A mass increasing mixing unit, a gaseous material supply device, and a supply method

Abstract

The application provides a body mixing unit, a gaseous raw material feeding device and a feeding method for preparing quartz glass by a vapor deposition method. The body mixing unit comprises a first feeding pipeline, a second feeding pipeline, a tank, a mixing output pipeline and a compensation gas input pipeline. The gaseous raw material feeding device comprises the whole mixing unit. The gaseous raw material feeding method is implemented on the gaseous raw material feeding device. By using the body mixing unit, the gaseous raw material feeding device and the feeding method, the gaseous silicon-containing raw material and the gaseous titanium-containing raw material can be uniformly premixed in the tank according to a certain mass ratio in advance, and condensation and dewing do not occur, so that the internal component mass fraction of the mixed particles of the deposited silica and titanium dioxide on the deposition surface is fixed, the composition is uniform, the deposition rate is stable, and the titanium-doped quartz glass with higher optical uniformity and zero expansion can be prepared.

Description

Technical Field

[0001] This invention relates to the field of quartz glass preparation technology, and in particular to a bulk mixing unit, a gaseous raw material feeding device, and a feeding method. Background Technology

[0002] Titanium-doped quartz glass is an excellent optical material due to its extremely low coefficient of thermal expansion (approximately 5.7 x 10⁻⁶). -7 With its characteristics such as ℃ and good thermal workability, it occupies an important position in high-tech fields such as astronomy and semiconductors.

[0003] Currently, domestic processes for producing titanium-doped quartz glass include axial vapor deposition (VAD) or chemical vapor deposition (CVD). For example, Patent Document 1 discloses the vaporization of silicon tetrachloride (SiCl4, at temperatures above 85°C) and titanium tetrachloride (TiCl4, at temperatures above 135°C), both containing silicon and titanium, with a purity >99.99%. Alternatively, it discloses the vaporization of octamethyltetrasiloxane (OMCTS, at temperatures above 180°C) and titanium tetrachloride (TiCl4, at temperatures above 135°C). The vaporized silicon tetrachloride or octamethyltetrasiloxane and titanium tetrachloride are then introduced into an oxyhydrogen flame, and the deposition surface temperature is controlled at 900°C to 950°C. Through chemical vapor deposition, a mixed powder of silicon dioxide and titanium dioxide particles with a particle size not exceeding 1 μm is generated.

[0004] During transport, gaseous silicon-containing and gaseous titanium-containing raw materials experience condensation and condensation, leading to rapid contamination and blockage of equipment and pipelines. This makes it difficult for these materials to hydrolyze in a fixed mass ratio within the hydrogen-oxygen flame generated by the burner, resulting in unstable mass ratios and total amounts of generated silica and titanium dioxide particles. Furthermore, the extremely short period of random movement before hydrolysis in the hydrogen-oxygen flame makes it difficult to achieve uniform mixing, further hindering the uniform mixing of the generated silica and titanium dioxide particles. Under these two conditions, zero-expansion titanium-doped quartz glass cannot be produced, and optical uniformity is reduced. Summary of the Invention

[0005] This invention aims to provide a bulk mixing unit, a gaseous raw material feeding device, and a feeding method, which enables gaseous silicon-containing raw materials and gaseous titanium-containing raw materials to be uniformly premixed in the tank at a fixed mass ratio in advance without condensation. This ensures that the mass fraction of each component in the mixed particles of silicon dioxide and titanium dioxide deposited on the deposition surface is fixed, the composition is uniform, and the deposition rate is stable. This can produce titanium-doped quartz glass with extremely low thermal expansion coefficient and higher optical uniformity.

[0006] The technical solution adopted in this invention is:

[0007] A bulking mixing unit includes a first conveying pipe and a second conveying pipe for conveying gaseous silicon-containing raw materials and gaseous titanium-containing raw materials, respectively. The bulking mixing unit further includes a tank, which is a mixing zone for the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials at a preset mixing temperature to form a mixed gas with a fixed mass fraction of each component, uniform mixing, and no condensation. The first conveying pipe and the second conveying pipe are respectively connected to the tank and input the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials into the tank according to a preset ratio, and the temperature of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials when they enter the tank reaches the preset mixing temperature.

[0008] A mixing output pipe, which is connected to the tank, to guide the mixed gas in the tank to the burner;

[0009] A compensation gas input pipeline is connected to the tank body and inputs compensation gas into the tank body according to a preset ratio. The temperature of the compensation gas when it enters the tank body is higher than the preset mixing temperature, so as to compensate for the preset mixing temperature fluctuation caused by the premixing of gaseous silicon-containing raw materials and gaseous titanium-containing raw materials into the tank body, and to avoid the condensation of gaseous silicon-containing raw materials and gaseous titanium-containing raw materials in the tank body.

[0010] The volume of the tank should be greater than the sum of the volumes of the gaseous silicon-containing raw material, the gaseous titanium-containing raw material, and the compensation gas input within a specified time; the pressure inside the tank should be less than the pressure inside the first conveying pipeline, the second conveying pipeline, and the compensation gas input pipeline.

[0011] Furthermore, one-way valves are respectively installed at the connection points of the first conveying pipe and the second conveying pipe with the tank body.

[0012] Furthermore, a heat tracing cable is installed on the first material conveying pipe;

[0013] And / or, a heat tracing cable is provided on the second conveying pipe;

[0014] And / or, a heat tracing cable is provided on the compensation gas inlet pipe.

[0015] And / or, a heat tracing cable is provided on the mixed output pipe.

[0016] Furthermore, a stirrer is also provided inside the tank.

[0017] Furthermore, the directions in which the gaseous silicon-containing raw material enters the tank in the first conveying pipe, the directions in which the gaseous titanium-containing raw material enters the tank in the second conveying pipe, and the directions in which the compensating gas enters the tank in the compensating gas input pipe are not all coincident or are different from each other.

[0018] Furthermore, the tank is connected to a safety pipeline; the safety pipeline is equipped with a safety valve and a flame arrester, using a Spirax Sarco SV615 safety valve (DN30, 316SS) for overpressure protection of the tank; and a Lockheed CNG flame arrester (threaded connection) for high-altitude discharge of the mixed gas to prevent backfire.

[0019] Based on the same inventive concept, the present invention also provides a gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass, comprising a silicon-containing raw material electric heating evaporator, a titanium-containing raw material electric heating evaporator, and a PLC controller. The gaseous raw material feeding device further includes a compensating gas electric heating evaporator and the aforementioned bulking mixing unit; the silicon-containing raw material electric heating evaporator, the titanium-containing raw material electric heating evaporator, and the compensating gas electric heating evaporator are respectively connected to a first conveying pipe, a second conveying pipe, and a compensating gas input pipe of the bulking mixing unit; the PLC controller is electrically connected to the silicon-containing raw material electric heating evaporator, the titanium-containing raw material electric heating evaporator, and the compensating gas electric heating evaporator.

[0020] Furthermore, the gaseous raw material feeding device also includes a filter; the filter is respectively disposed on the first conveying pipe and the second conveying pipe, or the filter is respectively disposed on the first conveying pipe, the second conveying pipe and the compensation gas input pipe.

[0021] Based on the same inventive concept, the present invention also provides a gaseous raw material feeding method for the preparation of zero-expansion titanium-doped quartz glass, which is implemented based on the aforementioned gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass. The gaseous raw material feeding method includes the following steps:

[0022] The silicon-containing raw material and the titanium-containing raw material are heated separately to produce gaseous silicon-containing raw material and gaseous titanium-containing raw material;

[0023] The compensating gas is heated;

[0024] According to a preset ratio, gaseous silicon-containing raw materials, gaseous titanium-containing raw materials, and compensating gas are fed into the tank for mixing; the temperature of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials when they enter the tank is controlled to be the preset mixing temperature; the temperature of the compensating gas when it enters the tank is controlled to be higher than the preset mixing temperature; and the pressure inside the tank is controlled to be lower than the pressure inside the first conveying pipe, the second conveying pipe, and the compensating gas input pipe.

[0025] After the gaseous silicon-containing raw material and the gaseous titanium-containing raw material are mixed, a uniformly mixed gas with fixed mass fractions of each component and no condensation is obtained. The gas is then introduced into the burner as a carrier gas by the compensation gas.

[0026] Furthermore, the gaseous silicon-containing raw material, gaseous titanium-containing raw material, and compensation gas input into the tank are gaseous SiCl4, gaseous TiCl4, and hydrogen, respectively.

[0027] Furthermore, with the sum of their mass ratios set at 100%, the mass percentages of gaseous SiCl4, gaseous TiCl4, and H2 are 88-93%, 5-10%, and the balance, respectively.

[0028] Furthermore, the temperature of gaseous SiCl4 and gaseous TiCl4 when they enter the tank is 135℃~140℃; the temperature of H2 when it enters the tank is 145℃~150℃.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention provides a volumetric mixing unit. This volumetric mixing unit adds a tank and a compensating gas inlet pipe. Inside the tank, gaseous silicon-containing raw materials and gaseous titanium-containing raw materials are premixed. Simultaneously, compensating gas is introduced through the compensating gas inlet pipe to compensate for temperature fluctuations during the premixing of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials in the tank. Based on this, it is possible to achieve uniform premixing of gaseous silicon-containing raw materials and gaseous titanium-containing raw materials in the tank at a fixed mass ratio without condensation.

[0031] 2. This invention also provides a gaseous raw material feeding device and method for the preparation of zero-expansion titanium-doped quartz glass, capable of providing a SiCl4 and TiCl4 mixed gas with fixed mass fractions of internal components, uniform mixing, and fixed flow rate to the burner. Because the gaseous SiCl4 and gaseous TiCl4, configured according to a preset ratio, are premixed in the bulk mixing unit of the gaseous raw material feeding device for zero-expansion titanium-doped quartz glass preparation, and because the bulk mixing unit of the gaseous raw material feeding device for zero-expansion titanium-doped quartz glass preparation provided in this invention is designed with a compensation gas input pipe, the compensation gas is used to compensate for temperature fluctuations of the premixed gaseous SiCl4 and gaseous TiCl4 in the tank. Based on this, it is possible to achieve uniform premixing of gaseous SiCl4 and gaseous TiCl4 in the tank at a fixed mass ratio without condensation, ensuring that the mass fractions of internal components of the mixed particles of silica and titanium dioxide deposited on the deposition surface are fixed, the composition is uniform, and the deposition rate is stable, thus enabling the preparation of titanium-doped quartz glass with higher optical uniformity. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram of the structure of an augmentation hybrid unit in Embodiment 1 of this application;

[0034] Figure 2 A schematic diagram of the structure of a zero-expansion quartz glass preparation apparatus in Embodiment 2 of this application;

[0035] Figure 3 The vapor pressure and temperature curves of SiCl4 and TiCl4 in Example 3 of this application;

[0036] Figure 4 The gas-liquid phase diagram of the TiCl4-SiCl4 binary system in Example 3 of this application. Detailed Implementation

[0037] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0038] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0039] In the embodiments of this application, unless otherwise explicitly specified and limited, the terms "installation," "connection," etc., should be interpreted broadly. For example, they can refer to direct connection or indirect connection through an intermediate medium, or to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0040] Example 1

[0041] like Figure 1As shown, this embodiment provides a bulk mixing unit for uniformly premixing two gaseous raw materials for preparing titanium-doped quartz glass in a tank 1 at a fixed mass ratio, and no condensation or condensation occurs before and after premixing in the tank 1, or during the process of transferring the premixed raw materials from the tank 1 to the burner 8.

[0042] The bulk mixing unit includes a first conveying pipe 2 and a second conveying pipe 3. The first conveying pipe 2 and the second conveying pipe 3 are respectively the conveying pipelines for gaseous silicon-containing raw materials and gaseous titanium-containing raw materials. Furthermore, in order to maintain the gaseous state of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials during the conveying process of the first conveying pipe 2 and the second conveying pipe 3, respectively, an insulation layer (such as asbestos) is wrapped around the outer walls of the first conveying pipe 2 and the second conveying pipe 3 to reduce heat loss. By increasing the conveying pressure within the first conveying pipe 2 and the second conveying pipe 3 and maintaining the temperature inside the pipes, the dew point temperature of the gaseous silicon-containing raw materials can be increased, preventing condensation of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials.

[0043] During the mixing process, condensation occurs between gaseous silicon-containing raw materials and gaseous titanium-containing raw materials. This is mainly because, during contact, the gaseous silicon-containing raw materials cause a slight temperature decrease in the gaseous titanium-containing raw materials, leading to condensation, or vice versa. To premix the gaseous silicon-containing and gaseous titanium-containing raw materials and prevent condensation during mixing, the volumetric mixing unit in this embodiment further includes a tank 1, a mixing output pipe 5, and a compensation gas input pipe 4. Tank 1 is the main mixing area for the gaseous silicon-containing and gaseous titanium-containing raw materials at a preset mixing temperature. (See attached...) Figure 1As shown, the tank 1 is a hollow cylindrical structure. An insulation layer or a jacketed heating layer is provided on the outer wall of the tank 1 to reduce heat loss and maintain the temperature inside the tank 1. The first conveying pipe 2 and the second conveying pipe 3 are located at one end along the axial direction of the tank 1. The first conveying pipe 2 and the second conveying pipe 3 are connected to the hollow interior of the tank 1 to introduce gaseous silicon-containing raw materials and gaseous titanium-containing raw materials into the tank 1 according to a preset ratio. The mixing output pipe 5 is located at the other end along the axial direction of the tank 1. The mixing output pipe 5 is a pipeline for conveying the mixed gas formed by mixing the gaseous silicon-containing raw materials and the gaseous titanium-containing raw materials, guiding the mixed gas to the burner 8. Furthermore, the outer wall of the mixing output pipe 5 is also wrapped with an insulation layer (such as asbestos) to reduce heat loss and prevent condensation of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials. The compensation gas input pipe 4 is also connected to the hollow interior of the tank 1 to input heated compensation gas (oxygen or hydrogen) into the tank 1 according to a preset ratio. The temperature of the compensating gas entering tank 1 is higher than the preset mixing temperature. This compensates for temperature fluctuations that occur during the mixing of gaseous silicon-containing and gaseous titanium-containing raw materials within tank 1, preventing condensation of the gaseous silicon-containing and gaseous titanium-containing raw materials within tank 1. An insulation layer (such as asbestos) is also installed on the outer wall of the compensator input pipe 4 to reduce heat loss and maintain the temperature of the compensating gas.

[0044] Before the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials are transported to tank 1 via the first conveying pipe 2 and the second conveying pipe 3, they have different vapor pressures. The volume of tank 1 should be greater than the sum of the volumes of the gaseous silicon-containing raw materials, gaseous titanium-containing raw materials, and compensating gas input through the first conveying pipe 2, the second conveying pipe 3, and the compensating gas input pipe 4 within a specified time. When the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials in the preset proportion enter tank 1, the constraints imposed on them by the first conveying pipe 2 and the second conveying pipe 3 disappear, causing a sudden release of pressure and resulting in temperature fluctuations. The compensating gas, simultaneously input into tank 1 according to the preset proportion, compensates for these temperature fluctuations, ensuring that the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials in tank 1, after mixing, form a uniformly mixed gas with fixed mass fractions of each component, free from condensation. Simultaneously, the compensating gas also acts as a carrier gas to guide the mixed gas flow to burner 8. Furthermore, the pressure inside tank 1 is lower than the pressure of the first conveying pipe 2, the second conveying pipe 3, and the compensation gas input pipe 4, which respectively input gaseous silicon-containing raw materials, gaseous titanium-containing raw materials, and compensation gas into tank 1, ensuring that the gaseous silicon-containing raw materials, gaseous titanium-containing raw materials, and compensation gas can be supplied normally.

[0045] In this embodiment, one-way valves 9 are respectively provided at the connection between the first conveying pipe 2 and the second conveying pipe 3 and the tank 1, which respectively restrict the gaseous silicon-containing raw material and the gaseous titanium-containing raw material to flow into the tank 1 in one direction, while preventing the mixed gas in the tank 1 from flowing back.

[0046] In this embodiment, several heating cables 10 are provided on the first conveying pipe 2 and the second conveying pipe 3 to gradually heat the gaseous silicon-containing raw material transported in the first conveying pipe 2 and the gaseous titanium-containing raw material transported in the second conveying pipe 3 to a preset mixing temperature. A heating cable 10 is also provided on the compensation gas input pipe 4 to maintain the temperature of the compensation gas above the preset mixing temperature. A heating cable 10 is also provided on the mixing output pipe 5 to further gradually heat the mixed gas to a preset feeding temperature. Simultaneously, as the heating cables 10 gradually heat the gaseous silicon-containing raw material transported in the first conveying pipe 2 and the gaseous titanium-containing raw material transported in the second conveying pipe 3 to the preset mixing temperature, the combined effect with the conveying pressure within the first conveying pipe 2 and the second conveying pipe 3 also helps to increase the dew point temperature of the gaseous silicon-containing raw material and the gaseous titanium-containing raw material, preventing condensation of the gaseous silicon-containing raw material and the gaseous titanium-containing raw material.

[0047] For example, a heating tape 10 is installed near the beginning, middle, and end of the first conveying pipeline 2 in the transmission direction to gradually increase the temperature of the gaseous silicon-containing raw material from 100°C to 140°C. Similarly, a heating tape 10 is installed near the beginning, middle, and end of the second conveying pipeline 3 in the transmission direction to gradually increase the temperature of the gaseous titanium-containing raw material from 135°C to 140°C. A heating tape 10 is installed near the middle section of the mixing output pipeline 5 to increase the temperature of the mixed gas from 140°C to 145°C. Hydrogen is selected as the compensating gas, and a heating tape 10 is installed near the beginning and middle sections of the compensating gas input pipeline 4 to maintain the hydrogen temperature at 150°C.

[0048] In this embodiment, to accelerate the uniform mixing of gaseous silicon-containing raw materials and gaseous titanium-containing raw materials within the tank 1, a stirrer 6 is also provided inside the tank 1. The stirrer 6 is driven to rotate by a motor. When the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials are transported to the tank 1, they are rapidly and uniformly dispersed by the stirring action of the stirrer 6, thereby improving the uniform mixing efficiency of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials.

[0049] In this embodiment, the direction in which the compensating gas input pipe 4 introduces hydrogen into the tank 1 intersects with the connection direction of the first conveying pipe 2 and the second conveying pipe 3 with the mixing output pipe 5. Therefore, the compensating gas can provide some assistance in the mixing of the gaseous silicon-containing raw material and the gaseous titanium-containing raw material, accelerating the uniform mixing process. For example, by positioning the compensating gas input pipe 4 in the tangential direction of the outer circumference of the tank 1, hydrogen can form a circulation within the tank 1.

[0050] In this embodiment, to ensure operational safety, the mixing unit also includes a safety conduit 7. The safety conduit 7 is connected to the hollow interior of the tank 1. A safety valve 11 and a flame arrester 12 are installed on the safety conduit 7. In the event of a sudden emergency that increases the pressure in the tank 1, the mixed gas can be safely released through the safety conduit 7.

[0051] The operation of the volumetric mixing unit is as follows: gaseous silicon-containing raw materials are transported by the first conveying pipe 2, gaseous titanium-containing raw materials are transported by the second conveying pipe 3, and compensating gas is transported by the compensating gas input pipe 4, according to a preset ratio. The temperature of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials when they enter the tank 1 is the preset mixing temperature. The temperature of hydrogen entering the tank 1 is higher than the preset mixing temperature. The stirrer 6, driven by a motor, stirs and mixes the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials in the tank 1 to form a premixed, non-condensable, saturated mixture. The finally uniformly mixed mixture is output from the mixing output pipe 5 and directed to the burner 8.

[0052] Example 2

[0053] Based on the bulk mixing unit in Example 1, this example provides a gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass, so as to provide a uniformly mixed gas to the burner 8.

[0054] The gaseous raw material feeding device includes a silicon-containing raw material electric heating evaporator, a titanium-containing raw material electric heating evaporator, a compensating gas electric heating evaporator, a PLC controller, and a volume-enhancing mixing unit. The structure of the volume-enhancing mixing unit is the same as described in Example 1. The silicon-containing raw material electric heating evaporator and the titanium-containing raw material electric heating evaporator are respectively connected to the starting ends of the first conveying pipe 2 and the second conveying pipe 3. The compensating gas electric heating evaporator is connected to the starting end of the compensating gas input pipe 4. Electronic thermometers and electronic pressure gauges are also installed in the tank 1, the first conveying pipe 2, the second conveying pipe 3, the mixing output pipe 5, and the compensating gas input pipe 4. The PLC controller is electrically connected to the motors of the silicon-containing raw material electric heating evaporator, the titanium-containing raw material electric heating evaporator, the compensating gas electric heating evaporator, the electronic thermometer, the electronic pressure gauge, the heating tape 10, and the stirrer 6. The PLC controller controls the heating temperatures of the silicon-containing raw material electric evaporator, the titanium-containing raw material electric evaporator, and the compensating gas electric evaporator, generating gaseous silicon-containing raw material, gaseous titanium-containing raw material, and high-temperature compensating gas, which are respectively introduced into tank 1 through the first conveying pipe 2, the second conveying pipe 3, and the compensating gas input pipe 4. The PLC controller controls the rotation of the stirrer 6 to rapidly and uniformly mix the gaseous silicon-containing raw material and gaseous titanium-containing raw material into a homogeneous mixture with fixed mass fractions of each component, without condensation. The mixture is then carried by the compensating gas through the mixing output pipe 5 to the burner 8. Simultaneously, the PLC controller dynamically regulates the evaporation and mixing processes based on the flow rate, temperature, and pressure detected by the electronic thermometer and electronic pressure gauge.

[0055] The gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass provided in this embodiment can supply the burner 8 with a SiCl4 and TiCl4 mixture gas with fixed mass fractions of each component, uniform mixing, and a fixed flow rate. Since the gaseous SiCl4 and gaseous TiCl4, configured according to a preset ratio, are premixed in the tank 1 of the bulk mixing unit within the gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass, and the bulk mixing unit within the gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass provided in this invention is designed with a compensation gas input pipe, the compensation gas is used to compensate for temperature fluctuations in the premixed gaseous SiCl4 and gaseous TiCl4 within the tank 1. Based on this, the gaseous SiCl4 and gaseous TiCl4 can be uniformly premixed in the tank 1 in a fixed ratio without condensation, ensuring that the mass fractions of each component in the mixed particles of silica and titanium dioxide deposited on the deposition surface are fixed, the composition is uniform, and the deposition rate is stable, thereby producing titanium-doped quartz glass with higher optical uniformity and zero expansion.

[0056] In this embodiment, to reduce the impact of impurities in gaseous silicon-containing raw materials and gaseous titanium-containing raw materials, the gaseous raw material feeding device includes filters. Filters are respectively installed on the first conveying pipe 2 and the second conveying pipe 3 to filter impurities in the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials, thereby improving their purity. Furthermore, a filter can also be installed on the compensation gas input pipe 4 to filter impurities in the compensation gas, thereby improving its purity.

[0057] Example 3

[0058] Based on the gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass in Example 2, this example provides a gaseous raw material feeding method for the preparation of zero-expansion titanium-doped quartz glass, comprising the following steps:

[0059] The silicon-containing raw material and the titanium-containing raw material are heated separately to produce gaseous silicon-containing raw material and gaseous titanium-containing raw material;

[0060] The compensating gas is heated;

[0061] According to a preset ratio, gaseous silicon-containing raw materials, gaseous titanium-containing raw materials, and compensating gas are input into tank 1 for mixing; the temperature of gaseous silicon-containing raw materials and gaseous titanium-containing raw materials when entering tank 1 is controlled to be the preset mixing temperature; the temperature of compensating gas when entering tank 1 is controlled to be higher than the preset mixing temperature; the pressure inside tank 1 is controlled to be lower than the pressure inside the first conveying pipe 2, the second conveying pipe 3, and the compensating gas input pipe 4.

[0062] After mixing gaseous silicon-containing raw materials and gaseous titanium-containing raw materials, a uniformly mixed gas with fixed mass fractions of each component and no condensation is obtained. This gas is then introduced into the next process as a compensating gas.

[0063] The following describes the preparation of titanium-doped quartz glass using SiCl4 and TiCl4 as raw materials, with hydrogen as the compensating gas, and mainly includes the following steps:

[0064] Step (1): Heating liquid SiCl4 and liquid TiCl4 separately to evaporate and vaporize them, yielding gaseous SiCl4 and gaseous TiCl4. At this time, the temperature of gaseous SiCl4 is 100℃ and the temperature of gaseous TiCl4 is 135℃.

[0065] Step (2) involves gradually heating the temperature of the vaporized SiCl4 from 100°C to 140°C; simultaneously, the temperature of the vaporized TiCl4 from 135°C to 140°C is gradually heated.

[0066] Step (3) involves transporting the gaseous SiCl4, gaseous TiCl4 and hydrogen at 150°C, which were simultaneously heated in step (2), into the tank 1 of the bulk mixing unit to obtain a mixed gas with fixed mass fractions of each component, uniform mixing, and no condensation. Hydrogen is then used as the carrier gas to introduce the mixture into the next process.

[0067] Among them, with the sum of their mass ratios being 100%, the mass percentages of gaseous SiCl4, gaseous TiCl4, and H2 input into tank 1 are 88~93%, 5~10%, and the remainder, respectively.

[0068] According to the Clausius-Clapeyron equation, the saturated vapor pressure versus temperature curves of SiCl4 and TiCl4 can be obtained, as shown in the attached figure. Figure 3 As shown.

[0069] Based on Raoult's law and Dalton's law of partial pressures, the bubble point and dew point of TiCl4-SiCl4 at different temperatures under different mole fractions were calculated, resulting in the vapor-liquid phase diagram of the TiCl4-SiCl4 binary system, as shown in the attached diagram. Figure 4 As shown in the attached figure, by controlling the mixing ratio and mixing temperature of TiCl4-SiCl4, gaseous TiCl4 and gaseous SiCl4 can be made to reach a non-condensed state in tank 1.

[0070] At this point, assume that the gas composition of tank 1 is as shown in Table 1, and that the volume of tank 1 is V and the temperature is T.

[0071] The molar mass of the gas mixture inside tank 1 is:

[0072] M = M1×y1 + M2×y2 + M3×y3

[0073] Wherein, H2 has a molar mass of M1 and a molar fraction of y1; SiCl4 has a molar mass of M2 and a molar fraction of y1. TiCl4: molar mass is The mole fraction is The molar mass M of the mixed gas is calculated to be 63.66 or 61.4.

[0074] Table 1-2 Proportion of each component in the gas mixture inside tank 1

[0075]

[0076] According to Avogadro's law, the total pressure P of the mixture in tank 1 at this time is:

[0077]

[0078] Assume that the mass and volumetric flow rates of H2 are m1 and q, respectively. v1The mass and volumetric flow rates of SiCl4 are m2 and q, respectively. v2 The mass and volumetric flow rates of TiCl4 were m3 and q, respectively. v3 The total pressure of the air-fuel mixture is:

[0079]

[0080] or:

[0081]

[0082] When M=63.66, q v1 3~5slm, q v2 For 6~10 slm, q v3 It is 0.5-2 slm;

[0083]

[0084] Or when M=61.4, q v1 3~5slm, q v2 For 6~10 slm, q v3 It is 0.5-2 slm;

[0085]

[0086] Assuming the gas volume in the pipeline is V*, the temperature is T*, and the gas pressure in each pipeline is:

[0087]

[0088]

[0089]

[0090] Using hydrogen as an example to illustrate pipeline pressure With the total pressure of the mixture Size relationship:

[0091]

[0092] Since T and T* are controllable, and V* and V are controllable, let:

[0093]

[0094] but Similarly, it can achieve , .

[0095] In summary, the first conveying pipe 2, the second conveying pipe 3, and the compensating gas input pipe 4 are all greater than the total pressure in tank 1, which meets the requirements for inputting gaseous SiCl4, gaseous TiCl4, and hydrogen into tank 1 through the first conveying pipe 2, the second conveying pipe 3, and the compensating gas input pipe 4.

Claims

1. A bulk mixing unit, comprising a first conveying pipe and a second conveying pipe for conveying gaseous silicon-containing raw materials and gaseous titanium-containing raw materials, respectively, characterized in that, The proliferating mixing unit further includes: The tank is a mixing zone for gaseous silicon-containing raw materials and gaseous titanium-containing raw materials at a preset mixing temperature, so as to form a mixed gas with a fixed mass fraction of each component, uniform mixing, and no condensation. The first conveying pipe and the second conveying pipe are respectively connected to the tank and input gaseous silicon-containing raw materials and gaseous titanium-containing raw materials into the tank according to a preset ratio, and the temperature of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials when they enter the tank reaches the preset mixing temperature. A mixing output pipe, which is connected to the tank, to guide the mixed gas in the tank to the burner; A compensation gas input pipeline is connected to the tank body and inputs compensation gas into the tank body according to a preset ratio. The temperature of the compensation gas when it enters the tank body is higher than the preset mixing temperature, so as to compensate for the preset mixing temperature fluctuation caused by the premixing of gaseous silicon-containing raw materials and gaseous titanium-containing raw materials when they enter the tank body, and to avoid the condensation of gaseous silicon-containing raw materials and gaseous titanium-containing raw materials in the tank body. The volume of the tank should be greater than the sum of the volumes of the gaseous silicon-containing raw material, the gaseous titanium-containing raw material, and the compensation gas input within a specified time; the pressure inside the tank should be less than the pressure inside the first conveying pipeline, the second conveying pipeline, and the compensation gas input pipeline.

2. The volumetric hybridization unit according to claim 1, characterized in that, One-way valves are respectively installed at the connection points of the first and second conveying pipes with the tank.

3. The volumetric hybridization unit according to claim 1, characterized in that, A heat tracing cable is installed on the first material conveying pipeline; And / or, a heat tracing cable is provided on the second conveying pipe; And / or, a heat tracing cable is provided on the compensation gas inlet pipe. And / or, a heat tracing cable is provided on the mixed output pipe.

4. The volumetric hybridization unit according to claim 1, characterized in that, A stirrer is also provided inside the tank.

5. The volumetric hybridization unit according to claim 1, characterized in that, The directions in which gaseous silicon-containing raw materials enter the tank in the first conveying pipe, the directions in which gaseous titanium-containing raw materials enter the tank in the second conveying pipe, and the directions in which compensating gas enters the tank in the compensating gas input pipe are not all coincident or are different from each other.

6. The volumetric hybridization unit according to claim 1, characterized in that, The tank is also connected to a safety pipeline; the safety pipeline is equipped with a safety valve and a flame arrester.

7. A gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass, comprising a silicon-containing raw material electric heating evaporator, a titanium-containing raw material electric heating evaporator, and a PLC controller, characterized in that, The gaseous raw material feeding device further includes a compensating gas electric heating evaporator and a bulk mixing unit as described in any one of claims 1 to 6; the silicon-containing raw material electric heating evaporator, the titanium-containing raw material electric heating evaporator, and the compensating gas electric heating evaporator are respectively connected to the first material conveying pipe, the second material conveying pipe, and the compensating gas input pipe of the bulk mixing unit; the PLC controller is electrically connected to the silicon-containing raw material electric heating evaporator, the titanium-containing raw material electric heating evaporator, and the compensating gas electric heating evaporator.

8. The gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass according to claim 7, characterized in that, The gaseous raw material feeding device further includes a filter; the filter is respectively disposed on the first conveying pipe and the second conveying pipe, or the filter is respectively disposed on the first conveying pipe, the second conveying pipe and the compensating gas input pipe.

9. A method for feeding gaseous raw materials for the preparation of zero-expansion titanium-doped quartz glass, implemented based on the gaseous raw material feeding device for the preparation of zero-expansion titanium-doped quartz glass as described in claim 7 or 8, characterized in that, The gaseous raw material feeding method includes the following steps: The silicon-containing raw material and the titanium-containing raw material are heated separately to produce gaseous silicon-containing raw material and gaseous titanium-containing raw material; The compensating gas is heated; According to a preset ratio, gaseous silicon-containing raw materials, gaseous titanium-containing raw materials, and compensating gas are fed into the tank for mixing; the temperature of the gaseous silicon-containing raw materials and gaseous titanium-containing raw materials when they enter the tank is controlled to be the preset mixing temperature; the temperature of the compensating gas when it enters the tank is controlled to be higher than the preset mixing temperature; and the pressure inside the tank is controlled to be lower than the pressure inside the first conveying pipe, the second conveying pipe, and the compensating gas input pipe. After the gaseous silicon-containing raw materials and the gaseous titanium-containing raw materials are mixed, a uniformly mixed gas with fixed mass fractions of each component and no condensation is obtained. The gas is then introduced into the burner as a carrier gas by the compensation gas.

10. The method for feeding gaseous raw materials for the preparation of zero-expansion titanium-doped quartz glass according to claim 9, characterized in that, The gaseous silicon-containing raw material, gaseous titanium-containing raw material, and compensation gas in the input tank are gaseous SiCl4, gaseous TiCl4, and hydrogen, respectively.

11. The method for feeding gaseous raw materials for the preparation of zero-expansion titanium-doped quartz glass according to claim 10, characterized in that, Based on a total mass ratio of 100%, the mass percentages of gaseous SiCl4, gaseous TiCl4, and H2 are 88-93%, 5-10%, and the balance, respectively.

12. The gaseous raw material feeding method for the preparation of zero-expansion titanium-doped quartz glass according to claim 10, characterized in that, The temperature of gaseous SiCl4 and gaseous TiCl4 when they enter the tank is 135℃~140℃; the temperature of H2 when it enters the tank is 145℃~150℃.

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