Reactor for the production of molybdenum hexafluoride

Abstract

This invention relates to a reactor for preparing molybdenum hexafluoride, comprising an inner shell and a jacket. The inner shell consists of multiple series-connected pipes, with adjacent pipes connected by bends. One end of the inner shell is a gas inlet, and the other end is a gas outlet. A nitrogen pipe and a vacuum pipe are connected to the inner shell. Each series-connected pipe in the inner shell has a feed port, and each pipe has several baffles spaced apart inside. The upper end of the baffle is connected to the inner wall of the pipe, and the lower end forms a gap between the baffle and the inner wall of the pipe to allow gas to pass through. The jacket surrounds the outer shell and extends along the axial direction of the inner shell, forming a sandwich between the inner wall of the jacket and the outer wall of the inner shell. Both ends of the jacket are sealed to the inner shell. One end of the sandwich has a heat transfer medium inlet, and the other end has a heat transfer medium outlet. This invention allows the reactant gas to react completely with the molybdenum powder, reduces by-products, and improves product yield.

Description

Technical Field

[0001] This invention belongs to the field of reactor technology, and specifically relates to a reactor for preparing molybdenum hexafluoride. Background Technology

[0002] Molybdenum hexafluoride (MoF6) is the only stable molybdenum fluoride compound. As a metal fluoride, it is mainly used for isotope separation of molybdenum and in the microelectronics industry for chemical vapor deposition of molybdenum silicide or molybdenum to create low-resistance, high-melting-point interconnects. The synthesis of MoF6 mainly involves the following methods: direct reaction of molybdenum powder with fluorine gas at 200-400℃; reaction of molybdenum powder with nitrogen trifluoride; and reaction of molybdenum powder with bromine trifluoride and chlorine trifluoride.

[0003] In the process of producing molybdenum hexafluoride by reacting molybdenum powder with nitrogen trifluoride, the currently used reactors have poor distribution of nitrogen trifluoride gas, poor molybdenum powder bed laying, poor reaction temperature uniformity, and insufficient contact between nitrogen trifluoride gas and molybdenum powder in the reactor, which greatly affects the reaction yield. Utility Model Content

[0004] To address the problems in the existing technology, this invention proposes a reactor for preparing molybdenum hexafluoride, thereby solving the problem of low reaction yield in the current reactors used to prepare molybdenum hexafluoride from molybdenum powder and nitrogen trifluoride.

[0005] The objective of this utility model and the technical problem it solves are achieved by the following technical solution. The reactor for preparing molybdenum hexafluoride according to this utility model includes an inner shell and a jacket. The inner shell is composed of multiple series-connected pipes, with adjacent pipes connected by a bend inlet. One end of the inner shell is a gas inlet, and the other end is a gas outlet. A nitrogen pipe and a vacuum pipe are connected to the inner shell. Each series-connected pipe in the inner shell has a feed port, and each pipe has several baffles spaced apart inside. The upper end of the baffle is connected to the inner wall of the pipe, and the lower end forms a gap between the baffle and the inner wall of the pipe for gas passage. The jacket wraps around the outside of the inner shell and extends axially along the inner shell, so that the inner wall of the jacket and the outer wall of the inner shell form a sandwich, and both ends of the jacket are sealed to the inner shell. One end of the sandwich has a heat medium inlet, and the other end has a heat medium outlet.

[0006] Furthermore, it also includes a vibration component, which consists of a support leg and a vibration module, with the vibration module connected to the jacket via the support leg.

[0007] Furthermore, a weighing module is also connected to the lower end of the vibration module.

[0008] Furthermore, a sieve plate is provided at the end of the inner shell near the gas inlet.

[0009] Furthermore, a thermometer is installed at each bend end cap, and the thermometer is inserted into the inner shell through the jacket.

[0010] Furthermore, the feeding port is circular and connected to an automatic feeder.

[0011] Furthermore, several baffles are evenly spaced inside the pipe.

[0012] Furthermore, the bend end cap is connected to the pipe via a detachable flange.

[0013] In summary, this utility model has the following advantages:

[0014] By installing a jacket on the outside of the inner shell, the heat medium in the jacket can maintain the reaction at a constant temperature. On the one hand, this increases the reaction temperature, and on the other hand, the heat medium can remove the heat of reaction in time, thereby improving the conversion rate. At the same time, the medium in the jacket adopts a bottom-in, top-out form, which ensures the heat transfer effect of the jacket. Multiple baffles are installed inside the pipeline. The reactant gas passes through multiple baffles, achieving full contact with the molybdenum powder, so that the reactant gas and molybdenum powder react completely, thereby improving the product yield.

[0015] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more obvious and understandable, preferred embodiments are given below, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the reactor used to prepare molybdenum hexafluoride according to this invention. Detailed Implementation

[0017] The technical solution of this utility model will be further described below with reference to the accompanying drawings and preferred embodiments.

[0018] Please see Figure 1 The reactor for preparing molybdenum hexafluoride includes an inner shell 1, one end of which is a gas inlet 9 and the other end is a gas outlet 3. A nitrogen pipe 13 and a vacuum pipe 14 for maintaining the pressure inside the shell are connected to the inner shell 1 near the gas outlet 3.

[0019] The inner shell 1 consists of multiple series of pipes. In this embodiment, it consists of three series of pipes. Adjacent pipes are connected by bend end caps, and the bend end caps are connected to the pipes by detachable flanges, which facilitates the disassembly and maintenance of each series of pipes. Each series of pipes in the inner shell 1 is provided with a circular feed port 4, which is connected to an automatic feeder. The automatic feeder consists of a hopper for filling molybdenum powder and a remotely controllable valve. By opening and closing the valve, the molybdenum powder in the hopper falls into the pipe by gravity. At the same time, several baffles 6 are evenly spaced inside each pipe. The upper end of the baffle 6 is connected to the inner wall of the pipe, and the lower end forms a gap between the baffle 6 and the inner wall of the pipe to allow gas to pass through. When the reactant gas passes through the baffle 6, it is intercepted and slowed down to increase the reaction time between the reactant gas and the molybdenum powder and ensure sufficient contact between the two. A sieve plate 15 is also provided at one end of the inner shell 1 near the gas inlet 9 to improve the uneven distribution of gas entering the molybdenum powder bed caused by the sudden increase in the gas channel area when the reactant gas enters the pipe.

[0020] The reactor also includes a jacket 2, which wraps around the outer shell 1 and extends axially along the inner shell 1, forming a sandwich between the inner wall of the jacket 2 and the outer wall of the inner shell 1. Both ends of the jacket 2 are sealed to the inner shell 1 to form a heat medium layer for storing the heat medium. One end of the sandwich is provided with a heat medium inlet 10, and the other end is provided with a heat medium outlet 11. The heat medium inlet 10 is located at the lower part of the reactor, and the heat medium outlet 11 is located at the upper part, forming a bottom-in, top-out heat medium transfer pattern to ensure the heat transfer effect of the jacket 2. Furthermore, each bend end cap... A thermometer 12 is provided, which passes through the jacket 2 and is inserted into the inner shell 1 to monitor the temperature in real time and ensure that the temperature conditions of the reaction meet the requirements. At the same time, the jacket 2 at the bend end cap is also detachably connected. Specifically, the flange on the pipe can be installed on the jacket 2, and the pipe can be fixed inside the jacket 2 by fixing rods or other means to facilitate the connection between the connected pipes during installation. Furthermore, sealing gaskets are provided between adjacent pipes and on the mating surfaces of the flanges of adjacent jackets 2 to ensure the sealing of the inner shell 1 and jacket 2 formed by their respective splicing.

[0021] The reactor also includes a vibration component, which consists of a support leg 7 and a vibration module 5. The vibration module 5 is connected to the jacket 2 via the support leg 7, meaning the entire reactor is supported by the support leg 7. The vibration module 5 is located at the lower part of the support leg 7. To ensure the vibration effect, the vibration module 5 can be composed of a base, a spring, and a vibration motor. The base is connected to the support leg 7 via the spring, and the vibration motor can be fixed to the reactor or the support leg 7 to transmit vibration force to the reactor, thereby flattening the molybdenum powder automatically added into the reactor, facilitating full contact and reaction between the reactant gas and the molybdenum powder. At the same time, a weighing module 8 is also connected to the lower end of the vibration module 5, i.e., the weighing module 8 is located at the lower end of the base. The weighing module 8 is used to monitor the weight of the reactor. Since the weight of the reactor remains constant, when the molybdenum powder reacts with the reactant gas, the amount of molybdenum powder decreases, and the weight measured by the weighing module 8 changes, thus allowing real-time monitoring of the reaction of the molybdenum powder. The weighing module 8 can be an electronic weighing scale or other equipment for convenient reading and monitoring.

[0022] Working process: Open the valve of the automatic feeder, add a certain amount of molybdenum powder into the reactor, and then close the valve;

[0023] Turn on the vibration module, vibrate several times to spread the molybdenum powder evenly, and then turn off the vibration module.

[0024] Next, the inner shell 1 is evacuated to -0.15 MPa through the vacuum tube 14, and then nitrogen is introduced into the inner shell 1 through the nitrogen tube 13 to atmospheric pressure. This process is repeated three times, and finally the reactor pressure is maintained at -0.15 MPa.

[0025] Heat the jacket 2 with a heat medium at 200-400℃ for 4 hours, then introduce nitrogen trifluoride gas to maintain the reaction temperature between 200-400℃. After the nitrogen trifluoride and molybdenum powder come into contact, they continue to react to generate molybdenum hexafluoride gas, which then flows out from the gas outlet 3. During the reaction, closely monitor the changes in the reading of the weighing module 8. When the reading of the weighing module is close to zero, it indicates that the reaction has ended and the reactor needs to be shut down to refill the molybdenum powder.

[0026] In other embodiments of this utility model, the number of pipe splicing levels depends on the requirements, and can be spliced ​​into three or more levels or at least one level of pipe.

[0027] The above description is merely a preferred embodiment of this utility model. Any simple modifications, equivalent changes, and alterations made by those skilled in the art to the above embodiments based on the technical essence of this utility model without departing from the scope of the technical solution of this utility model shall still fall within the scope of the technical solution of this utility model.

Claims

1. A reactor for preparing molybdenum hexafluoride, characterized in that: Includes inner shell (1) and jacket (2); The inner shell (1) is composed of multiple series of pipes. Adjacent pipes are connected by a bend end cap. One end of the inner shell (1) is a gas inlet (9) and the other end is a gas outlet (3). The inner shell (1) is connected to a nitrogen pipe (13) and a vacuum pipe (14). Each pipe in the inner shell (1) is provided with a feed port (4) and several baffles (6) are provided inside each pipe. The upper end of the baffle (6) is connected to the inner wall of the pipe, and the lower end forms a gap between the baffle and the inner wall of the pipe for gas to pass through. The jacket (2) is wrapped around the outside of the inner shell (1) and extends along the axial direction of the inner shell (1) so that the inner wall of the jacket (2) and the outer wall of the inner shell (1) form a sandwich, and the two ends of the jacket (2) are sealed to the inner shell (1). One end of the sandwich is provided with a heat medium inlet (10) and the other end is provided with a heat medium outlet (11).

2. The reactor for preparing molybdenum hexafluoride according to claim 1, characterized in that: It also includes a vibration component, which includes a support leg (7) and a vibration module (5), the vibration module (5) being connected to the sleeve (2) via the support leg (7).

3. The reactor for preparing molybdenum hexafluoride according to claim 2, characterized in that: The lower end of the vibration module (5) is also connected to a weighing module (8).

4. The reactor for preparing molybdenum hexafluoride according to claim 1, characterized in that: A sieve plate (15) is provided at one end of the inner shell (1) near the gas inlet (9).

5. The reactor for preparing molybdenum hexafluoride according to claim 1, characterized in that: Each bend end is equipped with a thermometer (12), which passes through the jacket (2) and is inserted into the inner shell (1).

6. The reactor for preparing molybdenum hexafluoride according to claim 1, characterized in that: The feeding port (4) is circular and connected to the automatic feeder.

7. The reactor for preparing molybdenum hexafluoride according to claim 1, characterized in that: Several baffles (6) are evenly spaced inside the pipe.

8. The reactor for preparing molybdenum hexafluoride according to claim 1, characterized in that: The bend end cap is connected to the pipe via a detachable flange.

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