A preparation device and method for large-size infrared synthetic quartz material

Abstract

The present invention relates to a preparation device for large-size infrared synthetic quartz materials, comprising a furnace body, a bottom cover installed under the furnace body, a support system arranged at the center of the bottom cover and capable of rotating and lifting under the drive of a power device, and a deposition crucible connected to the support system. The furnace body and the bottom cover together constitute a working chamber, the deposition crucible is fixedly installed on the top of the support system, the support system can also move laterally under the drive of the power device, the bottom cover is provided with a furnace bottom baffle separating the reaction chamber and the exhaust gas chamber, the furnace bottom baffle is provided with exhaust microholes and can move laterally under the drive of the support system. A blowtorch assembly is provided above the deposition crucible, the blowtorch assembly is an assembly comprising a production blowtorch, a dehydroxylation pre-degassing blowtorch and a titanium-containing halide blowtorch. The present invention solves the technical problem in the prior art that the loose body has a low density and has pores inside, resulting in a weak strength of the loose body and is not easy to be burned through, which in turn leads to the size of the infrared synthetic quartz not being too large.

Description

Technical Field

[0001] The invention relates to the technical field of infrared synthetic quartz material preparation, in particular to a preparation device and method for large-size infrared synthetic quartz material. Background Art

[0002] Synthetic quartz is a key substrate material for communication optical fiber preforms, LCD photomasks and semiconductor photomasks, and is also an important optical component material in aerospace, high-energy laser systems and lithography systems. Infrared synthetic quartz is a highly applied synthetic quartz with high UV transmittance, high optical uniformity, high intrinsic quality, high resistance to laser damage, and low absorption coefficient.

[0003] Infrared synthetic quartz is mainly synthesized by chemical reaction using silicon-containing compounds as raw materials. The main preparation methods include plasma chemical vapor deposition (PCVD) and VAD process. Among them, the PCVD method directly deposits silicon-containing compounds in a plasma flame water-free environment to obtain infrared synthetic quartz. The preparation cost is high and it is difficult to achieve industrial mass production. The VAD process uses a hydrogen-oxygen flame instead of a plasma flame, that is, firstly, the silicon-containing compound is deposited in a hydrogen-oxygen flame environment to form a loose body, and then the loose body is sintered to form infrared synthetic quartz. The quartz products prepared by the VAD process have extremely low impurity content, controllable hydroxyl content and low preparation cost, and have gradually become the mainstream preparation method for infrared synthetic quartz.

[0004] However, due to the limitations of the preparation device and method, the existing VAD process, although its cost is low, still has the following problems: Since the existing VAD process adopts a downward growth method, that is, in the device implementing the VAD process, the deposition seed rod is located at the bottom of the support system, and can be rotated and raised with the support system during the deposition production process. At the same time, the raw material is sprayed from bottom to top onto the seed rod for deposition to form a loose body. In this process, the loose body is gradually formed from top to bottom, which is called downward growth. The density of the loose body generated by this device is relatively small and there are defects such as pores inside, which leads to cracking and falling off, inability to burn through, and bubble defects when the diameter of the fired loose body is large. Therefore, the diameter of the infrared synthetic quartz obtained by the VAD process implemented by the existing device is generally controlled to be about 300mm, and when it is necessary to manufacture large-diameter components, the quartz rod needs to be reshaped by one or two groove sinking and then cold processed, which will reduce the material utilization rate and also cause a great risk of scrapping of the material during the groove sinking process, which limits the application of infrared synthetic quartz prepared by the existing device and method in large-diameter components. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the defects of the loose body prepared by the existing device and method, such as low density and internal pores, which makes the loose body weak in strength and difficult to be burned through, and further leads to the technical problem that the size of the infrared synthetic quartz should not be too large.

[0006] In order to solve the above technical problems, the present invention provides a preparation device for large-size infrared synthetic quartz materials, comprising a furnace body, a bottom cover installed under the furnace body, a support system arranged at the center of the bottom cover and capable of rotating and lifting under the drive of a power device, and a deposition crucible connected to the support system. The furnace body and the bottom cover together constitute a working chamber, and the deposition crucible is fixedly installed on the top of the support system; the support system can move laterally under the drive of the power device. The bottom cover is provided with a furnace bottom baffle that can move laterally under the drive of the support system, dividing the working chamber into a reaction chamber and an exhaust gas chamber. The furnace bottom baffle is provided with exhaust microholes, and a blowtorch assembly (6) is provided above the deposition crucible.

[0007] In one embodiment of the present invention, the furnace body is made of ceramic fiber material, and a quartz lining is arranged inside.

[0008] In one embodiment of the present invention, at least one air supply channel with an angle R less than 180 degrees with the side wall of the furnace body is set on the top of the reaction chamber for introducing inert gas, and an exhaust channel for exhausting exhaust gas is set on one side of the exhaust chamber.

[0009] In one embodiment of the present invention, the torch assembly comprises a production torch, a dehydroxylation pre-degassing torch and a titanium-containing halide torch. The number of the production torch, the dehydroxylation pre-degassing torch and the titanium-containing halide torch is the same, and each is at least one. The production torch, the dehydroxylation pre-degassing torch and the titanium-containing halide torch are evenly arranged.

[0010] In one embodiment of the present invention, the inner diameter of the deposition crucible is not less than 1100 mm and the depth is not less than 600 mm, and the material of the deposition crucible is ceramic material.

[0011] The present invention also provides a method for preparing a large-size infrared synthetic quartz material, comprising the following production steps:

[0012] Step S1: introducing hydrogen and oxygen into the reaction chamber through a production blowtorch, igniting to form a hydrogen-oxygen flame, and preheating the reaction chamber;

[0013] Step S2: When the temperature in the reaction chamber reaches 800° C., argon gas is continuously introduced into the reaction chamber through a production blowtorch;

[0014] Step S3: raising the support system to the deposition reaction position, at which point the lower end of the blowtorch assembly is located 300-500 mm above the bottom of the deposition crucible;

[0015] Step S4: When the temperature in the reaction chamber is stabilized at 800-1000°C, a gaseous silicon tetrachloride raw material is introduced into the deposition crucible through a production torch. Silicon tetrachloride undergoes a hydrolysis reaction during the hydrogen-oxygen combustion process to produce nano-scale silicon dioxide, which is accumulated in the deposition crucible to form a loose quartz ingot; while the deposition production is being carried out, a dehydroxylation pre-degassing torch introduces a mixed gas of chlorine and helium into the deposition crucible to perform a dehydroxylation pretreatment on the loose quartz ingot; at the same time, a titanium-containing halide torch introduces titanium halide into the deposition crucible to perform a titanium-doped treatment on the loose quartz ingot;

[0016] Step S5: During the deposition production process, the support system and the deposition crucible are driven by the power device to repeatedly move horizontally while rotating and descending, and the baffle plate at the bottom of the furnace is repeatedly moved horizontally under the drive of the support system; the distance between the lower end of the blowtorch assembly and the top of the loose quartz ingot is always controlled to be 300-500mm; high-clean inert gas is introduced into the reaction chamber through the air supply channel, and the wind speed range of the air supply is 2-10m / s; exhaust is carried out through the exhaust channel, and the waste gas and silicon dioxide in the reaction chamber enter the waste gas chamber through the exhaust micropores during the deposition production process, and then are discharged through the exhaust channel, and the exhaust wind speed range is 2-10m / s;

[0017] Step S6: After 50-80 hours of deposition production, a loose quartz ingot weighing not less than 250 kg is obtained, and then the process is finished and the material and gas are stopped. The loose quartz ingot is transferred to a sintering furnace for vitrification sintering, and finally a Φ600mm infrared synthetic quartz rod is obtained.

[0018] In one embodiment of the present invention, in step S1, hydrogen and oxygen are high-purity gases with a purity of 5N or above; the flow rate range of hydrogen is 75-230 L / min, and the flow rate range of oxygen is 50-150 L / min.

[0019] In one embodiment of the present invention, in step S2, the argon gas is a high-purity gas with a purity of 5N, and the flow rate range of the argon gas is 20-80 L / min.

[0020] In one embodiment of the present invention, in step S4, the flow rate range of the gaseous silicon tetrachloride raw material is 20-40 L / min; the chlorine and helium are high-purity gases with a purity of 5N or more, the molar ratio of the chlorine and helium mixed gas is 1:0.75, and the flow rate range of the mixed gas is 5-20 L / min; the flow rate range of the titanium halide is 3-20 L / min.

[0021] In one embodiment of the present invention, in step S5, the rotation speed of the deposition crucible is 15-50rpm, the lateral speed is 0.1-5m / s, the range is ±200mm, and it is a variable acceleration motion with a maximum center speed and a curve that gradually decreases toward the edge; when the deposition crucible moves laterally, the lower projection of the blowtorch assembly does not exceed the inner bottom of the deposition crucible.

[0022] The above technical solution of the present invention has the following advantages compared with the prior art:

[0023] The invention discloses a preparation device for a large-size infrared synthetic quartz material, comprising a furnace body, a bottom cover installed under the furnace body, a support system arranged at the center of the bottom cover and capable of rotating and lifting under the drive of a power device, and a deposition crucible connected to the support system. The furnace body and the bottom cover together constitute a working chamber. In the present invention, the deposition crucible is installed on the top of the support system. Compared with the prior art in which the deposition crucible is installed at the bottom of the support system, the present invention adopts an upward growth method, that is, in the deposition crucible of the present invention, the loose body is gradually formed from bottom to top. Compared with the prior art, the upward growth method of the present invention increases the density of the loose body under the action of gravity, has a higher strength, is not easy to crack and fall off, and has only a small amount of or even no defects such as pores inside. In addition, the deposition crucible of the present invention can be repeatedly moved horizontally while rotating and descending under the drive of the support system, so that the density distribution of the silicon dioxide deposited in the deposition crucible is more uniform. Furthermore, the bottom cover of the present invention is provided with a furnace bottom baffle, which divides the working chamber into a reaction chamber and an exhaust gas chamber, and the loose body is formed in the reaction chamber. The baffle plate at the bottom of the furnace is equipped with exhaust microholes, which can realize the uniform extraction of exhaust gas and silicon dioxide in the reaction chamber, ensuring the stability and consistency of the flow field in the reaction chamber. The baffle plate at the bottom of the furnace can move horizontally driven by the support system, so that the deposited loose body powder is repeatedly shaken, making the loose body density higher and the growth process more uniform.

[0024] The present invention installs a blowtorch assembly above the deposition crucible. The blowtorch assembly is an assembly comprising at least one production blowtorch, at least one dehydroxylation pre-degassing blowtorch and at least one titanium-containing halide blowtorch. The three types of blowtorches are of the same number and are evenly arranged, so that the dehydroxylation treatment and the titanium doping treatment are more uniform, thereby making the dehydroxylation of the loose body quartz ingot more thorough, and further making the optical properties of the infrared synthetic quartz after sintering better. In the upward production method of the present invention, gaseous silicon tetrachloride raw material is introduced into a deposition crucible through a production blowtorch to produce a deposition reaction to produce a loose body powder. While depositing and producing a microlayer of loose body powder, a mixed gas of chlorine and helium is introduced into the deposition crucible through a dehydroxylation pre-degassing blowtorch to perform a dehydroxylation pretreatment on the generated loose body powder. At the same time, titanium halide is introduced into the deposition crucible through a titanium halide blowtorch to perform a titanium doping treatment on the generated loose body powder, thereby achieving simultaneous deposition and simultaneous process treatment, solving the problem that dehydration during the sintering process will cause the hydroxyl content to gradually decrease from the core to the edge, and achieving uniform distribution and stable incorporation of titanium compounds, thereby improving the optical uniformity of the material. Because the upward growth method implemented by the preparation device of a large-size infrared synthetic quartz material of the present invention is adopted, the density of the loose body is increased and the distribution is more uniform, and the strength of the loose body is increased and it is easier to sinter. Therefore, the upward growth method implemented by the preparation device of a large-size infrared synthetic quartz material of the present invention can significantly increase the size of the obtained loose body, and then a larger-sized infrared synthetic quartz can be sintered.

[0025] Furthermore, the furnace body is made of thermally insulating ceramic fiber material, which isolates the temperature of the external environment and ensures the smooth progress of the reaction. A quartz lining is set inside the furnace body to prevent the metal impurities in the cavity from causing the purity of the loose body to decrease, the material transmittance to deteriorate, and the key indicators such as light absorption and anti-laser damage threshold to deteriorate.

[0026] Furthermore, the present invention sets at least one air supply channel at the top of the working chamber, the angle R of which is less than 180 degrees with the side wall of the furnace body, and the angle R is less than 180 degrees to avoid affecting the deposition reaction when supplying air. An exhaust channel for exhausting waste gas is set on one side of the waste gas chamber. High-clean inert gas is introduced into the reaction chamber through the air supply channel, and the wind speed range of the air supply is 2-10m / s, ensuring that the wind speed of the air supply is not less than the wind speed of the exhaust micropores to maintain the positive pressure in the reaction chamber. Exhaust is carried out through the exhaust channel, and the waste gas and silicon dioxide in the deposition production process enter the waste gas chamber through the exhaust micropores, and then are discharged through the exhaust channel. The wind speed range of the exhaust is 2-10m / s, and the negative pressure of the waste gas chamber is maintained. In the prior art, the atmosphere in the reaction chamber is maintained by air that has been filtered through high efficiency as clean air, but various impurities are easily introduced during the ventilation process, thereby causing the various optical indicators of the material to deteriorate. Therefore, in the embodiment of the present invention, a highly clean inert gas with a purity of 5N or above can be used instead of the air that has been filtered through high efficiency as the clean wind, so as to maintain the atmosphere in the reaction chamber while keeping the gas in the chamber circulating.

[0027] In addition, the present invention also provides a method for preparing a large-size infrared synthetic quartz material, which utilizes the above-mentioned large-size infrared synthetic quartz material preparation device. The preparation method is an upward growth method, which well solves the defects of the existing downward growth method, such as the prepared loose body has a small density and pores inside, resulting in the loose body having a weak strength and not easy to be burned through, which in turn leads to the technical problem that the size of the infrared synthetic quartz should not be too large.

[0028] In summary, the present invention solves the problems existing in the prior art well and achieves the beneficial effect of obtaining large-sized infrared synthetic quartz. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0030] Figure 1 It is a schematic diagram of a preparation device of an embodiment of a preparation device and method of a large-size infrared synthetic quartz material of the present invention;

[0031] Figure 2 It is a schematic diagram of a uniform arrangement of the blowtorch components of an embodiment of a device and method for preparing a large-size infrared synthetic quartz material of the present invention;

[0032] Figure 3 It is a schematic diagram of a uniform distribution of the blowtorch components along concentric circles in an embodiment of a device and method for preparing a large-size infrared synthetic quartz material of the present invention;

[0033] Explanation of the reference numerals in the specification: 1. furnace body; 11. quartz lining; 2. bottom cover; 21. baffle plate at the bottom of the furnace; 211. exhaust microholes; 22. positioning block; 23. reset spring; 24. bearing; 25. groove; 3. support system; 4. working chamber; 41. reaction chamber; 411. air supply channel; 42. exhaust chamber; 421. exhaust channel; 5. deposition crucible; 6. blowtorch assembly; 60. mounting plate; 61. production blowtorch; 62. dehydroxylation pre-degassing blowtorch; 63. titanium halide blowtorch; 7. loose body quartz ingot. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0035] Reference Figure 1As shown, a preparation device for a large-size infrared synthetic quartz material of the present invention is hereinafter referred to as "this preparation device". "This preparation device" includes a furnace body 1, a bottom cover 2 installed under the furnace body 1, a support system 3 arranged at the center of the bottom cover 2 and capable of rotating and lifting under the drive of a power device, and a deposition crucible 5 fixedly installed on the top of the support system 3. The furnace body 1 and the bottom cover 2 together constitute a working chamber 4, and the support system 3 can also move laterally under the drive of the power device. The power device can adopt any existing well-known form, as long as the support system 3 can repeatedly move laterally while rotating and lifting, which will not be described here. In this embodiment, the power device includes three stepper motors, wherein the output end of one stepper motor is fixedly connected to the support system 3, so as to drive the support system 3 to rotate; the output ends of the other two stepper motors are connected to gears, and the gears are meshed with racks, respectively driving the support system 3 to lift and lower and move laterally. Compared with the prior art, the deposition crucible 5 is fixedly installed on the top of the support system 3, so that the "preparation device" can be used to implement the upward growth method, that is, the raw materials in the deposition crucible 5 are deposited from bottom to top to form a loose body. Compared with the downward growth method used in the prior art, the upward growth method implemented by the "preparation device" can increase the density of the loose body under the action of gravity, increase the strength, and is not easy to crack and fall off. At the same time, there are only a small amount of or even no defects such as pores inside. The bottom cover 2 of the present invention is provided with a furnace bottom baffle 21, and the furnace bottom baffle 21 divides the working chamber 4 into a reaction chamber 41 and an exhaust gas chamber 42. The furnace bottom baffle 21, the deposition crucible 5 and the support system 3 move horizontally synchronously. The repeated horizontal movement of the deposition crucible 5 causes the deposited loose body powder to be repeatedly shaken, so that the loose body density is higher and the growth process is more uniform. The furnace bottom baffle 21 is provided with exhaust microholes 211, through which exhaust microholes 211 are used to evenly discharge exhaust gas and silica from the reaction chamber 41, thereby ensuring the stability and consistency of the flow field in the reaction chamber 41. A blowtorch assembly 6 is installed above the furnace body 1. The blowtorch assembly 6 is a component including at least one production blowtorch 61, at least one dehydroxylation pre-degassing blowtorch 62, and at least one titanium-containing halide blowtorch 63. The production blowtorch 61, the dehydroxylation pre-degassing blowtorch 62, and the titanium-containing halide blowtorch 63 are arranged on the mounting plate 60. The three types of blowtorches are the same in number and are evenly arranged with each other. The "evenly arranged with each other" mentioned here means:

[0036] When the production burner 61, the dehydroxylation pre-degassing burner 62 and the titanium-containing halide burner 63 are all one:

[0037] Method 1: The production burner 61, the dehydroxylation pre-degassing burner 62 and the titanium-containing halide burner 63 can be arranged in a straight line, that is, the centers of the production burner 61, the dehydroxylation pre-degassing burner 62 and the titanium-containing halide burner 63 are on the same straight line, and the distances between the centers of adjacent burners of the production burner 61, the dehydroxylation pre-degassing burner 62 and the titanium-containing halide burner 63 are equal.

[0038] Mode 2: The production burner 61, the dehydroxylation pre-degassing burner 62 and the titanium-containing halide burner 63 can be arranged in a triangle, that is, the center line of the production burner 61, the dehydroxylation pre-degassing burner 62 and the titanium-containing halide burner 63 forms an equilateral triangle.

[0039] When there are multiple production torches 61, dehydroxylation pre-degassing torches 62 and titanium-containing halide torches 63:

[0040] Take the case where there are three production torches 61, three dehydroxylation pre-degassing torches 62 and three titanium-containing halide torches 63 as an example.

[0041] Method 1: Reference Figure 2 The three production burners 61 form a production burner group, and the centers of the three production burners 61 are in the same straight line, and the distance between the centers of two adjacent production burners 61 is equal; the three dehydroxylation pre-degassing burners 62 form a dehydroxylation pre-degassing burner group, and the centers of the three dehydroxylation pre-degassing burners 62 are in the same straight line, and the distance between the centers of two adjacent dehydroxylation pre-degassing burners 62 is equal; the three titanium-containing halide burners 63 form a titanium-containing halide burner group, and the centers of the three titanium-containing halide burners 63 are in the same straight line, and the distance between the centers of two adjacent titanium-containing halide burners 63 is equal.

[0042] The production burner group, the dehydroxylation pre-degassing burner group and the titanium-containing halide burner group are arranged in three corresponding rows, that is, for example: three production burners 61 correspond to three dehydroxylation pre-degassing burners 62, and three dehydroxylation pre-degassing burners 62 correspond to three titanium-containing halide burners 63. In this case, the distance between the center of the three production burners 61 and the center of the three dehydroxylation pre-degassing burners 62 is equal to the distance between the center of the three dehydroxylation pre-degassing burners 62 and the center of the three titanium-containing halide burners 63.

[0043] Method 2: Reference Figure 3 The three production burners 61 form a production burner group, and the centers of the three production burners 61 are in the same straight line, and the distance between the centers of two adjacent production burners 61 is equal; the three dehydroxylation pre-degassing burners 62 form a dehydroxylation pre-degassing burner group, and the centers of the three dehydroxylation pre-degassing burners 62 are in the same straight line, and the distance between the centers of two adjacent dehydroxylation pre-degassing burners 62 is equal; the three titanium-containing halide burners 63 form a titanium-containing halide burner group, and the centers of the three titanium-containing halide burners 63 are in the same straight line, and the distance between the centers of two adjacent titanium-containing halide burners 63 is equal.

[0044] The straight line formed by the center lines of the three production burners 61, the straight line formed by the center lines of the three dehydroxylation pre-degassing burners 62, and the straight line formed by the center lines of the three titanium-containing halide burners 63 intersect at the same point, which is called the intersection point. The distance between the intersection point and the nearest production burner 61 is equal to the distance between two connected production burners 61, the distance between the intersection point and the nearest dehydroxylation pre-degassing burner 62 is equal to the distance between two adjacent dehydroxylation pre-degassing burners 62, and the distance between the intersection point and the nearest titanium-containing halide burner 63 is equal to the distance between two connected titanium-containing halide burners 63.

[0045] Gaseous silicon tetrachloride raw material is introduced into the reaction chamber 41 through the production torch 61 for deposition production, chlorine and helium mixed gas is introduced into the reaction chamber 41 for dehydroxylation pretreatment through the dehydroxylation pre-degassing torch 62, and titanium halide is introduced into the reaction chamber 41 for titanium doping treatment through the titanium halide torch 63, so that dehydroxylation and titanium doping can be carried out simultaneously during the deposition production process, achieving the purpose of synchronous deposition and synchronous process treatment, and also solving the problem that dehydration during sintering will cause the hydroxyl content to gradually decrease from the core to the edge, while achieving the purpose of uniform distribution and stable incorporation of titanium compounds, and also improving the optical uniformity of the material.

[0046] Production torch 61, dehydroxylation pre-degassing torch 62 and titanium halide torch 63

[0047] Specifically, the installation of the furnace body 1 and the bottom cover 2 can adopt any existing known form, as long as the connection can be sealed, which will not be repeated here. In this embodiment, the furnace body 1 and the bottom cover 2 are connected by bolts, and a sealing gasket is provided at the connection. The deposition crucible 5 can be installed on the top of the support system 3 in any existing known form, as long as the installation strength can be guaranteed at high temperature, such as welding, threaded connection, etc. In this embodiment, the deposition crucible 5 is welded on the top of the support system 3. In addition, a groove 25 is provided at the position where the furnace bottom baffle 21 is arranged on the bottom cover 2, and the two ends of the furnace bottom baffle 21 extend into the groove 25, and the two ends of the furnace bottom baffle 21 form a moving gap with the bottom D of the groove 25, so that the two ends of the furnace bottom baffle 21 can move horizontally in the groove XX. In order to ensure the smooth movement of the furnace bottom baffle 21, the thickness H of the furnace bottom baffle 21 can be made slightly thinner than the height L of the groove 25, and the specific size is based on the smooth movement of the furnace bottom baffle 21. Furthermore, a positioning block 22 can be set at the end of the furnace bottom baffle 21 extending into the groove 25, and the thickness M of the positioning block 22 is greater than the thickness H of the furnace bottom baffle 21. The furnace bottom baffle 21 is installed in the middle of the positioning block 22, so that the upper surface and the lower surface of the furnace bottom baffle 21 do not contact the inner wall of the groove 25. Its function is: during the process of the furnace bottom baffle 21 moving horizontally driven by the support system 3, only the positioning block 22 is always in contact with the inner wall of the groove 25. The purpose of reducing friction can be achieved by adjusting the size of the positioning block 22 to minimize the contact area between the positioning block 22 and the inner wall of the groove 25. For example, the bottom area of ​​the positioning block 22 can be reduced to reduce the contact area between the bottom surface of the positioning block 22 and the bottom inner wall of the groove 25, thereby reducing friction. That is, the positioning block 22 achieves the purpose of reducing friction while ensuring the stability of the horizontal movement of the furnace bottom baffle 21. In addition, in order to prevent the positioning block 22 from hitting the bottom D of the groove 25, a buffer device can be installed between the positioning block 22 and the bottom D of the groove 25. The buffer device can adopt any existing known form, as long as it can meet the requirements of slowing down the impact of the positioning block 22 on the bottom D of the groove 25 and being resistant to high temperature. In this embodiment, a reset spring 23 is installed between the positioning block 22 and the bottom D of the groove 25. When the furnace bottom baffle 21 moves toward the bottom D of the groove 25 driven by the support system 3, the reset spring 23 is compressed, and the reset spring 23 buffers the impact of the positioning block 22 on the bottom D of the groove 25. When the furnace bottom baffle 21 moves away from the bottom D of the groove 25 driven by the support system 3, the reset spring 23 is stretched and reset. Since the support system 3 not only drives the furnace bottom baffle 21 to move horizontally repeatedly, but also has a rotation and lifting movement relative to the furnace bottom baffle 21, a bearing 24 can also be set on the side of the furnace bottom baffle 21 close to the support system 3 to ensure that the connection can form a closed working environment while reducing friction resistance.

[0048] Optionally, the furnace body 1 may be made of a thermally insulating ceramic fiber material to isolate the temperature of the external environment and ensure that the reaction proceeds smoothly. In addition, a quartz lining 11 may be provided on the inner side of the furnace body 1 to avoid the problem that metal impurities in the cavity cause the purity of the loose body to decrease, the material transmittance to deteriorate, and key indicators such as light absorption and anti-laser damage threshold to deteriorate. The installation of the quartz lining 11 may adopt any of the existing known forms, as long as it is resistant to high temperatures while forming a clean reaction chamber 41. In this embodiment, the quartz lining 11 is interference fit with the furnace body 1 and is embedded in the inner side of the furnace body 1.

[0049] Optionally, at least one air supply channel 411 having an angle R less than 180 degrees with the side wall of the furnace body 1 is provided at the top of the working chamber 4, and multiple air supply channels 411 may be provided. An exhaust channel 421 for exhausting exhaust gas may also be provided on one side of the exhaust chamber 42. The angle R between the air supply channel 411 and the side wall of the furnace body 1 is less than 180 degrees to avoid affecting the deposition reaction during air supply. During the deposition production process, the gas that maintains the atmosphere in the reaction chamber 41 enters the reaction chamber 41 through the air supply channel 411, driving the exhaust gas and silicon dioxide in the deposition production process into the exhaust chamber 42 through the exhaust micropores 211, and then discharged through the exhaust channel 421. During the deposition production process, while air is being supplied, the gas in the reaction chamber 41 is discharged into the exhaust chamber 42 through the exhaust micropores 211. The wind speed range of the air supply is 2-10m / s, which needs to meet the continuous positive pressure in the reaction chamber 41. When the air pressure in the reaction chamber 41 is relatively low, the air supply speed is appropriately increased within the air supply speed range, and when the air pressure in the reaction chamber 41 is relatively high, the air supply speed is appropriately reduced within the air supply speed range. During the deposition production process, the gas in the reaction chamber 41 is discharged into the exhaust chamber 42 through the exhaust micropores 211, and then discharged through the exhaust channel 421. The exhaust speed range is 2-10m / s, which needs to meet the continuous negative pressure in the exhaust chamber 42. When the negative pressure in the exhaust chamber 42 is relatively low, the exhaust speed is appropriately increased within the exhaust speed range, and when the negative pressure in the reaction chamber 41 is relatively high, the exhaust speed is appropriately reduced within the air supply speed range.

[0050] Optionally, the inner diameter of the deposition crucible 5 may be not less than 1100 mm, and the depth may be not less than 600 mm. The material of the deposition crucible 5 may be any one of high-cleanliness, high-temperature resistant ceramic materials with a total content of metal impurities not exceeding 500 ppm and a melting point higher than 1500° C. The size of the deposition crucible 5 is determined according to the number of the three types of burners and the required loose body diameter. In this embodiment, the inner diameter of the deposition crucible 5 is 1100 mm, the depth is 600 mm, and the material is high-cleanliness, high-temperature resistant zirconia ceramic.

[0051] The second aspect of the embodiment of the present invention further provides a method for preparing a large-size infrared synthetic quartz material, which is applied to the preparation device in the above embodiment. The specific embodiments are as follows:

[0052] Embodiment 1:

[0053] Step S1: hydrogen and oxygen are introduced into the reaction chamber 41 through the production torch 61, and the hydrogen and oxygen burn to form a hydrogen-oxygen flame, so that the reaction chamber 41 is heated and preheated;

[0054] Optionally, in step S1, hydrogen and oxygen are high-purity gases with a purity of 5N or more; the flow rate range of hydrogen is 75-230L / min, and the flow rate range of oxygen is 50-150L / min. In this embodiment, in step S1, the flow rate range of hydrogen is 75L / min, and the flow rate range of oxygen is 50L / min. The production torch 61 introduces hydrogen and oxygen into the reaction chamber 41 and ignites to form a hydrogen-oxygen flame, while the temperature in the reaction chamber 41 rises, achieving a preheating effect.

[0055] Step S2: When the temperature in the reaction chamber 41 reaches 800° C., argon gas is introduced into the reaction chamber 41 through the production torch 61;

[0056] Optionally, in step S2, argon is a high-purity gas with a purity of 5N, and the flow rate range of argon is 20-80L / min. In this embodiment, in step S2, the flow rate range of argon is 20L / min. The loose body deposition reaction needs to be carried out at a temperature above 800°C, but due to the limitations of the preparation device, the temperature in the reaction chamber 41 should not be too high. Therefore, when the temperature in the reaction chamber 41 reaches 800°C, while hydrogen and oxygen are introduced into the reaction chamber 41 through the production torch 61, argon is introduced into the reaction chamber 41 through the production torch 61. Argon is a typical inert gas. While argon is introduced to maintain the atmosphere in the reaction chamber 41, the concentrations of hydrogen and oxygen are reduced, the combustion reaction is suppressed, and the temperature is prevented from rising sharply in a short period of time.

[0057] Step S3: Raise the support system 3 to the deposition reaction position, at which time the lower end of the blowtorch assembly 6 is located 300-500 mm above the inner bottom of the deposition crucible 5;

[0058] Specifically, the essence of the deposition reaction is that the production torch 61 passes raw materials into the deposition crucible 5 of the reaction chamber 41 to form silicon dioxide, and the silicon dioxide accumulates and grows on the deposition crucible 5 to form a loose body. Since the torch has a certain speed when spraying the raw materials, and the raw materials also need a certain time to react, the distance between the lower end of the torch assembly 6 and the bottom of the deposition crucible 5 should not be too small. In this embodiment, the lower end of the torch assembly 6 is located 300 mm above the bottom of the deposition crucible 5.

[0059] Step S4: When the temperature in the reaction chamber 41 is lower than 900°C, stop passing argon into the reaction chamber 41; when the temperature in the reaction chamber 41 is higher than 900°C, continue to pass argon into the reaction chamber 41. When the temperature in the reaction chamber 41 is stabilized at 800-1000°C, gaseous silicon tetrachloride raw material is passed into the deposition crucible 5 through the production torch 61 to produce a loose body powder for deposition production, and the loose body powder is accumulated in the deposition crucible 5 to form a loose body quartz ingot 7. While the deposition production is in progress, the dehydroxylation pre-degassing torch 62 passes a mixed gas of chlorine and helium into the deposition crucible 5 to perform a dehydroxylation pretreatment on the loose body quartz ingot 7. At the same time, the titanium halide torch 63 passes titanium halide into the deposition crucible 5 to perform a titanium doping treatment on the loose body quartz ingot 7. Commonly used titanium halides include TiCl4, TiCl3, TiCl2, TiOCl2, TiOCl and TiI4. In this embodiment, TiCl4 is used as the titanium halide to perform titanium doping on the loose body quartz ingot 7.

[0060] Optionally, in step S4, the flow rate of the gaseous silicon tetrachloride raw material is in the range of 20-40 L / min. Chlorine and helium are high-purity gases with a purity of 5N or more, the molar ratio of the chlorine and helium mixed gas is 1:0.75, and the flow rate of the mixed gas is in the range of 5-20 L / min. The flow rate of the titanium halide is in the range of 3-20 L / min. In this embodiment, in step S4, the flow rate of the gaseous silicon tetrachloride raw material is in the range of 20 L / min; the flow rate of the chlorine and helium mixed gas is in the range of 5 L / min; and the flow rate of the titanium halide is in the range of 3 L / min. The production torch 61 introduces the gaseous silicon tetrachloride raw material into the reaction chamber 41, which is oxidized in the hydrogen-oxygen flame atmosphere to form SiO2 silicon dioxide, which is deposited at the bottom of the deposition crucible 5 in a rotating descending state, forming a loose body rod that grows axially upward, and the loose body rod rotates and descends with the deposition crucible 5 and repeatedly moves horizontally, forming a loose body quartz ingot 7 with a large density and uniformity. After the dehydroxylation pre-degassing torch 62 introduces a chlorine and helium mixed gas into the reaction chamber 41, the hydroxyl groups in the loose body are removed, thereby avoiding the problem of uneven dehydroxylation effect during the subsequent sintering process. The titanium-containing halide torch 63 introduces titanium halide into the reaction chamber 41 for titanium doping treatment, thereby improving the optical properties of the infrared synthetic quartz after sintering.

[0061] Step S5: During the deposition production process, the supporting system 3 and the deposition crucible 5 are driven by the power device to repeatedly move horizontally while rotating and descending, and the furnace bottom baffle 21 is repeatedly moved horizontally under the drive of the supporting system 3. The distance between the lower end of the blowtorch assembly 6 and the top of the loose body quartz ingot 7 is always controlled to be 300-500mm;

[0062] Optionally, in step S5, the rotation speed of the deposition crucible 5 is 15-50rpm, and the lateral movement frequency is 60-300s / time, that is, the deposition crucible 5 takes 60-300s for each swing back and forth. At the same time, when the deposition crucible 5 moves laterally, the lower projection of the blowtorch assembly 6 does not exceed the inner bottom of the deposition crucible 5. In this embodiment, in step S5, the rotation speed of the support system 3 is 15rpm and the lateral movement frequency is 60s / time. During the deposition production process, silica accumulates at the bottom of the deposition crucible 5. Since the deposition crucible 5 always rotates at a certain speed, the distribution of silica at the bottom of the deposition crucible 5 is mainly concentric circles, and the silica accumulation in some concentric circle areas is convex, and the silica accumulation in some concentric circle areas is concave, which will make the density of the obtained loose body uneven. In the present invention, driven by the power device, the support system 3 rotates and descends while driving the deposition crucible 5 to move horizontally repeatedly, so that the silicon dioxide accumulated in the deposition crucible 5 is repeatedly shaken, so that the silicon dioxide is accumulated more tightly and evenly, so that a loose quartz ingot 7 with a larger density and more even distribution can be obtained. The distance between the lower end of the blowtorch assembly 6 and the top of the loose quartz ingot 7 is consistent with step S3 and is always controlled at 300mm. Since the loose quartz ingot 7 is constantly growing, it is necessary to adjust the height of the deposition crucible 5 at any time through the support system 3. Therefore, the distance between the lower end of the blowtorch assembly 6 and the top of the loose quartz ingot 7 allows the existence of an error, and the error range is controlled within 2mm. High-purity inert gas is introduced into the reaction chamber 41 through the air supply channel 411, and the wind speed range of the air supply is 2-10m / s to maintain a positive pressure in the reaction chamber 41. The exhaust is carried out through the exhaust channel 421, so that the waste gas and silicon dioxide in the deposition production process enter the waste gas chamber 42 through the exhaust micropores 211, and then are discharged through the exhaust channel 421. The wind speed of the exhaust is in the range of 2-10m / s, and the negative pressure in the waste gas chamber 42 is maintained.

[0063] In the prior art, the atmosphere in the reaction chamber 41 is maintained by air that has been filtered through high efficiency as clean air. Impurities are easily introduced during the process of introducing air, which leads to deterioration of key indicators such as the transmittance, light absorption characteristics, and anti-laser damage threshold of the material. In this embodiment, a highly clean inert gas is used instead of air that has been filtered through high efficiency as clean air to maintain the atmosphere of the working space while ensuring the circulation of the gas in the chamber. Commonly used inert gases include helium, argon, and nitrogen. The highly clean inert gas in this embodiment can be any of the existing known inert gases, as long as the purity is not less than 3N, which will not be described here.

[0064] Step S6: After 80 hours of deposition, a loose quartz ingot 7 weighing not less than 250 kg is obtained, and then the process is completed, and the material and gas are stopped. The waste gas in the production process is discharged into a professional waste gas treatment device; the loose quartz ingot 7 is transferred to a sintering furnace for vitrification sintering, and finally a Φ600 mm infrared synthetic quartz rod is obtained.

[0065] Embodiment 2:

[0066] Step S1: hydrogen and oxygen are introduced into the reaction chamber 41 through the production torch 61, and the hydrogen and oxygen burn to form a hydrogen-oxygen flame, so that the reaction chamber 41 is heated and preheated;

[0067] Optionally, in step S1, hydrogen and oxygen are high-purity gases with a purity of 5N or more; the flow rate range of hydrogen is 75-230L / min, and the flow rate range of oxygen is 50-150L / min. In this embodiment, in step S1, the flow rate range of hydrogen is 230L / min, and the flow rate range of oxygen is 150L / min. The production torch 61 introduces hydrogen and oxygen into the reaction chamber 41 and ignites to form a hydrogen-oxygen flame, while the temperature in the reaction chamber 41 rises, achieving the effect of temperature rise and preheating.

[0068] Step S2: When the temperature in the reaction chamber 41 reaches 800° C., argon gas is introduced into the reaction chamber 41 through the production torch 61;

[0069] Optionally, in step S2, argon is a high-purity gas with a purity of 5N, and the flow rate range of argon is 20-80L / min. In this embodiment, in step S2, the flow rate range of argon is 80L / min. The loose body deposition reaction needs to be carried out at a temperature above 800°C, but due to the limitations of the preparation device, the temperature in the reaction chamber 41 should not be too high. Therefore, when the temperature in the reaction chamber 41 reaches 800°C, while hydrogen and oxygen are introduced into the reaction chamber 41 through the production torch 61, argon is introduced into the reaction chamber 41 through the production torch 61. Argon is a typical inert gas. While argon is introduced to maintain the atmosphere in the reaction chamber 41, the concentrations of hydrogen and oxygen are reduced, the combustion reaction is suppressed, and the temperature is prevented from rising sharply in a short period of time.

[0070] Step S3: Raise the support system 3 to the deposition reaction position, at which time the lower end of the blowtorch assembly 6 is located 300-500 mm above the inner bottom of the deposition crucible 5;

[0071] Specifically, the essence of the deposition reaction is that the production torch 61 passes raw materials into the deposition crucible 5 of the reaction chamber 41 to form silicon dioxide, and the silicon dioxide accumulates and grows on the deposition crucible 5 to form a loose body. Since the torch has a certain speed when spraying the raw materials, and the raw materials also need a certain time to react, the distance between the lower end of the torch assembly 6 and the bottom of the deposition crucible 5 should not be too small. In this embodiment, the lower end of the torch assembly 6 is located 500 mm above the bottom of the deposition crucible 5.

[0072] Step S4: When the temperature in the reaction chamber 41 is lower than 900°C, stop passing argon into the reaction chamber 41; when the temperature in the reaction chamber 41 is higher than 900°C, continue to pass argon into the reaction chamber 41. When the temperature in the reaction chamber 41 is stabilized at 800-1000°C, gaseous silicon tetrachloride raw material is passed into the deposition crucible 5 through the production torch 61 to produce a loose body powder for deposition production, and the loose body powder is accumulated in the deposition crucible 5 to form a loose body quartz ingot 7. While the deposition production is in progress, the dehydroxylation pre-degassing torch 62 passes a mixed gas of chlorine and helium into the deposition crucible 5 to perform a dehydroxylation pretreatment on the loose body quartz ingot 7. At the same time, the titanium halide torch 63 passes titanium halide into the deposition crucible 5 to perform a titanium doping treatment on the loose body quartz ingot 7. Commonly used titanium halides include TiCl4, TiCl3, TiCl2, TiOCl2, TiOCl and TiI4. In this embodiment, TiCl4 is used as the titanium halide to perform titanium doping on the loose body quartz ingot 7.

[0073] Optionally, in step S4, the flow rate of the gaseous silicon tetrachloride raw material is in the range of 20-40 L / min. Chlorine and helium are high-purity gases with a purity of more than 5N, the molar ratio of the chlorine and helium mixed gas is 1:0.75, and the flow rate of the mixed gas is in the range of 5-20 L / min. The flow rate of the titanium halide is in the range of 3-20 L / min. In this embodiment, in step S4, the flow rate of the gaseous silicon tetrachloride raw material is in the range of 40 L / min; the flow rate of the chlorine and helium mixed gas is in the range of 20 L / min; the flow rate of the titanium halide is in the range of 20 L / min. The production torch 61 introduces the gaseous silicon tetrachloride raw material into the reaction chamber 41, which is oxidized in the hydrogen-oxygen flame atmosphere to form SiO2 silicon dioxide, which is deposited at the bottom of the deposition crucible 5 in a rotating descending state, forming a loose body rod growing axially upward, and the loose body rod continuously rotates and descends with the deposition crucible 5 and repeatedly moves horizontally, forming a loose body quartz ingot 7 with a large density and uniformity. After the dehydroxylation pre-degassing torch 62 introduces a chlorine and helium mixed gas into the reaction chamber 41, the hydroxyl groups in the loose body are removed, thereby avoiding the problem of uneven dehydroxylation effect during the subsequent sintering process. The titanium-containing halide torch 63 introduces titanium halide into the reaction chamber 41 for titanium doping treatment, thereby improving the optical properties of the infrared synthetic quartz after sintering.

[0074] Step S5: During the deposition production process, the supporting system 3 and the deposition crucible 5 are driven by the power device to repeatedly move horizontally while rotating and descending, and the furnace bottom baffle 21 is repeatedly moved horizontally under the drive of the supporting system 3. The distance between the lower end of the blowtorch assembly 6 and the top of the loose body quartz ingot 7 is always controlled to be 300-500mm;

[0075] Optionally, in step S5, the rotation speed of the deposition crucible 5 is 15-50rpm, and the lateral movement frequency is 60-300s / time, that is, the deposition crucible 5 takes 60-300s for each swing back and forth. At the same time, when the deposition crucible 5 moves laterally, the lower projection of the blowtorch assembly 6 does not exceed the inner bottom of the deposition crucible 5. In this embodiment, in step S5, the rotation speed of the support system 3 is 50rpm and the lateral movement frequency is 300s / time. During the deposition production process, silica accumulates at the bottom of the deposition crucible 5. Since the deposition crucible 5 always rotates at a certain speed, the distribution of silica at the bottom of the deposition crucible 5 is mainly concentric circles, and the silica accumulation in some concentric circle areas is convex, and the silica accumulation in some concentric circle areas is concave, which will make the density of the obtained loose body uneven. In the present invention, driven by the power device, the support system 3 rotates and descends while driving the deposition crucible 5 to move horizontally repeatedly, so that the silicon dioxide accumulated in the deposition crucible 5 is repeatedly shaken, so that the silicon dioxide is accumulated more tightly and evenly, so that a loose quartz ingot 7 with a larger density and more even distribution can be obtained. The distance between the lower end of the blowtorch assembly 6 and the top of the loose quartz ingot 7 is consistent with step S3 and is always controlled at 500mm. Since the loose quartz ingot 7 is constantly growing, it is necessary to adjust the height of the deposition crucible 5 at any time through the support system 3. Therefore, the distance between the lower end of the blowtorch assembly 6 and the top of the loose quartz ingot 7 allows the existence of an error, and the error range is controlled within 2mm. High-purity inert gas is introduced into the reaction chamber 41 through the air supply channel 411, and the wind speed range of the air supply is 2-10m / s to maintain a positive pressure in the reaction chamber 41. The exhaust is carried out through the exhaust channel 421, so that the waste gas and silicon dioxide in the deposition production process enter the waste gas chamber 42 through the exhaust micropores 211, and then are discharged through the exhaust channel 421. The wind speed of the exhaust is in the range of 2-10m / s, and the negative pressure in the waste gas chamber 42 is maintained.

[0076] In the prior art, the atmosphere in the reaction chamber 41 is maintained by air that has been filtered through high efficiency as clean air. Impurities are easily introduced during the process of introducing air, which leads to deterioration of key indicators such as the transmittance, light absorption characteristics, and anti-laser damage threshold of the material. In this embodiment, a highly clean inert gas is used instead of air that has been filtered through high efficiency as clean air to maintain the atmosphere of the working space while ensuring the circulation of the gas in the chamber. Commonly used inert gases include helium, argon, and nitrogen. The highly clean inert gas in this embodiment can be any of the existing known inert gases, as long as the purity is not less than 3N, which will not be described here.

[0077] Step S6: After 50 hours of deposition, a loose quartz ingot 7 weighing not less than 250 kg is obtained, and then the process is completed, and the material and gas are stopped. The waste gas in the production process is discharged into a professional waste gas treatment device; the loose quartz ingot 7 is transferred to a sintering furnace for vitrification sintering, and finally a Φ600mm infrared synthetic quartz rod is obtained.

[0078] The efficiency of the loose body obtained by the existing VAD process and the embodiment of the present invention and the performance of the obtained infrared synthetic quartz are shown in the following table:

[0079]

[0080] Fewer metal impurities and controllable hydroxyl content are the biggest advantages of the VAD process for preparing infrared synthetic quartz. As can be seen from the above table, compared with the existing VAD process, the present invention can prepare infrared synthetic quartz of Φ600mm. At the same time, the deposition efficiency of the loose body has been greatly improved, the metal impurities have been reduced tenfold, the expansion coefficient of the infrared synthetic quartz has been reduced, and the optical performance has been significantly improved, which can further meet the application needs in the field of optoelectronic technology.

[0081] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0082] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0083] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for preparing a large-sized infrared synthetic quartz material, implemented by using a preparation device for a large-sized infrared synthetic quartz material, the preparation device comprising a furnace body (1), a bottom cover (2) installed below the furnace body (1), a support system (3) arranged at the center of the bottom cover (2) and capable of rotating and lifting under the drive of a power device, and a deposition crucible (5) connected to the support system (3); the furnace body (1) and the bottom cover (2) together constitute a working chamber (4), characterized in that: The deposition crucible (5) is fixedly mounted on the top of the support system (3); the support system (3) can be moved laterally under the drive of a power device; the bottom cover (2) is provided with a furnace bottom baffle (21) that can be moved laterally under the drive of the support system (3), and divides the working chamber (4) into a reaction chamber (41) and an exhaust chamber (42); the furnace bottom baffle (21) is provided with exhaust microholes (211); a blowtorch assembly (6) is provided above the deposition crucible (5); The top of the reaction chamber (41) is provided with at least one air supply channel (411) whose included angle R with the side wall of the furnace body (1) is less than 180 degrees, and is used to introduce inert gas; and one side of the waste gas chamber (42) is provided with an exhaust channel (421) for exhausting waste gas; The torch assembly (6) comprises a production torch (61), a dehydroxylation pre-degassing torch (62) and a titanium-containing halide torch (63); the number of the production torch (61), the dehydroxylation pre-degassing torch (62) and the titanium-containing halide torch (63) is the same, and each is at least one; the production torch (61), the dehydroxylation pre-degassing torch (62) and the titanium-containing halide torch (63) are evenly arranged; The preparation method comprises the following production steps: Step S1: introducing hydrogen and oxygen into the reaction chamber (41) through the production torch (61), igniting them to form a hydrogen-oxygen flame, thereby preheating the reaction chamber (41); Step S2: when the temperature in the reaction chamber (41) reaches 800° C., argon gas is continuously introduced into the reaction chamber (41) through the production torch (61); Step S3: raising the support system (3) to a deposition reaction position, at which point the lower end of the blowtorch assembly (6) is located 300-500 mm above the bottom of the deposition crucible (5); Step S4: when the temperature in the reaction chamber (41) is stabilized at 800-1000° C., a gaseous silicon tetrachloride raw material is introduced into the deposition crucible (5) through the production torch (61), and the silicon tetrachloride undergoes a hydrolysis reaction during the hydrogen-oxygen combustion process to produce nano-scale silicon dioxide, which is accumulated in the deposition crucible (5) to form a loose quartz ingot (7); while the deposition production is being carried out, the dehydroxylation pre-degassing torch (62) introduces a mixed gas of chlorine and helium into the deposition crucible (5) to perform a dehydroxylation pretreatment on the loose quartz ingot (7); at the same time, the titanium-containing halide torch (63) introduces titanium halide into the deposition crucible (5) to perform a titanium doping treatment on the loose quartz ingot (7); Step S5: During the deposition production process, the support system (3) and the deposition crucible (5) are driven by a power device to repeatedly move horizontally while rotating and descending, and the furnace bottom baffle (21) is repeatedly moved horizontally under the drive of the support system (3); the distance between the lower end of the blowtorch assembly (6) and the top of the loose quartz ingot (7) is always controlled to be 300-500 mm; high-clean inert gas is introduced into the reaction chamber (41) through the air supply channel (411), and the air supply wind speed range is 2-10 m / s; exhaust is carried out through the exhaust channel (421), and during the deposition production process, the waste gas and silicon dioxide in the reaction chamber (41) enter the waste gas chamber (42) through the exhaust micropores (211), and then are discharged through the exhaust channel (421), and the exhaust wind speed range is 2-10 m / s; Step S6: After 50-80 hours of deposition production, the loose quartz ingot (7) weighing not less than 250 kg is obtained, and then the process is finished and the material and gas are stopped; the loose quartz ingot (7) is transferred to a sintering furnace for vitrification sintering, and finally a Φ600 mm infrared synthetic quartz rod is obtained.

2. The method for preparing a large-size infrared synthetic quartz material according to claim 1, characterized in that: In step S1, hydrogen and oxygen are high-purity gases with a purity of 5N or above; the flow rate range of hydrogen is 75-230 L / min, and the flow rate range of oxygen is 50-150 L / min.

3. The method for preparing a large-size infrared synthetic quartz material according to claim 2, characterized in that: In step S2, the argon gas is a high-purity gas with a purity of 5N, and the flow rate range of the argon gas is 20-80 L / min.

4. The method for preparing a large-size infrared synthetic quartz material according to claim 3, characterized in that: In step S4, the flow rate of the gaseous silicon tetrachloride raw material is in the range of 20-40 L / min; the chlorine and helium are high-purity gases with a purity of 5N or more, the molar ratio of the chlorine and helium mixed gas is 1:0.75, and the flow rate of the mixed gas is in the range of 5-20 L / min; the flow rate of the titanium halide is in the range of 3-20 L / min.

5. The method for preparing a large-size infrared synthetic quartz material according to claim 4, characterized in that: In step S5, the rotation speed of the deposition crucible (5) is 15-50 rpm, the lateral speed is 0.1-5 m / s, the interval is ±200 mm, and it is a variable acceleration motion with a curve in which the center speed is the maximum and gradually decreases toward the edge; when the deposition crucible (5) is lateralized, the lower projection of the blowtorch assembly (6) does not exceed the inner bottom of the deposition crucible (5).

6. The method for preparing a large-size infrared synthetic quartz material according to claim 1, characterized in that: The furnace body (1) is made of ceramic fiber material, and a quartz lining (11) is arranged inside.

7. The method for preparing a large-size infrared synthetic quartz material according to claim 1, characterized in that: The inner diameter of the deposition crucible (5) is not less than 1100 mm and the depth is not less than 600 mm. The material of the deposition crucible (5) is a ceramic material.

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