JP2018132222A - Fuel nozzle cooling structure for regenerative burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel nozzle cooling structure for a regenerative burner which is capable of reducing required installation cost and required installation space for cooling a fuel nozzle and also simplifies layout of piping or the like by utilizing an exhaust blower that performs exhaustion in an exhaust operation mode.SOLUTION: The present invention relates to a regenerative burner which alternately repeats an exhaust mode and a combustion mode. The regenerative burner comprises: a hollow cylindrical fuel nozzle which is provided inside of a burner body and injects a fuel that is mixed with combustion air to generate a flame, from its distal end; a cooling tube which is provided while enclosing an outer periphery of the fuel nozzle and includes a communication part for communicating to an exhaust system and an opening that is opened in atmospheric air; and a connection pipe which connects the communication part to the exhaust system. The fuel nozzle is cooled by atmospheric air that is circulated through the opening to the communication part by an exhaustion/suction operation of the exhaust system via the connection pipe.SELECTED DRAWING: Figure 1

Description

  By using an exhaust blower that performs exhaust in the exhaust operation mode, the present invention can reduce the equipment cost and installation space necessary for cooling the fuel nozzle, and the layout of piping and the like can also be reduced. The present invention relates to a fuel nozzle cooling structure of a simple regenerative burner.

  Various types of furnaces using regenerative burners (see Patent Document 1) are known, and structures for cooling the regenerative burner (see Patent Documents 2 and 3) are also known. Patent Document 1 “Industrial Furnace, Energy Saving Operation Method of Industrial Furnace, and Remodeling Method of Industrial Furnace” discloses that an exhaust pipe connecting a combustion chamber and a chimney is opened, and outside air (ATM) is placed in the exhaust pipe. An intake opening / closing valve to be taken in and an impeller connected to a suction blower functioning as a generator, which is taken in from the opened intake opening / closing valve and rotated by outside air flowing through the exhaust pipe to generate electric power. In Patent Document 1, two pairs of regenerative burners are configured such that their combustion operation and exhaust operation are switched alternately.

  The “low NOx burner for high-temperature air” disclosed in Patent Document 2 has a configuration in which a baffle is externally attached to the tip of a fuel nozzle that injects fuel and a slit-like secondary air supply hole is formed on the outer periphery of the baffle. The fuel nozzle is configured as a double pipe having an inner peripheral portion as a fuel passage and an outer peripheral portion as a cooling air passage, and the baffle is provided with an injection hole for fuel and cooling air at the center. Are provided with a plurality of primary air supply holes with an angle of 30 to 50 ° in a plane having the same pitch circle diameter from the inlet toward the outlet, and these ejection holes and primary air supply holes. An outlet of fuel, cooling air, and primary air is formed at the outlet of the nozzle. In the burner of Patent Document 2, air used for cooling the fuel nozzle is discharged into the furnace.

  Patent Document 3 “Cooling Device for Regenerative Burner Fuel Nozzle Pipe” uses a cooling air pipe that does not release the introduced air into the furnace but only cools the cooling air pipe, and cools it by reciprocating forward and marching. In order to effectively prevent overheating of the fuel nozzle pipe, a double pipe consisting of an inner pipe and an outer pipe is disposed on the outer periphery of the fuel nozzle pipe, and the end opening of the outer pipe and the fuel nozzle pipe is closed with a lid, A cooling air pipe is provided in which an outer passage between the outer pipe and the inner pipe and an inner passage between the inner pipe and the fuel nozzle pipe are communicated with each other via a lid. In Patent Document 3, the introduction air used for cooling is not discharged into the furnace, and in order to send the introduction air into the air cooling pipe, it is necessary to provide a blower.

JP-A-2006-133255 Japanese Patent Laid-Open No. 10-185128 JP 2001-182915 A

  The atmosphere in the furnace heated by the regenerative burner is preferably uniform without fluctuation. In this respect, the cooling structure of the fuel nozzle provided in the regenerative burner releases the introduced air into the furnace. It is preferable to use the double tube structure of Patent Document 3 that does not occur.

  However, Patent Document 3 does not disclose how to supply the introduction air to the air cooling pipe. In general, it can be considered that a blower is newly installed or added and the introduction air is supplied from the blower to the air supply pipe. When a blower is newly installed, there is a problem that it is necessary to secure an installation space at the same time as equipment costs for the piping and the like are generated.

  The present invention was devised in view of the above-described conventional problems, and by using an exhaust blower that performs exhaust in the exhaust operation mode, it is possible to reduce the facility cost and the necessary installation space necessary for cooling the fuel nozzle. An object of the present invention is to provide a fuel nozzle cooling structure for a regenerative burner that can be reduced and the layout of piping and the like is simple.

  The fuel nozzle cooling structure of the regenerative burner according to the present invention is an exhaust that stores exhaust heat by circulating the furnace exhaust sucked from the crater of the burner body through the exhaust suction action of the exhaust system having the exhaust blower to the heat storage section. A regenerative burner that alternately repeats a mode and a combustion mode in which a flame generated by combustion air that is circulated and heated in the heat storage section is ejected from the crater of the burner body into the furnace, A hollow cylindrical fuel nozzle that is provided inside the main body and injects fuel that is mixed with combustion air to generate a flame from its tip, and is provided so as to surround the outer periphery of the fuel nozzle. A cooling tube having a communication portion for communicating with the air and an opening that is open to the atmosphere; and a connecting pipe for connecting the communication portion to the exhaust system. In air suction, characterized in that so as to cool the fuel nozzle by the air flowing toward the communicating portion through the opening.

  In the fuel nozzle cooling structure for a regenerative burner according to the present invention, an exhaust valve for opening and closing an exhaust system having an exhaust blower is opened and an air supply valve for opening and closing an air supply system having an air supply blower is closed. And an exhaust mode in which the exhaust in the furnace sucked from the crater of the burner body by the exhaust suction action of the exhaust system is circulated through the heat storage unit to store the exhaust heat, and is discharged to the exhaust system through the exhaust valve; The exhaust valve is closed and the air supply valve is opened, and the combustion air supplied to the burner main body by the air supply action of the air supply system is circulated through the heat storage section and heated. A regenerative burner in which a flame generated by combustion air alternately repeats a combustion mode ejected from a crater of the burner body into the furnace, and is provided inside the burner body and mixed with the combustion air to form a flame That produces fuel at its tip A hollow cylindrical fuel nozzle to be injected, a cooling tube provided surrounding the outer periphery of the fuel nozzle, having a communication part for communicating with the exhaust system and an opening part opened to the atmosphere, and the heat storage And a connecting pipe that connects the communicating part to the exhaust system at an intermediate position between the exhaust valve and the exhaust valve, and in the exhaust mode, the exhaust system performs exhaust suction action of the exhaust system through the connecting pipe through the opening. The fuel nozzle is cooled by the air flowing toward the communication portion, and in the combustion mode, the opening portion passes through the communication portion via the connection pipe, bypassing the heat storage portion by the air supply action of the air supply system. The cooling nozzle is cooled by the combustion air flowing toward the front.

  The communication portion and the opening of the cooling tube are formed on the base end side opposite to the fuel nozzle tip, and the cooling tube surrounds the outer periphery of the fuel nozzle and has a length thereof. A first flow path formed from the front end side to the base end side in the direction and communicating with the communication section; and surrounding the outer periphery of the first flow path, the front end section in the length direction of the fuel nozzle The second flow path formed from the side to the base end side and communicated with the opening, and the connection flow for communicating the first flow path and the second flow path on the distal end side of the fuel nozzle And a road.

  A pair of the regenerative burners operated when one is in the combustion mode and the other is operated in the exhaust mode, and the exhaust systems of these regenerative burners are joined together at a junction, and a single unit is provided downstream of the junction. The exhaust blower is provided.

  In the fuel nozzle cooling structure of the regenerative burner according to the present invention, by using the exhaust blower that performs exhaust in the exhaust operation mode, the equipment cost and the necessary installation space required for cooling the fuel nozzle are reduced. This can be reduced, and the layout of piping and the like can be simplified.

It is a block diagram which shows 1st Embodiment of the fuel nozzle cooling structure of the regenerative burner which concerns on this invention. It is a block diagram which shows 2nd Embodiment of the fuel nozzle cooling structure of the regenerative burner which concerns on this invention.

  Hereinafter, a preferred embodiment of a fuel nozzle cooling structure for a regenerative burner according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing a fuel nozzle cooling structure of a regenerative burner according to the first embodiment.

  As shown in FIG. 1, the regenerative burners 1L and 1R are connected to the burner main bodies 3L and 3R having craters 2L and 2R at one end toward the furnace 5, and the other end 3a of the burner main bodies 3L and 3R, as is conventionally known. And a heat storage section 4L, 4R provided directly adjacent to the burner bodies 3L, 3R, and a flame F is ejected from the craters 2L, 2R of the burner bodies 3L, 3R into the furnace 5 The combustion mode in which the inside of the furnace 5 is heated (for example, about 1,000 ° C.) and the exhaust mode in which the exhaust E in the furnace 5 is sucked and discharged from the craters 2L and 2R face each other, and are alternately and repeatedly switched. It is designed to be driven.

  In the regenerative burner 1L, 1R, in the exhaust mode, the exhaust E is sucked from the furnace 5 by the exhaust suction action of the exhaust system 16 having the exhaust blower 14, and the sucked exhaust E is circulated to the heat storage units 4L, 4R. Thus, the exhaust heat of the exhaust E is stored in the heat storage units 4L and 4R, and the exhaust E passing through the heat storage units 4L and 4R is cooled (for example, about 200 ° C.) and discharged to the exhaust system 16. Thereafter, when the operation is switched from the exhaust mode to the combustion mode, the combustion air is circulated to the heat storage units 4L and 4R by the air supply action of the air supply system 13 having the air supply blower 11, and the heat storage units 4L and 4R store heat. The combustion air is preheated (heated) by the exhaust heat of the exhaust E.

  Then, the preheated combustion air is supplied to the burner main bodies 3L and 3R, mixed with the fuel gas supplied through the fuel nozzles 6L and 6R provided in the burner main bodies 3L and 3R, and burned. Thus, the burner main bodies 3L and 3R generate the flame F by energy saving operation using exhaust heat.

  When the regenerative burners 1L and 1R are employed, the burners 1L and 1R are used in a pair so that the furnace temperature does not fluctuate with the mode switching between the combustion mode and the exhaust mode.

  When one of the regenerative burners 1L (1R) is in the combustion mode, the other regenerative burner 1R (1L) is operated in the exhaust mode, and when the former is switched to the exhaust mode, the latter is in the combustion mode. Operation is controlled so that the combustion mode and the exhaust mode are alternated between the pair of regenerative burners 1L and 1R so as to be switched.

  In the illustrated example, a pair of burner bodies 3L and 3R are provided on each of the left and right furnace side walls facing each other among the square-shaped furnace walls constituting the furnace 5. The pair of burner bodies may be provided adjacent to the same wall surface.

  In the fuel nozzle cooling structure of the regenerative burner according to the present embodiment, as shown in FIG. 1, the pair of left and right regenerative burners 1L, 1R has craters 2L, 2R opened toward the inside of the furnace 5. Passing through the burner main bodies 3L, 3R in the form of passages at one end, the heat storage parts 4L, 4R having one end 4a connected to the other end 3a of the burner main bodies 3L, 3R, and the other end 3a side of the burner main bodies 3L, 3R Then, the burner main body 3L, 3R is inserted from the outside, the tip opening 6a faces the craters 2L, 2R, and a fuel such as a fuel gas that is mixed with the combustion air to generate the flame F is supplied. Hollow cylindrical fuel nozzles 6L, 6R that are injected from the tip opening 6a toward the craters 2L, 2R, and the outer periphery of the fuel nozzles 6L, 6R are provided so as to surround the other ends 3a of the burner bodies 3L, 3R. Penetrate the side Then, inside the burner main bodies 3L, 3R, cooling tubes 8L, 8R extending from the outside to the front end openings 6a of the fuel nozzles 6L, 6R or in the vicinity thereof, and fuel opening / closing for controlling the supply / stop of the fuel Each of the fuel nozzles 6L and 6R has a fuel nozzle on the side opposite to the tip end opening 6a on the one end side in the length direction. A fuel supply system 10 connected to the base end 6b side of 6L and 6R to supply fuel toward the front end opening 6a of the fuel nozzles 6L and 6R, and a supply for supplying combustion air to the burner bodies 3L and 3R The air blower 11 and the air supply valves 12L and 12R that can be opened and closed to control the supply / stop of combustion air (in the figure, the white display is open; the black solid display is closed), and each of the heat storage units 4L and 4R 4L connected to the end 4b to store the combustion air An air supply system 13 for supplying air to 4R, an exhaust blower 14 for sucking the exhaust E in the furnace 5 from the craters 2L and 2R and discharging it to the outside of the furnace 5, and an open / close control for controlling the discharge / stop of the exhaust E Exhaust valves 15L and 15R (in the figure, the white display is open; the black solid display is closed) are connected to the other ends 4b of the heat storage units 4L and 4R, and exhaust E flows out of the heat storage units 4L and 4R. And an exhaust system 16 through which the gas flows.

  Specifically, the air supply system 13 is directly connected to the heat storage units 4L and 4R of the pair of regenerative burners 1L and 1R, respectively, and a pair of combustions through which the combustion air supplied to the heat storage units 4L and 4R is circulated. It comprises an air supply pipe 13a, a combustion air merging section 13b that joins these combustion air supply pipes 13a, and a combustion air supply main pipe 13c that is connected to each combustion air supply pipe 13a via the combustion air merging section 13b. The air supply blower 11 is provided in the combustion air supply main pipe 13c to supply combustion air to both the pair of regenerative burners 1L and 1R, and the air supply valves 12L and 12R include the pair of regenerative burners 1L. , 1R are provided in the combustion air supply pipe 13a in order to individually switch the operation mode.

  In the regenerative burner 1R (1L) in the combustion mode, the exhaust valve 15R (15L) is closed and the air supply valve 12R (12L) is opened, and combustion is sent by the air supply action of the air supply system 13 The air is circulated to the heat storage unit 4R (4L) via the air supply valve 12R (12L), and is further supplied from the heat storage unit 4R (4L) toward the crater 2R (2L) of the burner body 3R (3L). It is like that.

  Specifically, the exhaust system 16 is directly connected to the heat storage units 4L and 4R of the pair of regenerative burners 1L and 1R, and a pair of exhaust pipes through which the exhaust E discharged from the heat storage units 4L and 4R is circulated. 16a, an exhaust merging portion 16b where these exhaust pipes 16a merge with each other, and an exhaust main pipe 16c connected to each exhaust pipe 16a via the exhaust merging portion 16b. The exhaust blower 14 includes a pair of regenerative generators. The exhaust main pipe 16c is provided to exhaust the exhaust E from both the lative burners 1L and 1R, and the exhaust valves 15L and 15R are exhausted to individually switch the operation modes of the pair of regenerative burners 1L and 1R. It is provided in the tube 16a.

  Then, in the regenerative burner 1L (1R) in the exhaust mode, the exhaust valve 15L (15R) is opened and the air supply valve 12L (12R) is closed, and the exhaust sucked by the exhaust suction action of the exhaust system 16 E is circulated from the crater 2L (2R) of the burner body 3L (3R) to the heat storage unit 4L (4R), and is further discharged from the heat storage unit 4L (4R) to the exhaust system 16 via the exhaust valve 15L (15R). It has become so.

  The fuel on-off valves 9L and 9R are opened to supply fuel to the fuel nozzles 6L and 6R when the regenerative burners 1L and 1R are in the combustion mode, and to stop supplying fuel when in the exhaust mode. Closed.

  The supply valves 12L and 12R are opened to supply combustion air to the craters 2L and 2R of the burner main bodies 3L and 3R via the heat storage units 4L and 4R when the regenerative burners 1L and 1R are in the combustion mode. In the exhaust mode, it is closed to stop the supply of combustion air.

  The exhaust valves 15L and 15R suck the exhaust E in the furnace 5 from the craters 2L and 2R of the burner main bodies 3L and 3R through the heat storage portions 4L and 4R when the regenerative burners 1L and 1R are in the exhaust mode. And closed in order to stop the suction of the exhaust E when in the combustion mode. The air supply blower 11 and the exhaust blower 14 are normally operated during the operation of the furnace 5.

  In the present embodiment, the fuel nozzles 6L, 6R are arranged so as to face the hot craters 2L, 2R with respect to the basic configuration of the regenerative burners 1L, 1R described above, and the high temperature exhaust E circulates in the vicinity thereof. Each regenerative burner 1L, 1R is provided with a cooling structure for cooling. The cooling structure of the fuel nozzles 6L and 6R is mainly composed of the cooling tubes 8L and 8R and connecting tubes 17L and 17R that connect the cooling tubes 8L and 8R to the exhaust system 16.

  The cooling tubes 8L and 8R surround the outer periphery of the fuel nozzles 6L and 6R, and are formed in a pipe shape in the length direction from the tip end opening 6a side to the base end portion 6b side, and are outside the burner main bodies 3L and 3R. On the side of the base end portion 6b of the fuel nozzle 6L, 6R, the base end portion is sealed by an annular closed end plate 19a joined to the outer peripheral surface of the fuel nozzle 6L, 6R, and close to the craters 2L, 2R The inner tube 19 with the distal end side open, and the outer circumference of the inner tube 19 are formed in a pipe shape from the distal end opening 6a side to the proximal end portion 6b side in the length direction of the fuel nozzles 6L and 6R. At the base end 6b side of the fuel nozzles 6L, 6R outside the burner bodies 3L, 3R, the base end is sealed by an annular first sealing end plate 20a joined to the outer peripheral surface of the inner tube 19. In addition, it is extended to the crater 2L, 2R side from the inner pipe 19 An annular second sealed end plate that is joined to the outer peripheral surface of the fuel nozzles 6L and 6R while covering the tip end side of the inner tube 19 from the crater 2L and 2R side at the position of the tip opening 6a of the fuel nozzles 6L and 6R. The outer tube 20 whose front end side is sealed with 20b, and the opening 21 formed in the outer tube 20 on the base end portion 6b side of the fuel nozzles 6L and 6R outside the burner main bodies 3L and 3R and opened to the atmosphere. , And a communication portion 22 formed to communicate with the exhaust system 16 in the inner pipe 19.

  The inner tube 19 and the outer tube 20 allow the cooling tubes 8L and 8R to surround the outer periphery of the fuel nozzles 6L and 6R, and extend in the length direction from the distal end opening 6a side to the proximal end portion 6b side. The first flow path 23 that is formed in communication with the communication portion 22 and surrounds the outer periphery of the first flow path 23 and extends in the length direction of the fuel nozzles 6L and 6R from the front end opening 6a side to the base end portion 6b side The first flow path 23 and the second flow path are formed so that the flow path is folded back on the side of the second flow path 24 that is formed over the front end and communicates with the opening 21 and the front end opening 6a of the fuel nozzles 6L and 6R. 24 is provided with a connection flow path 25 that communicates with 24.

  That is, the exhaust system 16 having an exhaust suction action is opened to the atmosphere via the outer periphery of the fuel nozzles 6L and 6R. And the communicating part 22 of the tubes 8L and 8R for cooling is connected to the exhaust system 16 via the connecting pipes 17L and 17R, and in this embodiment, the exhaust joining part 16b where the exhaust pipes 16a from the heat storage parts 4L and 4R are joined. , The exhaust blower 14 is connected to an exhaust main pipe 16c provided as a single unit. As long as the connection positions of the connection pipes 17L and 17R of the regenerative burners 1L and 1R to the exhaust system 16 are intermediate positions between the exhaust valves 15L and 15R and the exhaust blower 14, they may be connected to any position. .

  Next, the operation of the fuel nozzle cooling structure of the regenerative burner according to the first embodiment will be described. During operation of the furnace 5, for example, as shown in FIG. 1, in either one (right side) regenerative burner 1R, the fuel on-off valve 9R and the air supply valve 12R are opened, and the exhaust valve 15R is closed. In the other (left side) regenerative burner 1L, the fuel on-off valve 9L and the supply valve 12L are closed, and the exhaust valve 15L is opened to operate in the exhaust mode. The operation of the regenerative burner 1L, 1R itself is well known as described above.

  Due to the exhaust suction action of the exhaust blower 14, the exhaust E that flows through the heat storage section 4L of the regenerative burner 1L in the exhaust mode and stores the heat in the heat storage section 4L and cools down is exhausted through the open exhaust valve 15L. It reaches the blower 14 and is discharged.

  The exhaust suction action of the exhaust blower 14 acts on the communication portion 22 of each of the cooling tubes 8L and 8R from the exhaust main pipe 16c through the both connection pipes 17L and 17R. The communication portion 22 communicates with the opening 21 that is open to the atmosphere via the first flow path 23, the connection flow path 25, and the second flow path 24. However, it is circulated in both the cooling tubes 8L and 8R toward the communicating portion 22 through the opening 21.

  The atmospheric air at a temperature much lower than the temperature (about 1,000 ° C.) at the one end 4a of the heat storage section 4L, 4R is on the base end side of the cooling tubes 8L, 8R of both the pair of regenerative burners 1L, 1R. Front ends of fuel nozzles 6L and 6R provided in a pair of regenerative burners 1L and 1R in both the combustion mode and the exhaust mode, which are installed in the craters 2L and 2R facing the furnace 5 from the opening 21 and are in a high temperature state. Toward the opening 6a, the second flow path 24 in the outer pipe 20 is circulated, folded back at the connection flow path 25 and further circulated through the first flow path 23 in the inner pipe 19, whereby both regenerations are performed. The fuel nozzles 6L and 6R of the latent burners 1L and 1R are cooled, and after being cooled, of course, the fuel nozzles 6L and 6R are not discharged into the furnace 5 and are singlely supplied from the communication portion 22 to the exhaust system 16 through which the exhaust E flows. Exhaust vent Is sucked by the exhaust suction action of A 14 is discharged.

  Even if the left regenerative burner 1L is switched to the combustion mode and the right regenerative burner 1R is switched to the exhaust mode, both the left and right fuel nozzles 6L and 6R are always exhausted when the exhaust blower 14 is in operation. Cooling is ensured by the air introduced by the suction action.

  In the fuel nozzle cooling structure of the regenerative burner according to the first embodiment described above, suction is performed from the craters 2L and 2R of the burner main bodies 3L and 3R by the exhaust suction action of the exhaust system 16 having the exhaust blower 14. The furnace exhaust E is passed through the heat storage units 4L and 4R provided directly adjacent to the burner bodies 3L and 3R, and the exhaust mode for storing the exhaust heat and the heat storage units 4L and 4R are passed through and heated. Are regenerative burners 1L, 1R that alternately repeat a combustion mode in which the flame F generated by the combustion air is injected into the furnace 5 from the craters 2L, 2R of the burner bodies 3L, 3R, Fuel cylinders 6L, 6R in the form of hollow cylinders that are provided inside 3R and inject fuel that is mixed with combustion air and generates flame F into the furnace 5 from the opening 6a of the tip, and fuel nozzle 6L Cooling tubes 8L and 8R which are provided to surround the outer periphery of 6R and have a communication part 22 for communicating with the exhaust system 16 and an opening 21 opened to the atmosphere, and the communication part 22 are connected to the exhaust system 16. The connection nozzles 17L and 17R are provided, and the fuel nozzles 6L and 6R are cooled by the air flowing toward the communication portion 22 through the opening 21 by the exhaust suction action of the exhaust system 16 through the attachment tubes 17L and 17R. Therefore, using the exhaust blower 14 that exhausts the exhaust E in the exhaust mode, the cooling atmosphere is caused to flow into the cooling tubes 8L and 8R to cool the fuel nozzles 6L and 6R, and this is thermally deformed. The equipment necessary for cooling the fuel nozzles 6L and 6R can be prevented, and the cooling tubes 8L and 8R and the cooling tubes 8L and 8 surrounding the fuel nozzles 6L and 6R are provided. Since only the connecting pipes 17L and 17R for connecting the exhaust system 16 to the exhaust system 16 are required, the equipment cost and the necessary installation space can be reduced by the space of the pipe, and therefore the layout can be simplified. it can.

  The communication portion 22 and the opening 21 of the cooling tubes 8L and 8R are formed on the base end 6b side opposite to the tip opening 6a of the fuel nozzles 6L and 6R. A first flow path 23 that surrounds the outer periphery of the nozzles 6L and 6R and is formed in the length direction from the distal end opening 6a side to the base end 6b side, and communicates with the communication portion 22, and a first flow path A second flow path 24 that surrounds the outer periphery of the fuel nozzle 6 and is formed in the length direction of the fuel nozzles 6L and 6R from the front end opening 6a side to the base end portion 6b side and communicates with the opening 21; Since the first flow path 23 and the second flow path 24 are connected to each other at the tip end opening 6a side of the 6L and 6R, the second flow path is formed in the length direction of the fuel nozzles 6L and 6R. Circulates from 24 to the first flow path 23 to ensure a cooling effect by reciprocation Can be, it is possible to efficiently cool and does not emit air for cooling into the furnace 5, it is possible to prevent the furnace atmosphere is varied.

  A pair of regenerative burners 1L and 1R are operated such that when one is in the combustion mode and the other is operated in the exhaust mode. The exhaust systems 16 of these regenerative burners 1L and 1R are joined together at the exhaust merging section 16b. Since the single exhaust blower 14 is provided downstream of the merging portion 16b, even in the furnace 5 operated by the pair of regenerative burners 1L and 1R, both the fuel nozzles 6L are provided by the single exhaust blower 14. , 6R can be cooled and the alternate combustion operation can be ensured.

  In the description of the present embodiment, the application to the pair of regenerative burners 1L and 1R has been described. However, the present invention is not limited to a pair, and the above-described effects can be obtained even if the regenerative burner is a single unit. .

  FIG. 2 is a configuration diagram showing a fuel nozzle cooling structure of the regenerative burner according to the second embodiment. The second embodiment differs from the first embodiment in the connection positions of the connection pipes 26L and 26R with respect to the exhaust system 16, and thus the operation is different.

  In the first embodiment, the connection pipes 17L and 17R from the communication part 22 are connected to the exhaust main pipe 16c. In the second embodiment, the connection pipes 26L and 26R from the communication part 22 are connected to each regeneration unit. In each of the burners 1L and 1R, it is connected to an intermediate position between the heat storage portions 4L and 4R and the exhaust valves 15L and 15R which are provided directly adjacent to the burner main bodies 3L and 3R. Other configurations are the same as those in the first embodiment.

  The operation of the fuel nozzle cooling structure of the regenerative burner according to the second embodiment will be described. As described above, in the regenerative burner 1L, 1R, in the combustion mode, the vicinity of the tip opening 6a of the fuel nozzle 6L, 6R facing the crater 2L, 2R where the flame F is generated is located in the fuel nozzle 6L, 6R. On the other hand, in the exhaust mode, although the flame F is extinguished, the hot exhaust E flows around the fuel nozzles 6L and 6R.

  For this reason, with respect to cooling of the fuel nozzles 6L, 6R by the cooling tubes 8L, 8R, it is preferable that the temperature in the inner tube 19 side is low in the combustion mode, while the temperature in the outer tube 20 side is low in the exhaust mode.

  In the second embodiment, the connection position of the connection pipes 26L, 26R with respect to the exhaust system 16 is connected to an intermediate position between the heat storage units 4L, 4R and the exhaust valves 15L, 15R. As shown in the operation of the regenerative burner 1L), the air flowing toward the communication portion 22 through the opening portion 21 by the exhaust suction action of the exhaust system 16 via the connection pipe 26L is the same as in the first embodiment. By flowing first through the outer pipe 20 and then through the inner pipe 19, the outer pipe 20 exposed to the exhaust E by the cooler air can be cooled more efficiently and appropriately cooled so that the fuel nozzle 6L is not overheated. it can.

  On the other hand, in the combustion mode (shown by the operation of the regenerative burner 1R on the right side in the figure), unlike the first embodiment, the heat is supplied by the air supply action of the air supply system 13 having the air supply blower 11. A part of the combustion air toward the part 4R bypasses the heat storage part 4R, flows into the connection pipe 26R via the exhaust system 16 (exhaust pipe 16a) in which the exhaust valve 15R is closed, and The combustion air flowing toward the opening 21 through the communication portion 22 through the connection pipe 26R first flows through the inner pipe 19 and then flows through the outer pipe 20, thereby being exposed to the flame F by the lower temperature combustion air. It is possible to cool the pipe 19 more efficiently so that the fuel nozzle 6R is not overheated.

  That is, the flow direction in the cooling tubes 8L and 8R changes with respect to the switching of the operation state such as the combustion mode and the exhaust mode, and a good cooling effect of the fuel nozzles 6L and 6R can be ensured.

  Further, since the connecting pipes 26L, 26R may be disposed between the burner bodies 3L, 3R and the heat storage parts 4L, 4R that are directly connected adjacent to each other, the connecting pipes 17L, It is not necessary to extend 17R to at least the downstream side of the exhaust valves 15L and 15R, the pipe space can be reduced, and the equipment cost can be reduced and the equipment layout can be made compact.

  Even in the second embodiment, not only the application to the pair of regenerative burners 1L and 1R but also the above-described effects can be obtained even if the regenerative burner is a single unit. Moreover, even if it exists in 2nd Embodiment, of course, there exists another effect which 1st Embodiment has.

1L, 1R Regenerative burner 2L, 2R crater 3L, 3R burner body 3a other end of burner body 4L, 4R heat storage section 4a one end of heat storage section 4b other end of heat storage section 5 furnace 6L, 6R fuel nozzle 6a tip of fuel nozzle Part opening 6b Base end of fuel nozzle 8L, 8R Cooling tube 9L, 9R Fuel on-off valve 10 Fuel supply system 11 Supply air blower 12L, 12R Supply valve 13 Supply system 13a Combustion air supply pipe 13b Combustion air confluence 13c Combustion air supply main pipe 14 Exhaust blower 15L, 15R Exhaust valve 16 Exhaust system 16a Exhaust pipe 16b Exhaust merge part 16c Exhaust main pipe 17L, 17R Connection pipe 19 Inner pipe 19a Sealed end plate 20 Outer pipe 20a First sealed end plate 20b 2nd sealing end plate 21 Opening part 22 Communication part 23 1st flow path 24 2nd flow path 25 Connection flow path 26L, 26R Contact Tube E exhaust F flame

Claims (4)

An exhaust mode in which the exhaust in the furnace sucked from the crater of the burner body by the exhaust suction action of the exhaust system having the exhaust blower is distributed to the heat storage part to store the exhaust heat, and the combustion air that is distributed and heated to the heat storage part A regenerative burner that alternately repeats the combustion mode in which the flame generated in is burned into the furnace from the crater of the burner body,
A hollow cylindrical fuel nozzle that is provided inside the burner body and injects fuel that is mixed with combustion air to generate a flame from its tip, and is provided to surround the outer periphery of the fuel nozzle, and the exhaust A cooling tube having a communicating part for communicating with the system and an opening opened to the atmosphere, and a connecting pipe for connecting the communicating part to the exhaust system,
A fuel nozzle for a regenerative burner characterized in that the fuel nozzle is cooled by the air flowing toward the communication portion through the opening by the exhaust suction action of the exhaust system through the connection pipe. Cooling structure. The exhaust valve for opening and closing the exhaust system having the exhaust blower is opened and the air supply valve for opening and closing the air supply system having the air supply blower is closed and sucked from the crater of the burner body by the exhaust suction action of the exhaust system An exhaust mode in which the exhaust in the furnace is circulated through the heat storage section to store the exhaust heat and is discharged to the exhaust system through the exhaust valve, the exhaust valve is closed and the supply valve is opened, Combustion air supplied to the burner main body by the air supply operation of the air supply system is circulated through the heat accumulator and heated, and a flame generated by the heated combustion air is transferred from the crater of the burner main body into the furnace. A regenerative burner that alternately repeats the combustion mode to be ejected,
A hollow cylindrical fuel nozzle that is provided inside the burner body and injects fuel that is mixed with combustion air to generate a flame from its tip, and is provided to surround the outer periphery of the fuel nozzle, and the exhaust A cooling tube having a communication part for communicating with the system and an opening opened to the atmosphere, and a connecting pipe for connecting the communication part to the exhaust system at an intermediate position between the heat storage part and the exhaust valve. ,
In the exhaust mode, the exhaust nozzle of the exhaust system through the connection pipe cools the fuel nozzle by the atmosphere flowing toward the communication portion through the opening, and in the combustion mode, the air supply of the supply system The regenerative burner is characterized in that the cooling nozzle is cooled by the combustion air that circulates toward the opening through the communication pipe and bypassing the heat storage section by the action. Fuel nozzle cooling structure.   The communication portion and the opening of the cooling tube are formed on the base end side opposite to the fuel nozzle tip, and the cooling tube surrounds the outer periphery of the fuel nozzle and has a length thereof. A first flow path formed from the front end side to the base end side in the direction and communicating with the communication section; and surrounding the outer periphery of the first flow path, the front end section in the length direction of the fuel nozzle The second flow path formed from the side to the base end side and communicated with the opening, and the connection flow for communicating the first flow path and the second flow path on the distal end side of the fuel nozzle A fuel nozzle cooling structure for a regenerative burner according to claim 1 or 2, further comprising a passage.   A pair of the regenerative burners operated when one is in the combustion mode and the other is operated in the exhaust mode, and the exhaust systems of these regenerative burners are joined together at a junction, and a single unit is provided downstream of the junction. The regenerative burner cooling structure according to any one of claims 1 to 3, wherein the exhaust blower is provided.

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