JP6532902B2 - Multi-tube burner - Google Patents

Description

  The present invention relates to a multi-tube burner, which is suitable, for example, for producing an optical fiber base material and the like.

  When manufacturing an optical fiber base material etc., the manufacturing method which sprays source gas with a flame, and deposits the glass particle obtained by the combustion reaction on a target is used. As such a production method, for example, VAD method (vapor-phase axial deposition), OVD (outside vapor deposition) method, MCVD (modified chemical vapor deposition) method and the like can be mentioned. The glass particles are called soot.

  As a burner used for the manufacturing method of such a porous glass deposit, the burner which oxidizes the silicon containing compound which does not contain a halide is disclosed by the following patent document 1. FIG. A plurality of injection regions are provided on one surface of the burner of Patent Document 1 below.

  Specifically, a first region for injecting a mixed gas of octamethylcyclotetrasiloxane which is a raw material gas and oxygen which is an auxiliary gas is disposed at the center of the injection port of the burner, and a second region for injecting nitrogen is It is provided to surround the first area. Also, a plurality of third regions for injecting oxygen, which is a combustion-supporting gas, are provided at predetermined intervals around the second region, and a plurality of nozzles that inject a mixed gas of methane, which is a flammable gas, and oxygen, which is a combustion-assisting gas. A fourth area of the second area is provided at a predetermined interval outside the third area.

Japanese Patent Publication Hei 11-510778

By the way, when the amount of the raw material gas increases, the spread of the flame when the combustion reaction occurs is increased, and the soot tends to be diffused by the flame. In the burner of the patent document 1, a first region for injecting a mixed gas of the source gas and the supporting gas is provided on the most inner circumferential side of the exit of the burner. For this reason, there is a concern that the soot spreads to the outer peripheral side than the first region by the widely spread flame, and the deposition amount of the soot deposited on the target decreases.

On the other hand, it is considered that the diffusion of soot outside the first region can be reduced by increasing the flow velocity of the nitrogen gas ejected from the second region . However, when the flow rate of nitrogen gas is increased, there is a concern that the temperature of the soot is lowered by the gas flow, and the amount of soot deposition is reduced without depositing soot on the target.

  Therefore, the present invention provides a multi-tube burner capable of efficiently depositing soot.

  In order to solve the above problems, the multi-tube burner of the present invention is provided with a raw material gas pipe for flowing the raw material gas, a combustible gas pipe for flowing the combustible gas, and a first combustion gas pipe for flowing the combustion enhancing gas. An injection port of the raw material gas pipe and an injection port of the first auxiliary combustion gas pipe are disposed inside an injection port of the combustible gas pipe, and an injection port of the first combustion gas pipe is the raw material gas It is characterized in that it is disposed to surround the injection port of the tube.

According to such a multi-tube burner, the raw material gas is injected inside the auxiliary gas, and the combustible gas is injected so as to surround the auxiliary gas and the raw material gas. Therefore, the combustion assisting gas acts like a wall that suppresses the diffusion of the source gas, and it becomes easy to confine the source gas inside the combustion promoting gas. Therefore, the diffusion of soot outward can be reduced. Thus, the diffusion of soot can be suppressed, and the reduction in the amount of soot deposited on the target can be suppressed.
In addition, since the injection port of the first auxiliary combustion gas pipe and the injection port of the raw material gas pipe are separately disposed, the flow velocity of the gas can be set individually. Therefore, even if the spread of the flame is increased by the increase of the amount of the raw material gas, the flow velocity of the auxiliary combustion gas injected from the injection port of the first combustion gas pipe is set so that the spread flame does not diffuse the soot to the outside. It can be adjusted. As a result, the flow rate of the flammable gas does not have to be increased so much, and the soot temperature is lowered by the gas flow, so that it is possible to reduce the tendency of the soot to adhere to the target. As a result, it is possible to suppress a decrease in the amount of soot deposited on the target.
Thus, according to the multi-tube burner of the present invention, the amount of soot deposition per unit feed gas can be increased. Thus, the soot can be deposited efficiently.

  The fuel cell further includes a second combustion gas pipe for flowing the combustion-supporting gas, and the injection port of the second combustion gas pipe is located inside the injection port of the combustible gas pipe. It is preferable to arrange | position out of the injection | emission port.

  In this way, the combustible gas can be burned more efficiently, and the temperature of soot deposited on the target can be controlled. In addition, since the auxiliary gas doubly encloses the source gas, the source gas can be more easily confined inside the auxiliary gas.

  The fuel cell system may further include a first seal gas pipe for flowing a seal gas, wherein the injection port of the source gas pipe is disposed inside the injection port of the first seal gas pipe, and the injection port of the first combustion gas pipe is Preferably, the first seal gas pipe is disposed so as to surround an injection port of the first seal gas pipe.

  In this way, it is possible to suppress the diffusion of the source gas to the outside, and seal the reaction position between the source gas injected from the source gas injection port and the injection port for the flammable gas and the flammable gas. It can adjust by the flow velocity of gas etc. Therefore, the diffusion of soot to the outside can be further reduced, and the soot can be deposited in an appropriate range of the target.

  Moreover, it is preferable that ratio of the flow velocity of the said source gas which flows through the said source gas pipe, and the flow velocity of the said auxiliary combustion gas which flows through a said 1st auxiliary combustion gas pipe exists in the range of 0.35-0.75.

In this way, the flow rate of the source gas changes within a predetermined range when the deposition efficiency is 100% when all the Si atoms contained in the source are soot (SiO ₂ ) and adhere to the target. Even in this case, deposition efficiency of 50% or more can be ensured.

  The ratio is preferably in the range of 0.4 to 0.75.

In this way, the flow rate of the source gas changes within a predetermined range when the deposition efficiency is 100% when all the Si atoms contained in the source are soot (SiO ₂ ) and adhere to the target. Even in this case, deposition efficiency of 70% or more can be ensured.

  In addition, the injection port of the source gas pipe is disposed inside the injection port of the first auxiliary gas pipe, and the injection port of the first auxiliary gas pipe extends all around the injection port of the source gas pipe. It is preferable to surround it.

  Thus, the injection port of the first auxiliary gas pipe surrounds the injection port of the source gas pipe, whereby the injection area of the injection port of the first auxiliary gas pipe surrounds the entire periphery of the injection port of the source gas pipe over the entire circumference It will be. Therefore, the diffusion of the raw material gas can be further suppressed by the auxiliary gas, and uniform combustion can be approximated in the circumferential direction, and generation of soot can be approximated uniformly in the circumferential direction.

  Further, a plurality of first auxiliary combustion gas pipes are provided, and injection ports of the plurality of first auxiliary combustion gas pipes are arranged at predetermined intervals around the injection port of the raw material gas pipe. It is also possible. In this case, the production of the multi-tube burner can be facilitated.

  As described above, according to the present invention, there is provided a multi-tube burner capable of efficiently depositing soot.

It is a figure which shows a mode that the injection port of the multi-tube burner which concerns on 1st Embodiment of this invention was seen from the injection side of gas. It is a figure which shows a mode that the injection port of the multi-tube burner which concerns on 2nd Embodiment of this invention was seen from the injection side of gas. 7 is a graph showing the relationship between the gas flow rate and the deposition efficiency in Example 1. 7 is a graph showing the relationship between the gas flow rate and the deposition efficiency in Example 2.

  Hereinafter, preferred embodiments of the multi-tube burner according to the present invention will be described in detail with reference to the drawings.

First Embodiment
FIG. 1 is a view showing an injection port, which is an injection port of a multi-tube burner according to the present embodiment, viewed from the gas injection side. As shown in FIG. 1, the multi-tube burner 1 includes a raw material gas pipe 11, a first seal gas pipe 12, a plurality of first combustion-supporting gas pipes 13, a plurality of second combustion-supporting gas pipes 14, and Gas pipe 15 and a second seal gas pipe 16. In FIG. 1, the raw material gas pipe 11, the first seal gas pipe 12, the respective first auxiliary combustion gas pipes 13, the respective second combustible gas pipes 14, the combustible gas pipes 15, the first seal gas pipe 12 for easy visual recognition. Although the two-seal gas pipe 16 is indicated by hatching, the hatching does not indicate the cross section of the pipe.

  The raw material gas pipe 11 is a pipe for flowing the raw material gas, and a gas supply device is connected to an end of the raw material gas pipe 11 opposite to the injection end side via a connecting pipe. As a raw material of source gas, octamethyl cyclotetrasiloxane etc. are mentioned, for example. When such a octamethylcyclotetrasiloxane or a silicon-containing compound containing no halide such as hexamethyldisiloxane is used as the raw material gas, no hydrochloric acid is generated due to the combustion reaction of the raw material, and therefore the halide is contained. Silicon-containing compounds that do not react are preferred as source gases.

  The first seal gas pipe 12 is a pipe for flowing a seal gas, and a gas supply device is connected to an end of the first seal gas pipe 12 opposite to the injection end side via a connection pipe. As a seal | sticker gas, inert gas, such as nitrogen and argon, is mentioned, for example.

  Each of the plurality of first auxiliary combustion gas pipes 13 is a pipe for flowing the auxiliary combustion gas. The end opposite to the injection end side of the first auxiliary combustion gas pipe 13 is connected to the gas supply device via a connection pipe. Examples of the auxiliary gas include oxygen.

  Each of the plurality of second combustion assisting gas pipes 14 is a pipe through which the combustion assisting gas flows. The end of the second auxiliary gas pipe 14 opposite to the injection end side is connected to the gas supply device via a connecting pipe. Note that the first auxiliary combustion gas pipe 13 and the second auxiliary combustion gas pipe 14 may be connected to the gas supply device through the common communication pipe, and may be connected to the gas supply device through separate connection pipes. May be However, when the first auxiliary combustion gas pipe 13 and the second auxiliary combustion gas pipe 14 are connected to the gas supply device via separate connection pipes, the first auxiliary combustion gas pipe 13 and the second auxiliary combustion gas pipe 14 The flow rate and type of auxiliary gas can be changed.

  The flammable gas pipe 15 is a pipe for flowing flammable gas, and a gas supply device is connected to an end of the flammable gas pipe 15 opposite to the injection end side via a connecting pipe. Examples of the flammable gas include hydrogen and methane.

  The second seal gas pipe 16 is a pipe for flowing a seal gas, and a gas supply device is connected to an end of the second seal gas pipe 16 opposite to the injection end side via a connection pipe. The first seal gas pipe 12 and the second seal gas pipe 16 may be connected to the gas supply device through the common communication pipe, and are connected to the gas supply device through the separate connection pipes. Also good. However, when the first seal gas pipe 12 and the second seal gas pipe 16 are connected to the gas supply device via separate connection pipes, the seal gas in the first seal gas pipe 12 and the second seal gas pipe 16 is used. Flow rate and type can be changed.

  The gas supply apparatus described above supplies the raw material gas to the raw material gas pipe 11, supplies the flammable gas to the flammable gas pipe 15, and supplies the first combustion gas pipe 13 and the second combustion gas pipe 14. The auxiliary gas is supplied to the first seal gas pipe 12 and the seal gas is supplied to the first seal gas pipe 12 and the second seal gas pipe 16. This gas supply device is configured to be able to individually change the supply amounts and flow rates of the raw material gas, the flammable gas, the auxiliary gas, and the seal gas.

  Next, the arrangement of the injection ports 11A to 16A which are the injection ports of the respective gas pipes will be described. When each injection port 11A-16A is seen from the injection side of gas, each injection port 11A-16A is arrange | positioned as follows.

  The injection port 12A of the first seal gas pipe 12 is disposed so as to surround the entire periphery of the injection port 11A of the raw material gas pipe 11. That is, the injection port 11A of the source gas pipe 11 is disposed inside the injection port 12A of the first seal gas pipe 12. The injection ports 13A of the plurality of first auxiliary combustion gas pipes 13 are arranged at predetermined intervals so as to surround the outer periphery of the injection port 12A of the first seal gas pipe 12. Therefore, the injection port 13A of each of the plurality of first auxiliary combustion gas pipes 13 also encloses the injection port 11A of the source gas pipe 11. Further, outside the injection ports 13A of the plurality of first auxiliary combustion gas pipes 13, the injection ports 14A of the plurality of second auxiliary combustion gas pipes 14 are disposed at predetermined intervals.

  In the case of this embodiment, a plurality of injection ports 13A are disposed at predetermined intervals equal to each other on a circle whose diameter is the same as the center of the injection port 11A and larger than the diameter of the injection port 12A. A plurality of injection ports 14A are arranged at predetermined intervals equal to one another on a circle larger than the circle.

  Outside the injection port 14A of each of the plurality of second auxiliary combustion gas pipes 14, a flammable gas pipe 15 is disposed so as to surround the injection port 14A. That is, the injection port 11A of the raw material gas pipe 11, the injection port 12A of the first seal gas pipe 12, the injection ports 13A of the plurality of first auxiliary combustion gas pipes 13, and the plurality of injection ports 13A Each injection port 14A of the second auxiliary gas pipe 14 is disposed inside the injection port 15A of the flammable gas pipe 15. Further, the injection port 16A of the second seal gas pipe 16 is disposed outside the injection port 15A of the flammable gas pipe 15 so as to surround the entire periphery of the injection port 15A.

  Further, in the present embodiment, the injection port 11A of the raw material gas pipe 11, the injection port 12A of the first seal gas pipe 12, the injection port 15A of the flammable gas pipe 15, and the The injection ports are arranged concentrically in the order of the injection port 16 A of the two-seal gas pipe 16.

  Further, the area of the flammable gas injection area AR4 is made larger than the area of the injection area AR1 of the source gas at the injection port 11A of the source gas pipe 11. Further, the area of the injection area AR4 of the flammable gas is larger than the area of the injection area AR2 of the seal gas in which the injection port 12A of the first seal gas pipe 12 and the injection port 16A of the second seal gas pipe 16 are combined. It is done. Further, compared with the area of the injection area AR3 of the combustion assisting gas in which the injection port 13A of each of the plurality of first auxiliary combustion gas pipes 13 and the injection port 14A of each of the plurality of second auxiliary combustion gas pipes 14 are combined. The area of the flammable gas injection area AR4 is increased. These injection areas AR1 to AR4 are areas from which gas is injected, and the injection area AR4 of the flammable gas is the outer circumference of each injection port 13A of the first auxiliary combustion gas pipe 13 and the second auxiliary gas pipe The outer circumference of each injection port 14A of 14 and the outer circumference of the injection port 12A of the first seal gas pipe 12 are all surrounded.

  Next, gas combustion and soot generation by the multi-tube burner 1 will be described. The combustible gas injected from the injection port 15A of the flammable gas pipe 15 burns together with the combustion-supporting gas injected from the injection port 13A of the first combustion-supporting gas pipe 13. In this combustion flame, soot is generated by the combustion reaction of the raw material gas injected from the injection port 11A of the raw material gas pipe 11. Then, the generated soot is deposited on the target.

  At this time, the temperature of the soot deposited on the target is controlled by the auxiliary combustion gas injected from the injection port 14A of the second auxiliary combustion gas pipe 14. Specifically, the temperature can be raised by the combustion of the combustion assisting gas injected from the injection port 14A of the second combustion assisting gas pipe 14 with the combustible gas. Further, the source gas can be prevented from diffusing to the outside by the seal gas injected from the injection port 12A of the first seal gas pipe 12, and the flow rate of the seal gas or the like makes the source gas and the flammable gas The reaction position can be adjusted. Further, the spread of the flame can be suppressed by the seal gas injected from the injection port 16A of the second seal gas pipe 16, and the contact of the combustible gas with the gas around the seal gas can be further suppressed. it can.

  As described above, in the multi-tube burner 1 according to the present embodiment, the injection port 11A of the raw material gas pipe 11 and the injection port 13A of the first auxiliary combustion gas pipe 13 are disposed inside the injection port 15A of the flammable gas pipe 15 It is done. Further, the injection port 13A of the first auxiliary combustion gas pipe 13 is disposed so as to surround the injection port 11A of the raw material gas pipe 11 via the injection port 12A of the first seal gas pipe 12.

  According to such a multi-tube burner 1, the raw material gas is injected inside the auxiliary gas, and the combustible gas is injected so as to surround the auxiliary gas and the raw material gas. Therefore, the combustion assisting gas acts like a wall that suppresses the diffusion of the raw material gas, so that the raw material gas can be easily confined inside the combustion promoting gas. Therefore, the diffusion of soot outward can be reduced. As a result, soot diffusion can suppress a decrease in the amount of soot deposited on the target.

  Further, since the injection port 13A of the first auxiliary combustion gas pipe 13 and the injection port 11A of the raw material gas pipe 11 are separately disposed, the flow velocity of the gas can be set individually. Therefore, the flow velocity of the auxiliary combustion gas injected from the injection port 13A of the first auxiliary combustion gas pipe 13 is set so that the soot does not diffuse to the outside by the increased flame even if the flame becomes larger by the increase of the raw material gas amount. It can be adjusted. As a result, the flow rate of the flammable gas does not have to be increased so much, so that the soot temperature is lowered by the gas flow, and it is possible to reduce the tendency of the soot to adhere to the target. As a result, it is possible to suppress a decrease in the amount of soot deposited on the target. In addition, since the flow rates of the source gas and the flammable gas can be individually adjusted, it is possible to adjust the optimum deposition efficiency according to the increase or decrease of the amount of the source gas.

  As described above, according to the multi-tube burner 1 according to the present embodiment, the amount of soot deposition per unit raw material gas can be increased. Thus, the soot can be deposited efficiently.

  In addition, the multi-tube burner 1 of the present embodiment further includes a second combustion gas pipe 14 for flowing the combustion supporting gas. The injection port 14 A of the second auxiliary gas pipe 14 is disposed inside the injection port 15 A of the flammable gas pipe 15 and is disposed outside the injection port 13 A of the first auxiliary gas pipe 13. Therefore, the flammable gas can be burned more efficiently, and the temperature of the soot deposited on the target can be controlled. Further, since the auxiliary gas doubly encloses the source gas, the source gas can be more easily confined inside the auxiliary gas.

  Furthermore, the multi-tube burner 1 of the present embodiment further includes a first seal gas pipe 12 for flowing a seal gas, and the injection port 11A of the source gas pipe 11 is disposed inside the injection port 12A of the first seal gas pipe 12 It is done. Therefore, the source gas can be prevented from diffusing to the outside, and the reaction position between the source gas injected from the injection ports 11A and 15A and the flammable gas can be adjusted by the flow velocity of the seal gas or the like. . Therefore, the diffusion of soot to the outside can be further reduced, and the soot can be deposited in an appropriate range of the target.

  Further, in the multi-tube burner 1 of the present embodiment, the injection port 16A of the second seal gas pipe 16 is disposed so as to surround the outer periphery of the injection port 15A of the flammable gas pipe 15. Therefore, it is possible to suppress the spread of the flame and deposit soot in a more appropriate range of the target.

Second Embodiment
Next, a multi-tube burner according to a second embodiment of the present invention will be described with reference to FIG. In addition, about the component the same as that of 1st Embodiment, or equivalent, the same referential mark is attached | subjected and the overlapping description is abbreviate | omitted unless it demonstrates in particular.

  FIG. 2 is a view showing the injection port of the multi-tube burner according to the present embodiment as viewed from the gas injection side. As shown in FIG. 2, the multi-tube burner 2 according to the second embodiment includes a raw material gas pipe 11, a first seal gas pipe 12, a first combustible gas pipe 23, and a first combustion-supporting gas pipe 24. And a plurality of second combustion-supporting gas pipes 14, a second combustible gas pipe 25, and a second seal gas pipe 16. That is, in the present embodiment, instead of the plurality of first auxiliary combustion gas pipes 13 of the first embodiment, the first auxiliary combustion gas pipe 24 is provided. Further, in the present embodiment, instead of the combustible gas pipe 15 of the first embodiment, the first combustible gas pipe 23 disposed on the inner side across the first combustion-supporting gas pipe 24 and the first combustible gas pipe 23 are provided outside 2 A flammable gas pipe 25 is provided. In FIG. 2, the raw material gas pipe 11, the first seal gas pipe 12, the first combustible gas pipe 23, and the first auxiliary combustion gas pipe 24, the respective second auxiliary combustion gas pipes 14, and the second 2 The flammable gas pipe 25 and the second seal gas pipe 16 are hatched, but the hatching does not indicate the cross section of the pipe.

  The first combustible gas pipe 23 is a pipe for flowing combustible gas in the same manner as the combustible gas pipe 15 of the first embodiment, and the end of the first combustible gas pipe 23 opposite to the injection end side is The gas supply device is connected via the connection pipe. As combustible gas, the gas similar to the combustible gas of 1st Embodiment can be mentioned.

  The first auxiliary combustion gas pipe 24 is a pipe for flowing the auxiliary combustion gas similarly to the first auxiliary combustion gas pipe 13 of the first embodiment. The end of the first auxiliary gas pipe 24 opposite to the injection end side is connected to the gas supply device via a connecting pipe. Examples of the auxiliary gas include the same gas as the auxiliary gas of the first embodiment.

  The second combustible gas pipe 25 is a pipe having the same configuration as the combustible gas pipe 15 of the first embodiment, and is a pipe through which combustible gas flows. As combustible gas, the gas similar to the combustible gas of 1st Embodiment can be mentioned.

  Next, the arrangement of the injection port of each gas pipe will be described. However, the description of the arrangement of the injection port similar to that of the first embodiment will be omitted. The injection port 11A of the raw material gas pipe 11 and the injection port 12A of the first seal gas pipe 12 surrounding the same are disposed inside the injection port 23A of the first combustible gas pipe 23. Accordingly, the injection port 23A of the first combustible gas pipe 23 surrounds the entire periphery of the injection port 12A of the first seal gas pipe 12 over the entire circumference, and the raw material gas pipe is connected via the injection port 12A of the first seal gas pipe 12 The 11 injection ports 11A are surrounded all around.

  Further, the injection port 23A of the first combustible gas pipe 23 is disposed inside the injection port 24A of the first auxiliary combustion gas pipe 24. Therefore, the injection port 24A of the first auxiliary combustion gas pipe 24 surrounds the entire periphery of the injection port 23A of the first combustible gas pipe 23, and the injection port 23A of the first combustible gas pipe 23 and the first seal gas The injection port 11A of the raw material gas pipe 11 is surrounded all around through the injection port 12A of the pipe 12. Further, on the outside of the injection port 13A of the first auxiliary combustion gas pipe 13, the injection ports 14A of the plurality of second auxiliary combustion gas pipes 14 are disposed at predetermined intervals.

  Further, the injection port 25A of the second combustible gas pipe 25 is disposed so as to surround the entire outer circumference of the injection port 24A of the first auxiliary combustion gas pipe 24. That is, the injection port 11A of the raw material gas pipe 11, the injection port 12A of the first seal gas pipe 12, the injection port 23A of the first combustible gas pipe 23, and the first auxiliary combustion gas pipe arranged in the positional relationship as described above. The twenty-four injection ports 24 A and the injection ports 14 A of the plurality of second combustion-supporting gas pipes 14 are disposed inside the injection port 15 A of the second combustible gas pipe 25. Therefore, between the inner wall of the injection port 25A of the second combustible gas pipe 25 and the outer wall of the injection port 24A of the first auxiliary combustion gas pipe 24, a plurality of second combustion gas pipes 14 are arranged.

  In such a multi-tube burner 2, the injection area AR 4 of the injection port 23 A of the first combustible gas pipe 23 surrounds the entire circumference of the injection port 12 A of the first seal gas pipe 12. Further, the injection area AR3 of the injection port 24A of the first auxiliary combustion gas pipe 24 surrounds the entire circumference of the injection port 23A of the first combustible gas pipe 23. Therefore, the injection area AR3 of the injection port 24A of the first auxiliary combustion gas pipe 24 surrounds the entire periphery of the injection port 11A of the raw material gas pipe 11 through the injection port 23A of the first combustible gas pipe 23 There is. Further, the injection area AR4 of the injection port 25A of the second combustible gas pipe 25 includes the outer circumference of each injection port 14A of the second combustion gas pipe 14 and the outer circumference of the injection port 24A of the first combustion gas pipe 24. Is surrounded all around.

  As described above, according to the multi-tube burner 2 of the present embodiment, the injection port 24A of the first auxiliary combustion gas pipe 24 surrounds the entire circumference of the outside of the injection port 11A of the raw material gas pipe 11. Therefore, compared with the case where the injection port 13A of each of the plurality of first auxiliary combustion gas pipes 13 is disposed at a predetermined interval around the injection port 11A of the raw material gas pipe 11 as in the first embodiment, By this, the diffusion of the source gas can be further suppressed further, and since uniform combustion can be approached in the circumferential direction, generation of soot can be made uniform in the circumferential direction.

  The embodiments of the present invention have been described above by way of example, but the present invention is not limited to these.

  For example, when the injection ports 11A to 16A of the first embodiment are viewed from the gas injection side, the injection ports 11A to 16A have the same positional relationship as described above in the first embodiment, on the same plane. It may or may not be arranged. Similarly, when the injection ports 11A, 12A, 23A, 24A, 14A, 25A, and 16A of the second embodiment are viewed from the gas injection side, the injection ports have the positional relationship described in the second embodiment. As long as it has become, it may or may not be disposed on the same plane. Further, each injection port described above is circular, but may be other than circular.

  Moreover, in the said embodiment, the 2nd combustion auxiliary gas pipe 14, the 1st seal gas pipe 12, and the 2nd seal gas pipe 16 were provided. However, all of the second auxiliary combustion gas pipe 14, the first seal gas pipe 12, and the second seal gas pipe 16 may be omitted, and the second auxiliary combustion gas pipe 14, the first seal gas pipe 12, and the first One or two of the two-seal gas pipe 16 may be omitted.

  EXAMPLES Hereinafter, the contents of the present invention will be more specifically described by way of examples, but the present invention is not limited thereto.

Example 1
The soot was deposited on the target by the OVD method using the multi-tube burner 1 according to the first embodiment. At this time, the deposition efficiency of the soot was measured when the flow velocity of the raw material gas flowed to the raw material gas pipe 11 and the flow velocity of the auxiliary combustion gas flowed to the first additive gas pipe 13 were changed. The deposition efficiency is calculated from the weight of soot deposited on the target when the experiment is performed, assuming that all Si atoms contained in the raw material become SiO ₂ and adhere to the target as 1.0 (100%). .

  The diameter of the injection port 11A of the raw material gas pipe 11 was 3.6 mm, and the diameter of the injection port 13A of the first auxiliary combustion gas pipe 13 was 1.6 mm. Further, the raw material of the raw material gas was octamethylcyclotetrasiloxane, the combustible gas was hydrogen, the auxiliary gas was oxygen, and the seal gas was nitrogen. Further, the flow velocity of the source gas was changed at 20 m / s to 35 m / s, and the flow velocity of the auxiliary gas was changed to 10 m / s to 20 m / s.

  The flow velocity of the source gas was changed so as to be a predetermined ratio with the flow velocity of the combustion-supporting gas. Moreover, the flow velocity of the flammable gas was fixed at 0.15 m / s. Further, the diameter of the injection port 14A of the second auxiliary gas pipe 14 is the same as the injection port 13A of the first auxiliary gas pipe 13, and the flow velocity of the auxiliary gas flowing through the second auxiliary gas pipe 14 is the first auxiliary flame The flow velocity is the same as the flow velocity through the gas pipe 13. Furthermore, the flow velocity of the seal gas was fixed at 0.3 m / s.

  FIG. 3 is a graph showing the relationship between the gas flow rate and the deposition efficiency in Example 1. As shown in FIG. 3, when the ratio (flow velocity ratio) of the flow velocity of the auxiliary gas to the flow velocity of the source gas is in the range of 0.35 to 0.75, the deposition efficiency is 0.5 or more. When the flow rate ratio was in the range of 0.4 to 0.75, the deposition efficiency was 0.7 or more.

  Thus, if the flow rate ratio is in the range of 0.35 to 0.75, deposition efficiency of 50% or more is ensured even if the flow rate of the source gas changes in the range of 20 g / min to 38 g / min. I could confirm that I could do it. In addition, if the flow velocity ratio is in the range of 0.4 to 0.75, deposition efficiency of 70% or more should be ensured even if the flow rate of the source gas changes in the range of 20 g / min to 38 g / min. It could be confirmed that

(Example 2)
The diameter of the injection port of the source gas pipe is 2.8 mm, and the flow velocity of the source gas flowing through the source gas pipe and the flow velocity of the auxiliary gas flowing through the first combustion gas pipe are changed under the same conditions as in Example 1 The deposition efficiency of soot was measured.

  FIG. 4 is a graph showing the relationship between the gas flow rate and the deposition efficiency in Example 2. As shown in FIG. 4, when the ratio (flow velocity ratio) of the flow velocity of the auxiliary gas to the flow velocity of the raw material gas is in the range of 0.35 to 0.75, the deposition efficiency is 0. It became 5 or more. When the flow rate ratio was in the range of 0.4 to 0.75, the deposition efficiency was 0.7 or more, as in the first embodiment.

  As described above, it was confirmed that the deposition efficiency can be secured as in Example 1 even when the diameter of the injection port of the raw material gas pipe is small. In addition, it is thought that the ratio of the flow velocity of the source gas and the flow velocity of the first auxiliary combustion gas mainly contributes to the deposition efficiency. For example, when the seal gas is not used, the range in which the source gas diffuses and soot deposits becomes wider than in the case where the seal gas is used, but the effect on the deposition efficiency is an enhancement to the flow velocity of the source gas. It is considered to be small compared to the influence of the ratio of the flow velocity of the hydrogen gas.

  As described above, according to the present invention, a multi-tube burner capable of efficiently depositing soot is provided, and can be used in the industry etc. for manufacturing an optical fiber.

1, 2 ... Multi-tube burner 11 ... Raw material gas pipe 12 ... First seal gas pipe 13, 24 ... First combustion gas pipe 14 ... Second combustion gas pipe 15 ... · Flammable gas pipe 16 ··· Second seal gas pipe 23 · · · First combustible gas pipe 25 · · · Second combustible gas pipe 11A · · · · · · · · · · · First injection port 12A of the source gas pipe · · · Injection port 13A, 24A of the seal gas pipe ... Injection port 14A of the first auxiliary combustion gas pipe ... Injection port 15A of the second combustion gas pipe ... Injection port 16A of the flammable gas pipe ... 2 Seal gas pipe injection port 23A: first combustible gas pipe injection port 25A: second combustible gas pipe injection port

Claims (7)

A source gas pipe for flowing source gas,
A first combustible gas pipe and a second combustible gas pipe for flowing combustible gas ;
A first combustion gas pipe for flowing a combustion supporting gas,
Equipped with
The injection port of the source gas pipe, the exit port of the first combustible gas pipe, and the injection port of the first combustion-supporting gas pipe are disposed inside the injection port of the second combustible gas pipe,
The exit port of the first combustible gas pipe is disposed inside the exit port of the first combustion-supporting gas pipe,
The exit port of the source gas pipe is disposed inside the exit port of the first combustible gas pipe,
An exit port of the first combustible gas pipe and an exit port of the first combustion-supporting gas pipe adjacent to each other;
The outlet port of the raw material gas pipe, the outlet port of the first combustible gas pipe, the outlet port of the second combustible gas pipe, and the outlet port of the first combustible gas pipe are disposed on the same plane. multi-tube burner, characterized in <br/> Being. The system further comprises a plurality of second combustion gas pipes for flowing the combustion-supporting gas,
Injection port of said plurality of second supporting gas tube being disposed at predetermined intervals the contact had been inside the injection port of the second combustible gas pipe around the injection port of the first supporting gas pipe A multi-tube burner according to claim 1, characterized in that Further comprising a first seal gas pipe for flowing a seal gas;
The injection port of the source gas pipe is disposed inside the injection port of the first seal gas pipe,
The multi-tube burner according to claim 1 or 2 , wherein the injection port of the first seal gas pipe is disposed inside the exit port of the first combustible gas pipe . The ratio of the flow velocity of the raw material gas flowing through the raw material gas pipe to the flow velocity of the auxiliary combustion gas flowing through the first auxiliary combustion gas pipe is in the range of 0.35 to 0.75. The multi-tube burner according to any one of Items 1 to 3. 5. A multi-tube burner according to claim 4, wherein the ratio is in the range of 0.4 to 0.75. The multi-tube burner according to any one of claims 1 to 5 , wherein the source gas is a halide-free silicon-containing compound . The ratio of the flow velocity of the raw material gas flowing through the raw material gas pipe to the flow velocity of the auxiliary combustion gas flowing through the first auxiliary combustion gas pipe is in the range of 0.35 to 0.75.
The multi-tube burner according to claim 6 , wherein the flow rate of the raw material gas is in the range of 20 g / min to 38 g / min .

Images