stress or the like even when a combustion gas, which is passing through the heat storage body, is drifted. SOLUTION: A regenerative burner is provided with a combustion air passage 13, which forms a passage for combustion air and exhaust gas, a heat storage body 17 provided thereon and a combustion air jetting opening 33 provided on the end of the combustion air passage 13. It is also arranged to preheat the combustion air with the heat storage body 17 during main combustion time and jets the combustion air from the combustion air spray opening 33 and takes in combustion exhaust gas from the combustion air spray opening 33 except for the main combustion and recovers the heat with the heat storage body 17. In this case, the inflow cross section of the combustion gas in the heat storage body 17 is set to a smaller value than the cross section of the combustion air passage between the heat storage body 17 and the combustion air spray opening 33 and arranged to lay out the heat storage body 17 so that the combustion exhaust gas introduced from the combustion air jetting opening 33 may not flow straightly into the heat reservoir wholly or partially.

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. Then, 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 a 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 (heat storage medium). (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 a side of the fuel cell, wherein during main combustion, combustion air is preheated by the regenerator and jetted from the combustion air injection port. In the structure in which the heat storage medium is introduced from the injection port and passes through the heat storage body, and heat is recovered by the heat storage body, an inflow cross section of the combustion exhaust gas in the heat storage body is formed between the heat storage body and the combustion air injection port. And the heat storage body is arranged so that all or a part of the combustion exhaust gas introduced from the combustion air injection port does not flow straight into the heat storage body.

[0011] Further, there is provided an air passage serving as a passage for combustion air and combustion exhaust gas, a heat storage body provided in the air passage, and a combustion air injection port provided at one end of the air passage.
At the time of main combustion, combustion air is preheated by the heat accumulator and is ejected from the combustion air injection port.Other than main combustion, combustion exhaust gas is introduced from the combustion air injection port and passed through the heat accumulator, In a regenerative burner having a structure in which heat is recovered by a regenerator, a part of an inflow cross section of the flue gas in the regenerator forms a wall through which the flue gas cannot pass, and is introduced from the combustion air injection port. All or a part of the combustion exhaust gas is prevented from flowing straight into the heat storage body.

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 wall body 12 formed on the outer periphery of the heat storage body 17, a baffle 15 installed at the tip of the burner gun 11, 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 wall body 12 has a function of diffusing the high-temperature and unevenly flowing combustion exhaust gas sucked from the combustion air injection port 33 formed in the baffle 15 and causing the combustion exhaust gas to flow into the regenerator 17 almost uniformly. Have. If the wall body 12 is not provided, the flue gas flowing in a deviated manner flows into the heat storage body 17 while being deflected, and as described in the section of the problem to be solved by the invention of the present specification, Heat storage 1
7 will be damaged, but this wall 1
Due to the diffusion effect of 2, the occurrence of such a problem can be suppressed.

When the wall body 12 is not provided, the space between the combustion air injection port 33 and the heat storage body 17 is lengthened, and the combustion exhaust gas that flows in 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, the provision of the wall 12 can provide a diffusion / rectification effect with a simple configuration, and can suppress a rise in equipment costs. In addition, as the material of the wall body 12, any material can be used as long as it is a material that does not corrode even when a high-temperature combustion exhaust gas collides at a high speed, but in the present embodiment, the same properties as the refractory brick are used. Uses plastic refractories.

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 the pilot combustion air is supplied under pressure. 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 containing the burner gun 11 is arranged and supported on the cylindrical portion 15e. And Burnagan 11
Is inserted into the radiant tube 3 through 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 wall 12 is formed on the outer periphery of the heat storage body 17, and the radial height of a portion facing the combustion air injection port 33 is substantially the same as the height of the combustion air injection port 33. Is set. With this setting, almost all the combustion exhaust gas sucked from the combustion air injection port 33 can be made to collide with the wall 12 and diffuse.

FIG. 6 shows a sectional view of the wall 12 and the heat storage 17 used in the present embodiment. As shown in FIG.
The wall 12 is formed over the entire outer periphery of the heat storage body 17, and a portion facing the combustion air injection port 33 is formed to be thicker. As described above, by forming the portion facing the combustion air injection port 33 thicker, the combustion exhaust gas sucked from the combustion air injection port 33 surely collides, and the uniform flow into the heat storage body is achieved. To make sure. In addition,
In this embodiment, the portion of the wall body 12 facing the combustion air injection port 33 is formed thicker, but the entire circumference of the wall body 12 may be formed with the same thickness. In this way, the manufacture of the wall body 12 is facilitated.

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 collides with the wall body 12B and is diffused, and flows almost uniformly into the heat storage body 17B in the burner body 9B. The combustion exhaust gas that has flowed into the heat storage body 17B is recovered and exhausted there. In addition, the temperature of each heat storage body 17B that has recovered heat from the combustion exhaust gas rises and is used for preheating the combustion air.

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. The control valve 25B is opened, 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, the main combustion is performed by the burner 5B, and the pilot combustion is performed by the burner 5A. Will be

FIG. 7 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. 7, 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. 8 is a sectional view of a burner according to another embodiment of the present invention. In the first embodiment, the example in which the heat storage body 17 is arranged only in the main combustion air passage 13 and the wall body 12 is formed around the entire circumference of the heat storage body 17 has been described. The heat storage 17 is arranged side by side in the main combustion air passage 13 and the lower side in the burner body 9, and the wall 12 is provided on a part of the outer peripheral portion of the heat storage 17 arranged in the main combustion air passage 13. It is formed. FIG. 9 is a cross-sectional view of the heat storage body 17 and the wall 12 arranged in the main combustion air passage 13. By providing the wall body 12 at a part of the outer periphery of the heat storage body 17 as in the second embodiment, the cross section of the flow path of the heat storage body 17 can be widened, and the stagnation of the combustion exhaust gas can be reduced.

In the first and second embodiments, the heat storage 17 is formed smaller than the cross section of the main combustion air passage 13 and the wall 12 is separately provided on the outer periphery of the heat storage 17. Although shown, the heat storage body 17 may be formed in the same shape as the cross section of the main combustion air passage 13, and a wall may be formed by filling a hole in a portion of the heat storage body 17 facing the combustion air injection port 33. . In this case, since the heat storage body 17 and the wall body 12 do not need to be newly manufactured, the cost can be reduced.

The installation position of each heat storage element 17 is not limited to the above-described first and second embodiments, but may be in the main combustion air passage 13 or the air passage mechanism 10 connected thereto.
Any position as long as it is in the middle of the path.

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 gist 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.

Further, the burner of the present invention may be applied to a type independent of the radiant tube, that is, to a furnace for directly heating an object to be heated by filling a 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.

[0042]

As described above, in the present invention, the inflow section of the combustion exhaust gas in the regenerator is set smaller than the cross section of the ventilation path between the regenerator and the combustion air injection port, and the combustion air injection is performed. The regenerator is arranged so that all or a part of the flue gas introduced from the mouth does not flow straight into the regenerator. A heat storage system that allows the heat to flow almost evenly into the body, preventing heat deviation in the heat storage body, preventing the heat storage body from cracking due to thermal stress, etc., prolonging the life of the heat storage body and ensuring stable operation for a long period of time Burner enabled. This will reduce the cost of repairing thermal equipment,
As an emergency measure due to burner damage, various effects can be obtained, such as a reduction in the amount of heat input to the furnace generated when the combustion of the burner is stopped and a reduction in opportunity loss such as a reduction in work efficiency.

Further, a wall body through which the combustion exhaust gas cannot pass is formed at a part of the inflow section of the combustion exhaust gas in the regenerator,
Since all or part of the flue gas introduced from the combustion air injection port is prevented from flowing straight into the heat storage body, the combustion exhaust gas introduced from the combustion air injection port collides with the wall and is diffused, The heat flows into the heat accumulator almost uniformly, so that the heat accumulator is prevented from being deviated in temperature and the heat accumulator is prevented from cracking due to thermal stress or the like. For this reason, the life of the heat storage body can be extended, and a heat storage burner that can be operated stably for a long time has been realized. 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, by arranging at least one regenerative burner provided with a rectifying plate or a wall at the end of the radiant tube, it is possible to obtain the effect of the radiant tube burner in addition to the above effect.

Further, the combustion air injection port of the regenerative burner in the radiant tube burner is provided eccentrically in the radial direction of the radiant tube. 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 sectional view of a wall and a heat storage body applied to the first embodiment of the present invention.

FIG. 7 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. 8 is a sectional view near a burner according to a second embodiment of the present invention.

FIG. 9 is a cross-sectional view of a wall and a heat storage body applied to Embodiment 2 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]

 Reference Signs List 1 radiant tube burner 3 radiant tube 5 burner 11 burner gun 12 wall 13 combustion air passage 15 baffle 19 fuel passage 21 pilot combustion air passage 33 combustion air injection port

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeo Kurioka 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan Inside Nihon Kokan Co., Ltd. (72) Tatsuya Shimada 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan (72) Inventor Suga Politics 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Ryoichi Tanaka 2-1-1, Shirite, Tsurumi-ku, Yokohama, Japan Japan Inside Furnace Industry Co., Ltd. (72) Inventor Takuya Igarashi 2-1-153 Shirite, Tsurumi-ku, Yokohama-shi, Kanagawa Japan Furnace Industry Co., Ltd.

Claims (4)

[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. At the time of main combustion, combustion air is preheated by the heat accumulator and is ejected from the combustion air injection port.Other than main combustion, combustion exhaust gas is introduced from the combustion air injection port and passed through the heat accumulator, In a regenerative burner having a structure in which heat is recovered by a regenerator, an inflow cross section of the combustion exhaust gas in the regenerator is set to be smaller than a cross section of an air passage between the regenerator and the combustion air injection port. A heat storage burner, wherein the heat storage body is arranged so that all or a part of the combustion exhaust gas introduced from the air injection port does not flow straight into the heat storage body. 2. A ventilation path that serves as a path for combustion air and combustion exhaust gas, a heat storage body disposed in the ventilation path, and a combustion air injection port provided at one end of the ventilation path. At the time of main combustion, combustion air is preheated by the heat accumulator and is ejected from the combustion air injection port.Other than main combustion, combustion exhaust gas is introduced from the combustion air injection port and passed through the heat accumulator, In a regenerative burner having a structure in which heat is recovered by a regenerator, a wall body through which the flue gas cannot pass is formed at a part of an inflow cross section of the flue gas in the regenerator, and is introduced from the combustion air injection port. A regenerative burner wherein all or a part of the flue gas is prevented from flowing straight into the regenerator. 3. A radiant tube burner, wherein at least one regenerative burner according to claim 1 is arranged at an end of a 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.