Plasma torch and its application method

Abstract

The present invention provides a plasma torch, which includes a body, a nozzle assembly, a water cooling assembly and an ignition assembly, wherein the nozzle assembly is installed in the body, the water cooling assembly is partially installed outside the body, the ignition assembly is used to excite plasma gas, the body includes an input end, an output end and a lamp wall, the input and output ends are relatively arranged at two ends of the body, the lamp wall is formed by the output end being concave toward the input end, and the lamp wall has a structure in which the inner diameter gradually shrinks along the direction from the output end to the input end. The present invention also provides an application method of the plasma torch, and the plasma torch and the application method thereof have the advantages of reducing internal attachment and increasing service life.

Description

Technical Field

[0001] The invention relates to the field of ultra-high temperature heating tools, and in particular to a plasma torch and an application method thereof. Background Art

[0002] As an ultra-high temperature heating tool, high-temperature plasma gas is widely used in the manufacturing fields of nano-level advanced powder preparation, optical fiber, metal powder, etc. The hot plasma formed by induction plasma technology has the advantages of high energy density, high heating intensity and large temperature gradient. However, due to the high temperature, the high temperature resistance requirements for the material wrapping the plasma gas are very strict, resulting in an unstable plasma flame state in the existing blowtorch structure, and the powder is easy to adhere to the inside of the blowtorch during the production process. After exceeding 50KW, the blowtorch material is easy to deform due to high temperature, and quartz blowtorches are prone to crystallization, resulting in a very short blowtorch life. Ceramic blowtorches are prone to cracking during the process of alternating hot and cold. Summary of the invention

[0003] In view of this, it is necessary to provide a plasma torch and an application method thereof which can reduce internal adhesion and increase service life.

[0004] The present invention provides a plasma torch, which comprises a body, a nozzle assembly, a water cooling assembly and an ignition assembly. The nozzle assembly is installed in the body, the water cooling assembly is partially installed outside the body, and the ignition assembly is used to excite plasma gas. The body comprises an input end, an output end and a lamp wall, the input and output ends are relatively arranged at two ends of the body, the lamp wall is formed by the output end being concave toward the input end, and the lamp wall has a structure in which the inner diameter gradually shrinks in the direction from the output end to the input end.

[0005] Furthermore, one end of the nozzle assembly passes through the input end and is connected to the lamp wall.

[0006] Furthermore, the water cooling assembly includes a first water cooling assembly and a second water cooling assembly which are interconnected, the first water cooling assembly is installed between the nozzle assembly and the body, and the second water cooling assembly is installed outside the body.

[0007] Furthermore, one end of the first water cooling component passes through the input end, and the other end wraps around the lamp wall.

[0008] Furthermore, the second water cooling component is spirally arranged outside the body corresponding to the lamp wall.

[0009] Furthermore, the nozzle assembly includes a first nozzle and a second nozzle, the nozzle assembly includes a first nozzle and a second nozzle, the first nozzle and the second nozzle are coaxially arranged, and the second nozzle is installed outside the first nozzle.

[0010] Furthermore, the first water-cooling component includes an inner tube and an outer tube, the inner tube and the outer tube are coaxially arranged with the second nozzle, the inner tube is installed outside the second nozzle, the outer tube is installed outside the inner tube, and both ends of the second water-cooling component are respectively connected to the outer tube and the inner tube.

[0011] The present invention provides an application method of a plasma torch, wherein the method comprises the following steps:

[0012] S1, introducing plasma gas into the second nozzle;

[0013] S2, introducing carrier gas and raw materials into the first nozzle;

[0014] S3, introducing coolant into the water cooling assembly;

[0015] S4, start the ignition component;

[0016] S5, adjusting the flow rate of the coolant in the water cooling assembly to control the temperature of the lamp wall, so as to control the temperature of the reaction zone, and further control the morphology of the product in the reaction zone.

[0017] Furthermore, the plasma gas of S1 is a rotating jet gas.

[0018] Furthermore, the angle between the plasma gas flow direction and the axial direction of the second nozzle is A, and the value range of A is 45°≤A≤90°.

[0019] In the above plasma torch and application method, the lamp wall adopts a variable diameter structure, so as to increase the gas flow rate under the same gas flux, improve the energy density of plasma, and reduce the adhesion of powder on the lamp wall. The water cooling component keeps the lamp wall at a low temperature, ensures the performance of the lamp wall material, prolongs the service life, and reduces the use cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of a plasma torch in one embodiment of the present invention.

[0021] Figure 2 The figure is a flow chart of an application method of a plasma torch in one embodiment of the present invention.

[0022] Main component symbols

[0023]

[0024]

[0025] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0026] In order to more clearly understand the above-mentioned purposes, features and advantages of the embodiments of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the present invention.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the technical field of the embodiments of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific implementation methods and are not intended to limit the embodiments of the present invention.

[0029] See also Figure 1 , the plasma torch 100 is used to perform ultra-high temperature heating on an object. The plasma torch 100 includes a body 10, a nozzle assembly 20, a water cooling assembly 30 and an ignition assembly (not shown). The nozzle assembly 20 is installed in the body 10, the water cooling assembly 30 is installed between the nozzle assembly 20 and the body 10, and partially extends outside the body 10, and the ignition assembly is installed at one end of the body 10 to excite plasma gas. The plasma torch 100 is made of one or more of glass, ceramic or quartz materials. Preferably, the plasma torch 100 is made of quartz material.

[0030] The main body 10 includes an input end 11, an output end 12 and a lamp wall 13. The input end 11 and the output end 12 are relatively arranged at two ends of the main body 10, the input end 11 is used to input carrier gas and raw materials, and the output end 12 is used to output high-temperature plasma gas. The output end 12 is recessed toward the input end 11 to form a lamp wall 13, and a reaction zone 14 is arranged in the lamp wall 13, and the reaction zone 14 is used for the carrier gas, raw materials and plasma gas to react at high temperature. In one embodiment, the lamp wall 13 adopts a variable diameter structure, and the inner diameter of the lamp wall 13 gradually shrinks from the output end 12 to the input end 11 in a gradual or stepped shape, so as to increase the gas flow rate under the same gas flux, improve the energy density of the plasma, and reduce the adhesion of powder to the lamp wall 13 during the production process. In another embodiment, the lamp wall 13 partially adopts a variable diameter structure. Specifically, the lamp wall 13 includes a tubular portion 131 and a variable diameter portion 132 that are connected to each other. One end of the tubular portion is connected to the output end 12, and the other end is connected to the variable diameter portion. The inner diameter of the variable diameter portion gradually shrinks along the output end 12 toward the input end 11, showing a gradual or stepped shape.

[0031] One end of the nozzle assembly 20 passes through the input end 11 and is connected to the lamp wall 13 to input carrier gas, raw material and plasma gas into the lamp wall 13. The nozzle assembly 20 includes a first nozzle 21 and a second nozzle 22. In one embodiment, the second nozzle 22 is coaxially arranged outside the first nozzle 21. In another embodiment, the second nozzle 22 is arranged in parallel with the first nozzle 21, and passes through the input end 11 to be connected to the lamp wall 13 respectively.

[0032] Specifically, one end of the first nozzle 21 is connected to the lamp wall 13, and the other end is provided with a first connection portion 211. The first connection portion 211 is used to connect a carrier gas and raw material input device, so that the carrier gas and raw material are input into the reaction zone 14 through the first nozzle 21. One end of the second nozzle 22 is connected to the lamp wall 13, and the other end is connected to the tube wall of the first nozzle 21, so that the second nozzle 22 is fixed outside the first nozzle 21 and the end of the second nozzle 22 away from the lamp wall 13 is closed. A second connection portion 221 is provided on the tube wall of the second nozzle 22 away from the lamp wall 13, and the second connection portion 221 is used to connect a plasma gas input device, so that the plasma gas is input into the reaction zone 14 through the second nozzle 22. In one embodiment, the plasma gas includes argon, oxygen, nitrogen, helium, or a gas capable of plasma excitation.

[0033] The water cooling assembly 30 includes a first water cooling assembly 31 and a second water cooling assembly 32. One end of the first water cooling assembly 31 is connected to the second water cooling assembly 32 so that the coolant can flow. One end of the first water cooling assembly 31 passes through the input end 11, and the other end wraps around the lamp wall 13 so as to cool the lamp wall 13 through the coolant. Specifically, the first water cooling assembly 31 includes an inner tube 311 and an outer tube 312. The inner tube 311 and the outer tube 312 are respectively coaxially arranged with the second nozzle 22. The inner tube 311 is arranged outside the second nozzle 22. The tube wall of the inner tube 311 and the tube wall of the second nozzle 22 form a first cavity 313. The end of the inner tube 311 close to the input end 11 is connected to the tube wall of the second nozzle 22 so as to fix the inner tube 311 outside the second nozzle 22 and close the end of the inner tube 311 away from the lamp wall 13. A water outlet pipe 3111 is provided on the wall of the inner tube 311 close to the input end 11 . The water outlet pipe 3111 passes through the outer tube 312 and one side of the body 10 to discharge the coolant.

[0034] The outer tube 312 is installed outside the inner tube 311, and the wall of the outer tube 312 and the wall of the inner tube 311 form a second cavity 314. The end of the outer tube 312 close to the input end 11 is connected to the wall of the inner tube 311 to fix the outer tube 312 outside the inner tube 311 and seal the end of the outer tube 312 away from the lamp wall 13. A water inlet pipe 3121 is provided on the wall of the outer tube 312 close to the input end 11, and the water inlet pipe 3121 passes through one side of the body 10 to input the coolant.

[0035] The second water-cooling assembly 32 is spirally arranged around the outside of the body 10 at the corresponding position of the lamp wall 13. The second water-cooling assembly 32 is provided with a second water inlet pipe 321 at one end close to the output end 12. The second water inlet pipe 321 passes through one side of the body 10 and is connected to the outer tube 312 to input the coolant in the outer tube 312 into the second water-cooling assembly 32. The second water-cooling assembly 32 is provided with a second water outlet pipe 322 at one end away from the output end 12. The second water outlet pipe 322 passes through the body 10 and the outer tube 312 and is connected to the inner tube 311 to output the coolant in the second water-cooling assembly 32 to the inner tube 311.

[0036] When the water cooling assembly 30 is in use, the coolant enters the second cavity 314 through the water inlet pipe 3121. When the coolant reaches the end of the outer tube 312 close to the output end 12, the coolant performs heat exchange with the heat in the lamp wall 13 to cool the lamp wall 13. The coolant in the second cavity 314 is transported to the second water cooling assembly 32 through the second water inlet pipe 321 to further cool the outer layer of the plasma torch 100. The coolant in the second water cooling assembly 32 is output to the first cavity 313 through the second water outlet pipe 322 to cool the nozzle assembly 20. The coolant in the first cavity 313 is finally discharged through the water outlet pipe 3111. The water cooling assembly 30 can maintain the low temperature state of the lamp wall 13, ensure the performance of the material of the lamp wall 13, and increase the service life by 5 to 6 times compared with ordinary air-cooled torches, thereby reducing the cost of use. The water cooling component 30 can control the temperature of the lamp wall 13 by adjusting the flow rate of the coolant, so that the reaction zone 14 can be suitable for plasma gases matching a variety of gases, and the plasma reaction atmosphere can be freely selected. The water cooling component 30 can also cool the outer layer of the plasma torch 100, reducing the material requirements of the outer layer of the plasma torch 100, without using high-purity quartz or special ceramics, so as to reduce production costs.

[0037] The ignition assembly is mounted on the side wall of the body 10 near the reaction zone 14 to ignite the plasma gas. In one embodiment, the ignition assembly instantly applies a high voltage spark to the gas passing through the reaction zone 14 to ignite the plasma gas.

[0038] See also Figure 2 , Figure 2 1 is a flow chart of an application method of a plasma torch 100 according to an embodiment of the present invention, which specifically includes the following steps:

[0039] S1, introducing plasma gas into the second nozzle;

[0040] Specifically, the plasma gas is introduced into the second nozzle 22 through the second connection portion 221, and the second nozzle 22 inputs the plasma gas into the reaction zone 14. The plasma gas is a rotating jet gas, and the angle between the plasma gas flow direction and the axial direction of the second nozzle 22 is in the range of 45° to 90°, so that the plasma gas is rotated and ejected into the reaction zone 14.

[0041] The plasma gas includes argon, oxygen, nitrogen, helium or a gas capable of plasma excitation. In one embodiment, the plasma gas is argon.

[0042] S2, introducing carrier gas and raw materials into the first nozzle;

[0043] Specifically, the carrier gas and the raw material are introduced into the first nozzle 21 through the first connection portion 211, and the first nozzle 21 inputs the carrier gas and the raw material into the reaction zone 14. The carrier gas is argon, oxygen, nitrogen, etc. The raw material is a gas or a powder particle. In one embodiment, the raw material is a gas. Specifically, the raw material is SiCL4, SiF4 and a dopant.

[0044] S3, introducing coolant into the water cooling assembly;

[0045] Specifically, the coolant enters the second cavity 314 through the water inlet pipe 3121. When the coolant reaches the end of the outer tube 312 close to the output end 12, the coolant performs heat exchange with the heat in the lamp wall 13 to cool the lamp wall 13. The coolant in the second cavity 314 is input to the second water cooling assembly 32 through the second water inlet pipe 321 to further cool the outer layer of the plasma torch 100. The coolant in the second water cooling assembly 32 is output to the first cavity 313 through the second water outlet pipe 322 to cool the nozzle assembly 20. The coolant in the first cavity 313 is finally discharged through the water outlet pipe 3111. In one embodiment, the coolant is pure water to ensure that it does not affect the stability of the plasma gas.

[0046] S4, start the ignition component;

[0047] Specifically, the ignition component applies a high-voltage spark to the plasma gas at the moment when the plasma gas passes through the reaction zone 14 to ignite the plasma gas.

[0048] S5, adjusting the flow rate of the coolant in the water cooling assembly to control the temperature of the lamp wall, so as to control the temperature of the reaction zone, and further control the morphology of the product in the reaction zone.

[0049] Specifically, after the coolant is introduced, the temperature of the lamp wall 13 is maintained below 300°C, and the raw gas SiCL4, SiF4 and dopants generate SiO2 powder after passing through the reaction zone 14. By adjusting and accelerating the flow rate of the coolant in the water cooling assembly 30, the temperature of the lamp wall 13 is reduced to below 200°C, and the center temperature of the reaction zone 14 that the lamp wall 13 can withstand is increased to above 10000°C, at which time the raw gas SiCL4, SiF4 and dopants generate vitrified SiO2 after passing through the reaction zone 14.

[0050] In one embodiment, S1 and S2 may occur simultaneously.

[0051] The present invention provides a plasma torch 100, wherein the lamp wall 13 has a variable diameter structure, which increases the gas flow rate under the same gas flux, improves the energy density of plasma, and reduces the adhesion of powder to the lamp wall 13. The low temperature state of the lamp wall of the water cooling component 30 ensures the performance of the lamp wall 13, prolongs the service life, and reduces the use cost. The present invention also provides an application method of the plasma torch 100, which controls the lamp wall 13 by adjusting the flow rate of the cooling liquid of the water cooling component 30 to control the shape of the reaction zone 14. The production efficiency is improved and the use cost is reduced.

[0052] The above implementation modes are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit the present invention. Although the embodiments of the present invention are described in detail with reference to the above preferred implementation modes, those skilled in the art should understand that the technical solutions of the embodiments of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A plasma torch, characterized in that: The plasma torch comprises a body, a nozzle assembly, a water cooling assembly and an ignition assembly, wherein the nozzle assembly is installed in the body, the water cooling assembly is partially installed outside the body, the ignition assembly is used to excite plasma gas, the body comprises an input end, an output end and a lamp wall, the input and output ends are relatively arranged at two ends of the body, the lamp wall is formed by the output end being concave toward the input end, and the lamp wall has a structure in which the inner diameter gradually shrinks in the direction from the output end to the input end; The water cooling assembly comprises a first water cooling assembly and a second water cooling assembly which are interconnected, one end of the first water cooling assembly passes through the input end, and the other end wraps around the lamp wall, and the second water cooling assembly is spirally arranged around the body at a corresponding position of the lamp wall; The first water-cooling assembly comprises an inner tube and an outer tube, the inner tube and the outer tube are coaxially arranged with the nozzle assembly, the inner tube is installed outside the nozzle assembly, the tube wall of the inner tube and the tube wall of the nozzle assembly form a first cavity, the outer tube is installed outside the inner tube, the tube wall of the outer tube and the tube wall of the inner tube form a second cavity, the two ends of the second water-cooling assembly are respectively connected to the outer tube and the inner tube, the end of the second water-cooling assembly close to the output end is provided with a second water inlet pipe, the second water inlet pipe passes through one side of the body and is connected to the outer tube, the end of the second water-cooling assembly away from the output end is provided with a second water outlet pipe, the second water outlet pipe passes through the body and the outer tube and is connected to the inner tube; The cooling liquid passes through the second cavity, the second water-cooling assembly and the first cavity in sequence, and the cooling liquid located at a position of the outer tube close to the output end is used to cool the lamp wall.

2. The plasma torch according to claim 1, characterized in that: One end of the nozzle assembly passes through the input end and is connected to the lamp wall.

3. The plasma torch according to claim 2, characterized in that: The nozzle assembly includes a first nozzle and a second nozzle, the first nozzle and the second nozzle are coaxially arranged, and the second nozzle is installed outside the first nozzle.

4. A method for using the plasma torch according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1, introducing plasma gas into the second nozzle; S2, introducing carrier gas and raw materials into the first nozzle; S3, introducing coolant into the water cooling assembly; S4, start the ignition component; S5, adjusting the flow rate of the coolant in the water cooling assembly to control the temperature of the lamp wall, so as to control the temperature of the reaction zone, and further control the morphology of the product in the reaction zone.

5. The method for using a plasma torch according to claim 4, characterized in that: The plasma gas of S1 is a rotating jet gas.

6. The method for using a plasma torch according to claim 5, characterized in that: The angle between the plasma gas flow direction and the axial direction of the second nozzle is A, and the value range of A is 45°≤A≤90°.

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