JP2008232544A - Installation structure of burner nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide installation structure of a burner nozzle in which a ceramic-made burner nozzle for a heating furnace is connected to a metal tube with high safety and inexpensively. <P>SOLUTION: In this installation structure of a ceramic-made burner nozzle 1, the burner nozzle is connected and communicated to the metal tube 9 for supplying fuel gas to jet fuel gas fed through the metal tube 9 toward the inside of the heating furnace 2. The upstream end of the burner nozzle 1 is fitted and supported to the downstream end of the metal tube 9, and the downstream end of the burner nozzle 1 is fitted and supported in a support hole 23 provided in the heating furnace 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for installing a burner nozzle for injecting fuel gas into a heating furnace, and more particularly to a technique for connecting a ceramic burner nozzle to a metal pipe.

  A heating furnace such as a forging furnace is provided with a burner for injecting fuel gas or combustion air into the heating furnace to cause combustion (see, for example, Patent Document 1). This burner has a structure in which a burner nozzle is connected in communication with the tip of a metal tube for supplying fuel gas, and fuel gas is jetted into a heating furnace from a jet outlet at the tip of the burner nozzle.

  Conventionally, it is common to use a metal nozzle as the burner nozzle. In this case, however, there is a problem that if the burner nozzle exceeds 800 to 900 ° C., the life becomes extremely short. Therefore, it has also been proposed to use a ceramic nozzle as the burner nozzle. In this case, the burner nozzle can withstand up to 1000 ° C. or more, and the burner nozzle can be installed on the higher temperature side to improve the combustion performance.

Here, as a connection means between the ceramic burner nozzle and the metal tube, for example, connection by screwing is conceivable. However, since the thermal expansion coefficient differs greatly between ceramic and metal, there is a risk of cracking at the threaded portion during expansion in this connection by screwing, which is a problem in safety. Another connection means may be a connection by welding. According to this welding, although the safety problem is solved, there is a problem that the cost is high.
Japanese Patent Laid-Open No. 9-210346

  The present invention has been invented in view of the above problems, and a burner nozzle installation structure in which a ceramic burner nozzle for a heating furnace can be installed by being connected to a metal pipe has high safety and low cost. It is an object to provide as a thing.

  In order to solve the above-described problems, the present invention is provided with a ceramic burner nozzle 1 that is connected to a metal pipe 9 for supplying fuel gas and jets fuel gas fed through the metal pipe 9 into the heating furnace 2. In this structure, the upstream end portion of the burner nozzle 1 is fitted and supported on the downstream end portion of the metal tube 9, and the downstream end portion of the burner nozzle 1 is placed in a support hole 24 provided in the heating furnace 2. To be fitted and supported.

  By adopting the installation structure of the burner nozzle 1 having the above configuration, the burner nozzle 1 made of ceramic and capable of withstanding up to 1000 ° C. or more can be installed on the high temperature side to improve the combustion performance. The metal tube 9 can be connected and installed with a safe and low-cost structure that is not damaged due to a difference in thermal expansion with the metal tube 9.

  Further, the outer peripheral surface of the downstream end portion of the burner nozzle 1 is provided with a tapered surface 18 that becomes smaller in diameter toward the downstream end, and the tapered surface is provided on the inner peripheral surface of the support hole 24 provided in the heating furnace 2. It is preferable that a support taper surface 25 for fitting support inclined so as to be along 18 is provided. By doing so, the burner nozzle 1 is reliably prevented from coming off, and even when the burner nozzle 1 undergoes thermal expansion, the taper surface 18 and the support taper surface 25 are displaced to smoothly absorb the difference in thermal expansion. .

  Further, a tapered surface 30 having a smaller diameter as it approaches the upstream end is provided on the outer peripheral surface of the upstream end portion of the burner nozzle 1, and the tapered surface 30 is provided on the inner peripheral surface of the downstream end portion of the metal tube 9. It is also preferable that a support taper surface 31 for fitting and supporting that is inclined so as to be along is provided. By doing so, even when the burner nozzle 1 undergoes thermal expansion, the taper surface 30 and the support taper surface 31 are displaced, so that the difference in thermal expansion from the metal tube 9 is smoothly absorbed.

  The present invention has an effect that it is possible to provide an installation structure of a burner nozzle that can be installed by connecting a ceramic burner nozzle for a heating furnace to a metal pipe as a high safety and low cost.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings. In FIG. 3, the heating furnace 2 which installed the burner nozzle 1 of an example in embodiment of this invention is shown. The heating furnace 2 is a regenerative burner system that is a regenerative burner that is suitably used in an industrial furnace such as a forging furnace and that alternately burns a regenerative burner 3 that forms a pair.

  A pair of regenerative burners 3 are installed at opposite locations of the furnace wall 4 of the heating furnace 2, and penetrate the air flow path 6 and the piping path 7 through a pair of burner tiles 5 installed in the furnace wall 4. (See FIG. 1), a heat storage chamber 8 is connected to the air flow path 6 and a metal pipe 9 for supplying fuel gas is inserted into the pipe path 7. Note that the installation location of the burner 3 is not limited to the location facing the furnace wall 4, and may be provided side by side on the furnace wall 4. Both the heat storage chambers 8 are connected to the four-way valve 10 outside the furnace wall 4, and both the heat storage chambers 8 are connected to the supply blower 11 and the exhaust blower 12 through the four-way valve 10. The upstream end of the metal tube 9 is connected to the fuel supply path 14 provided with the fuel valve 13 outside the furnace wall 4. The burner nozzle 1 is installed at the downstream end of the metal tube 9 as shown in FIG. 1, and this installation structure will be described later.

  In the regenerative alternating combustion furnace provided with the regenerative burner 3 having the above-described configuration, combustion air is supplied through the air flow path 6 in one burner 3 (see arrow A in FIG. 1) and a metal tube The fuel gas is supplied through 9 (see arrow B) to cause combustion. During the combustion of one burner 3, the fuel gas in the heating furnace 2 is exhausted through the air passage 6 in the other burner 3. To do. Then, the combustion and exhaust of each burner 3 are alternated by switching the four-way valve 10. When performing this alternating combustion, in the burner 3 on the exhaust side, the heat of the fuel gas is stored in the heat storage body 15 accommodated in the heat storage chamber 8, and then when the combustion is performed in this burner 3, The combustion air is preheated by the stored heat. Thereby, the exhaust heat of the high-temperature fuel gas is recovered with high efficiency.

  Hereinafter, the installation structure of the burner nozzle 1 will be described in detail. As shown in FIG. 2 in an enlarged manner, the burner nozzle 1 of this example is a cylindrical ceramic one, with one opening serving as a downstream jet 16 and the other serving as an upstream inlet 17. ing. Here, upstream and downstream are based on the flow direction of the fuel gas. The outer peripheral surface formed so as to surround the ejection port 16 at the downstream end of the burner nozzle 1 is a tapered surface 18 provided on the entire periphery so as to become smaller in diameter toward the downstream end. Further, a concave step portion 19 is formed on the outer peripheral surface formed so as to surround the inflow port 17 at the upstream end portion of the burner nozzle 1, and the concave step portion 19 allows the upstream side of the burner nozzle 1. The end portion is a small-diameter cylindrical portion 20 surrounding the inflow port 17.

  The metal tube 9 for supplying fuel gas has a cylindrical shape having an inner diameter approximately equal to the inner diameter of the burner nozzle 1. A concave step portion 21 is provided at the downstream end of the inner peripheral surface of the metal tube 9. A cylindrical portion 22 that is larger in diameter than the cylindrical portion 20 of the burner nozzle 1 and fits with the cylindrical portion 20 is formed. That is, in the burner nozzle 1 of this example, the small diameter cylindrical portion 20 formed around the inlet 17 at the upstream end portion of the burner nozzle 1 is inside, and is formed at the downstream end portion of the metal tube 9. The upstream end portion of the burner nozzle 1 is supported by fitting both the cylindrical portions 20 and 22 so that the large-diameter cylindrical portion 22 faces the outside.

  Further, the downstream end portion of the burner nozzle 1 is structured to be fitted and supported in the support hole 24 of the holding plate 23 disposed in the pipe line 7. The holding plate 23 is made of various materials such as a refractory material, metal, and ceramic. As the refractory material, a refractory brick, a castable refractory, and the like are appropriately used. The inner peripheral surface of the support hole 24 is a support taper surface 25 that is inclined so as to have a smaller diameter toward the downstream side. When the downstream end of the burner nozzle 1 is inserted into the support hole 24, the burner nozzle The inclination angles are made to coincide with each other so that the one taper surface 18 and the support taper surface 25 of the support hole 24 are along.

  As shown in FIG. 1, the holding plate 23 is securely fixed to the downstream end portion of the auxiliary flame fuel gas pipe 26 for supplying the auxiliary flame fuel gas (see arrow C) via a fixing portion 27. Combustion air is also sent through a combustion cylinder 28 fitted in the piping 7 so as to surround the auxiliary flame fuel gas pipe 26 (see arrow D), and an air hole penetrating the holding plate 23 (see FIG. It is provided so as to be supplied into the heating furnace 2 through (not shown).

  According to the installation structure of the above configuration, the burner nozzle 1 can be stably installed and supported by a simple structure in which the upstream end and the downstream end of the ceramic burner nozzle 1 are fitted and supported. Even if there is a difference in thermal expansion between the metal tube 9 and the metal part of the holding plate 23, the structure is provided with a predetermined gap so as to be fitted and supported, so that damage due to the difference in thermal expansion is prevented. . Particularly in this example, since the downstream end of the burner nozzle 1 is fitted and supported while being prevented from coming off by the taper structure, the taper surface 18 of this taper structure even if a difference in thermal expansion occurs. 25 are displaced smoothly.

  The fixing structure of the holding plate 23 is not limited to the structure based on the fixing portion 27 as shown in FIG. 1, and for example, a step portion 29 is provided in the pipe line 7 as shown in FIG. A structure may be adopted in which the peripheral edge of the pressing plate 23 is applied to 29 and the burner nozzle 1 is applied and fixed from the opposite side. Moreover, as shown in FIG. 5, the structure provided integrally with the combustion cylinder 28 fixed in the piping 7 may be sufficient. In the structure of FIG. 5, the holding flame combustion gas pipe 26 is not provided, and the combustion air is not supplied through the inside of the combustion cylinder 28.

  Next, a heating furnace 2 provided with another example of the burner nozzle 1 in the embodiment of the present invention will be described with reference to FIG. 6, but detailed description of the same configuration as the above-described example will be omitted. In the burner nozzle 1 of this example, the upstream end portion of the burner nozzle 1 and the metal tube 9 are also connected and supported using the same taper structure as the downstream end portion.

  That is, the outer peripheral surface formed so as to surround the inflow port 17 at the upstream end portion of the burner nozzle 1 is a tapered surface 30 provided on the entire periphery so as to become smaller in diameter toward the upstream end. Further, the inner peripheral surface of the downstream end of the metal tube 9 for supplying fuel gas is a support taper surface 31 that is inclined over the entire circumference so as to increase in diameter toward the downstream side. When the upstream end is inserted into the downstream end of the metal tube 9, the inclination angles are made to coincide with each other so that the tapered surface 30 of the burner nozzle 1 and the support tapered surface 31 of the metal tube 9 are along.

  According to the installation structure of the above configuration, the ceramic burner nozzle 1 is stably provided by a simple structure in which both the upstream end and the downstream end of the burner nozzle 1 are fitted and supported by a taper structure with a predetermined gap therebetween. Can be installed. In this example, even if a thermal expansion difference occurs, the taper surfaces 30 and 31 are shifted in the upstream taper structure and the taper surfaces 18 and 25 are shifted in the downstream taper structure. It is absorbed smoothly.

  In the above example and other examples, the support hole 24 that fits and supports the downstream end of the burner nozzle 1 is formed through the holding plate 23 fixed to the furnace wall 4. The structure is not limited, and a structure in which the furnace wall 4 itself made of refractory or metal is used as the holding plate 23, that is, a structure in which the ceramic nozzle 1 is fitted and supported by penetrating the support hole 24 in the furnace wall 4. Good.

It is a schematic sectional drawing which shows the installation structure of the example burner nozzle in embodiment of this invention. It is a principal part enlarged view of FIG. It is explanatory drawing of the heating furnace which installs a burner nozzle same as the above. It is a schematic sectional drawing which shows the modification of the fixing structure of a press plate same as the above. It is a schematic sectional drawing which shows the modification of the fixing structure of a press plate same as the above. It is a schematic sectional drawing which shows the principal part of the installation structure of the burner nozzle of the other example in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Burner nozzle 2 Heating furnace 4 Furnace wall 9 Metal pipe 18 Tapered surface 24 Support hole 25 Support taper surface 30 Tapered surface 31 Support taper surface

Claims (3)

  A ceramic burner nozzle installation structure connected to a metal pipe for supplying fuel gas and ejecting fuel gas fed through the metal pipe into a heating furnace, wherein the upstream end of the burner nozzle is connected to the metal pipe A burner nozzle installation structure characterized in that the downstream end of the tube is fitted and supported, and the downstream end of the burner nozzle is fitted and supported in a support hole provided in a heating furnace.   The outer peripheral surface of the downstream end of the burner nozzle is provided with a tapered surface that becomes smaller in diameter toward the downstream end, and the inner peripheral surface of the support hole provided in the heating furnace is inclined along the tapered surface. The installation structure of the burner nozzle according to claim 1, wherein a support taper surface for fitting support is provided.   The outer peripheral surface of the upstream end portion of the burner nozzle is provided with a tapered surface that becomes smaller in diameter toward the upstream end, and the inner peripheral surface of the downstream end portion of the metal tube is inclined along the tapered surface. The installation structure of the burner nozzle according to claim 1 or 2, wherein a support taper surface for fitting support is provided.

Images