TW201829964A - Fuel nozzle cooling system in regenerative burner - Google Patents

Abstract

This invention provides for a fuel nozzle cooling system in a regenerative burner capable of a cost down and space saving on cooing a fuel nozzle and simplifying a layout of piping and so forth, by means of utilizing an exhausting blower exhausting an exhaust gas in an exhaust mode. A fuel nozzle cooling system in a regenerative burner in which a regenerative burner 1L, 1R is alternately driven in an exhaust mode and combustion mode, includes a hollow cylindrical type fuel nozzle 6I, 6L installed within a burner body 3L, 3R and discharging a fuel from a tip end part 6a of the fuel nozzle, the fuel being mixed with a combustion air and generating a flame; a cooling tube 8L, 8R surrounding an outer periphery of the fuel nozzle, and having a communication part 20b communicated with an exhaust line 16 and an opening port 21 opened to an atmosphere; and a joint pipe 22 connecting the communication part of the cooling tube with an exhaust line; wherein an the atmosphere flows in the cooling tube from the opening port to the communication part by means of an exhaust gas absorb action in the exhaust line through the joint pipe, and cools the fuel nozzle.

Description

 Fuel nozzle cooling structure of regenerative burner  

The present invention relates to a fuel nozzle cooling structure for a regenerative burner, which is capable of reducing the equipment cost and required installation space for cooling the fuel nozzle by using an exhaust blower that exhausts in an exhaust operation mode. The layout of piping and the like is also simplified.

Various types of furnaces using a regenerative burner are known (see Patent Document 1). At this time, a structure in which a regenerative burner is cooled is also known (see Patent Documents 2 and 3). The "industrial furnace, industrial furnace energy-saving operation method, and industrial furnace modification method" of Patent Document 1 includes an exhaust pipe that connects a combustion chamber and a chimney, and an intake opening and closing valve that is opened. The external atmosphere (ATM, Atmosphere) is taken into the exhaust pipe; and the impeller is connected to the suction blower functioning as a generator, and is taken in and exhausted from the exhausted opening and closing valve that is opened The external atmosphere of the tube rotates to generate electricity. In Patent Document 1, two types of regenerative burners are alternately switched between the combustion operation and the exhaust operation.

The Patent Document 2, "hot air with a low NO _x burners" is configured to be attached to the outside of baffles fitted shaped distal end portion of the fuel injection of the fuel nozzle, the baffle and the outside periphery of a slit-shaped secondary air In the supply hole, the fuel nozzle is configured such that the inner peripheral portion serves as a fuel passage and the outer peripheral portion serves as a double pipe for the cooling air passage, and the baffle plate is formed as a discharge hole in which the fuel and the cooling air are provided at the center, and is disposed on the outer side of the discharge hole. Providing a plurality of primary air supply holes at an angle of 30 to 50 degrees from a surface of the same pitch circle from the inlet to the outlet, and forming fuel, cooling air, and cooling air at the outlets of the primary air supply holes The outlet of the air once. In the burner of Patent Document 2, the air for cooling of the fuel nozzle is released into the furnace.

The problem of the "cooling device for a regenerative burner fuel nozzle tube" of Patent Document 3 is that the introduced air is not released into the furnace, but is used only for cooling of the cooling air tube, and in the round trip of advancement and travel. Cooling is performed to effectively prevent overheating of the cooling air tube, and a double tube including an inner tube and an outer tube is disposed outside the fuel nozzle tube, and a cooling air tube is disposed, and the cooling air tube is configured to The fuel nozzle tube front end opening portion is sealed by a lid body, and the outer side passage between the outer tube and the inner tube and the inner passage between the inner tube and the fuel nozzle tube are communicated via the lid body. In Patent Document 3, the introduced air for cooling is not released into the furnace, but the introduced air is sent to the air cooling pipe, so that it is necessary to equip the air blower.

 [Previous Technical Literature]    [Patent Literature]  

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2016-133255

[Patent Document 2] Japanese Patent Laid-Open No. Hei 10-185128

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2001-182915

The ambient gas in the furnace heated in the regenerative burner is preferably homogeneous and does not fluctuate. In this regard, as the cooling structure of the fuel nozzle provided in the regenerative burner, it is preferred that the air is not introduced. The double tube structure of Patent Document 3 released to the furnace.

However, in Patent Document 3, there is no disclosure as to how to supply the introduced air to the air cooling duct. Generally, in general, a new or additional blower is considered, and the introduced air is supplied to the air supply pipe from the blower. If a blower or the like is newly installed, there is a problem that the required equipment cost including the piping is generated, and at the same time, it is necessary to secure the installation space.

The present invention has been made in view of the above-described problems, and it is an object of the invention to provide a fuel nozzle cooling structure for a regenerative burner which can reduce the cooling of a fuel nozzle by using an exhaust blower that exhausts in an exhaust operation mode. The equipment cost and the required installation space, and the layout of piping and the like are also simplified.

In the fuel nozzle cooling structure of the regenerative burner of the present invention, the regenerative burner alternately repeats an exhaust mode and a combustion mode, and the exhaust mode is exhausted to an exhaust system having an exhaust blower. The exhaust gas in the furnace sucked from the burner port of the burner body is circulated to the heat accumulating portion to accumulate heat, and the combustion mode is to burn the flame generated by the combustion air heated to the heat accumulating portion. The blast port of the main body is ejected into the furnace; and is characterized in that: a hollow cylinder-shaped fuel nozzle is provided in the burner body, and a fuel mixed with combustion air is generated from the front end portion to generate a flame; a tube that surrounds the fuel nozzle and has an opening for communicating with the communication portion of the exhaust system and the atmosphere; and a connection pipe that connects the communication portion to the exhaust system; The fuel nozzle is cooled by an atmosphere that flows through the opening to the communication portion through the exhaust suction of the exhaust system of the connecting pipe.

Further, in the fuel nozzle cooling structure of the regenerative burner of the present invention, the regenerative burner alternately repeats an exhaust mode and a combustion mode, and the exhaust mode opens and closes an exhaust system having an exhaust blower. The air valve is closed and the air supply valve having the air supply system of the air supply blower is closed, so that the exhaust gas in the furnace sucked from the fire exit of the burner body flows to the heat storage under the exhaust suction of the exhaust system And accumulating heat and discharging to the exhaust system via the exhaust valve, the combustion mode is to close the exhaust valve and open the air supply valve, so as to be supplied to the air supply system The combustion air supplied from the burner body flows to the heat accumulating portion to be heated, and the flame generated by the heated combustion air is ejected from the blast port of the burner body into the furnace; and is characterized in that: a hollow cylinder-shaped fuel nozzle is provided Provided inside the burner body, jetting a fuel mixed with combustion air to generate a flame from a front end portion thereof; and a cooling pipe disposed around the fuel nozzle and having a periphery thereof a communication portion that communicates with the communication portion of the exhaust system and an open atmosphere; and a connection pipe that connects the communication portion to the exhaust system at an intermediate position between the heat storage portion and the exhaust valve; The fuel nozzle is cooled by the air flowing through the opening to the communication portion through the exhaust suction of the exhaust system of the connecting pipe, and in the combustion mode, by the gas supply system The cooling nozzle that is bypassed in the heat accumulating portion and flows through the connecting pipe and flows through the communicating portion to the opening portion is cooled by the air supply.

The communication portion and the opening portion of the cooling pipe are formed on a base end side opposite to a fuel nozzle tip end portion, and the cooling pipe includes a first flow path, a second flow path, and a connection. a flow path in which the first flow path surrounds the periphery of the fuel nozzle, and is formed in a longitudinal direction from the front end side to the base end side, and communicates with the communication portion, and the second flow path surrounds the first flow path The periphery of the first flow path is formed in the longitudinal direction of the fuel nozzle from the front end side to the base end side, and communicates with the opening, and the connection flow path connects the first flow path and the second flow path The front end side of the fuel nozzle is in communication.

A regenerative burner is provided, wherein one of the pair of regenerative burners is in a combustion mode, and the other is operated in an exhaust mode, and the exhaust systems of the regenerative burners are mutually The confluence unit merges, and a single exhaust blower is provided downstream of the confluence unit.

In the fuel nozzle cooling structure of the regenerative burner of the present invention, the equipment cost and the required installation space required for cooling the fuel nozzle can be reduced by using the exhaust blower that exhausts in the exhaust operation mode, and the piping is provided. The layout can be simplified.

1L, 1R‧‧‧ regenerative burner

2L, 2R‧‧‧ spout

3L, 3R‧‧‧ burner body

3a‧‧‧The other end of the burner body

4L, 4R‧‧‧ Thermal Storage Department

4a‧‧‧One end of the heat storage department

4b‧‧‧The other end of the heat storage department

5‧‧‧ furnace

6L, 6R‧‧‧ fuel nozzle

6a‧‧‧Fuel nozzle front end opening

6b‧‧‧The base end of the fuel nozzle

8L, 8R‧‧‧ cooling tube

9L, 9R‧‧‧ fuel on-off valve

10‧‧‧fuel supply system

11‧‧‧Air supply blower

12L, 12R‧‧‧ gas supply valve

13‧‧‧ gas supply system

13a‧‧‧Combustion air supply pipe

13b‧‧‧Combustion Air Confluence

13c‧‧‧Combustion Air Supply Supervisor

14‧‧‧Exhaust air blower

15L, 15R‧‧‧ exhaust valve

16‧‧‧Exhaust system

16a‧‧‧Exhaust pipe

16b‧‧‧Exhaust Confluence Department

16c‧‧‧Exhaust supervisor

17L, 17R‧‧‧ connection tube

19‧‧‧Inside

19a‧‧‧Closed end plate

20‧‧‧External management

20a‧‧‧1st sealed end plate

20b‧‧‧2nd sealed end plate

21‧‧‧ openings

22‧‧‧Connecting Department

23‧‧‧1st flow path

24‧‧‧2nd flow path

25‧‧‧Connected flow path

26L, 26R‧‧‧ connection tube

E‧‧‧Exhaust

F‧‧‧flame

Fig. 1 is a configuration diagram showing a first embodiment of a fuel nozzle cooling structure of a regenerative burner according to the present invention.

Fig. 2 is a configuration diagram showing a second embodiment of a fuel nozzle cooling structure of the regenerative burner of the present invention.

Hereinafter, preferred embodiments of the fuel nozzle cooling structure of the regenerative burner of 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 provided with burner bodies 3L and 3R having burner ports 2L and 2R toward one end of the furnace 5, and heat accumulating portions 4L and 4R. The other end 3a of the burner bodies 3L, 3R is disposed adjacent to and directly connected to the burner bodies 3L, 3R; and the regenerative burners 1L, 1R are from the burner ports 2L, 2R of the burner bodies 3L, 3R A combustion mode in which the flame F is ejected into the furnace 5 to heat the inside of the furnace 5 (for example, about 1,000 ° C), and an exhaust mode in which the exhaust gas E in the suction furnace 2 L, 2R is sucked into the furnace 5 and discharged is opposite. It operates alternately and repeatedly.

In the regenerative burners 1L, 1R, in the exhaust mode, the exhaust gas E is sucked from the furnace 5 by the exhaust suction function of the exhaust system 16 having the exhaust blower 14, and the suction is performed. The exhaust gas E flows to the heat accumulating portions 4L and 4R, whereby the exhaust heat of the exhaust gas E is accumulated in the heat accumulating portions 4L and 4R, and the exhaust gas E that has passed through the heat accumulating portions 4L and 4R is cooled (for example, at about 200° C.) toward When the exhaust system 16 is exhausted, the combustion air is circulated to the heat accumulating portions 4L and 4R by the air supply function of the air supply system 13 having the air supply blower 11 when the operation is switched from the exhaust mode to the combustion mode. The exhaust gas E of the heat accumulating portions 4L and 4R is exhausted to preheat (heat) the combustion air.

Then, the preheated combustion air is supplied to the burner bodies 3L, 3R, and is mixed with the fuel gas supplied through the fuel nozzles 6L, 6R provided inside the burner bodies 3L, 3R, whereby the burner is combusted. The bodies 3L and 3R generate a flame F under the energy-saving operation using the exhaust heat.

When the regenerative burners 1L and 1R are used, the burners 1L and 1R are used in a pair to prevent the furnace temperature from changing depending on the mode of 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 to switch the latter to combustion when the former is switched to the exhaust mode. The mode is operated in such a manner that the combustion mode and the exhaust mode alternate between the pair of regenerative burners 1L, 1R.

In the illustrated example, the burner bodies 3L and 3R are provided in a pair on each of the left and right furnace side walls of the furnace wall constituting the four-sided cross section of the furnace 5. A pair of burner bodies may also be disposed adjacent to the same wall surface.

In the fuel nozzle cooling structure of the regenerative burner of the present embodiment, as shown in Fig. 1, each of the pair of right and left regenerative burners 1L and 1R is configured to include burner bodies 3L and 3R in a passage form, which is equal to One end has blast ports 2L, 2R open to the inside of the furnace 5; heat accumulating portions 4L, 4R, one end 4a of which is connected to the other end 3a of the burner bodies 3L, 3R; and a hollow cylindrical fuel nozzle 6L, 6R. The other end 3a of the burner bodies 3L, 3R is inserted and inserted into the inside of the burner bodies 3L, 3R from the outside, and the front end opening 6a faces the firing ports 2L, 2R, and is mixed with combustion air to generate a flame F. Fuel such as fuel gas is injected from the front end opening 6a to the firing ports 2L and 2R, and cooling pipes 8L and 8R are provided around the fuel nozzles 6L and 6R, and penetrate the other end 3a side of the burner bodies 3L and 3R. Inside the burner bodies 3L, 3R, extending from the outside to the end portions 6a of the fuel nozzles 6L, 6R or the vicinity thereof, and the fuel supply system 10 having the fuel opening and closing valve 9L for controlling the supply and stop of the fuel, 9R (in the figure, the blank is displayed as on, Black is shown as being closed, and the fuel nozzles 6L, 6R on the opposite side to the end opening 6a on the one end side in the longitudinal direction are connected to the respective fuel nozzles 6L, 6R, and the fuel is directed to the front end of the fuel nozzles 6L, 6R. The opening 6a is supplied; the air supply system 13 has an air supply blower 11 for supplying combustion air to the burner bodies 3L, 3R, and an air supply valve 12L, 12R for controlling the opening and closing of the supply and stop of the combustion air. , the blank is displayed as open, the black is shown as closed, and is connected to the other end 4b of each of the heat storage portions 4L, 4R to supply combustion air to the heat storage portions 4L, 4R; and the exhaust system 16 has a self-injection Exhaust gas E in the 2L, 2R suction furnace 5 and the exhaust blower 14 that discharges it to the outside of the furnace 5, and the exhaust valves 15L and 15R that control the opening and closing of the exhaust E to be opened and closed (in the figure, blank) The exhaust gas E which flows out from the heat storage units 4L and 4R flows through the other end 4b of each of the heat storage units 4L and 4R, and is connected to the other end 4b of each of the heat storage units 4L and 4R.

Specifically, the air supply system 13 is composed of a pair of combustion air supply pipes 13a that are directly connected to the heat storage portions 4L and 4R of the pair of regenerative burners 1L and 1R, respectively. The combustion air supplied from the heat accumulating portions 4L and 4R flows; the combustion air merging portion 13b merges the combustion air supply pipes 13a; and the combustion air supply main pipe 13c is connected to each of the combustion air supply pipes via the combustion air merging portion 13b. 13a; and the air supply blower 11 is provided in the combustion air supply main pipe 13c to supply combustion air to both of the pair of regenerative burners 1L and 1R, and the supply air valves 12L and 12R are provided in the combustion air supply pipe 13a to regenerate a pair. The operation modes of the burners 1L, 1R are individually switched.

Further, 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 to be fed by the air supply system 13 by the air supply. The air flows through the air supply valve 12R (12L) to the heat accumulating portion 4R (4L), and is supplied from the heat accumulating portion 4R (4L) to the blast port 2R (2L) of the burner body 3R (3L).

Specifically, the exhaust system 16 is composed of a pair of exhaust pipes 16a that are directly connected to the heat storage portions 4L and 4R of the pair of regenerative burners 1L and 1R, respectively, and are supplied from the respective heat storage portions 4L. The exhaust gas E discharged from the 4R flows; the exhaust gas confluence portion 16b for the exhaust pipes 16a to merge with each other; and the exhaust gas main pipe 16c connected to each of the exhaust pipes 16a via the exhaust gas confluence portion 16b; The air blower 14 is disposed in the exhaust main pipe 16c to discharge the exhaust gas E from both of the pair of regenerative burners 1L, 1R, and the exhaust valves 15L, 15R are provided in the exhaust pipe 16a to connect the pair of regenerative burners 1L, The 1R operation mode is individually switched.

Further, in the regenerative burner 1L (1R) of the exhaust mode, the exhaust valve 15L (15R) is opened and the air supply valve 12L (12R) is closed to be exhausted by the exhaust system of the exhaust system 16 The sucked exhaust gas E flows from the burner port 2L (2R) of the burner main body 3L (3R) to the heat accumulating portion 4L (4R), and further flows toward the exhaust gas from the heat accumulating portion 4L (4R) via the exhaust valve 15L (15R). System 16 is discharged.

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

The gas supply valves 12L, 12R are opened when the regenerative burners 1L, 1R are in the combustion mode, so that the combustion air is supplied to the burner ports 3L, 3R of the burner bodies 3L, 3R via the heat accumulating portions 4L, 4R in the exhaust mode. The time is turned off to stop the supply of combustion air.

The exhaust valves 15L and 15R are opened when the regenerative burners 1L and 1R are in the exhaust mode, so that the exhaust gas in the furnace 5 is sucked from the burner ports 2L and 2R of the burner bodies 3L and 3R via the heat accumulating portions 4L and 4R. E, is turned off in the combustion mode to stop the suction of the exhaust gas E. The air supply blower 11 and the exhaust blower 14 are generally operated throughout the operation of the furnace 5.

In the present embodiment, each of the regenerative burners 1L and 1R has a basic structure for cooling the blast ports 2L and 2R facing the high temperature and has a high temperature flowing around the regenerative burners 1L and 1R. The cooling structure of the fuel nozzles 6L, 6R of the exhaust gas E. The cooling structures of the fuel nozzles 6L and 6R mainly constitute the cooling pipes 8L and 8R and the connecting pipes 17L and 17R that connect the cooling pipes 8L and 8R to the exhaust system 16 by the following members.

The cooling pipes 8L and 8R are composed of an inner pipe 19 that surrounds the outer periphery of the fuel nozzles 6L and 6R and is formed in a tubular shape from the side of the front end opening 6a and the side of the proximal end portion 6b in the longitudinal direction thereof. On the proximal end portion 6b side of the fuel nozzles 6L, 6R on the outer sides of the main bodies 3L, 3R, the base end portion is sealed by an annular blocking end plate 19a joined to the outer peripheral surfaces of the fuel nozzles 6L, 6R, and the base end portion is blocked. The end portion side is open before the blast ports 2L and 2R, and the outer tube 20 surrounds the outer periphery of the inner tube 19, and is formed in the longitudinal direction of the fuel nozzles 6L and 6R from the side of the front end opening 6a and the side of the base end portion 6b. The tubular end portion seals the base end portion on the proximal end portion 6b side of the fuel nozzles 6L, 6R outside the burner bodies 3L, 3R by an annular first seal end plate 20a joined to the outer peripheral surface of the inner tube 19, and The front end opening 6a of the fuel nozzles 6L, 6R on the side of the blast ports 2L, 2R is extended to the inner tube 19, and the front end side of the inner tube 19 is covered from the side of the blast port 2L, 2R, and is connected to the fuel nozzle. The second sealing end plate 20b of the ring-shaped outer surface joined by the outer surface of 6L and 6R seals the front end side; and the burner Body 3L, 3R of the outer fuel nozzle 6L, 6R end portion 6b of the base side was opened to the atmosphere is formed in the opening portion 20 of the outer tube 21 and inner tube 19 is formed so as to communicate with the exhaust system 16 of the communication unit 22.

Further, the inner tubes 19 and the outer tubes 20 include the first flow path 23, the second flow path 24, and the connection flow path 25 in the cooling pipes 8L and 8R, and the first flow path 23 surrounds the fuel nozzle. The periphery of the 6L and 6R is formed from the side of the front end opening 6a and the side of the base end portion 6b in the longitudinal direction thereof, and communicates with the communicating portion 22, and the second flow path 24 surrounds the periphery of the first flow path 23. The fuel nozzles 6L and 6R are formed in the longitudinal direction from the front end opening 6a side to the base end portion 6b side, and communicate with the opening portion 21, which is connected to the front end opening 6a of the fuel nozzles 6L, 6R. On the side, the first flow path 23 and the second flow path 24 are communicated so that the flow path is folded back.

In other words, the exhaust system 16 that functions as an exhaust gas is opened to the atmosphere via the periphery of the fuel nozzles 6L and 6R. Further, the communication portions 22 of the cooling pipes 8L and 8R are connected to the exhaust system 16 via the connecting pipes 17L and 17R, and in the present embodiment are connected to the exhaust pipes 16a from the respective heat accumulating portions 4L and 4R. The exhaust main pipe 16c of the exhaust blower 14 is provided singly on the downstream side of the exhaust merging portion 16b. The connection position of the connecting pipes 17L and 17R of each of the regenerative burners 1L and 1R with respect to the exhaust system 16 can be connected to any position as long as it is intermediate between the exhaust valves 15L and 15R and the exhaust blower 14.

Next, the action of the fuel nozzle cooling structure of the regenerative burner of the first embodiment will be described. In the operation of the furnace 5, for example, as shown in Fig. 1, in one (right) regenerative burner 1R, the fuel on-off valve 9R and the supply valve 12R are opened and the exhaust valve 15R is closed to be in a combustion mode. In one (left) 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 burners 1L and 1R itself is well known as described above.

Exhaust gas E generated by the exhaust blower 14 flows through the heat accumulating portion 4L of the regenerative burner 1L in the exhaust mode, and is stored in the heat accumulating portion 4L to be cooled, and the exhaust gas E is cooled via the opened exhaust valve 15L. The exhaust blower 14 is reached and discharged.

The exhaust suction function of the exhaust blower 14 acts on the communication portion 22 of each of the cooling pipes 8L, 8R from the exhaust main pipe 16c via the two connecting pipes 17L, 17R. The communication unit 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, so that the atmosphere passes through the opening by the exhaust suction function of the exhaust blower 14. 21 flows into the communication unit 22 into the two cooling pipes 8L and 8R.

At a normal temperature in which the temperature is much lower than the temperature (about 1,000 ° C) of the one end 4a of the heat accumulating portions 4L and 4R, the opening portion on the base end side of the cooling tubes 8L and 8R of the pair of regenerative burners 1L and 1R 21 is open to the front end of the fuel nozzles 6L and 6R provided in the regenerative burners 1L and 1R in one of a combustion mode and an exhaust mode which are disposed in a high temperature state in the blast ports 2L and 2R facing the furnace 5. 6a flows through the second flow path 24 in the outer tube 20, and is folded back in the connection flow path 25 to flow through the first flow path 23 in the inner tube 19, whereby the two regenerative burners 1L, 1R are The fuel nozzles 6L, 6R are cooled, and of course, do not flow out into the furnace 5 after cooling, but are exhausted from the communication portion 22 to the exhaust gas E under the exhaust suction of the single exhaust blower 14. 16 suction and discharge.

Even if the regenerative burner 1L on the left side is switched to the combustion mode and the regenerative burner 1R on the right side is switched to the exhaust mode, it is also ensured that the exhaust blower 14 is always introduced by the exhaust suction function during the operation of the exhaust blower 14 The left and right fuel nozzles 6L, 6R are cooled by the atmosphere.

In the fuel nozzle cooling structure of the regenerative burner according to the first embodiment described above, the regenerative burners 1L and 1R alternately perform an exhaust mode and a combustion mode, and the exhaust mode is provided with an exhaust blower. The exhaust gas E of the exhaust system 16 of the exhaust system 16 is ventilated from the burner ports 3L, 3R of the burner bodies 3L, 3R, and is exhausted to the burner bodies 3L, 3R and directly connected thereto. The heat accumulating portions 4L and 4R accumulate heat, and the combustion mode is a flame F generated by the combustion air heated by the heat accumulating portions 4L and 4R from the burner ports 2L and 2R of the burner bodies 3L and 3R to the furnace 5. The inside of the fuel injection nozzles 6L and 6R are provided in a hollow cylindrical shape, and are disposed inside the burner bodies 3L and 3R, and the fuel which is mixed with the combustion air to generate the flame F is supplied from the front end opening 6a to the furnace 5. Internal injection; cooling pipes 8L, 8R, which are provided around the periphery of the fuel nozzles 6L, 6R, and have an opening portion 21 for communicating with the communication portion 22 of the exhaust system 16 and the atmosphere; and a connecting pipe 17L , 17R, etc. connect the connecting portion 22 to the row The system 16 is cooled by the air flowing through the opening 21 to the communication portion 22 through the exhaust suction of the exhaust system 16 of the connecting pipes 17L and 17R, so that the fuel nozzles 6L and 6R are cooled, so that they are used in the exhaust mode. The exhaust blower 14 that discharges the exhaust gas E causes the cooling air to flow into the cooling pipes 8L and 8R to cool the fuel nozzles 6L and 6R, thereby preventing thermal deformation of the fuel nozzles 6L and 6R and, in addition, for The equipment required to cool the fuel nozzles 6L, 6R is only the cooling pipes 8L, 8R surrounding the fuel nozzles 6L, 6R, and the connecting pipes 17L, 17R connecting the cooling pipes 8L, 8R and the exhaust system 16, so that the equipment The cost can be reduced, and the required installation space can be reduced to the space of the tube, so the layout can be simplified.

The communication portion 22 and the opening portion 21 of the cooling pipes 8L and 8R are formed on the side of the base end portion 6b of the fuel nozzles 6L and 6R opposite to the front end opening 6a, and the first tubes are provided in the cooling pipes 8L and 8R. The road 23 surrounds the periphery of the fuel nozzles 6L and 6R, and is formed in the longitudinal direction from the front end opening 6a side to the base end portion 6b side, and communicates with the communication portion 22; the second flow path 24 surrounds the The periphery of the flow path 23 is formed in the longitudinal direction of the fuel nozzles 6L and 6R from the front end opening 6a side and the base end portion 6b side, and communicates with the opening portion 21; and the connection flow path 25 is formed at the fuel nozzle. The first flow path 23 communicates with the second flow path 24 on the side of the end opening 6a before the 6L and 6R. Therefore, the atmosphere extends from the second flow path 24 to the first flow path 23 in the longitudinal direction of the fuel nozzles 6L and 6R. By circulating and reciprocating, the cooling action can be ensured, the cooling can be performed efficiently, and the atmosphere for cooling is not released into the furnace 5, so that the environmental gas in the furnace can be prevented from fluctuating.

One of the regenerative burners 1L and 1R that operates in the exhaust mode while the other is in the combustion mode, and the exhaust systems 16 of the regenerative burners 1L and 1R merge with each other in the exhaust merging portion 16b, and Since the single exhaust blower 14 is provided downstream of the exhaust merging portion 16b, even if the furnace 5 is operated by the pair of regenerative burners 1L, 1R, the fuel can be ensured by the single exhaust blower 14 The nozzles 6L, 6R are alternately combusted while cooling.

Further, in the description of the present embodiment, the case of 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 when the regenerative burner is a separate body.

Fig. 2 is a configuration diagram showing a fuel nozzle cooling structure of the regenerative burner of the second embodiment. Compared with the above-described first embodiment, in the second embodiment, the connection positions of the connecting pipes 26L and 26R with respect to the exhaust system 16 are different, and the effects are different.

In the first embodiment, the connecting pipes 17L and 17R from the communicating portion 22 are connected to the exhaust main pipe 16c. However, in the second embodiment, the connecting pipes 26L and 26R from the communicating portion 22 are provided in the respective regenerative burners 1L, Each of the 1R is connected to an intermediate position between the heat accumulating portions 4L and 4R provided adjacent to the burner main bodies 3L and 3R and directly connected to the exhaust valves 15L and 15R. The other configuration is the same as that of the first embodiment described above.

The action of the fuel nozzle cooling structure of the regenerative burner of the second embodiment will be described. As described above, in the combustion mode, the regenerative burners 1L, 1R are in the vicinity of the end portions 6a of the fuel nozzles 6L, 6R facing the blast ports 2L, 2R for generating the flame F, and are higher than the other portions of the fuel nozzles 6L, 6R. On the other hand, in the exhaust mode, the flame F is extinguished, but a high-temperature exhaust gas E flows through the periphery of the fuel nozzles 6L, 6R.

Therefore, it is preferable that the cooling nozzles 8L and 8R cool the fuel nozzles 6L and 6R so that the inner tube 19 side is at a low temperature in the combustion mode, and the outer tube 20 side is in the exhaust mode. Low temperature.

In the second embodiment, the connection positions of the connecting pipes 26L and 26R with respect to the exhaust system 16 are connected to the intermediate positions of the heat accumulating portions 4L and 4R and the exhaust valves 15L and 15R. Therefore, in the exhaust mode (in the figure, In the same manner as in the above-described first embodiment, the atmosphere that flows through the opening 21 to the communication portion 22 through the exhaust suction function of the exhaust system 16 of the connection pipe 26L is shown in the same manner as in the above-described first embodiment. Initially flowing to the outer tube 20, thereafter flowing to the inner tube 19, whereby the tube 20 exposed to the exhaust gas E can be more efficiently cooled by the lower temperature atmosphere, so that the fuel nozzle 6L can be appropriately cooled. Will not overheat.

On the other hand, in the combustion mode (indicated by the operation of the regenerative burner 1R on the right side in the figure), unlike the above-described first embodiment, the air supply system 13 having the air supply blower 11 is supplied with air. In the combustion air that has moved toward the heat storage unit 4R, a part of the combustion air is bypassed and flows into the connection pipe 26R via the exhaust system 16 (exhaust pipe 16a) that closes the exhaust valve 15R, and then passes through the communication portion 22 via the connection pipe 26R. The combustion air flowing to the opening portion 21 initially flows to the inner tube 19 and thereafter flows to the outer tube 20, whereby the inner tube 19 exposed to the flame F is more efficiently cooled by the combustion air having a lower temperature, thereby The fuel nozzle 6R can be appropriately cooled without overheating.

In other words, the flow directions in the cooling pipes 8L and 8R are changed in accordance with the switching of the operating conditions such as the combustion mode and the exhaust mode, and the good cooling effect of the fuel nozzles 6L and 6R can be ensured.

Further, the connecting pipes 26L and 26R need to be disposed between the burner bodies 3L and 3R which are adjacent to each other and directly connected to the heat accumulating portions 4L and 4R. Therefore, it is not necessary to extend the connecting pipes 17L and 17R as in the first embodiment. By at least the downstream side of the exhaust valves 15L and 15R, the space of the pipe can be reduced, and the reduction in equipment cost and the simplification of the equipment layout can be achieved.

In the second embodiment, it is applied not only to the pair of regenerative burners 1L and 1R but also to the above-described effects when the regenerative burner is a separate body. Further, in the second embodiment, of course, the other operational effects exhibited by the first embodiment are also exhibited.

Claims (4)

 A fuel nozzle cooling structure for a regenerative burner, wherein the regenerative burner alternately performs an exhaust mode and a combustion mode, and the exhaust mode is performed under an exhaust suction function of an exhaust system having an exhaust blower The exhaust gas in the furnace sucked from the burner port of the burner body flows to the heat accumulating portion to accumulate heat, and the combustion mode is a flame generated by the combustion air heated by the heat accumulating portion from the burner body. The fuel injection port is sprayed into the furnace; the fuel nozzle cooling structure of the regenerative burner is characterized in that: a hollow cylinder-shaped fuel nozzle is provided in the burner body, and is sprayed from the front end portion to be mixed with combustion air. a fuel for generating a flame; a cooling pipe provided around the fuel nozzle, having an opening for communicating with the communication portion of the exhaust system and the atmosphere; and a connecting pipe connecting the communication portion to The exhaust system is circulated to the communication portion through the opening portion by an exhaust suction function of the exhaust system via the connection pipe Gas, and the cooling of the fuel nozzle.    A fuel nozzle cooling structure for a regenerative burner in which an exhaust mode and a combustion mode are alternately repeated, and the exhaust mode opens an exhaust valve that opens and closes an exhaust system having an exhaust blower and is closed The air supply valve having the air supply system of the air supply blower is opened and closed, and the exhaust gas in the furnace sucked from the fire outlet of the burner body is circulated to the heat storage portion by the exhaust suction of the exhaust system The heat is accumulated and discharged to the exhaust system via the exhaust valve, the combustion mode is to close the exhaust valve and open the air supply valve to be supplied to the burner body under the air supply of the air supply system The combustion air flows to the heat accumulating portion to be heated, and the flame generated by the heated combustion air is ejected from the blast port of the burner body into the furnace; the fuel nozzle cooling structure of the regenerative burner is characterized by: hollow a cylindrical fuel nozzle which is disposed inside the burner body and sprays a fuel which is mixed with combustion air to generate a flame from a front end portion thereof; and a cooling pipe which surrounds the burning Provided around the material nozzle, having a communication portion for communicating with the exhaust system and an opening portion for opening the atmosphere; and a connection pipe connecting the communication portion between the heat storage portion and the exhaust valve In the exhaust system, in the exhaust mode, the fuel nozzle is cooled and burned by the atmosphere that flows through the opening through the opening through the exhaust system of the connecting pipe. In the mode, the cooling nozzle is cooled by the combustion air that flows through the connection pipe and flows through the communication portion to the opening portion by the air supply of the air supply system.    The fuel nozzle cooling structure of the regenerative burner according to claim 1 or 2, wherein the communication portion and the opening portion of the cooling tube are formed on a base end side opposite to a tip end portion of the fuel nozzle, The cooling pipe includes a first flow path, a second flow path, and a connection flow path; the first flow path surrounds the periphery of the fuel nozzle, and is formed in the longitudinal direction from the front end side to the base end side, and is connected In the communication portion, the second flow path surrounds the periphery of the first flow path, and is formed in the longitudinal direction of the fuel nozzle from the front end side to the base end side, and communicates with the opening; the connection flow The road system connects the first flow path and the second flow path to the front end side of the fuel nozzle.    The regenerative burner cooling structure according to any one of claims 1 to 3, further comprising: a pair of the regenerative burners, wherein one of the pair of regenerative burners is in a combustion mode, and the other The exhaust system is operated in an exhaust mode; the exhaust systems of the regenerative burners merge with each other at a merging portion, and a single exhaust blower is provided downstream of the merging portion.