JPS6225930B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a burner mechanism used in a high-temperature furnace with an internal temperature of 1500°C to 1900°C.
An object of the present invention is to provide an energy-saving oil burner that reduces heat loss from a burner section.

Conventional burners used in high-temperature furnaces, especially tunnel kilns,
℃ high temperature atmosphere from inside the furnace and temperature 700℃~
A water-cooled pipe is also used to protect the burner tip from high-temperature secondary air of 1200℃.

Furthermore, recently, as part of energy conservation, it has become increasingly common to recover and use waste gas sensible heat as secondary air for combustion, and as the temperature of secondary air for combustion increases, conventional metal nozzles Burners are moving toward shorter lifespans such as high-temperature oxidation. In order to protect the tip of the burner from this high temperature, many burners of this type use a water cooling system.

However, such water-cooled burners have the following drawbacks. That is, the heat loss due to water cooling is as high as 8,000 to 12,000 KCal/hr per burner, and there are also problems such as leakage of water cooling pipes and carbon adhesion to the tips, which requires a lot of effort to maintain and manage the burners. For example, in the case of a tunnel kiln with 14 burners, the total water cooling heat loss is 112,000 ~
It becomes 168000KCal/hr. Even if a water-cooled system is adopted, the service life is short when used in a high-temperature furnace, making it unsuitable for long-term use.

The present applicant previously developed a burner with an air nozzle in which the air nozzle and the attached components burner tile, wind box, and burner support tile were made of ceramic materials (Japanese Unexamined Patent Application Publication No. 1989-1999).
164033: Patent No. 1195723). Although this burner relates to a so-called top-combustion type burner and partially uses ceramic materials, its purpose of use and structure are completely different from the side-combustion type high-temperature ceramic burner of the present invention. be.

The present invention has been made to solve the problems of the water-cooled burner described above.

If the high-temperature burner is not water-cooled, a high-temperature refractory material is required in place of metal. Ceramic materials are generally considered for this, but ceramic materials have the following properties: There are problems such as damage due to the difference in expansion. For this reason, among the members that make up the burner, we first considered using ceramic for the tip and the outer peripheral protection tube to suppress the effects of radiant heat received by the tip and cross-flow heat from high-temperature secondary air. In particular, the ceramic material used in the present invention is selected to be sufficiently resistant to thermal shock, and the joint portion with metal has a structure in which the difference in expansion does not have a relatively negative effect. That is, as an alternative to metal, the end air nozzle of the burner and the outer circumferential protective cylinder of the air pipe are made of ceramic to suppress the effects of radiant heat received at the end and heat passing through from high-temperature secondary air, and are used in the present invention. The ceramic material used for this purpose was selected to be sufficiently resistant to thermal shock, and the joint between the tip air nozzle and the metal part was designed with screws to prevent damage to the ceramic due to differences in thermal expansion. A metal part with a large coefficient is placed outside the ceramic part. Furthermore, this burner is characterized by a structure that has a sufficient air cooling effect by using a small amount of cooling air to reduce heat accumulation in the metal part inside the ceramic protective tube and prevent overheating. .

Next, an embodiment of the present invention will be described in detail based on the accompanying drawings.

FIG. 1 shows a partial vertical cross-section of an embodiment of the present invention, and FIG. 2 is an enlarged vertical cross-sectional view of the distal end portion of FIG. As shown in FIG. 1, the burner according to the present invention has an oil pipe 1 in the center, an air pipe 7 around the outer periphery with a certain gap, and a certain gap in the outermost part. Install air cooling pipe 1
6 and a protective cylinder 18, the oil pipe 1 has a spray nozzle 3 at its tip end, as shown in FIG. .

A spray air ventilation groove 11 is formed on the outer periphery of the spray nozzle mounting member 2, and the outer periphery of the groove partially contacts the air pipe 7 and the inner surfaces of the air nozzle mounting member 8 and the air nozzle 9.

A spiral spray air swirling groove 12 is formed in a part of the outer circumference of the spray nozzle 3, and the outer circumference of this part partially abuts the inner surface of the air nozzle 9, similar to the spray nozzle mounting member 2. Furthermore, spray nozzle 3
A spray air vent 14 is bored in the wall of the spray nozzle 3 and communicates with a central jet hole 15 formed at the tip of the insert member 4 joined within the spray nozzle 3. An oil passage groove 5 is formed in a part of the outer periphery of the insert member 4, and the outer periphery of this part partially contacts the inner surface of the spray nozzle 3. 6 is an oil jet hole.

As shown in FIG. 2, the air pipe 7 has an air nozzle 9 connected to its tip by an air nozzle attachment member 8. A cooling air ventilation groove 22 is formed on the outer periphery of the air nozzle mounting member 8, and the outer periphery of the groove 22 is partially connected to the inner surface of the protective cylinder 18 connected to the tip of the air cooling pipe 16 by a connecting member 17. be touched. 13 is an atomizing air outlet.

A centering member 1 having cooling air ventilation grooves 21 on the outer periphery at an intermediate portion of the entire length of the air pipe 7.
0, and the outer circumferential surface of the portion is partially in contact with the inner surface of the connecting member 17.

The air cooling pipe 16 having cooling air branch holes 20 on its circumference and the protection tube 18 are connected to each other by a connecting member 17. A connecting member ventilation groove 37 is formed in the protective tube receiving piece of the connecting member 17, and the inner surface of the burner mounting member 31 and the outer circumferential surface of this portion partially abut. A heat insulating cover 19 may be fixed to the tip of the protection tube 18, if necessary.

23 is a cooling air outlet. The openings at the base ends of the oil pipe 1, the air pipe 7, and the air cooling pipe 16 are the oil pipe 24 and the atomizing air pipe 2, respectively.
6. Joined to air cooling pipe 29. 28 is an air cooling pipe mounting member, and 25 is an air pipe mounting member.

The burner body constructed as described above is set on a furnace wall 39 using a box-shaped burner mounting member 31, as shown in FIG. 44 is inside the furnace, 40
4 is a burner tile, 43 is a throat portion, 41 is a secondary air passage, and 42 is a secondary air chamber. The outer periphery of the burner mounting member 31 inside the furnace is surrounded by a heat insulating material 32 and protected from the high temperature atmosphere from the inside of the furnace 44. 38
is a conical columnar space provided between the burner protection cylinder 18 and the heat insulating material 32.

How to attach the burner body to the furnace wall 39
The outer periphery of the connection member ventilation groove 37 formed in the connection member 17 is inserted into the inner surface of the burner attachment member 31 through the furnace outer opening of the burner attachment member 31 that has been fitted in advance, and the sealing material 34 is inserted into the inner surface of the burner attachment member 31. Attach the internal sealing material holding fitting 33 by screwing or the like,
Adjust the inclination of the burner body using the set bolt 35 and fix it. 36 is a space formed by the burner mounting member 31 and the air cooling pipe 16.

This burner configured as described above has a length of approximately 1000 mm.
mm, and the outer diameter of the protective tube 18 is approximately 70 mm.
In this burner, oil is supplied from the oil pipe 24, passes through the oil pipe 1, passes through the oil passage groove 5 inside the spray nozzle 3, and is sprayed from the oil jet hole 6.

The atomizing air is 1 to 2 kg/cm ² from the atomizing air pipe 26.
The atomized air is supplied at a pressure of 1, passes through the inside of the air pipe 7, passes through the atomizing air ventilation groove 11 and the atomizing air swirling groove 12, and is ejected from the atomizing air outlet 13. A portion also passes through the atomizing air vent 14 and is also ejected from the central jet hole 15 . The amount of spray air is controlled by a control valve 27.

Cooling air is 200 to 400 mm from cooling air pipe 29
It is supplied at the pressure of H ₂ O, and the amount of cooling air is controlled by a control valve 30. The supplied cooling air passes through the inside of the air cooling pipe 16,
The cooling air passes through the cooling air ventilation groove formed in the centering member 10 attached to the air pipe 7, passes through the inside of the protection cylinder 18, reaches the air nozzle 9, and is ejected from the outer periphery thereof. A part of the air also passes through the cooling air branch hole 20, reaches the space 36, passes through the connection member ventilation groove 37 in the connection member 17, passes through the space 38, and reaches the secondary air chamber 4.
Enter 2.

In this way, the cooling air passing through the cooling air branch hole 20 cools the connecting member 17, a part of the protective tube 18, and a part of the burner mounting member 31 appropriately, and is heated and used as part of the combustion air. be done.

The remaining cooling air passes through the cooling air ventilation groove 21 on the centering member 10, and passes through the protection tube 18, the air pipe 7, the air nozzle mounting member 8, and the air nozzle 9.
The cooling air passes through the cooling air while exchanging cooling heat, and the cooling air
3 and becomes part of the combustion air. Inside the burner mounting member 31, there is a space 3 that prevents the cooling air coming out of the cooling air branch hole 20 from leaking out of the furnace.
6 is sealed with a sealing material 34 installed in a sealing material holding fitting 33. High temperature secondary air (1200~
700° C.) enters the secondary air chamber 42 through the secondary air passage 41, passes through the throat portion 43 inside the burner tile 40, and enters the furnace interior 44.

The protective tube 18 and the air nozzle 9 are made of ceramic material such as silicon nitride, and are made of ceramic material such as silicon nitride.
It can be used stably for a long time even at temperatures (℃). These protective tubes 18 and air nozzles 9 are connected to connecting members 17, respectively.
The air nozzle mounting member 8 allows for easy installation and replacement.

With the above structure and configuration, the cooling air ultimately becomes combustion air, but the amount is determined by the ambient temperature in the burner section, regardless of the amount of fuel, and a sufficient effect can be achieved with a small amount.

According to the results of the ultra-high temperature tunnel kiln according to the embodiment of the present invention, the total amount of atomizing air and cooling air is:
It is in the range of 13 to 18% of the theoretical combustion air amount, and if this ratio is 25% or more, it is not preferable from the point of view of energy saving.

The burner of the present invention had the following effects.

The use of ceramic material for the protective tube and air nozzle allows stable characteristics even at high temperatures, and improvements in the cooling method have made it possible to use the burner for a long time with a small amount of air even with an air cooling system.

As a result of the above, cooling heat loss has been significantly reduced, resulting in fuel (oil) energy savings of about 7% compared to when using a conventional water-cooled burner.

Water cooling equipment is not required, and burner maintenance and management is also superior to conventional burners.

Therefore, the ceramic burner of the present invention is suitable for use in high-temperature atmosphere furnaces other than tunnel kilns.

[Brief explanation of the drawing]

Fig. 1 is a partial longitudinal sectional view showing an embodiment of the high temperature ceramic burner of the present invention, and Fig. 2 is an enlarged longitudinal sectional view of the tip of Fig. 1. In the figure, 1 is an oil pipe, and 2 is a spray Nozzle mounting member, 3 is a spray nozzle,
4 is an insert member, 5 is an oil passage groove, 7 is an air pipe, 8 is an air nozzle mounting member, 9 is an air nozzle, 10 is a centering member, 11 is a spray air ventilation groove, 12 is a spray air swirl groove, 14 is a Atomizing air vent, 15 is a center nozzle, 16 is an air cooling pipe,
17 is a connecting member, 18 is a protection tube, 20 is a cooling air branch hole, 21 is a cooling air vent groove, 22 is a cooling air vent groove, 24 is an oil pipe, 26 is a spray air pipe, and 29 is an air cooling pipe.

Claims (1)

[Claims] 1. An insert member having a central jet hole at the tip, a spray air vent hole, and an oil passage groove on the outer periphery is inscribed in a spray nozzle having a spray air swirl groove on the outer periphery,
The spray nozzle is connected to an oil pipe disposed in the center of the burner via a spray nozzle mounting member having a spray air ventilation groove on the outer periphery, and an appropriate gap is provided between the oil pipe and the outside of the oil pipe. A ceramic air nozzle is attached via an air nozzle mounting member having a cooling air ventilation groove, and a centering member with a cooling air ventilation groove is provided inside the connection member between the air cooling pipe and the protection tube. An air pipe is installed, a ceramic protection tube is attached to the outside of the air pipe inside the furnace via a connecting member, and an air cooling pipe is installed with cooling air branch holes. Oil piping is connected to each base end of the pipe and air-cooled pipe.
A main cooling air flow path that is configured to be connectable to the atomizing air piping and the air cooling piping, and is composed of the air pipe, the air nozzle mounting member, the space around the air nozzle, and the cooling air ventilation groove that communicates these spaces. A side-combustion type high-temperature ceramic burner having a cooling air flow path consisting of a space around the air cooling pipe and the protective tube, a connecting member ventilation groove communicating these spaces, and a branch cooling air flow path consisting of a cooling air branch hole. .