JP2004020090A - Regeneration burner for connecting passage for filling filling fluid to exhaust passage and its operation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a regeneration burner for connecting a passage for filling a filling fluid to an exhaust passage and for preventing the occurrence of a hindrance to operation of the regeneration burner due to corrosion of a directional control valve for exhaust air installed in a pipe of the exhaust passage, and also to provide its operation method. <P>SOLUTION: This regeneration burner is provided with: burners 2 arranged in a plurality toward the inside of a furnace for generating exhaust gas including an SO<SB>2</SB>component, supplying fuel gas from a fuel supply passage 6 at combustion operation time, supplying combustion air from an air supply passage 3 and exhausting the exhaust gas to the exhaust passage at suction operation time; and a directional control valve 16 for fuel, a directional control valve 14 for air supply and the directional control valve 15 for exhaust air, associatively arranged to the respective burners in the air supply passage and the exhaust passage and opened-closed for switching combustion operation and suction operation of the burners. While putting a part in an operation state among a plurality of burners, a residual burner is connected with a fluid filling passage 22 for filling the fluid in the exhaust passage between the respective burners and the directional control valve for exhaust air when put in a stopping state, by closing all of the directional control valve for fuel, the directional control valve for air supply, and the directional control valve for exhaust air. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a regenerative burner in which a path for charging a filling fluid is connected to an exhaust path, which can prevent the operation of the regenerative burner from being hindered due to corrosion of an exhaust switching valve attached to a pipe of the exhaust path. And its operation method.
[0002]
[Prior art]
As is well known, a regenerative burner is provided with a plurality of sets of a pair of burners arranged facing each other toward the inside of the furnace, each of these burners is provided with a regenerator, and a pair of burners is provided. At the same time, fuel gas and combustion air are supplied to one side to perform combustion, and at the same time, exhaust gas is sucked from the other burner, and this combustion operation and suction operation are alternately performed by each pair of burners. The exhaust heat is recovered from the exhaust gas by the regenerator during the suction operation, and the combustion air is heated by the exhaust heat recovered by the regenerator during the combustion operation, thereby saving energy.
[0003]
A system for supplying and discharging combustion air and exhaust gas to the burner b in the conventional regenerative burner a will be described according to the operating state of the burner b with reference to FIG. 2. It is supplied to burner b. When the air supply solenoid valve e provided on the upstream side of the branch portion d of the air supply path c connected to another burner is opened, the combustion air is supplied while the air volume is controlled by the air supply volume control vane f. The gas is introduced into the air supply path c by the blower g, and further, by opening the air supply switching valve h of each burner b provided on the downstream side of the branch portion d, the gas passes through the regenerator i and is heated to the burner b. Supplied. The fuel gas is introduced by opening the fuel solenoid valve l provided on the upstream side of the branch k of the fuel supply path j connected to another burner, and furthermore, each burner b provided downstream of the branch k. Is opened, the fuel is supplied to the burner nozzle n of the burner b. As the fuel gas, a coke oven gas (hereinafter, referred to as COG), a gas obtained by mixing COG with a blast furnace gas or a converter gas (hereinafter, referred to as M gas), or the like is used. During this combustion operation, the exhaust path o is closed by the exhaust switching valve p of each burner b.
[0004]
On the other hand, during the suction operation, the exhaust gas is discharged from the furnace. The exhaust gas passes through the exhaust switching valve p of each burner provided on the upstream side of the branch q while the exhaust electromagnetic valve r on the downstream side of the branch q of the exhaust path o connected to another burner is opened. By being opened, the exhaust air is controlled by the exhaust air flow control vanes s while being exhausted and recovered through the regenerator i, and is sucked from the furnace by the exhaust blower t. During this suction operation, the air supply path c and the fuel supply path j are closed by the switching valves h and m. Further, a cooling medium supply system u and a cooling medium discharge system v are connected to the burner b in order to allow a cooling medium such as water or air to flow through the burner nozzle n for cooling.
[0005]
A typical control method of the regenerative burner a that controls a plurality of sets of burners b is “proportional control” in which all burners b are proportionally turned down (increase or decrease the thermal power) until the load is about 100% to 30%. For the turndown with a load less than that, execute “time proportional ON-OFF control” for all burners b to start and stop them at appropriate intervals. When the temperature decreases, a method of executing “thinning control” in which some of the burners b are stopped is performed. In the burner b in the stopped state subjected to the thinning control, not only the combustion operation but also the suction operation is stopped, and the switching valves m, h, and p for controlling the burner b are all closed.
[0006]
[Problems to be solved by the invention]
Incidentally, in the exhaust gas after burning a fuel gas such as a COG or M gas described above, it includes SO _2. When the temperature of the exhaust gas falls below the acid dew point (generally 130 ° C. to 140 ° C. for desulfurized COG combustion exhaust gas), the SO ₂ condenses and reacts with water (H ₂ O) to produce sulfuric acid (H ₂ SO ₄ ). Is generated. Conventionally, the sulfuric acid causes corrosion in the exhaust switching valve p attached to the pipe of the exhaust path o, and the corrosion of the exhaust switching valve p hinders the operation of the regenerative burner a. There was a problem that there was a possibility of causing.
[0007]
For example, if the closing performance of the exhaust switching valve p is deteriorated due to corrosion, and if the exhaust path o of the burner b to be thinned out is not properly shut off during thinning control or the like and a leak occurs, the exhaust blower The low temperature side of the regenerator i of the burner b is liable to be in a negative pressure state due to the suction effect of t, whereby the exhaust gas in the furnace continues to flow from the burner b to the exhaust path o, and the pipe temperature including the area around the regenerator i Excessively rises, and as a result, the overheat of the low temperature side of the regenerator i for which the upper limit temperature limit is set by the limiter is caused, and the limiter is activated as soon as the burner b is released from the thinning control target and the combustion operation is started. It is assumed that the operation of the regenerating burner a cannot be continued.
[0008]
The present invention has been made in view of the above-mentioned conventional problems, and it is possible to prevent an exhaust gas from being hindered from operating due to corrosion of an exhaust switching valve attached to a pipe of an exhaust path. An object of the present invention is to provide a regenerative burner in which a path for filling a filling fluid is connected to the path, and an operation method thereof.
[0009]
[Means for Solving the Problems]
A plurality of regenerative burners, each having an exhaust path according to the present invention connected to a path for filling a filling fluid, are installed toward a furnace in which exhaust gas containing SO ₂ components is generated, and a fuel gas is supplied from a fuel supply path during a combustion operation. The burner is supplied with combustion air from an air supply path and discharges exhaust gas to an exhaust path during a suction operation, and the fuel supply path, the air supply path, and the exhaust path are respectively provided corresponding to each burner, A fuel switching valve, an air supply switching valve, and an exhaust switching valve that are opened / closed to switch between a combustion operation and a suction operation of the burner. In a regenerative burner in which all of the fuel switching valve, the air supply switching valve, and the exhaust switching valve are closed and stopped, the exhaust gas between each burner and the exhaust switching valve is closed. A fluid filling path for filling a fluid is connected to the air path. As a result, it is possible to prevent the operation of the regenerating burner from being hindered due to corrosion of the exhaust gas switching valve attached to the exhaust path piping.
[0010]
Further, the fluid filling path is provided with flow rate adjusting means for adjusting a flow rate of the filling fluid. This makes it possible to introduce a required amount of the filling fluid into the exhaust path.
[0011]
Further, the fluid filling path is connected to the supply path upstream of each supply switching valve, and combustion air in the supply path is introduced as a filling fluid. Thereby, equipment can be provided at low cost.
[0012]
In addition, the method for operating a regenerative burner according to the present invention is provided such that a plurality of regenerative burners are installed toward a furnace in which exhaust gas containing SO ₂ components is generated, and during combustion operation, fuel gas is supplied from a fuel supply path and combustion is performed from an air supply path. And a burner that supplies exhaust air and discharges exhaust gas to an exhaust path during a suction operation, and is provided in correspondence with each burner in the fuel supply path, the air supply path, and the exhaust path. A switching valve for fuel, a switching valve for air supply, and a switching valve for exhaust, which are opened and closed to switch between the burner and the fuel supply switching valve. In the regenerative burner operating method in which all of the air switching valve and the exhaust switching valve are closed and the operation is stopped, the burner stopped when the burner was stopped. A fluid is filled into the exhaust path between the exhaust gas and the exhaust switching valve. As a result, it is possible to prevent the operation of the regenerating burner from being hindered due to corrosion of the exhaust gas switching valve attached to the exhaust path piping.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of a regenerative burner in which a path for charging a filling fluid is connected to an exhaust path according to the present invention and a method for operating the regenerative burner will be described in detail with reference to the accompanying drawings. FIG. 1 shows a preferred embodiment of a regenerative burner 1 according to the present invention. The basic configuration of a supply / discharge system for combustion air, fuel gas, and exhaust gas in the regenerative burner 1 of the present embodiment is almost the same as the conventional technology shown in FIG. The regenerative burner 1 includes a plurality of pairs of burners 2 (one burner 2 is shown in FIG. 1), which are arranged in a furnace so as to face each other.
[0014]
The plurality of burners 2 are connected to an air supply path 3 for collectively supplying combustion air thereto and an exhaust path 4 for collectively discharging exhaust gas in the furnace therefrom. The supply path 3 and the exhaust path 4 are provided with branch portions 3a and 4a for connecting them to the respective burners 2. Further, a fuel supply path 6 for collectively supplying a fuel gas such as COG or M gas to a burner nozzle 5 provided in each of the plural sets of the plurality of burners 2 is connected. Also, a branch 6a for connecting this to each burner is provided.
[0015]
The air supply path 3 has a solenoid valve 7 for opening and closing the air supply path 3 that opens and closes the air supply path 3 upstream of the branch portion 3 a in the flow direction of the combustion air, and a supply air supply that controls the air volume of the combustion air. An air volume control vane 8 and an air supply blower 9 for feeding combustion air to each burner 2 via the air supply path 3 are provided. Similarly, the exhaust passage 4 has an exhaust solenoid valve 10 that can be opened and closed to open and close the exhaust passage 4, and an exhaust air volume control vane 11 that controls the air volume of the exhaust gas, on the downstream side of the branch portion 4 a in the exhaust gas flow direction. And an exhaust blower 12 for sucking exhaust gas from the furnace through the exhaust path 4. The fuel supply path 6 is provided with an openable and closable fuel solenoid valve 13 for opening and closing the fuel supply path 6 on the upstream side of the branch portion 6a in the fuel gas flow direction.
[0016]
Further, the air supply path 3 is provided with an air supply switching valve 14 that can be opened and closed to switch between supply and stop of the combustion air to each of the burners 2 downstream of the branch portion 3a. Further, the exhaust path 4 is provided with an openable and closable exhaust switching valve 15 for switching between discharge and stop of exhaust gas from each burner 2 on the upstream side of the branching portion 4a. Further, the fuel supply path 6 is provided with a fuel switching valve 16 that can be opened and closed to switch between supply and stop of fuel gas to each of the burner nozzles 5 downstream of the branch portion 6a. The air supply path 3 and the exhaust path 4 are gathered before the connection position with each burner 2 and are connected to the burner 2 collectively.
[0017]
Each burner 2 is disposed between a burner nozzle 5 and an air supply path 3 and an exhaust path 4 which are gathered, and recovers exhaust heat from exhaust gas passing therethrough and discharged from the furnace to the exhaust path 4. Further, a regenerator 17 is provided for heating the combustion air supplied from the air supply path 3 to the burner 2 through the air supply path 3 with the recovered exhaust heat. Further, a cooling medium supply system 18 and a cooling medium discharge system 19 are connected to each burner 2 in order to allow a cooling medium such as water or air to flow through the burner nozzles 5 for cooling.
[0018]
In addition, the regenerative burner 1 in which the path for filling the filling fluid is connected to the exhaust path according to the present embodiment basically transmits the fluid to the exhaust path 4 between each burner 2 and the exhaust switching valve 15. A fluid filling path 22 for filling is connected. The fluid filling path 22 is provided with a filling fluid amount adjusting cock 23 and a throttle as flow rate adjusting means for adjusting the flow rate of the filling fluid, and more preferably, the fluid filling path 22 is provided with a switching valve for each air supply. 14 is connected to the supply path 3 on the upstream side, and combustion air in the supply path 3 is introduced as a filling fluid.
[0019]
More specifically, according to the illustrated example, one end of the fluid charging path 22 is provided in the exhaust path 4 on the upstream side in the exhaust gas flow direction from the exhaust switching valve 15 of each burner 2 and on the low temperature side of the regenerator 17. The other end of the fluid filling path 22 is connected to the fluid introduction path 20 at a position upstream of the introduction fluid amount adjusting cock 21 of the same burner 2 in the flow direction of the combustion air. Thus, the combustion air being pumped by the air supply blower 9 is filled between the exhaust switching valve 15 and the regenerator 17. Further, the filling fluid amount adjusting cock 23 is configured to be capable of adjusting the opening degree in order to adjust the filling flow rate of the combustion air from the air supply passage 3 to the exhaust passage 4. As a result, a required amount of combustion air can be introduced into the exhaust path 4.
[0020]
In the present embodiment, a fluid introduction path 20 for introducing a fluid for dilution is connected to the exhaust path 4 on the downstream side of the exhaust switching valve 15 of each burner 2. In addition, the fluid introduction path 20 is provided with an introduction fluid amount adjusting cock 21 and a throttle as flow rate adjusting means for adjusting the flow rate of the dilution fluid. More preferably, the fluid introduction path 20 is provided with a switching valve for each air supply. 14 is connected to the air supply path 3 on the upstream side, and the combustion air in the air supply path 3 is introduced as a dilution fluid.
[0021]
Specifically, one end of the fluid introduction path 20 is connected to the exhaust path 4 at a position downstream of the exhaust switching valve 15 of each burner 2 in the exhaust gas flow direction and at an upstream position of the branch portion 4a. The other end of the fluid introduction path 20 is connected to the air supply path 3 at a position upstream of the air supply switching valve 14 of the same burner 2 in the flow direction of the combustion air and at a downstream position of the branch portion 3a. Thus, the combustion air being pressure-fed by the air supply blower 9 is introduced into the exhaust path 4 downstream of the exhaust switching valve 15. Further, the introduction fluid amount adjusting cock 21 is configured to be capable of adjusting the opening degree in order to adjust the introduction flow rate of the combustion air from the air supply passage 3 to the exhaust passage 4. As a result, a required amount of combustion air can be introduced into the exhaust path 4.
[0022]
Further, in the present embodiment, an introduction path 24 for introducing an inert gas is connected to the fuel supply path 6 between each burner 2 and its fuel switching valve 16. In the introduction path 24, an inert gas switching valve 25 is provided as switching means for switching the introduction / stop of the inert gas into the fuel supply path 6. A detection means 26 for detecting that all of the fuel switching valve 16, the air supply switching valve 14, and the exhaust switching valve 15 are closed and outputting a detection signal is connected to the inert gas switching valve 25. The inert gas switching valve 25 is configured to introduce an inert gas into the fuel supply path 6 when a detection signal is input from the detection means 26. In addition, the introduction path 24 is provided with an inert gas introduction amount adjusting cock 27 and a throttle as flow rate adjusting means for adjusting the flow rate of the inert gas.
[0023]
Specifically, one end of the introduction path 24 is connected to the fuel supply path 6 on the downstream side in the fuel gas flow direction from the fuel switching valve 16 of each burner 2 and on the upstream side of the burner nozzle 5. An inert gas such as N ₂ gas is introduced between the fuel switching valve 16 and the burner nozzle 5 from an unillustrated inert gas supply source connected to the other end of the introduction path 24. . The detection means 26 is operated under normal sequence control or computer control, monitors the open / close state of the fuel switching valve 16, the air supply switching valve 14, and the exhaust switching valve 15, and closes all of these switching valves 14 to 16. When it is detected, a detection signal is generated and output to the inert gas switching valve 25. Thereby, the supply control of the inert gas can be automated. The inert gas switching valve 25 is configured to be openable and closable to open and close the introduction path 24, and opens the introduction path 24 in response to the detection signal being input from the detection unit 26. Thus, the inert gas can be introduced into the fuel supply path 6 when necessary. The inert gas introduction amount adjusting cock 27 is configured to be capable of adjusting the opening degree in order to adjust the introduction flow rate of the inert gas from the inert gas supply source to the fuel supply path 6. Thereby, the required amount of the filling fluid can be introduced into the fuel supply path 6.
[0024]
Next, an operation method of the regenerative burner 1 according to the present embodiment will be described. The operating state of the regenerative burner 1 is switched according to the load state, as described in the related art. Normally, by setting all the burners 2 in a plurality of operating states and controlling the opening and closing of the fuel switching valve 16, the air supply switching valve 14, and the exhaust switching valve 15, the fuel gas and the combustion gas are supplied to one of the pair of burners 2. At the same time as supplying air for combustion and performing a burning operation, a suction operation for sucking exhaust gas in the furnace is performed from the other burner 2, and the combustion operation and the suction operation are alternately performed by a pair of the burners 2 in each set. It is designed to be performed alternatively.
[0025]
That is, when the regenerative burner 1 is operated, all the solenoid valves 7, 10, 13 are opened and the air supply blower 9 and the exhaust blower 12 are driven to supply the fuel gas from the fuel supply path 6 to the burner 2 and to reduce the air volume. While controlling the air volume by the control vane 8, the combustion air is supplied from the air supply path 3 to the burner 2, and the exhaust gas is discharged from the exhaust path 4. At this time, of the plurality of burners 2, the burner 2 that performs combustion operation opens the fuel switching valve 16 and the air supply switching valve 14, closes the exhaust switching valve 15, and performs the suction operation. Control to open the exhaust switching valve 15 and close the fuel switching valve 16 and the air supply switching valve 14 is performed, and the regenerator 17 determines whether the burner 2 is performing the suction operation or the combustion operation. To recover the exhaust heat from the exhaust gas or heat the combustion air.
[0026]
On the other hand, when the load is reduced, all the burners 2 are not brought into the operating state, and some of the burners 2 are put into a stop state in which neither the combustion operation nor the suction operation is performed, for example, thinning control is performed. You. In the burner 2 in the stopped state, all the switching valves 14 to 16 for controlling the burner 2 are closed, so that neither the fuel gas nor the combustion air is supplied, and the discharge of the exhaust gas is stopped. As described above, while a part of the plurality of burners 2 is in the operating state, the remaining one is closed by closing all of the fuel switching valve 16, the air supply switching valve 14, and the exhaust switching valve 15. When the burner 1 is operated, in the present embodiment, the combustion air in the air supply path 3 is supplied as a filling fluid from the fluid filling path 22 to the exhaust path 4 between the stopped burner 2 and the exhaust switching valve 15. It is supposed to be introduced.
[0027]
Specifically, when the filling fluid amount adjusting cock 23 is opened, the combustion air from the air supply blower 9 that is forcing the combustion air toward the burner 2 in the operating state according to the opening amount. Introducing from the air supply path 3 upstream of the closed air supply switching valve 14 to the exhaust passage 4 between the closed exhaust gas switching valve 15 and the burner 2 via the fluid filling path 22. Can be. As a result, the pressure in the exhaust passage 4 between the regenerator 17 and the exhaust switching valve 15 can be increased, and even if the closing performance of the exhaust switching valve 15 is deteriorated due to corrosion, a leak may occur. Even so, it is possible to prevent the exhaust path 4 from becoming negative pressure due to this leak, thereby suppressing the flow of exhaust gas into the exhaust path 4 and suppressing the overheating on the low temperature side of the regenerator 17 due to this. Continuous operation of the regenerating burner 1 can be guaranteed. The filled combustion air can also dilute the concentration of the exhaust gas, lower the acid dew point of the exhaust gas, and prevent the exhaust switching valve 15 from being corroded.
[0028]
Normally, the filling fluid amount adjusting cock 23 is closed, and if overheating frequently occurs on the low-temperature side of the heat storage unit 17, it may be gradually opened and filled with combustion air. The filling amount of the combustion air may be set to a necessary minimum amount such that the pressure in the exhaust passage 4 does not become negative even if there is a leak. The filling fluid amount adjusting cock 23 may be set so as to be automatically opened at an appropriate opening in response to the detection signal from the detecting means 26 being input.
[0029]
Further, in this embodiment, a fluid introduction path 20 is provided, and the supply path 3 is used as a dilution fluid from the fluid introduction path 20 to the exhaust path 4 on the downstream side of the exhaust switching valve 15 of the burner 2 that has stopped. The air for combustion is introduced. Specifically, when the introduction fluid amount adjusting cock 21 is opened, the combustion air from the air supply blower 9 that is forcing the combustion air toward the burner 2 in the operating state according to the opening amount. The fluid can be introduced from the supply path 3 upstream of the closed supply switching valve 14 to the exhaust passage 4 downstream of the closed exhaust switching valve 15 via the fluid introduction path 20.
[0030]
Conventionally, there has been a problem that corrosion due to sulfuric acid occurs in the piping of the exhaust path 4. There are several causes for the occurrence of the corrosion, for example, the corrosion may be caused in connection with the operation control of the regenerative burner 1. More specifically, in the high-load operation state of the regenerative burner 1, the temperature of the exhaust gas immediately after leaving the regenerator 17 by the suction operation is usually set to about 200 ° C., and is sufficiently high without causing corrosion. The temperature has been set. However, when the load becomes low, the temperature of the exhaust gas decreases, and sometimes drops below the acid dew point while flowing through the exhaust path 4. In particular, when the regenerative burner 1 is shifted to the thinning control due to a decrease in the load, the exhaust switching valve 15 is closed and the suction operation is stopped in the exhaust path 4 of the burner 2 in the stopped state, which is the target of the thinning control. Then, the flow of the exhaust gas is stopped. Due to the stop of the suction operation, the temperature of the exhaust gas that has accumulated on the downstream side of the exhaust switching valve 15 gradually decreases, and the longer the thinning time, the lower the temperature and the temperature becomes lower than the acid dew point. On the other hand, for example, due to the piping structure, the longer the piping length of the exhaust path 4 is, the more the exhaust gas temperature tends to decrease, and there is a possibility that the exhaust gas temperature may drop below the acid dew point. Regardless of any of these causes, sulfuric acid was generated when the temperature of the exhaust gas in the exhaust path 4 reached the acid dew point or lower, thereby causing corrosion in the piping.
[0031]
The acid dew point of the exhaust gas generated by burning COG or M gas can be lowered by diluting the concentration, and in the present embodiment, the exhaust gas due to the introduction of combustion air into the exhaust path 4 is exhausted. By diluting the exhaust gas concentration on the downstream side of the switching valve 15, the generation of sulfuric acid can be suppressed, and the piping of the exhaust path 4 can be prevented from being corroded. Therefore, corrosion of the exhaust switching valve 15 can also be prevented. In addition, by introducing combustion air downstream of the exhaust switching valve 15 via the fluid introduction path 20, the internal pressure of the exhaust path 4 around the exhaust switching valve 15 is increased to reduce leakage from the exhaust switching valve 15. It is possible to suppress overheating on the low temperature side of the heat storage device 17 from this aspect as well.
[0032]
The introduction amount of the combustion air may be set to a necessary minimum amount that can lower the acid dew point of the exhaust gas below the temperature in the pipe of the exhaust path 4. The cock 21 for adjusting the amount of introduced fluid may be set so as to be automatically opened at an appropriate opening in response to a detection signal from the detection means 26 being input.
[0033]
Regardless of which of the fluid introduction path 20 and the fluid filling path 22 is used, these are connected to the air supply path 3 to perform dilution and filling with combustion air. Therefore, it can be configured at low cost.
[0034]
Further, in the present embodiment, an introduction path 24 is provided, and an inert gas such as N ₂ gas is supplied from the introduction path 24 to the fuel supply path 6 between the stopped burner 2 and the fuel switching valve 16. It is supposed to be introduced. More specifically, when the switching valves 14 to 16 are closed by the detecting means 26 and the stop state of the burner 2 is detected, the inert gas switching valve 25 is automatically opened in response to this, whereby According to the opening degree of the cock 27 for adjusting the amount of the active gas introduced, the inert gas is supplied from the inert gas supply source via the introduction path 24 to the fuel supply between the closed fuel switching valve 16 and the burner 2. It is introduced into the passage 6.
[0035]
Conventionally, the exhaust gas may enter the fuel supply path 6 and cause corrosion of the piping of the fuel supply path 6 due to sulfuric acid. In some cases, intrusion of the exhaust gas causing the corrosion into the fuel supply path 6 is caused in connection with the operation control of the regenerative burner 1. For example, when the regenerative burner 1 is shifted to the thinning control due to a decrease in load, the fuel switching valve 16 of the burner 2 subjected to the thinning control is closed, and the closed fuel switching valve 16 and the burner 2 are closed. Exhaust gas in the furnace intrudes from the burner nozzle 5 exposed in the furnace and diffuses into the fuel supply path 6 between the furnace. Since the burner nozzle 5 is cooled as described above, the temperature of the exhaust gas diffused into the pipe portion between the burner nozzle 5 and the fuel switching valve 16 due to the cooling is reduced to the acid dew point or lower, and as a result, the burner nozzle 5 Corrosion is caused in the surrounding pipes, the fuel switching valve 16 and the like. If the fuel switching valve 16 is corroded, the closing performance of the fuel switching valve 16 is degraded, and the switching operation failure of the regenerating burner 1 is easily caused. The problem of corrosion of the fuel supply path 6 was particularly remarkable when the burner nozzle 5 had a large diameter. The caliber of the burner nozzle 5 is small when the calorific value is small, and a fuel requiring a large flow rate for combustion, such as the above-mentioned COG or M gas, or when the fuel flow rate for a steel heating furnace reaches 6 million kcal / h, etc. It is designed to be large. In such a large-diameter burner nozzle 5, exhaust gas easily enters and diffuses, and the possibility of the above-described problem is high.
[0036]
In the present embodiment, since the inert gas can be introduced into the fuel supply path 6 between the burner 2 and the fuel switching valve 16, the exhaust gas can be prevented from entering from the burner nozzle 5, and The concentration of the exhaust gas in the fuel supply path 6 can be diluted by the inert gas to lower the acid dew point, and the burner nozzle 5 and its surrounding piping, the fuel switching valve 16 and the like can be prevented from being corroded. . In addition, since the inert gas is introduced into the fuel supply path 6, safety can be ensured. The introduction amount or introduction speed of the inert gas is set so that the acid dew point of the exhaust gas can be set lower than the temperature in the pipe of the fuel supply path 6, or more than the intrusion speed of the exhaust gas from the burner nozzle 5. Good.
[0037]
In the above embodiment, the case where the fluid introduction path 20 and the fluid filling path 22 are connected to the air supply path 3 has been described as an example. However, the present invention is not limited to this, and the fluid used is also combustion air. It is needless to say that the present invention is not limited to this. For example, an independent path may be provided, and outside air may be introduced as a fluid. In addition, the inert gas introduction amount adjusting cock 27 can be switched between supply and stop of the inert gas by the inert gas switching valve 25. Therefore, the cock 27 is not an essential element and may be provided as necessary.
[0038]
Further, the cock 21 for adjusting the amount of the introduced fluid, the cock 23 for adjusting the amount of the filled fluid, and the switching valve 25 for the inert gas, which have been described in the above embodiment, are alternatively provided according to the conditions of the exhaust path 4 and the fuel supply path 6. It may be opened, or any two or even all of them may be opened at the same time. The opening / closing operation of the introduction fluid amount adjusting cock 21, the filling fluid amount adjusting cock 23, and the inert gas switching valve 25 is performed. The introduction and filling of the combustion air into the exhaust path 4 by the coordination and the adjustment of the inert gas introduction amount adjusting cock 27 and the introduction of the inert gas into the fuel supply path 6 corrode the pipes and cause the switching valves 14 to 16. Thus, it is possible to effectively prevent the performance of the regenerative burner 1 from being deteriorated, so that the proper operation of the regenerative burner 1 can be guaranteed.
[0039]
【The invention's effect】
In short, in the regenerative burner and the operation method thereof according to the present invention in which the path for filling the filling fluid is connected to the exhaust path, the regenerative burner is attached to the exhaust path piping due to corrosion. It is possible to prevent the operation of the burner from being hindered.
[Brief description of the drawings]
FIG. 1 is a system diagram showing a preferred embodiment of a regenerative burner in which a path for filling a filling fluid is connected to an exhaust path according to the present invention.
FIG. 2 is a system diagram showing a conventional regenerative burner.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Regenerative burner 2 Burner 3 Air supply path 4 Exhaust path 6 Fuel supply path 14 Air supply switching valve 15 Exhaust switching valve 16 Fuel switching valve 22 Fluid filling path 23 Filling fluid amount adjusting cock

Claims (4)

Towards a furnace exhaust gas is generated containing SO ₂ component is more established, during the combustion operation is supplied with combustion air from the air supply path together with the fuel gas is supplied from the fuel supply path, the exhaust gas during the suction operation to the exhaust passage And a fuel switching valve, which is provided in the fuel supply path, the air supply path, and the exhaust path in correspondence with each burner, and is opened / closed to switch the combustion operation and the suction operation of the burner. A switching valve for air and a switching valve for exhaust are provided, and some of the plurality of burners are in an operating state, while the rest closes all of the switching valve for fuel, the switching valve for air supply, and the switching valve for exhaust. In a regenerative burner which is brought into a stopped state, a fluid filling path for filling a fluid is connected to the exhaust path between each burner and its exhaust switching valve. A regenerative burner connected to a path for filling a filling fluid. The regenerative burner according to claim 1, wherein a flow rate adjusting means for adjusting a flow rate of the filling fluid is provided in the fluid filling path. The fluid filling path is connected to the supply path upstream of each supply switching valve, and combustion air in the supply path is introduced as a filling fluid. A regenerating burner in which a path for filling a filling fluid is connected to the exhaust path described in the above. Towards a furnace exhaust gas is generated containing SO ₂ component is more established, during the combustion operation is supplied with combustion air from the air supply path together with the fuel gas is supplied from the fuel supply path, the exhaust gas during the suction operation to the exhaust passage And a fuel switching valve, which is provided in the fuel supply path, the air supply path, and the exhaust path in correspondence with each burner, and is opened / closed to switch the combustion operation and the suction operation of the burner. A switching valve for air and a switching valve for exhaust are provided, and some of the plurality of burners are in an operating state, while the rest closes all of the switching valve for fuel, the switching valve for air supply, and the switching valve for exhaust. In a regenerative burner operating method in which the burner is brought into a stopped state, when the burner is brought into a stopped state, a fluid is filled in the exhaust path between the stopped burner and its exhaust switching valve. A method for operating a regenerative burner, characterized in that the regenerative burner is charged.

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