JP5359573B2 - Multi-tube burner manufacturing method and multi-tube burner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a multiple pipe burner which can improve assembling accuracy in the longitudinal direction of a multiple pipe burner, and can suppress consumption and breakage at the tip of a quartz burner, and to provide a multiple pipe burner. <P>SOLUTION: In the method for producing the multiple pipe burner, quartz pipes are arranged into a multiple way, and are assembled so as to produce the multiple pipe burner. The method comprises: a stage where annular spacers 35a to 35g are externally inserted into an external quartz pipe; a stage where an external quartz pipe is inserted from the base end side into the outside of the internal quartz pipe, and further, the internal circumferences of the base end parts 19a to 31a are externally inserted into the annular spacers 35a to 35g; and a stage where the base end parts 19a to 31a of the external quartz pipe are heated and deformed in a size reduction direction over the circumferential direction of the base end parts 19a to 31a of the outside quartz pipe, and assembling is performed. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a multi-tube burner manufacturing method and a multi-tube burner in which a burner body is formed by welding a plurality of quartz tubes having different diameters to a multi-tube structure, and in particular, for improving the accuracy of the multi-tube structure. Related to improved technology.

As a method for producing a porous preform for an optical fiber, H ₂ gas is used as a combustion gas, O ₂ gas is used as a combustion gas, an inert gas such as Ar gas or N ₂ gas is used as a carrier gas or a seal gas, SiCl ₄ , There is a method in which various source gases such as GeCl ₄ as a dopant are supplied to a burner, and glass fine particles generated by hydrolysis reaction of these source gases are ejected and deposited toward a starting target material set at a deposition reference point. Are known.

  Since a porous preform for optical fiber causes an increase in transmission loss when it is made into an optical fiber if metallic impurities are mixed during manufacturing, a quartz burner is used for the purpose of preventing mixing of metallic impurities during manufacturing. (For example, refer to Patent Documents 1 and 2).

6 (a) and 6 (b) show a conventional quartz multiple tube (quadruple tube) burner.
The quartz multi-tube burner 500 is used for supplying a plurality of gases connected to each of the gas introduction paths 501a to 501d of the burner body 501 and a burner body 501 having a plurality of gas introduction paths 501a to 501d for various source gases. Branch pipes 503a to 503d are provided.

  The burner body 501 has a plurality of quartz tubes 505, 507, 509, and 511 having different diameters concentrically fitted to each other, and adjacent quartz tubes are connected to each other on the outer periphery of the inner quartz tube. The end portions 507a, 509a, and 511a are welded to form a concentric multiple tube structure. In the burner main body 501, the inner space of the innermost quartz tube 505 and the gap between adjacent quartz tubes serve as gas introduction paths 501a to 501d for introducing a raw material gas and the like, respectively.

  Each of the gas supply branch pipes 503a to 503d is a quartz glass tube, and each of the gas supply branch pipes 503a to 503d is connected to each of the gas introduction paths 501a to 501d described above. The quartz tubes 505 to 511 are welded at positions close to the base end portions 505a, 507a, 509a, and 511a. The quartz multi-tube burner 500 described above forms a flame with a plurality of types of source gases at the tip of the burner body 501 having a concentric multi-tube structure.

  Conventionally, this type of quartz multiple tube burner 500 has produced quartz tubes 505 to 511 with high accuracy, and at the welded portion between adjacent quartz tubes, as shown in FIG. The ends 507a, 509a, and 511a are assembled in a welded structure that is connected to the outer periphery of the inner quartz tube in the form of a curved surface that gradually decreases in diameter.

JP 2003-246627 A JP 2004-51378 A

  However, as disclosed in Patent Document 2, the conventional quartz multiple tube burner 500 is assembled while maintaining the accuracy of the tip by inserting an accurate alignment jig or spacer at the tip as disclosed in Patent Document 2. After the welding, the tip aligning jig is removed and assembled. For this reason, the gap S1 at the distal end (see FIG. 7) can be manufactured with high accuracy by inserting an alignment jig, but the base end portions 507a, 509a, and 511a are biased during welding, as shown in FIG. 7 (a). The gap S2 of the gas introduction path 501 is not constant over the entire length in the longitudinal direction of the multi-tube burner, and the accuracy in the longitudinal direction may not be achieved. If the accuracy in the longitudinal direction is poor, as shown in FIG. 7B, for example, the base end portion 509a of the outer quartz tube 509 and the inner quartz tube 507 are eccentric, and the flame emitted from the multi-tube burner is not stable. 7 and 8, G represents the axis of the multi-tube burner 500 (see FIG. 6). When the accuracy in the longitudinal direction is poor due to such eccentricity, as shown in FIG. 8, for example, eight quartz tubes having different diameters are mutually arranged, and the flame 512 generated by the inner quartz tube (group) 505 The plurality of flames 512 and 513 are generated by the flame 513 generated by the outer quartz tube group 507 and 509, and the inner flame 512 is formed from the tip position of the outer quartz tube group 507 and 509 that generates the outer flame 513. In the double flame burner in which the tip position of the inner quartz tube (group) 505 generating the inner side is retreated inward, the inner flame 512 becomes unstable, and the tips (particularly the inner circumference) of the outer quartz tubes 507, 509, etc. The parts 507b, 509b) are consumed or broken by the flame 512 inside them.

  The present invention has been made in view of the above situation, and the object thereof is to manufacture a multi-tube burner that can improve the assembly accuracy in the longitudinal direction of the multi-tube burner and suppress consumption and breakage of the tip of the quartz burner. It is to provide a method and a multi-tube burner.

The above object of the present invention is achieved by the following configuration.
(1) A method of manufacturing a multi-tube burner manufactured by arranging and assembling a plurality of quartz tubes,
Extrapolating an annular spacer near the position where the outer quartz tube of the inner quartz tube is welded;
Extrapolating the outer quartz tube from the proximal side to the outside of the inner quartz tube and extrapolating the proximal end of the outer quartz tube to the annular spacer; and
Performing a step of heat-deforming the base end portion of the outer quartz tube in the direction of diameter reduction in the circumferential direction and welding the outer end of the inner quartz tube,
A method of manufacturing a multi-tube burner, wherein the quartz tubes are assembled in multiple intervals at intervals set by the thickness of the spacer.

  According to this multi-tube burner manufacturing method, an accurate annular spacer is inserted on the outer periphery of the inner quartz tube, and the base end portion of the outer quartz tube that is extrapolated to the inner quartz tube is set by the thickness of the annular spacer. Since the base end is positioned with certainty by extrapolating at intervals and welding with the annular spacer inserted, the positional accuracy of the quartz tube in the radial direction at the base end is improved.

(2) A method of manufacturing a multi-tube burner according to (1),
A positioning jig at the tip is inserted between the outer periphery of the inner quartz tube and the inner periphery of the outer quartz tube, and the distance between the tip of the inner quartz tube and the outer quartz tube is the positioning jig. A method of manufacturing a multi-tube burner, characterized in that positioning is performed so as to have an interval set according to the thickness of the tube.

  According to this multi-tube burner manufacturing method, the radial positioning is reliably performed at both ends in the longitudinal direction of the inner quartz tube and the outer quartz tube, and the positional accuracy of the quartz tube is ensured over the entire length in the longitudinal direction. The

(3) A method of manufacturing a multi-tube burner according to (1) or (2),
Using the annular spacer made of quartz,
A method of manufacturing a multi-tube burner, wherein the annular spacer is welded to the outer periphery of the inner quartz tube together with the base end portion.

  According to this multi-tube burner manufacturing method, a part of the annular spacer is welded to the outer periphery of the inner quartz tube together with the base end portion of the outer quartz tube, so that the positional accuracy is improved.

(4) A method of manufacturing a multi-tube burner according to (1) or (2),
Using the annular spacer made of carbon,
After the base end portion is welded to the outer periphery of the inner quartz tube, the annular spacer is oxidized and removed.

  According to this multi-tube burner manufacturing method, after the base end of the outer quartz tube is positioned and welded with high accuracy by the annular spacer inserted on the outer periphery of the inner quartz tube, the annular spacer is removed by combustion or the like. As a result, a multiple tube having the same shape as a normal quartz tube can be manufactured with improved radial position accuracy in the vicinity of the welded portion. In the case of carbon, since the dimensional accuracy can be processed higher than that of quartz, the positional accuracy can be further increased.

(5) inner quartz tube;
An annular spacer extrapolated to the inner quartz tube;
The base end portion inserted from the base end side to the outside of the inner quartz tube, the base end portion being extrapolated by the annular spacer, and being thermally deformed in the diameter reducing direction in the circumferential direction is the outer periphery of the inner quartz tube. An outer quartz tube welded to the
A multi-tube burner comprising:

  According to this multi-tube burner, the gap between the inner surface of the outer quartz tube base end and the outer surface of the inner quartz tube becomes a value set by the thickness of the spacer so that the position accuracy of the quartz tube in the radial direction at the base end As a result, the gas flow is stabilized and the flame is stabilized.

(6) The multi-tube burner of (5),
A plurality of the quartz tubes having different diameters are arranged mutually,
A plurality of flames are generated by the flame generated by the inner quartz tube group and the flame generated by the outer quartz tube group, and the inner flame is moved from the tip position of the outer quartz tube group that generates the outer flame. A multi-tube burner characterized in that a tip position of the inner quartz tube group to be generated is provided so as to recede inward.

  According to this multi-tube burner, the accuracy (inclination) of the inner flame can be increased in a burner having multiple flames such as a double flame, so that the outer quartz tube is less likely to be damaged by the inner flame. The durability of the multi-tube burner can be increased.

  According to the method of manufacturing a multi-tube burner according to the present invention, an annular spacer is extrapolated to the inner quartz tube, an outer quartz tube is inserted into the inner quartz tube from the proximal end side, and is extrapolated to the outer periphery of the annular spacer. Since the portion is heated and deformed in the direction of diameter reduction in the circumferential direction and welded to the outer periphery of the inner quartz tube, the positional accuracy in the radial direction at the base end portion of the outer quartz tube can be improved. Furthermore, the assembly accuracy in the longitudinal direction of the multi-tube burner can be improved by inserting a positioning jig into the tip portion and then welding.

  According to the multiple tube burner of the present invention, an annular spacer that is extrapolated to the inner quartz tube, and a base end portion that is extrapolated to the inner quartz tube is extrapolated to the annular spacer. Since the outer quartz tube welded to the outer periphery is provided, the positional accuracy of the quartz tube in the radial direction in the vicinity of the welded portion is improved, the accuracy in the longitudinal direction of the multi-tube burner is increased, and the gas flow is stabilized. As a result, the flame is stabilized, and consumption and damage of the tip of the quartz burner can be suppressed.

(A) is a longitudinal cross-sectional view of the multiple tube burner by embodiment, (b) is CC sectional drawing of (a). It is the D section enlarged view of FIG. It is an assembly procedure explanatory view showing the assembly process of the multiple tube burner shown in Drawing 1 in (a)-(e). It is principal part sectional drawing which represented the position control condition in the front-end | tip part of an inner side quartz tube and an outer side quartz tube with (a) (b). It is a principal part expanded sectional view of the multiple tube burner by other embodiment. It is structure explanatory drawing of the conventional quartz multiple tube burner, (a) is a longitudinal cross-sectional view, (b) is A arrow directional view of (a). It is a figure showing the eccentric condition of the inner side quartz tube and the outer side quartz tube in the conventional quartz multiple tube burner, (a) is a longitudinal cross-sectional view, (b) is BB sectional drawing of (a). It is a longitudinal cross-sectional view of the tip of the quartz tube which is damaged by receiving a flame.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Fig.1 (a) is a longitudinal cross-sectional view of the multi-tube burner by embodiment, (b) is CC sectional drawing of (a).
A multi-tube burner (in this example, an eight-fold tube is shown) 100 is used for manufacturing a porous glass preform for optical fiber. Specifically, H ₂ gas is used as a combustion gas, and O ₂ gas is used as a combustion gas. Deposition standards for glass particles generated by flame hydrolysis reaction with various source gases such as SiCl ₄ and GeCl ₄ as a dopant using inert gas such as Ar gas or N ₂ gas as carrier gas or seal gas It is a burner that is used in a manufacturing method that ejects and deposits toward a starting target material installed at a point.

  This multi-tube burner 100 is provided with a burner body 13 having a plurality of gas introduction paths 11a to 11h for various source gases, and a plurality of gas supply units connected to the gas introduction paths 11a to 11h of the burner body 13. Branch pipes 15a to 15h. The total length in the direction along the axis G is about several hundred mm.

  The burner body 13 has a plurality of quartz tubes 17, 19, 21, 23, 25, 27, 29, 31 (17 to 31) having different diameters fitted and arranged concentrically with each other and adjacent quartz tubes to each other. Is formed in a concentric multiple tube structure by welding the base end portions 19a to 31a of the outer quartz tube to the outer periphery of the inner quartz tube. In the burner body 13, the internal space of the innermost quartz tube 17 and the gaps between adjacent quartz tubes are gas introduction paths 11 a to 11 h, respectively.

  Each of the gas supply branch pipes 15a to 15h is a quartz glass tube, and a base end portion 17a of each of the quartz pipes 17 to 31 is connected to connect a gas supply tube from a gas supply device (not shown). It is equipped with welding at a position close to ~ 31a. Further, in the multi-tube burner 100 according to the present embodiment, the tips of the quartz tubes 23 to 31 are arranged on a vertical surface 33 orthogonal to the axis G, and the quartz tubes 21 to 17 are arranged at a position retracted from the vertical surface 33. Is done. The multiple tube burner 100 described above forms a flame with a plurality of types of source gases at the tip of the burner body 13 having a concentric multiple tube structure. The multi-tube burner 100 is described and described as an example of the structure of an 8-fold tube burner that becomes a double flame, but a 12-fold tube burner that becomes a triple flame, a 16-fold tube burner that becomes a double flame, and the like. The same structure can be applied to other multi-tube burner structures.

Multi-tube burner 100, quartz annular spacer 35a extrapolated in the heart circle inside a quartz tube, 35b, 35c, 35d, 35e , 35f, 35g and (35a~35g), the proximal end portion of the outer quartz tube Between 19a and 31a. The annular spacers 35a to 35g are disposed closer to the base end portions 19a to 31a than the gas supply branch pipes 15a to 15h. In the annular spacers 35a to 35g, the inner periphery is in close contact with the outer periphery of the inner quartz tube, and the outer periphery is in close contact with the inner periphery of the outer quartz tube.

FIG. 2 is an enlarged view of a portion D in FIG.
The annular spacers 35a to 35g are formed with high accuracy with a predetermined thickness (defined thickness) d in the radial direction. Specifically, it is manufactured with a dimension of d = 1 mm and an intersection of about ± 0.05 mm. By providing the annular spacers 35a to 35g with an accuracy of ± 0.05 mm, the clearance accuracy over the entire length can be secured to about ± 0.1 to 0.2 mm. The dimension T of the annular spacers 35a to 35g in the direction along the axis G is, for example, about 5 mm, but is not particularly limited to this value, and may be 1 mm or 10 mm.

  The outer quartz tube is inserted into the outer side of the inner quartz tube from the base end portions 19a to 31a, and the inner circumferences of the base end portions 19a to 31a are extrapolated concentrically to the annular spacers 35a to 35g. The base end portions 19 a to 31 a that are extrapolated to the annular spacers 35 a to 35 g are heat-deformed in the diameter-reducing direction over the circumferential direction, and are welded to the outer periphery of the inner quartz tube by the welding portion 37. In the present embodiment, the annular spacers 35 a to 35 g are not directly melted, but are fitted between the inner quartz tube and the outer quartz tube and are provided integrally with the multi-tube burner 100.

  As described above, in the multi-tube burner 100 in which the annular spacers 35a to 35g are sandwiched between the outer periphery of the inner quartz tube and the outer quartz tube, the gap between the inner surface of the outer quartz tube and the outer surface of the inner quartz tube (gas introduction path 11a to 11a). 11h radial gap) S is constant, the annular gas flow path cross-sectional area becomes almost equal at any position of the quartz tube over the entire length in the longitudinal direction, and the gas flow is stabilized, resulting in a flame. Is stable.

Next, a method for manufacturing the multi-tube burner 100 having the above configuration will be described.
FIG. 3 is an explanatory diagram of the assembling procedure shown in (a) to (e) of the assembling process of the multi-tube burner shown in FIG. 1, and FIG. 4 shows the position regulation status at the tip portions of the inner and outer quartz tubes. It is principal part sectional drawing represented by (a) and (b).
In the present embodiment, the outer quartz tube 19 is welded to the outer periphery of the innermost quartz tube 17, but the manufacturing method according to the present invention inserts all the quartz tubes 19 to 31 in advance, and the base end 19a. ˜31a may be welded in one step.
For example, in order to weld the outer quartz tube 19 to the inner quartz tube 17, first, as shown in FIG. 3A, an annular spacer 35 a is extrapolated concentrically around the outer periphery of the inner quartz tube 17, and FIG. The annular spacer 35a is disposed at a predetermined position in the direction of the axis G of the inner quartz tube 17 as shown in FIG.

  Next, as shown in FIG. 3C, the outer quartz tube 19 is inserted into the outer side of the inner quartz tube 17 from the base end 19b side before molding. As shown in FIG. 3D, the outer quartz tube 19 is inserted until the inner circumference of the base end portion 19b is extrapolated concentrically to the annular spacer 35a. The base end portion 19b projects the welding allowance to the insertion direction side (right side in FIG. 3) from the annular spacer 35a.

  Next, as shown in FIG. 4A, a positioning jig 39 having a predetermined thickness d in the radial direction is inserted between the outer periphery of the tip of the inner quartz tube 17 and the inner periphery of the outer quartz tube 19, and the inner quartz tube The tip of 17 and the outer quartz tube 19 are positioned concentrically. A plurality of positioning jigs 39 may be inserted in the circumferential direction, or may be annular. For example, in the case of the inner quartz tube 21 and the outer quartz tube 23 in which the tip of the inner quartz tube recedes from the tip of the outer quartz tube, as shown in FIG. A positioning jig 39 is inserted between the inner periphery of the outer quartz tube 23.

  In this way, by inserting the positioning jig 39 on the distal end side, the radial positioning is reliably performed at both ends in the longitudinal direction of the inner quartz tube and the outer quartz tube, and the quartz tube 17 to the entire length in the longitudinal direction. The position accuracy of 31 is reliably ensured.

  When both ends of the inner quartz tube 17 and the outer quartz tube 19 are positioned, as shown in FIG. 3 (e), the base end portion 19a of the outer quartz tube 19 is circumferentially moved by a heating means 39 such as a burner. It is heated and deformed in the direction of diameter reduction, and the deformed tip is welded to the outer periphery of the inner quartz tube 17. During this time, the base end portion 19a is kept concentrically with high accuracy by the annular spacer 35a sandwiched between the inner quartz tube 17 and the base end portion 19a.

In this manufacturing method, an accurate annular spacer 35a is inserted into the outer periphery of the inner quartz tube 17, and the base end portion 19b of the outer quartz tube 19 that is externally inserted into the inner quartz tube 17 is concentric with the annular spacer 35a. Extrapolated. By performing welding with the annular spacer 35a inserted, positioning of the base end portion 19a after molding is reliably performed. Thereby, the positional accuracy of the quartz tubes 17 and 19 is improved over the entire length in the longitudinal direction.
In the above description, the spacers have a uniform thickness and are described on the assumption that the burners are arranged concentrically. For example, when the interval between the upper portions of the burner is wide and the lower portion is desired to be narrowed, the interval is set as such. The thickness of the spacer may be adjusted according to the above.

  In the manufacturing method according to the present embodiment, the welding of only the inner quartz tube 17 and the outer quartz tube 19 has been described as an example. However, the manufacturing method according to the present invention welds all the quartz tubes 19 to 31 simultaneously as described above. You may do. In this case, each outer quartz tube is extrapolated to the outer periphery of each inner quartz tube via annular spacers 35a to 35g, and the distal end of these quartz tubes 17 to 31 is positioned by the positioning jig 39, and the base end portion 19a. Weld ~ 31a. As the tip portion positioning jig 39 for performing such collective welding, for example, an alignment jig disclosed in Patent Document 2 can be suitably used in combination.

  Therefore, according to the manufacturing method of the multi-tube burner 100 according to the present embodiment, the annular spacers 35a to 35g are extrapolated to the inner quartz tube, and the outer quartz tube is inserted to the inner quartz tube from the base end side to insert the annular spacers 35a to 35g. Since the base end portions 19a to 31a are heat-deformed in the direction of diameter reduction in the circumferential direction and welded to the outer periphery of the inner quartz tube, the outer end of the outer quartz tube is welded to the outer end of the outer quartz tube. Position accuracy can be improved. Furthermore, the assembly accuracy in the longitudinal direction of the multi-tube burner 100 can be improved by inserting the positioning jig 39 into the tip portion and then welding.

  Further, according to the multi-tube burner 100 according to the present embodiment assembled in this way, the annular spacers 35a to 35g extrapolated to the inner quartz tube and the base end portions 19a to 31a extrapolated to the inner quartz tube are provided. Since the base end portions 19a to 31a are provided with the outer quartz tube welded to the outer periphery of the inner quartz tube while being extrapolated to the annular spacers 35a to 35g, the positional accuracy of the radial quartz tube in the vicinity of the welded portion is improved. And the precision of the longitudinal direction of the multi-tube burner 100 increases, and the gas flow is stabilized. As a result, the flame is stabilized, and consumption and damage of the tip of the quartz burner can be suppressed. In the double flame burner (multiple tube burner 100) according to the present embodiment, since the accuracy of the burner interval can be increased, the accuracy (tilt) of the inner flame can also be increased, and the outer quartz tube can be increased. Is less damaged by the inner flame and the durability of the multi-tube burner can be increased.

  In the multi-tube burner 100 improved in accuracy in the overall length in the longitudinal direction in this way, the life of the quartz multi-tube burner, which was conventionally 2 months to 1 year, is extended to the extent that it can be used continuously for an average of 2 years. It was confirmed. In addition, the total cost of the multi-tube burner 100 can be reduced because the lifetime is increased. Furthermore, since the accuracy in the longitudinal direction of the burner is improved, the quality of the optical fiber porous preform deposited using this burner can be improved.

Next, another embodiment according to the present invention will be described.
FIG. 5 is an enlarged cross-sectional view of a main part of a multi-tube burner according to another embodiment. In addition, in the following description, the same code | symbol is attached | subjected to the member and site | part equivalent to the above-mentioned member and site | part shown in FIGS.
The multi-tube burner 100A according to the present embodiment uses the same quartz annular spacers 35a to 35g as described above. In the above embodiment, the annular spacers 35a to 35g are not melted directly, but are melt bonded to the contact surface with the inner quartz tube or the outer quartz tube at the welding temperature of the base end portions 19a to 31a. In form, a portion of the annular spacers 35a-35g is welded directly.

  That is, the annular spacers 35a to 35g are welded to the outer periphery of the inner quartz tube 17 together with the base end portion 19a by melting the rear end portion 41. The whole annular spacers 35a to 35g may be melted, or only the rear end portion 41 may be left with its front end portion held in shape for regulating the positions of the inner quartz tube 17 and the outer quartz tube 19. When the spacers are welded in this way, there is a possibility that the spacers are cracked due to thermal strain depending on the heat treatment conditions. Therefore, it is necessary to perform heat treatment so that thermal strain does not occur.

  According to the manufacturing method and the multi-tube burner 100A according to this embodiment, a part of the annular spacers 35a to 35g is welded to the outer periphery of the inner quartz tube together with the base end portions 19a to 31a of the outer quartz tube, and the annular spacers 35a to 35g are formed. It becomes a part of the joint.

Next, still another embodiment according to the present invention will be described.
In the above embodiment, the case where the annular spacers 35a to 35g are made of quartz has been described as an example. However, in the multi-tube burner according to another embodiment, the annular spacers 35a to 35g are made of carbon.

  Although not shown, the carbon annular spacer is inserted into the inner quartz tube in the same manner as described above, and the outer quartz tube is positioned when welding the base end portions 19a to 31a of the outer quartz tube. Realize the attachment. The carbon annular spacer is oxidized and removed after the base end portions 19a to 31a are welded to the outer periphery of the inner quartz tube. Therefore, it is preferable that the carbon annular spacers are spaced apart from each other at a position where the carbon end spacers 19a to 31a are not burned by welding.

  According to the multi-tube burner manufacturing method and multi-tube burner using such a carbon annular spacer, the base end portions 19a to 31a of the outer quartz tube are formed by the carbon annular spacer inserted in the outer periphery of the inner quartz tube. After positioning and welding with high accuracy, the annular spacer made of carbon is removed by combustion, etc., so that multiple tubes with the same shape as ordinary quartz tubes are manufactured with improved radial position accuracy near the weld can do. Furthermore, by inserting a positioning jig into the tip portion and then welding it, it is possible to manufacture with improved longitudinal position accuracy. In the case of carbon, since the dimensional accuracy can be processed higher than that of quartz, the positional accuracy can be further increased. Since the carbon is oxidized and removed, the multi-tube burner becomes a multi-tube consisting of only a quartz tube.

17 inner quartz tube 19 outer quartz tube 19a to 31a base end 35a to 35g annular spacer 39 positioning jig 41 rear end of annular spacer 100 multiple tube burner d predetermined thickness

Claims (6)

A method of manufacturing a multi-tube burner which is manufactured by arranging and assembling quartz tubes in multiples,
Extrapolating an annular spacer near the position where the outer quartz tube of the inner quartz tube is welded;
Extrapolating the outer quartz tube from the proximal side to the inner quartz tube and extrapolating the proximal end of the outer quartz tube to the annular spacer;
Performing a step of heat-deforming the base end portion of the outer quartz tube in the direction of diameter reduction in the circumferential direction and welding the outer end of the inner quartz tube,
A method of manufacturing a multi-tube burner, wherein the quartz tubes are assembled in multiple intervals at intervals set by the thickness of the spacer. A method of manufacturing a multi-tube burner according to claim 1,
A positioning jig at the tip is inserted between the outer periphery of the inner quartz tube and the inner periphery of the outer quartz tube, and the distance between the tip of the inner quartz tube and the outer quartz tube is the positioning jig. A method of manufacturing a multi-tube burner, characterized in that positioning is performed so as to have an interval set according to the thickness of the tube. A method of manufacturing a multi-tube burner according to claim 1 or claim 2,
Using the annular spacer made of quartz,
A method of manufacturing a multi-tube burner, wherein the annular spacer is welded to the outer periphery of the inner quartz tube together with the base end portion. A method of manufacturing a multi-tube burner according to claim 1 or claim 2,
Using the annular spacer made of carbon,
After the base end portion is welded to the outer periphery of the inner quartz tube, the annular spacer is oxidized and removed. An inner quartz tube,
An annular spacer extrapolated to the inner quartz tube;
The base end portion inserted from the base end side to the outside of the inner quartz tube, the base end portion being extrapolated by the annular spacer, and being thermally deformed in the diameter reducing direction in the circumferential direction is the outer periphery of the inner quartz tube. An outer quartz tube welded to the
A multi-tube burner comprising: A multi-tube burner according to claim 5,
A plurality of the quartz tubes having different diameters are arranged mutually,
A plurality of flames are generated by the flame generated by the inner quartz tube group and the flame generated by the outer quartz tube group, and the inner flame is moved from the tip position of the outer quartz tube group that generates the outer flame. A multi-tube burner characterized in that a tip position of the inner quartz tube group to be generated is provided so as to recede inward.

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