JP2002333126A - Operation method for regenerative burner furnace, and regenerative burner furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple method and a simple apparatus capable of adjusting an oxygen concentration of supply gas in a regenerative burner furnace and combusting at low oxygen concentration. SOLUTION: A regenerative burner 2 and a non-combustion heat storage port 15 including a heat storage structure 16 which does not combust but is capable of storing heat of combustion waste gas are installed in a heating furnace 1. High temperature non-acidic gas is supplied into the furnace through the heat storage structure 16 of the heat storage port 15 during combustion of the regenerative burner 2 to adjust oxygen concentration of the supply gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a regenerative burner furnace having a regenerative burner and a regenerative burner furnace, and more particularly to a method for regenerating a non-oxidizing gas from a regenerative burner or a non-combustion regenerative port. The present invention relates to an operation method of a regenerative burner furnace and a regenerative burner furnace, in which the oxygen concentration in the furnace is adjusted by supplying the gas into the furnace, thereby enabling combustion at a low oxygen concentration.

[0002]

2. Description of the Related Art In a regenerative burner, a heat storage element is attached to each burner, heat exchange is performed between combustion exhaust gas and combustion air, and high-temperature preheated air is obtained to perform combustion with high thermal efficiency. It is a burner that can do it. The regenerative burner furnace is a heating furnace to which such a regenerative burner is attached. FIG. 3 shows a conceptual diagram of a conventional regenerative burner furnace. Although the number of regenerative burners installed in the heating furnace is increased or decreased as necessary, an example in which four regenerative burners are installed is shown here as an example. In FIG. 3, reference numeral 1 denotes a regenerative burner furnace, and 2 denotes a regenerative burner, four of (A), (I), (U), and (E).
A table is installed. Reference numeral 3 denotes a heat storage element attached to each regenerative burner 2, and 4 denotes a fuel pipe, and a fuel control valve 5 is attached to each regenerative burner 2. Reference numeral 6 denotes an air pipe, to which an air supply fan 7 and a combustion air control valve 8 for each regenerative burner 2 are attached. An exhaust gas pipe 9 for exhausting combustion exhaust gas is provided with an exhaust fan 10 and an exhaust gas control valve 11 for each regenerative burner 2. 12 is a flue. The collective exhaust pipe 13 of the exhaust gas pipe 9 communicates with the flue 12. The heat storage body 3 attached to each heat storage type burner 2 preferably has a large specific surface area and a small gas passage resistance. Further, it is preferable that the mass is small and the response to a temperature change is good. For example, a ceramic honeycomb is used. Fuel is supplied from a fuel supply source (not shown) through the fuel pipe 4 and pressurized fuel is supplied in an amount corresponding to the degree of opening only during the time when the fuel control valve 5 of the burner is open. Is supplied to the burner. The air pre-heated by passing through the heat accumulator 3 only during the time when the air compressed by the air supply fan 7 is supplied through the air pipe 6 and the combustion air control valve 8 of the burner is open is supplied. Is supplied to the burner in accordance with the degree of opening of the combustion air control valve 8. As for the flue gas, the flue gas that has passed through the heat accumulator 3 of the burner is sucked by the exhaust fan 10 only during the time when the flue gas valve 11 is open, passes through the exhaust gas pipe 9 and the collective exhaust pipe 13, and the flue of the heating furnace. It is released to 12. A indicated by an arrow indicates a flow of the high-temperature gas generated at another place in the regenerative burner furnace 1.

[0003] The combustion in this regenerative burner furnace will be described. For example, when the regenerative burners (A) and (U) are in a combustion state, the fuel control valve 5 of the regenerative burners (A) and (U) is turned on. Open to supply fuel. Further, the combustion air regulating valves 8 of the regenerative burners (A) and (U) are opened, the combustion exhaust gas valve 11 is closed, and air is pushed into the regenerator 3. The air that has passed through the heat accumulator 3 deprives the heat accumulator 3 of heat, becomes high-temperature preheated air, is supplied to the inside of the furnace, and mixes with fuel to perform combustion. On the other hand, at this time, a regenerative burner
In (e), the fuel control valve 5 and the combustion air control valve 8 are closed,
The flue gas valve 11 is open, and the flue gas is sucked from the regenerative burners (i) and (e), and the burner (i)
After heating through the heat storage body 3 of (e), the air is exhausted by the exhaust fan 10 through the exhaust gas pipe 9 and the collective exhaust pipe 13. If there is excess combustion exhaust gas, it is also exhausted from the flue 12 of the heating furnace. At this time, in a regenerative burner equipped with an appropriately designed honeycomb type regenerator,
For example, when the temperature of the gas in the furnace is 1300 ° C. and the temperature of the combustion air supplied to the regenerators of the burners (A) and (U) is about 30 ° C., the regenerator 3 heats the air to about 12 ° C.
It becomes preheated air of 50 ° C. Most of the combustion exhaust gas is at a temperature of about 1300 ° C.
, Which are heated and evacuated at about 200 ° C.

When performing heat storage combustion in a heating furnace using a regenerative burner, alternating combustion is performed in which the burner (a), (u) and the burner (i), (e) are switched at regular intervals. . The switching time is generally as short as about 10 seconds to 2 minutes. And the combustion switches, burner (i),
If (e) burns, burner (i),
(E) The fuel control valve 5 and the combustion air control valve 8 are opened, the combustion exhaust gas valve 11 is closed, and air is supplied to the heat storage body 3. The air that has passed through the heat accumulator 3 deprives the heat accumulator 3 of heat and is supplied as high-temperature preheated air to the inside of the furnace. On the other hand, at this time, in the burners (A) and (U), the fuel control valve 5 and the combustion air control valve 8 are closed and the combustion exhaust gas valve 11 is open, and the combustion exhaust gas is sucked from the burners (A) and (U). After being heated through the heat storage body 3, the air is exhausted by the exhaust fan 10.

[0005] In such a regenerative burner, alternating combustion is performed, so that the temperature distribution in the furnace is made uniform, and the combustion exhaust gas generated by combustion of one of the burners is sucked by the other burner storing heat to store the heat. As a result, the gas flow balance between the burner pairs is satisfied, and the flow of the combustion exhaust gas into the portions away from these burners is reduced. Therefore, there is a characteristic that the thermal influence on other parts is extremely small. Also, since the sensible heat of the combustion exhaust gas is recovered and preheated air of extremely high temperature is obtained, significant energy savings can be expected.

[0006]

In a conventional heating furnace equipped with a regenerative burner, the furnace heating capacity is uniquely determined only by the combustion amount of the regenerative burner, so that even under optimized operating conditions, It has not been practiced to freely adjust the oxygen concentration in the furnace and burn it. Therefore, the control of the oxide film and morphology of the object to be heated, which may cause surface defects after the rolling of the object to be heated or deteriorate the surface properties of the final product, for example, the formation of an oxide layer generated on a steel body such as a slab or a billet. It was impossible to suppress generation or control the composition of the oxide film. Also, it was not easy to suppress the generation of nitrogen oxides.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is an object of the present invention to make it possible to adjust the oxygen concentration of a supply gas in a regenerative burner furnace, and to make it possible to perform combustion at a low oxygen concentration. It is intended to provide a method and apparatus.

[0008]

According to a first aspect of the present invention, there is provided a method for operating a regenerative burner furnace, comprising a regenerative burner and a regenerator that does not burn but can store heat of combustion exhaust gas. By installing a combustion-type regenerative port in a heating furnace and supplying a high-temperature non-oxidizing gas into the furnace through a regenerator of the regenerative port during combustion of the regenerative burner, the oxygen concentration of the supplied gas is increased. Is adjusted.

That is, the present invention relates to a combination of a conventional regenerative burner and a non-combustion regenerative port. This non-combustion type heat storage port is a port having a heat storage body that does not burn but can store heat of the combustion exhaust gas. Therefore, by supplying a high-temperature non-oxidizing gas into the furnace through the regenerator of the regenerative port during combustion of the regenerative burner, the oxygen concentration of the combustion air can be diluted, and the oxygen concentration can be freely adjusted. And stable combustion at a low oxygen concentration as described later. The oxygen concentration can be adjusted by changing the ratio of the supply amounts of the combustion air and the non-oxidizing gas.

According to a second aspect of the present invention, there is provided a method for operating a regenerative burner furnace, wherein a plurality of regenerative burners are installed in a heating furnace.
By using at least one of them as a regenerative port and supplying a high-temperature non-oxidizing gas into the furnace through the regenerator of the regenerative port during combustion of the regenerative burner, the oxygen concentration of the supply gas is reduced. It is characterized by adjustment.

According to the second aspect of the present invention, at least one of the regenerative burners is used as a regenerative port. However, the heat storage type port referred to here is a combustion type unlike the heat storage type port described in claim 1. Therefore, a non-oxidizing gas pipe for supplying a non-oxidizing gas is provided in the combustion type heat storage type port (that is, the heat storage type burner). According to the second aspect of the invention, the same operation and effect as those of the first aspect of the invention can be obtained.

According to a third aspect of the present invention, there is provided a method for operating a regenerative burner furnace, comprising: installing a plurality of regenerative burners in a heating furnace;
During the combustion of the regenerative burner, a high-temperature non-oxidizing gas is supplied into the furnace through the regenerator of another regenerative burner to adjust the oxygen concentration of the supplied gas.

According to the third aspect of the present invention, all the regenerative burners can be used together as regenerative ports. The combination of the regenerative burner performing the combustion cycle and the regenerative port performing the non-combustion cycle can be alternated as described in claim 9.

According to a fourth aspect of the present invention, there is provided a method for operating a regenerative burner furnace, wherein the combustion air is heated at a temperature of 800 ° C. or more when the atmosphere temperature in the furnace is maintained at 900 ° C. or more. By supplying a non-oxidizing gas to the regenerative storage port or another regenerative burner so that the average oxygen concentration of the supplied gas is adjusted to 5% to 20%. It is assumed that.

According to a fifth aspect of the present invention, in the operating method of the regenerative burner furnace, the combustion air is stored at a temperature of 800 ° C. or more when the atmosphere temperature in the furnace is maintained at 1100 ° C. or more. The average oxygen concentration of the supplied gas is adjusted to 3% to 15% by supplying the non-oxidizing gas to the regenerative port or another regenerative burner by supplying the gas into the furnace from the burner. It is characterized by the following.

According to the fourth and fifth aspects of the present invention, the range of the supply gas average oxygen concentration is made different depending on the atmosphere temperature in the furnace. The lower limit (5%, 3%) of each average oxygen concentration is a limit for maintaining stable combustion at a low oxygen concentration at the furnace atmosphere temperature, and the upper limit (20%, 15%).
Is a limit coming from the regulation value of the generation amount of NOx.

According to a sixth aspect of the present invention, there is provided a method for operating a regenerative burner furnace, wherein the suction and discharge of combustion exhaust gas and the supply of non-oxidizing gas are alternately performed at one non-combustion type regenerative port. It is characterized by the following.

The number of the non-combustion regenerative ports may be one. In this case, the suction and discharge of the combustion exhaust gas and the supply of the non-oxidizing gas are alternately performed at one specific regenerative port. become.

According to a seventh aspect of the present invention, there is provided a method for operating a regenerative burner furnace, wherein the suction and discharge of the combustion exhaust gas and the supply of the non-oxidizing gas are performed between the same set of the non-combustion type regenerative ports. It is characterized by alternating. This is the case where two non-combustion regenerative ports are provided.

The method of operating a regenerative burner furnace according to claim 8 of the present invention is a combustion cycle for supplying combustion air and a non-combustion cycle for supplying non-oxidizing gas between the same set of regenerative burners. And alternately.

According to an eighth aspect of the present invention, when a regenerative burner is used as a regenerative port, an alternating operation between a combustion cycle and a non-combustion cycle is performed by the same set of regenerative burners. It is possible if there are three or more regenerative burners.

A method of operating a regenerative burner furnace according to claim 9 of the present invention, wherein a combustion cycle for supplying combustion air and a non-combustion cycle for supplying non-oxidizing gas between different sets of said regenerative burners. And alternately. This is a method of alternating between a combustion cycle and a non-combustion cycle between different burner pairs. As a result, the furnace atmosphere temperature can be made even more uniform, and the combustion of the regenerative burner can be equally borne.

According to a tenth aspect of the present invention, a regenerative burner furnace includes a regenerative burner, a non-combustion type regenerative port having a regenerator, and combustion exhaust gas in the furnace through the regenerator of the regenerative port. It is characterized by comprising exhaust means for discharging, and non-oxidizing gas supply means for supplying a non-oxidizing gas into the furnace through a heat storage element of the heat storage type port. According to this regenerative burner furnace, claims 1, 4, 5,
The invention methods described in 6, 7 can be carried out.

A regenerative burner furnace according to an eleventh aspect of the present invention is provided in a plurality of regenerative burners and a part or all of the plurality of regenerative burners, and supplies a non-oxidizing gas through a regenerator. Non-oxidizing gas supply means for supplying into the furnace;
It is characterized by having. With the regenerative burner furnace, the method according to the second, third, fourth, fifth, eighth and ninth aspects can be carried out.

The fact that stable combustion at a low oxygen concentration is possible in the regenerative burner furnace of the present invention will be described. FIG.
Is a magazine "Energy Conservation", Vol. 48, No.10 (1996
This is a figure described in the paper "Evolving High-Temperature Air Combustion Technology" published in 2011), where the temperature of dilution air, which is a mixture of oxygen and nitrogen, and the oxygen concentration in
It shows the combustible range of natural gas.
In FIG. 4, the “non-combustible region” is a region in which stable combustion cannot be performed, and is a region that is impossible as a design range of an industrial burner. Zone I (normal flame zone) is the design range of a conventional industrial burner in which heat is recovered by a metal tube exchanger to preheat combustion air. Region II (high-temperature flame region) is, for example, a high-temperature preheated air that is obtained by a regenerative burner and burned. However, it is within the design range of an industrial burner that mixes air and fuel near the burner to form a high-temperature flame. Oh, N
This is an area where generation of Ox is a problem. Zone III (new combustion zone) is a zone where the combustion air is diluted with an inert gas to reduce the oxygen concentration, and the combustion is performed while maintaining the temperature of the dilution air at a high temperature of 800 to 900 ° C or higher. And a region where low NOx combustion is possible. Therefore, high-temperature dilution air is obtained using a regenerative burner to
If a combustion system that performs combustion in I can be realized industrially, both energy saving and low NOx combustion can be achieved.
In addition, the current problems, such as surface defects after rolling and deterioration of the surface properties of the final product, are suppressed and controlled in the form of oxide films on the object to be heated, for example, oxidation that occurs in steel bodies such as slabs and billets. It is possible to suppress formation of a layer or control the composition of an oxide film.

According to the present invention, for example, in a state where the furnace atmosphere temperature of the regenerative burner furnace is maintained at 900 ° C. or higher, the regenerator of the regenerative burner and the regenerator of the combustion exhaust gas of the regenerative burner. Air is supplied to the regenerative burner and non-oxidized is supplied to the regenerative port so that the concentration of oxygen supplied to the furnace in the next cycle is adjusted to 5 to 20% by the flue gas passing through the regenerator of the port. An inert gas (eg, nitrogen, carbon dioxide, NH gas, etc.) is supplied. In the regenerative burner, air heated to 800 ° C. or higher and fuel are mixed and burnt, and in the vicinity of the burner, the air supplied from the regenerative port is supplied.
The presence of a non-oxidizing gas at a high temperature of 0 ° C. or higher enables low oxygen in the furnace, suppression of oxide film formation on an object to be heated, and control of the oxide film. Thereby, heat can be recovered with high efficiency by the regenerative burner, and the oxygen concentration can be adjusted by mixing with the non-oxidizing gas to realize combustion in the region III in FIG. When the atmosphere temperature in the furnace is 900 ° C. or higher, if the oxygen concentration of the combustion air is 5% or higher, combustion in the region III can be stably performed even locally. Therefore, the lower limit of the oxygen concentration is set to 5%. Further, when the oxygen concentration of the combustion air exceeds 20%, the generation amount of NOx approaches the regulation value. Therefore, the upper limit of the oxygen concentration is set to 20%.

Further, even when a regenerative burner is used as a regenerative port, the same combustion can be performed. When the furnace atmosphere temperature is 1100 ° C. or higher, combustion can be performed in the region III of FIG. 4 if the oxygen concentration in the combustion air is 3% or higher. When the oxygen concentration in the combustion air exceeds 15%, the amount of generated NOx approaches the regulation value. Therefore, when the furnace atmosphere temperature is 1100 ° C. or higher, the range of the oxygen concentration is set to 3 to 15%.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an outline of a regenerative burner furnace of the present invention. In FIG. 1, FIG.
The same components as those described above are denoted by the same reference numerals, and description thereof is omitted.
The regenerative burner furnace 1 shown in FIG. 1 is an example in which two regenerative burners 2 and two non-combustion regenerative ports 15 are installed. (A) and (U) show the regenerative burner 2, and (I) and (E) show the regenerative port 15. The number of the heat storage burners 2 and the heat storage ports 15 to be installed is not particularly limited. Although not shown here, a normal combustion type burner may be provided. The regenerative burner 2 is obtained by adding a non-oxidizing gas pipe 17 for supplying a non-oxidizing gas (for example, nitrogen gas) to a burner having the same structure as the conventional one. The non-oxidizing gas pipe 17 is provided with a non-oxidizing gas flow control valve 18. The non-oxidizing gas passes through the heat storage body 3 of the regenerative burner 2 and is supplied into the furnace. Further, a thermometer 19 for checking the temperature inside the furnace is installed on the high temperature side of the heat storage body 3.

The regenerative port 15 is configured as a port having a regenerator 16 similar to the regenerator 3 of the regenerative burner 2 and therefore does not perform combustion. Like the regenerative burner 2, the regenerative port 15 is provided with an exhaust gas pipe 9 for passing combustion exhaust gas in the furnace through the regenerator 16 and releasing it to the atmosphere, and a regenerator 16 for storing non-oxidizing gas. A non-oxidizing gas pipe 17 for passing the gas through the furnace is connected to the furnace. The non-oxidizing gas pipe 17 has a flow control valve 18,
An exhaust gas emission valve 20 is attached to the exhaust gas pipe 9.

The combustion in the regenerative burner furnace 1 will be described. For example, when the regenerative burners (A) and (U) are in an alternating combustion state, the regenerative burner (A)
(3) The fuel control valve 5 is opened to supply fuel. Further, the combustion air regulating valves 8 of the regenerative burners (A) and (U) are opened, the combustion exhaust gas valve 11 is closed, and air is pushed into the regenerator 3. The air that has passed through the heat storage body 3 deprives the heat storage body 3 of heat, becomes high-temperature preheated air, and is supplied to the inside of the furnace.
Combustes with fuel. On the other hand, at this time, in the regenerative storage port (i), the exhaust gas emission valve 20 is open, and the non-oxidizing gas flow control valve 18 is closed, and the combustion exhaust gas is sucked from the heat storage port (i) by an exhaust fan (not shown). The exhaust gas that has passed through the heat storage body 16 gives heat to the heat storage body 16 and then flows through the exhaust gas pipe 9 to the flue 12 and is released to the atmosphere. Further, at the regenerative port (e), the non-oxidizing gas flow control valve 18 is opened and the exhaust gas emission valve 20 is closed. In this embodiment, the nitrogen gas removes heat from the heat storage body 16 to become high-temperature nitrogen gas. Flow into the furnace. Thereby, the oxygen concentration of the combustion air can be adjusted, and combustion at a low oxygen concentration becomes possible. Further, a high-temperature non-oxidizing gas can be similarly supplied from another regenerative burner into the furnace. If there is excess flue gas, the flue 12
It is also exhausted from. At this time, in the regenerative burner provided with the honeycomb regenerator of the present embodiment, for example, when the gas temperature in the furnace is 1300 ° C., the combustion air supplied to the regenerator 3 of the burners (A) and (U) is If the temperature is about 30 ° C,
It is heated by the heat storage body 3 and becomes preheated air of about 1250 ° C.
Most of the flue gas passes through the heat storage body 3 of the burner (A) and (U) and the heat storage body 16 of the heat storage type port (I) and (E) at a temperature of about 1300 ° C. and heats it. Evacuated at about 200 ° C.

The oxygen concentration of the combustion air is adjusted by the ratio of the amount of air supplied to the regenerative burner 2 to the amount of non-oxidizing gas supplied to the regenerative port 15 and / or the regenerative burner 2. Further, in the present embodiment, a thermometer 19 is installed on the high temperature side of the heat storage body 3 to monitor the furnace atmosphere temperature, and the oxygen concentration is determined according to the furnace atmosphere temperature measured by the thermometer 19. The ratio of the supplied air amount and the non-oxidizing gas supply amount is changed so as to achieve the target oxygen concentration.

Tests were carried out under many furnace conditions. When the furnace temperature (furnace ambient temperature) was 900 ° C. or more and less than 1100 ° C., stable combustion of a regenerative burner was possible at an average supply gas oxygen concentration of 5% or more. When the oxygen concentration is increased, stable combustion can be maintained, but the amount of NOx generated tends to increase, and it has been confirmed that the regulation value approaches the regulation value when the average oxygen concentration exceeds 20%. Therefore, the furnace temperature is 900 ° C or higher and 1100 ° C
If it is less than 5, the operation is to be adjusted so that the average oxygen concentration is 5 to 20%. When the furnace temperature is 1100 ° C. or more, the regenerative burner can perform stable combustion at an average oxygen concentration of 3% or more. When the oxygen concentration is increased, stable combustion can be maintained, but the amount of NOx generated tends to increase. When the average oxygen concentration exceeds 15%, it approaches the regulation value. Therefore, when the furnace temperature is 1100 ° C. or more, the average oxygen concentration is 3 to 15
% To operate.

FIG. 2 shows another embodiment of the present invention, in which a regenerative burner is used as a regenerative port. That is, the non-oxidizing gas pipe 17 similar to the above embodiment is connected to the regenerative burner 2. Here, similarly, (A) and (U) can be used as the regenerative burner 2 and (I) and (E) can be used as the regenerative port 15, but the uniform heating temperature of the material to be heated is increased, and In order to suppress generation, regenerative burners (A),
(U), the regenerative burner (I), (E), and the regenerative burner ports (A), (U) may be alternately operated. That is, during a predetermined period, the regenerative burners (A) and (U) are alternately burned,
At this time, the heat storage type ports (i) and (e) are alternately operated to supply the non-oxidizing gas and exhaust the combustion exhaust gas. During the next predetermined period, the heat storage type burners (i) and (e) are turned on. At this time, the heat storage ports (A) and (U) are alternately operated to supply the non-oxidizing gas and exhaust the combustion exhaust gas. By alternating between the combustion cycle for supplying combustion air and the non-combustion cycle for supplying non-oxidizing gas between a plurality of sets of regenerative burners,
The temperature distribution of the furnace temperature is made uniform, the furnace temperature can be increased under stable combustion with a low oxygen concentration, and the formation of an oxide film on the material to be heated can be suppressed. Of course, generation of NOx can also be suppressed.

If the heating capacity is insufficient, for example, three of the four units may be used as regenerative burners, one may be used as a heat storage port, or all four units may be used as regenerative burners. It is possible. In this embodiment, although only four units are shown, for example, in the case of a regenerative burner furnace composed of 20 units or 30 units, the ratio of the number of regenerative burners to the number of heat storage ports Needless to say, the operation can be freely changed, so that the operation can be freely performed according to the heating pattern and the heating time.

In the above embodiment, nitrogen gas is used as the non-oxidizing gas. However, an inert gas such as argon gas or a reducing gas such as NH gas does not cause any problem. However, it is necessary to consider the calorific value of NH gas, and non-oxidizing gas such as carbon dioxide, which contains carbon, is not always preferable due to generation of oxygen due to dissociation. If you can use it. Preferably, an inert gas can be used without any problem.

Further, in each of the above embodiments, the non-oxidizing gas pipe is connected to the regenerative burner. However, a regenerative burner similar to the conventional one without the non-oxidizing gas pipe can be used. In the present invention, various modes can be considered for the combination and number of regenerative burners and regenerative ports (including non-combustion regenerative ports and regenerative burners) in which a heating furnace is installed. For example, two or more regenerative burners in FIG. 3 + regenerative port 1 in FIG.
At least two regenerative burners of FIG. 3 + regenerative burners 1 of FIG.
At least 2 regenerative burners in Fig. 1 + normal combustion type burner 1
At least one regenerative burner in Fig. 1 + regenerative port 1 in Fig. 1
More than one + one or more normal combustion type burners, and the like, and the present invention can be suitably implemented in a combination of these.

[0037]

As described above, according to the present invention, the oxygen concentration in the furnace can be freely adjusted, and combustion can be performed at a low oxygen concentration. And an oxide film can be controlled. On the other hand, the heating performance is not inferior to the conventional method, and the generation amount of nitrogen oxide can be suppressed. Furthermore, since the configuration can be easily made using a conventional regenerative burner, the equipment configuration can be simplified and the equipment cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a regenerative burner furnace of the present invention.

FIG. 2 is a schematic diagram showing another embodiment of the present invention.

FIG. 3 is a schematic diagram of a conventional regenerative burner furnace.

FIG. 4 is a diagram showing a combustible range of natural gas using variables of the temperature of the dilution air and the oxygen concentration in the dilution air as variables.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 regenerative burner furnace 2 regenerative burner 3 regenerator 4 fuel pipe 5 fuel control valve 6 air pipe 7 air supply fan 8 combustion air control valve 9 exhaust gas pipe 10 exhaust fan 11 combustion exhaust valve 12 flue 15 regenerative port 16 heat storage Body 17 Non-oxidizing gas pipe 18 Non-oxidizing gas flow control valve 19 Thermometer 20 Exhaust gas emission valve

Continuing from the front page (72) Yoshimichi Hino, Inventor 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd. (72) Tatsuya Shimada 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Stock Company F term (reference) 3K023 QC04 SA00 3K065 TA01 TB15 TC00 TD05 TM01

Claims (11)

[Claims] 1. A regenerative burner and a non-combustion regenerative port having a regenerator that does not burn but can store the heat of the combustion exhaust gas are installed in a heating furnace, and during the combustion of the regenerative burner, A method for operating a regenerative burner furnace, wherein the oxygen concentration of the supplied gas is adjusted by supplying a high-temperature non-oxidizing gas into the furnace through a regenerator of the regenerative port. 2. A plurality of regenerative burners are installed in a heating furnace,
By using at least one of them as a regenerative port and supplying a high-temperature non-oxidizing gas into the furnace through the regenerator of the regenerative port during combustion of the regenerative burner, the oxygen concentration of the supply gas is reduced. A method for operating a regenerative burner furnace, characterized by adjusting. 3. A plurality of regenerative burners are installed in a heating furnace,
During the combustion of the regenerative burner, a high-temperature non-oxidizing gas is supplied into the furnace through a regenerator of another regenerative burner, thereby adjusting the oxygen concentration of the supplied gas. Operation method. 4. When the atmosphere temperature in the furnace is maintained at 900 ° C. or higher, combustion air is supplied from the regenerative burner at a temperature of 800 ° C. or higher into the furnace. The regenerative burner according to any one of claims 1 to 3, wherein the supply gas average oxygen concentration is adjusted to 5% to 20% by supplying a non-oxidizing gas to the regenerative burner. How to operate the furnace. 5. When the atmosphere temperature in the furnace is maintained at 1100 ° C. or higher, combustion air is supplied from the regenerative burner to the furnace at a temperature of 800 ° C. or higher, wherein the regenerative port or another By supplying the non-oxidizing gas to the regenerative burner, the average oxygen concentration of the supplied gas can be increased from 3% to 15%.
2. The method according to claim 1, wherein the adjustment is performed such that
4. The method for operating a regenerative burner furnace according to any one of claims 1 to 3. 6. The operation of a regenerative burner furnace according to claim 1, wherein suction and discharge of combustion exhaust gas and supply of non-oxidizing gas are alternately performed at one of the non-combustion type regenerative ports. Method. 7. The regenerative burner furnace according to claim 1, wherein suction and discharge of combustion exhaust gas and supply of a non-oxidizing gas are alternated between the same set of the non-combustion type regenerative ports. Operating method. 8. The method according to claim 2, wherein a combustion cycle for supplying combustion air and a non-combustion cycle for supplying non-oxidizing gas are alternated between the same set of regenerative burners. The method for operating a regenerative burner furnace described in Crab. 9. The method according to claim 2, wherein a combustion cycle for supplying combustion air and a non-combustion cycle for supplying non-oxidizing gas are alternated between different sets of the regenerative burners. The method for operating a regenerative burner furnace described in Crab. 10. A regenerative burner, a non-combustion type regenerative port having a regenerator, exhaust means for discharging combustion exhaust gas in a furnace through a regenerator of the regenerative port, and a regenerator of the regenerative port And a non-oxidizing gas supply means for supplying a non-oxidizing gas into the furnace through the furnace. 11. A plurality of regenerative burners, a non-oxidizing gas supply means provided on a part or all of the plurality of regenerative burners and supplying a non-oxidizing gas into a furnace through a heat storage body. A regenerative burner furnace comprising: