TWI755441B - 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 of a regenerative burner, which can reduce the equipment cost and required installation space required for the cooling of the fuel nozzle by using an exhaust blower that discharges air in an exhaust operation mode, Furthermore, the layout of piping and the like is also simplified.

Various furnaces using a regenerative burner are known (refer to Patent Document 1), and at this time, a structure in which a regenerative burner is cooled is also known (refer to Patent Documents 2 and 3). The "Industrial Furnace, the Energy-Saving Operation Method of the Industrial Furnace, and the Renovation Method of the Industrial Furnace" of Patent Document 1 is configured to include: an exhaust pipe that connects the combustion chamber and the chimney; The external atmosphere (ATM, Atmosphere) is taken into the exhaust pipe; and the impeller, which is connected to the suction blower functioning as a generator, is taken in and flows through the opened suction valve The outside atmosphere of the tube rotates to generate electricity. In Patent Document 1, two regenerative burners are alternately switched between the combustion operation and the exhaust operation.

The "low _NOx burner for high-temperature air" disclosed in Patent Document 2 is configured such that a baffle plate is fitted to a front end portion of a fuel nozzle for injecting fuel in a shape of an outer fit, and a slit-shaped secondary air is formed on the outer periphery of the baffle plate. The supply hole, the fuel nozzle is constituted as a double tube with the inner peripheral part as the fuel passage and the outer peripheral part as the cooling air passage; A plurality of primary air supply holes at an angle of 30 to 50° are arranged in the plane with the same pitch circle diameter from the inlet to the outlet, and fuel, cooling air, and The primary air outlet. In the burner of Patent Document 2, the air used for cooling 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 only used for cooling the cooling air tube, and it is used during the traveling and traveling back and forth. Cooling is performed to effectively prevent overheating of the cooling air pipe. A double-layered pipe including an inner pipe and an outer pipe is arranged on the outer periphery of the fuel nozzle pipe, and a cooling air pipe is provided. The cooling air pipe is configured to connect the outer pipe and the outer pipe. The front end opening of the fuel nozzle pipe is closed with a cover, and the outer passage between the outer pipe and the inner pipe and the inner passage between the inner pipe and the fuel nozzle pipe are communicated via the cover. In Patent Document 3, the introduced air for cooling is not released into the furnace, but the introduced air is fed into the air cooling pipe, so it is necessary to provide a blower.

[Prior Art Literature] [Patent Literature]

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

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

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

The ambient gas in the furnace heated in the regenerative burner is preferably homogeneous and does not change. In this regard, it is preferable to use a cooling structure that does not introduce air into the fuel nozzle provided in the regenerative burner. The double tube structure of Patent Document 3 released into the furnace.

However, Patent Document 3 does not disclose anything about how to supply the introduced air to the air cooling pipe. Generally, it is considered to install a new blower or an additional blower, and to supply the intake air from the blower to the air supply pipe. When a blower or the like is newly installed, there is a problem in that the required equipment cost including piping is incurred, and at the same time, it is necessary to secure an installation space.

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

In the fuel nozzle cooling structure of the regenerative burner of the present invention, the regenerative burner alternately and repeatedly performs an exhaust mode and a combustion mode, and the exhaust mode causes the exhaust gas in the exhaust system with the exhaust blower to be pumped. The exhaust gas in the furnace, which is sucked from the nozzle of the burner body under the suction action, flows to the heat storage part to store the exhaust heat. The flame nozzle of the burner body is sprayed into the furnace; it is characterized by having: a hollow cylindrical fuel nozzle, which is arranged inside the burner body, and sprays fuel mixed with combustion air from its front end to generate a flame; cooling a pipe, which is provided to surround the outer periphery of the above-mentioned fuel nozzle, and has a communication part for communicating with the above-mentioned exhaust system and an opening part open to the atmosphere; and a connecting pipe, which connects the above-mentioned communication part to the above-mentioned exhaust system; by The fuel nozzle is cooled by the air flowing through the opening portion to the communication portion by the exhaust gas suction of the exhaust system through the connecting pipe.

In addition, in the fuel nozzle cooling structure of the regenerative burner of the present invention, the regenerative burner alternately repeats the exhaust mode and the combustion mode, and the exhaust mode opens and closes the exhaust system having the exhaust fan. The air valve is closed and the air supply valve that opens and closes the air supply system with the air supply blower, so that the exhaust gas in the furnace that is sucked from the flame outlet of the burner body under the exhaust suction action of the exhaust system can circulate to the heat storage. The exhaust heat is accumulated and discharged to the exhaust system through the exhaust valve. In the above combustion mode, the exhaust valve is closed and the air supply valve is opened, so that the air is supplied to the exhaust system under the action of the air supply system. The combustion air supplied by the burner body flows to the heat storage part for heating, and the flame generated by the heated combustion air is ejected from the burner body of the burner body into the furnace; it is characterized by having: a hollow cylindrical fuel nozzle , which is arranged inside the above-mentioned burner body, and injects fuel mixed with combustion air from its front end to generate flame; The communication part and the opening part open to the atmosphere; and the connecting pipe, which connects the communication part to the exhaust system at the intermediate position between the heat storage part and the exhaust valve; in the exhaust mode, the connection is made through the connection. The air flowing through the opening part to the communication part by the exhaust suction of the exhaust system of the pipe cools the fuel nozzle, and in the combustion mode, the heat is stored in the heat by the air supply of the air supply system. The cooling nozzle is cooled by the combustion air circulating through the connecting pipe and through the communication portion to the opening portion by detouring the portion.

The above-mentioned communication part and the above-mentioned opening part of the above-mentioned cooling pipe are formed on the base end part side opposite to the front end part of the above-mentioned fuel nozzle, and the above-mentioned cooling pipe is provided with: a first flow path, a second flow path and a connection a flow path, the first flow path surrounds the periphery of the fuel nozzle, is formed to span from the front end portion side to the base end portion side in the longitudinal direction, and communicates with the communication portion, and the second flow path surrounds the first flow path A periphery of a flow passage is formed to span from the front end portion side to the base end portion side in the longitudinal direction of the fuel nozzle, and communicate with the opening portion, and the connection flow passage connects the first flow passage and the second flow passage. It communicates with the front end side of the fuel nozzle.

It is characterized by comprising a pair of the above-mentioned regenerative burners, one of the pair of the above-mentioned regenerative burners is operated in the combustion mode, and the other is operated in the exhaust mode, and the above-mentioned exhaust systems of the regenerative burners are mutually Converging at the junction, the single exhaust blower described above is provided downstream of the junction.

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

1L, 1R‧‧‧Regenerative burner

2L, 2R‧‧‧Flat

3L, 3R‧‧‧burner body

3a‧‧‧The other end of the burner body

4L, 4R‧‧‧Regenerator

4a‧‧‧One end of the heat storage part

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

5‧‧‧furnace

6L, 6R‧‧‧fuel nozzle

6a‧‧‧Open front end of fuel nozzle

6b‧‧‧Base end of fuel nozzle

8L, 8R‧‧‧cooling tube

9L, 9R‧‧‧Open/close valve for fuel

10‧‧‧Fuel supply system

11‧‧‧Air supply blower

12L, 12R‧‧‧Air supply valve

13‧‧‧Air supply system

13a‧‧‧Combustion air supply pipe

13b‧‧‧Combustion air junction

13c‧‧‧Combustion air supply main

14‧‧‧Exhaust blower

15L, 15R‧‧‧exhaust valve

16‧‧‧Exhaust system

16a‧‧‧Exhaust pipe

16b‧‧‧Exhaust junction

16c‧‧‧Exhaust main

17L, 17R‧‧‧connecting pipe

19‧‧‧Inner tube

19a‧‧‧Blocking end plate

20‧‧‧Outer tube

20a‧‧‧First sealing end plate

20b‧‧‧Second sealing end plate

21‧‧‧Opening

22‧‧‧Connectivity

23‧‧‧First stream

24‧‧‧Second stream

25‧‧‧Connection flow path

26L, 26R‧‧‧connecting pipe

E‧‧‧Exhaust

F‧‧‧Flame

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

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

Hereinafter, a preferred embodiment 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 block 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 conventionally provided with: burner main bodies 3L and 3R, which have burner ports 2L and 2R at one end facing the inside of the furnace 5; The other ends 3a of the burner bodies 3L and 3R are adjacent to and directly connected to the burner bodies 3L and 3R; The combustion mode in which the flame F is sprayed into the furnace 5 to heat the furnace 5 (for example, about 1,000° C.), and the exhaust mode in which the exhaust gas E in the furnace 5 is sucked and discharged from the flame injection ports 2L and 2R is one of the opposite. The pairs are alternately and repeatedly switched to operate.

In the regenerative burners 1L, 1R, in the exhaust mode, the exhaust gas E is sucked from the furnace 5 by the exhaust suction action of the exhaust system 16 with the exhaust air blower 14, and the sucked The exhaust gas E flows through the heat storage parts 4L and 4R, whereby the exhaust heat of the exhaust gas E is accumulated in the heat storage parts 4L and 4R, and the exhaust gas E having passed through the heat storage parts 4L and 4R is cooled down (for example, about 200° C.) and directed toward the heat storage parts 4L and 4R. The exhaust system 16 is discharged, and then, when the operation is switched from the exhaust mode to the combustion mode, the combustion air is circulated to the heat storage parts 4L and 4R by the air supply of the air supply system 13 having the air supply blower 11, and the accumulated air is used. The combustion air is preheated (heated) by the exhaust heat of the exhaust gas E of the heat storage parts 4L and 4R.

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 inside the burner main bodies 3L and 3R, and burned. The main bodies 3L and 3R generate the flame F under the energy-saving operation utilizing the exhaust heat.

When the regenerative burners 1L and 1R are used, the burners 1L and 1R are used as a pair so that the temperature in the furnace does not change 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) operates in the exhaust mode, and when the former is switched to the exhaust mode, the latter is switched to the combustion mode The operation is controlled according to the mode so that the combustion mode and the exhaust mode are alternated between the pair of regenerative burners 1L and 1R.

In the example shown in the figure, burner bodies 3L and 3R are provided in a pair on each of the left and right furnace side walls which are opposed to each other among the furnace walls constituting the quadrangular cross-sectional shape of the furnace 5 . A pair of burner bodies can also be adjacently disposed on the same wall.

In the fuel nozzle cooling structure of the regenerative burner according to the present embodiment, as shown in FIG. 1 , each of the left and right regenerative burners 1L and 1R is configured to include the burner main bodies 3L and 3R in the form of passages, which are equal to One end is provided with flaming ports 2L, 2R open to the inside of the furnace 5; the heat storage parts 4L, 4R, one end 4a of which is connected to the other end 3a of the burner body 3L, 3R; the hollow cylinder-shaped fuel nozzles 6L, 6R, whose It is provided through the other end 3a side of the burner body 3L, 3R and inserted into the burner body 3L, 3R from the outside, and the front end opening 6a faces the burner ports 2L, 2R, and is mixed with the combustion air to generate the flame F. Fuel such as fuel gas is injected from the front end opening 6a to the burner ports 2L and 2R; the cooling pipes 8L and 8R are provided to surround the outer periphery of the fuel nozzles 6L and 6R and penetrate the other end 3a side of the burner bodies 3L and 3R. And inside the burner body 3L, 3R, it extends from the outside to the front end opening 6a of the fuel nozzles 6L, 6R or its vicinity; the fuel supply system 10 has a fuel on-off valve 9L for controlling the supply and stop of the fuel, 9R (in the figure, blank is shown as open, and black is shown as closed), which is connected to the respective fuel nozzles 6L, 6R at the base end 6b side of the fuel nozzles 6L, 6R on the opposite side of the front end opening 6a on the one end side in the longitudinal direction, The fuel is supplied to the front end openings 6a of the fuel nozzles 6L, 6R; the air supply system 13 has an air supply blower 11 for supplying combustion air to the burner bodies 3L, 3R, and an opening and closing control for supplying and stopping the combustion air The free air supply valves 12L and 12R (in the figure, the blank is shown as open, and the black is shown as closed) is connected to the other end 4b of each of the heat storage parts 4L and 4R to supply combustion air to the heat storage parts 4L and 4R; and The exhaust system 16 has an exhaust blower 14 for sucking the exhaust gas E in the furnace 5 from the burner ports 2L and 2R and discharging it to the outside of the furnace 5, and the control of the discharge and stop of the exhaust gas E can be freely opened and closed. Exhaust valves 15L and 15R (in the figure, the blank is shown as open, and the black is shown as closed) is connected to the other end 4b of each of the heat storage parts 4L and 4R, and the exhaust gas E flowing out of the heat storage parts 4L and 4R flows.

Specifically, the air supply system 13 is composed of a pair of combustion air supply pipes 13a, which are directly connected to the regenerators 4L, 4R of the pair of regenerative burners 1L, 1R, respectively, and are respectively supplied to the Combustion air supplied from the heat accumulators 4L, 4R circulates; a combustion air merging part 13b which joins the combustion air supply pipes 13a; and a combustion air supply main pipe 13c which is connected to each combustion air supply pipe via the combustion air merging part 13b 13a; and the air supply blower 11 is installed 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 are installed in the combustion air supply pipe 13a to regenerate the pair of regenerative burners 1L and 1R. The operation modes of the type burners 1L and 1R are individually switched.

Moreover, 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 the combustion is fed under the action of air supply from the air supply system 13 Air flows through the air supply valve 12R (12L) to the heat storage part 4R (4L), and is supplied from the heat storage part 4R (4L) to the burner port 2R (2L) of the burner body 3R (3L).

Specifically, the exhaust system 16 is constituted by a pair of exhaust pipes 16a, which are directly connected to the regenerators 4L and 4R of the pair of regenerative burners 1L and 1R, respectively, and are supplied from the respective regenerators 4L. The exhaust gas E discharged from 4R and 4R circulates; the exhaust gas merging portion 16b, which allows the exhaust pipes 16a to merge with each other; and the exhaust main pipe 16c, which is connected to each exhaust pipe 16a through the exhaust gas merging portion 16b; The air blower 14 is installed in the exhaust main pipe 16c to discharge the exhaust gas E from both of the pair of regenerative burners 1L and 1R, and the exhaust valves 15L and 15R are installed in the exhaust pipe 16a to connect the pair of regenerative burners 1L and 1R to the exhaust pipe 16a. The operation mode of 1R can be switched individually.

In addition, in the regenerative burner 1L (1R) in the exhaust mode, the exhaust valve 15L (15R) is opened and the supply valve 12L (12R) is closed to be sucked by the exhaust gas of the exhaust system 16. The suctioned exhaust gas E flows from the burner port 2L (2R) of the burner body 3L (3R) to the heat storage part 4L (4R), and then flows from the heat storage part 4L (4R) to the exhaust gas through the exhaust valve 15L (15R) System 16 drains.

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

The air supply valves 12L and 12R are opened when the regenerative burners 1L and 1R are in the combustion mode so as to supply combustion air to the burner ports 2L and 2R of the burner body 3L and 3R through the regenerators 4L and 4R, and in the exhaust mode 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 as to allow exhaust gas from the burner bodies 3L and 3R to be exhausted from the burner ports 2L and 2R of the suction furnace 5 via the heat storage parts 4L and 4R. E, is turned off in combustion mode to stop the suction of exhaust gas E. The supply air blower 11 and the exhaust air blower 14 are generally always running during the operation of the furnace 5 .

In the present embodiment, with respect to the basic configuration of the regenerative burners 1L and 1R described above, the regenerative burners 1L and 1R are provided with burner ports 2L and 2R for cooling the high temperature, respectively, and a high temperature is circulated in the periphery thereof. The cooling structure of the fuel nozzles 6L, 6R of the exhaust gas E. The cooling structure of the fuel nozzles 6L and 6R is mainly composed of the following components: the above-mentioned cooling pipes 8L and 8R and the connecting pipes 17L and 17R connecting the cooling pipes 8L and 8R to the exhaust system 16 .

The cooling pipes 8L and 8R are composed of an inner pipe 19 which surrounds the outer periphery of the fuel nozzles 6L and 6R and is formed in a tubular shape in the longitudinal direction from the front end opening 6a side to the base end 6b side. The base ends 6b of the fuel nozzles 6L and 6R on the outer sides of the fuel nozzles 3L and 3R are blocked by an annular blocking end plate 19a that engages with the outer peripheral surfaces of the fuel nozzles 6L and 6R. The front end side is open close to the flaming ports 2L and 2R; the outer tube 20, which surrounds the periphery of the inner tube 19, is formed to span from the front end opening 6a side to the base end 6b side in the longitudinal direction of the fuel nozzles 6L and 6R. Tubular, on the base end 6b side of the fuel nozzles 6L, 6R outside the burner body 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, and At the position of the front end openings 6a of the fuel nozzles 6L and 6R extending to the side of the burners 2L and 2R relative to the inner pipe 19, the front end side of the inner pipe 19 is covered from the side of the burners 2L and 2R, and is connected to the fuel nozzle. An annular second sealing end plate 20b joined to the outer peripheral surfaces of the 6L and 6R seals the front end portion side; The opening portion 21 of the outer pipe 20 and the communication portion 22 formed in the inner pipe 19 so as to communicate with the exhaust system 16 .

Furthermore, the cooling pipes 8L and 8R are provided with a first flow path 23, a second flow path 24, and a connecting flow path 25 by the inner pipe 19 and the outer pipe 20, and the first flow path 23 surrounds the fuel nozzle. The peripheries of 6L and 6R are formed to span from the front end portion opening 6a side to the base end portion 6b side in the longitudinal direction, and communicate with the communicating portion 22, the second flow path 24 surrounds the periphery of the first flow path 23, The fuel nozzles 6L and 6R are formed to span from the front end opening 6a side to the base end 6b side in the longitudinal direction of the fuel nozzles 6L and 6R, and communicate with the opening 21. The connecting flow path 25 is connected to the front end openings 6a of the fuel nozzles 6L and 6R. On the side, the first flow path 23 and the second flow path 24 are communicated with each other so that the flow path is folded back.

That is, the exhaust system 16 which performs the exhaust gas suction function is opened to the atmosphere through the periphery of the fuel nozzles 6L and 6R. Further, the communication portion 22 of the cooling pipes 8L, 8R is connected to the exhaust system 16 via the connection pipes 17L, 17R, and in the present embodiment is connected to the exhaust pipe 16a from each of the heat storage portions 4L, 4R merged The downstream side of the exhaust gas confluence part 16b is provided with the exhaust main pipe 16c of the exhaust air blower 14 only. The connection positions of the connecting pipes 17L and 17R of the regenerative burners 1L and 1R with respect to the exhaust system 16 can be connected to any position as long as they are the intermediate positions of the exhaust valves 15L and 15R and the exhaust blower 14 .

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

The exhaust gas E, which flows through the heat storage part 4L of the regenerative burner 1L in the exhaust mode and is stored in the heat storage part 4L to be cooled down by the exhaust suction action by the exhaust air blower 14, passes through the opened exhaust valve 15L. reaches the exhaust blower 14 and is discharged.

The exhaust suction action of the exhaust air blower 14 acts on the communication portion 22 of the cooling pipes 8L, 8R from the exhaust main pipe 16c via the two connecting pipes 17L, 17R. The communication portion 22 communicates with the opening portion 21 open to the atmosphere via the first flow path 23 , the connecting flow path 25 , and the second flow path 24 , so that the atmosphere is passed through the opening portion by the exhaust suction action of the exhaust blower 14 21 flows into the two cooling pipes 8L and 8R toward the communication portion 22 .

Atmosphere at room temperature with a temperature far lower than the temperature of one end 4a (about 1,000°C) of the regenerators 4L and 4R is released from the openings on the base end side of the cooling pipes 8L and 8R of the pair of regenerative burners 1L and 1R. 21. The front ends of the fuel nozzles 6L and 6R provided in the regenerative burners 1L and 1R are opened to the front ends of the fuel nozzles 6L and 6R provided in the regenerative burners 1L and 1R in one of the combustion mode and the exhaust mode, which are in a high temperature state. 6a flows through the second flow path 24 in the outer pipe 20, and is folded back at the connecting flow path 25 to flow through the first flow path 23 in the inner pipe 19, thereby connecting the two regenerative burners 1L and 1R. The fuel nozzles 6L and 6R are cooled, and after cooling, of course, they do not flow out into the furnace 5, but an exhaust system in which the exhaust gas E is circulated from the communication portion 22 under the exhaust suction action of the single exhaust blower 14. 16 Suction and discharge.

Even if the regenerative burner 1L on the left is switched to the combustion mode, and the regenerative burner 1R on the right is switched to the exhaust mode, it must be ensured that the exhaust blower 14 is always introduced by the exhaust suction when it is running. The left and right fuel nozzles 6L and 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 and repeatedly perform the exhaust mode and the combustion mode. The exhaust gas E in the furnace that is sucked from the burner bodies 3L, 3R from the burner ports 2L, 2R under the action of the exhaust gas suction of the exhaust system 16 of 14 circulates to the burner body 3L, 3R and is adjacent to and directly connected to the set. The heat storage parts 4L, 4R store the exhaust heat, and the above-mentioned combustion mode sends the flame F generated by the combustion air that flows through the heat storage parts 4L and 4R and is heated to the furnace 5 from the burner bodies 3L and 3R. The internal ejection is provided with: hollow cylindrical fuel nozzles 6L, 6R, which are arranged inside the burner bodies 3L, 3R, and the fuel that mixes with the combustion air to generate the flame F is directed to the furnace 5 from the front end opening 6a. Internal injection; cooling pipes 8L, 8R, which are provided to surround the outer periphery of the fuel nozzles 6L, 6R, and have a communication portion 22 for communicating with the exhaust system 16 and an opening portion 21 open to the atmosphere; and a connecting pipe 17L , 17R, etc. connect the communication part 22 to the exhaust system 16; by the air flowing through the opening part 21 to the communication part 22 under the action of exhaust suction of the exhaust system 16 through the connecting pipes 17L, 17R, the fuel Since the nozzles 6L and 6R are cooled, the exhaust air blower 14 for discharging the exhaust gas E in the exhaust mode allows the air for cooling to flow into the cooling pipes 8L and 8R to cool the fuel nozzles 6L and 6R, thereby preventing the fuel nozzles 6L and 6R from being cooled. Thermal deformation of 6L, 6R, and, furthermore, the equipment required for cooling the fuel nozzles 6L, 6R is only the cooling pipes 8L, 8R surrounding the fuel nozzles 6L, 6R and connecting the cooling pipes 8L, 8R to the exhaust system. The connecting pipes 17L and 17R connected by 16 are sufficient, so the equipment cost can be reduced, and the required installation space can also be reduced to the level of the pipe space, so the layout can also be simplified.

The communication portion 22 and the opening portion 21 of the cooling pipes 8L, 8R are formed on the base end portion 6b side of the fuel nozzles 6L, 6R on the opposite side to the front end portion opening 6a, and the cooling pipes 8L, 8R are provided with: a first flow A passage 23, which surrounds the periphery of the fuel nozzles 6L, 6R, is formed in the longitudinal direction from the front end portion opening 6a side to the base end portion 6b side, and communicates with the communication portion 22; the second flow passage 24, which surrounds the first 1. The periphery of the flow path 23 is formed to span from the front end portion opening 6a side to the base end portion 6b side in the longitudinal direction of the fuel nozzles 6L, 6R, and communicate with the opening portion 21; and the connecting flow path 25, which is connected to the fuel nozzle The front end openings 6a of 6L and 6R allow the first flow path 23 and the second flow path 24 to communicate with each other; therefore, the atmosphere is caused to span 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 effect can be ensured, the cooling can be efficiently performed, and the atmosphere for cooling is not released into the furnace 5, so the fluctuation of the ambient gas in the furnace can be prevented.

A pair of regenerative burners 1L and 1R is provided when one is in the combustion mode and the other is operated in the exhaust mode, and the exhaust systems 16 of the regenerative burners 1L and 1R merge with each other at the exhaust junction 16b, and A single exhaust air blower 14 is provided downstream of the exhaust gas confluence portion 16b, so even in the furnace 5 operating with the pair of regenerative burners 1L and 1R, the single exhaust air blower 14 can ensure that both the fuel and the The nozzles 6L and 6R alternately burn while cooling.

In addition, in the description of this embodiment, the case where it is applied to a pair of regenerative burners 1L and 1R has been described, but it is not limited to a pair.

Fig. 2 is a block diagram showing a fuel nozzle cooling structure of a regenerative burner according to a 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, which results in different functions.

In the first embodiment, the connection pipes 17L and 17R from the communication part 22 are connected to the exhaust main pipe 16c, but in the second embodiment, the connection pipes 26L and 26R from the communication part 22 are connected to the respective regenerative burners 1L and 16c. In each of 1R, it is connected to the intermediate position of the heat storage parts 4L and 4R and the exhaust valves 15L and 15R provided adjacent to and directly connected to the burner bodies 3L and 3R. The configuration other than that is the same as that of the above-mentioned 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 combustion mode of the regenerative burners 1L and 1R, the vicinity of the front end openings 6a of the fuel nozzles 6L and 6R facing the burners 2L and 2R where the flame F is generated is higher than the other parts of the fuel nozzles 6L and 6R. On the other hand, in the exhaust mode, the flame F is extinguished, but the high-temperature exhaust gas E circulates around the fuel nozzles 6L and 6R.

Therefore, with regard to the cooling of the fuel nozzles 6L and 6R by the cooling pipes 8L and 8R, it is preferable to make the inner pipe 19 side low temperature in the combustion mode, and to make the outer pipe 20 side low temperature in the exhaust mode. low temperature.

In the second embodiment, the connection positions of the connecting pipes 26L, 26R with respect to the exhaust system 16 are connected to the intermediate positions of the heat storage parts 4L, 4R and the exhaust valves 15L, 15R, so in the exhaust mode (in the figure, the In the operation of the regenerative burner 1L on the left), as in the first embodiment described above, the atmosphere that flows through the opening 21 to the communication portion 22 is caused by the exhaust gas suction of the exhaust system 16 via the connecting pipe 26L. It first flows through the outer pipe 20 and then flows through the inner pipe 19, whereby the outer pipe 20 exposed to the exhaust gas E can be cooled more efficiently by the lower temperature atmosphere, so that the fuel nozzle 6L can be properly cooled. Will not overheat.

On the other hand, in the combustion mode (in the figure, the operation of the regenerative burner 1R on the right side is shown), different from the above-mentioned first embodiment, the air supply is supplied by the air supply function of the air supply system 13 having the air supply blower 11 And a part of the combustion air toward the heat storage part 4R detours in the heat storage part 4R and flows into the connecting pipe 26R through the exhaust system 16 (exhaust pipe 16a) that closes the exhaust valve 15R, and then passes through the communication part 22 through the connecting pipe 26R. The combustion air flowing to the opening portion 21 first flows through the inner pipe 19 and then flows through the outer pipe 20, whereby the inner pipe 19 exposed to the flame F is more efficiently cooled by the combustion air having a lower temperature, so that The fuel nozzles 6R can be appropriately cooled without overheating.

That is, the flow direction in the cooling pipes 8L, 8R is changed according to the switching of the operation conditions such as the combustion mode or the exhaust mode, and the good cooling effect of the fuel nozzles 6L, 6R can be ensured.

In addition, the connecting pipes 26L and 26R only need to be arranged between the burner main bodies 3L and 3R and the heat storage parts 4L and 4R, which are adjacent to each other and directly connected to each other. Therefore, there is no need to extend the connecting pipes 17L and 17R as in the first embodiment. At least on the downstream side of the exhaust valves 15L and 15R, the space of the pipe can be reduced, and the reduction of the equipment cost and the simplification of the equipment layout can be achieved.

In the second embodiment, not only the application to the pair of regenerative combustors 1L and 1R, but also when the regenerative combustor is a single body, the above-mentioned effects can be obtained. In addition, in the second embodiment, it goes without saying that the other functions and effects exhibited by the first embodiment are also exhibited.

1L, 1R‧‧‧Regenerative burner

2L, 2R‧‧‧Flat

3L, 3R‧‧‧burner body

3a‧‧‧The other end of the burner body

4L, 4R‧‧‧Regenerator

4a‧‧‧One end of the heat storage part

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

5‧‧‧furnace

6L, 6R‧‧‧fuel nozzle

6a‧‧‧Open front end of fuel nozzle

6b‧‧‧Base end of fuel nozzle

8L, 8R‧‧‧cooling tube

9L, 9R‧‧‧Open/close valve for fuel

10‧‧‧Fuel supply system

11‧‧‧Air supply blower

12L, 12R‧‧‧Air supply valve

13‧‧‧Air supply system

13a‧‧‧Combustion air supply pipe

13b‧‧‧Combustion air junction

13c‧‧‧Combustion air supply main

14‧‧‧Exhaust blower

15L, 15R‧‧‧exhaust valve

16‧‧‧Exhaust system

16a‧‧‧Exhaust pipe

16b‧‧‧Exhaust junction

16c‧‧‧Exhaust main

17L, 17R‧‧‧connecting pipe

19‧‧‧Inner tube

19a‧‧‧Blocking end plate

20‧‧‧Outer tube

20a‧‧‧First sealing end plate

20b‧‧‧Second sealing end plate

21‧‧‧Opening

22‧‧‧Connectivity

23‧‧‧First stream

24‧‧‧Second stream

25‧‧‧Connection flow path

E‧‧‧Exhaust

F‧‧‧Flame

Claims (5)

A fuel nozzle cooling structure for a regenerative burner, the regenerative burner alternately and repeatedly performs an exhaust mode and a combustion mode, and the exhaust mode is made under the action of exhaust suction by an exhaust system with an exhaust blower The exhaust gas in the furnace sucked from the flame outlet of the burner body flows to the heat storage part to store the exhaust heat. The flame generated by the heated combustion air is ejected into the furnace from the nozzle of the burner body; the fuel nozzle cooling structure of the regenerative burner is characterized in that it includes a hollow cylindrical fuel nozzle, which is arranged on the burner. Inside the main body, the fuel that mixes with the combustion air to generate a flame is injected from its front end; the cooling pipe is arranged to surround the outer periphery of the above-mentioned fuel nozzle, and has a communication part for communicating with the above-mentioned exhaust system and an opening to the atmosphere. an opening; and a connecting pipe, which connects the communication part to the exhaust system; by the atmosphere that flows through the opening to the communication part under the action of exhaust suction from the exhaust system through the connection pipe, and Cool the above fuel nozzles. A fuel nozzle cooling structure for a regenerative burner that alternately and repeatedly performs an exhaust mode and a combustion mode, the exhaust mode opening and closing an exhaust valve that opens and closes an exhaust system with an exhaust blower Open and close the air supply valve of the air supply system with the air supply blower, so that the exhaust gas in the furnace that is sucked from the flame outlet of the burner body under the action of the exhaust gas suction of the exhaust system flows to the heat storage part to discharge the exhaust gas. The heat is accumulated and discharged to the exhaust system through the exhaust valve. The above combustion mode is to close the exhaust valve and open the air supply valve, so that the air is supplied to the burner body under the action of the air supply system. The combustion air circulates to the heat storage part for heating, and the flame generated by the heated combustion air is ejected into the furnace from the nozzle of the burner body; the regenerative burner has a The fuel nozzle cooling structure is characterized by comprising: a hollow cylindrical fuel nozzle installed inside the burner body, and injecting fuel that is mixed with combustion air to generate a flame from the front end thereof; and a cooling pipe that surrounds the fuel The nozzle is provided around the outside of the nozzle, and has an opening for communicating with a communication part of the exhaust system and an opening part open to the atmosphere; and a connecting pipe, which connects the communication part to the intermediate position of the heat storage part and the exhaust valve. The above-mentioned exhaust system; in the exhaust mode, the fuel nozzle is cooled by the air flowing through the above-mentioned opening part to the above-mentioned communication part by the exhaust gas suction of the above-mentioned exhaust system through the above-mentioned connecting pipe, and in the combustion mode During this time, the fuel nozzle is cooled by the combustion air circulating through the connecting pipe and through the connecting portion to the opening portion by detouring in the heat storage portion due to the air supply of the air supply system. The fuel nozzle cooling structure of a regenerative burner according to claim 1 or 2, wherein the communication portion and the opening portion of the cooling pipe are formed on the base end portion side opposite to the front end portion of the fuel nozzle, and are formed on the side of the base end portion opposite to the front end portion of the fuel nozzle. The cooling pipe includes a first flow path, a second flow path, and a connecting flow path; the first flow path surrounds the periphery of the fuel nozzle, is formed to span from the front end side to the base end side in the longitudinal direction, and communicate with each other. in the communication part; the second flow path surrounds the periphery of the first flow path, is formed from the front end side to the base end side in the longitudinal direction of the fuel nozzle, and communicates with the opening part; the connection flow The channel system communicates the first flow channel and the second flow channel on the front end side of the fuel nozzle. The fuel nozzle cooling structure for a regenerative burner according to claim 1 or 2, wherein a pair of the regenerative burners is provided, and when one of the pair of the regenerative burners is in the combustion mode, the other is in the exhaust mode. Air mode operation; the exhaust systems of the regenerative burners merge with each other at a junction, and a single exhaust blower is provided downstream of the junction. The fuel nozzle cooling structure for a regenerative burner according to claim 3, wherein a pair of the regenerative burners is provided, and when one of the pair of the regenerative burners is in the combustion mode, the other is in the exhaust mode Operation: The exhaust systems of the regenerative burners merge with each other at a junction, and a single exhaust blower is provided downstream of the junction.

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