Device for preparing metal powder by pressurizing high-temperature molten metal spray through high-temperature-resistant ceramic pump

Abstract

The invention relates to a device for preparing metal powder by pressurizing high-temperature molten metal spray through a high-temperature-resistant ceramic pump, which comprises a molten metal pool, a liquid suction pipe, a feeding pipe and a ceramic pump of a liquid conveying pressurizing part, and a liquid distribution pipe, a temperature controller, an atomizer, an atomizing chamber, an emergency discharging pipe, a support frame and an emergency groove of a temperature control atomizing part, and the backflow circulating part comprises a metal liquid backflow pipe, a liquid outlet pipe and a backflow groove. According to the device, a pipeline for liquid separation and backflow is installed on a pipeline pressurized by a ceramic pump to avoid pressure building, emergency plugs are installed at the highest end and the bottommost end of the pipeline and can break in emergency to stop pumping of molten metal, the molten metal is put into an emergency groove, and the temperature of the molten metal before atomization is changed through a temperature controller, so that the viscosity is changed, and the particle size of powder is adjusted. Operation control and operation safety of high-temperature molten metal pressurization atomization are achieved.

Description

Technical Field

[0001] The present invention is a device for preparing powder by pressurizing and spraying high-temperature molten metal with a high-temperature resistant ceramic pump, belonging to the technical field of powder preparation. Background Art

[0002] The methods for atomizing high-temperature molten metal to produce powder mainly rely on the self-flow of molten metal and external mechanical dispersion. The conventional technology of high-temperature molten metal flowing by itself and being sheared and dispersed by high-speed flowing liquid or gas on the side is a common and general technology. There are representative technologies such as the rotary disk centrifugal dispersion of molten metal into droplets for cooling and powder production in the publicly disclosed CN114951672A "A Circulating Cooling Type High-Temperature Metal Centrifugal Atomization Powder Preparation Device"; and the acoustic wave dispersion atomization and refrigeration powder production represented by the publicly disclosed CN118237591A "An Ultrasonic Atomization Plasma Torch Powder Preparation Device with High Thermal Energy Utilization Rate", both of which belong to external mechanical dispersion.

[0003] Currently, there is only one method for preparing metal powder from high-temperature molten metal, which is gas flow negative pressure adsorption dispersion atomization, belonging to directly pressurizing and driving the high-temperature molten metal to speed up for spray dispersion atomization. This method is represented by the pneumatic powder preparation equipment disclosed in CN200510004921.6 "Production Equipment for Fine Metal Powders". It uses high-temperature and high-pressure gas to flow out at high speed along the outer edge of the molten metal outlet pipe, forming a negative pressure to suck out the molten metal. The high-speed gas simultaneously shears or diffuses the molten metal into droplets, which are cooled to form powder. The flow pressure of the molten metal formed by negative pressure adsorption is very low. Under normal conditions, a gas pressure of 6 MPa can only generate a negative pressure suction of 0.03 PMa on the molten metal. Moreover, the reduction of pressure and heat absorption of the high-pressure gas cause the temperature of the molten metal to decrease and the viscosity to increase, which also affects the dispersion and atomization effects. This device has high safety requirements due to high temperature and high pressure, requires a huge equipment investment, and has a high production cost.

[0004] Ceramic materials such as silicon carbide and silicon nitride, which have very low coefficients of thermal expansion, are resistant to high temperatures and metal corrosion, have been widely used in metal smelting and processing, and have been widely applied in the melting, storage, and transportation of high-temperature molten metal in the preparation of containers, pipelines, etc. Silicon carbide and silicon nitride ceramic pumps that are resistant to high temperatures and can transport molten metal have also been manufactured and have been applied in the transportation of molten metal at relatively low pressures. A patent application with the application number ZL202520240291.5, "A Fully Ceramic Single Screw Pump for High-Temperature Molten Metal Transportation," has been accepted. However, high-temperature resistant ceramic valves for temperatures above 500°C are still lacking. Direct human contact with high-temperature devices is likely to cause harm, and there are still some safety problems to be solved in the direct pressurization and spray atomization of molten metal using high-temperature resistant silicon carbide and silicon nitride ceramic pumps. First, when the high-temperature resistant ceramic pump starts during the pressurized operation of molten metal, it generates a thermal shock, which easily causes thermal shock damage to components such as the atomizer at the rear end and requires a certain warm-up time. Second, if a malfunction occurs at the atomization end and the pump cannot be shut down, the molten metal will directly flow out of the pipeline and atomize, posing a safety hazard of high-temperature molten metal leakage. Third, when replacing the rear-end atomization device during the production process, the entire process needs to be stopped and the molten metal emptied, resulting in huge waste and reduced production efficiency. Fourth, after shutdown, there is molten metal remaining in the transfer pump and pipeline, which will cause the metal in the pipeline to solidify due to cooling and needs to be emptied in a timely manner. Fifth, in the emergency state where the atomization nozzle is blocked and the pressure continues to increase, an emergency device is required to empty all the high-temperature molten metal in the atomization system. With the above problems, it is difficult to carry out operation control and ensure safety in the pressurized spray atomization of high-temperature molten metal using high-temperature resistant silicon carbide and silicon nitride ceramic pumps to prepare powders. Summary of the Invention

[0005] The technical solution of the present invention to solve the above problems is to use a high-temperature resistant silicon carbide or silicon nitride ceramic pump to transport molten metal and pressurize it, and use an atomizer to spray and atomize it in an atomization chamber for condensation to prepare metal powders. A liquid separation and reflux pipeline is installed on the pipeline after the ceramic pump is pressurized to avoid pressure buildup, a facility at the bottom that can empty the molten metal in the pump and pipeline during emergencies, a facility at a high position that can introduce gas to interrupt the suction of molten metal during emergencies, a facility for adjusting the viscosity of the molten metal before atomization to change the particle size, and a facility for using a temperature controller to cool and solidify to interrupt atomization. These are combined to form a device to solve the operation and safety after the pressurization of high-temperature molten metal, and are used for the spray atomization production of metal powders for molten metal at temperatures above 500°C and below 1600°C.

[0006] The device for atomizing molten metal by the high-temperature resistant ceramic metal pump of the present invention is composed of an infusion and pressurization part, a temperature control and atomization part, and a reflux and circulation part.

[0007] The infusion pressurizing part consists of a metal liquid pool (1), a liquid suction pipe (2), a feed pipe (3), and a ceramic pump (4). The liquid suction pipe is a three-way pipe made of silicon carbide or silicon nitride ceramic. The liquid suction pipe is vertically placed, with one end of the pipe opening inserted into the metal liquid in the metal liquid pool, and the other end is the highest end of all the metal liquid pipes of the device, and a sealed emergency plug (15) is installed at the pipe opening. The bypass port of the liquid suction pipe is horizontally placed and connected to the feed pipe in a flange manner; the feed pipe is made of silicon carbide or silicon nitride ceramic, with a heater (14) installed outside the pipe and wrapped with a heat preservation layer (13), and the feed pipe is connected to the ceramic pump in a flange manner; the ceramic pump is made of silicon carbide or silicon nitride ceramic, with a heater installed outside the pump shell and wrapped with a heat preservation layer. The transmission shaft of the ceramic pump has a heat insulation coupling (16). When the ceramic pump is started, the metal liquid enters the feed pipe along the liquid suction pipe and is pressurized and output by the ceramic pump.

[0008] The temperature control atomization part consists of a liquid distribution pipe (5), a temperature controller (6), an atomizer (7), an atomization chamber (8), an emergency discharge pipe (9), and an emergency tank (21). The diameter of the liquid distribution pipe is the same as the outlet diameter of the ceramic pump, and it is made of silicon carbide or silicon nitride ceramic. A heater is installed outside the pipe and wrapped with a heat preservation layer. The liquid distribution pipe is horizontally placed, with its inlet connected to the outlet of the ceramic pump in a flange manner, and its outlet horizontally connected to the inlet of the temperature controller in a flange manner. The outlet of the temperature controller is connected to the atomizer in a flange manner, and the atomizer extends into the atomization chamber. There is a vertically downward emergency discharge pipe connected between the ceramic pump and the temperature controller, and there is a bypass port vertically upward connected to the circulation return pipe (10). The emergency discharge pipe is made of silicon carbide or silicon nitride ceramic, with a heater installed outside the pipe and wrapped with a heat preservation layer, and is connected to the liquid distribution pipe in a flange manner. The outlet is vertically downward and is the lowest end of the metal liquid pipe of the device, with a sealed pipe emergency plug installed, and there is a support frame (20) to support the emergency plug. An emergency tank is placed at the lower end of the outlet of the emergency discharge pipe. The outlet of the emergency discharge pipe is higher than the height of the emergency tank and cannot extend into the emergency tank. The inner pipe of the temperature controller is made of silicon carbide or silicon nitride ceramic, with the inlet diameter the same as the diameter of the liquid distribution pipe. The inner diameter of the pipe can be in the shape of a through diameter or a reduced diameter. A primary heat exchanger (17) and a secondary heat exchanger (18) are installed outside the pipe to control the viscosity of the metal liquid in the pipe by adjusting the temperatures of the two heat exchangers. A slow-melting thin sheet (19) made of the same material as the metal liquid can be selectively placed inside the pipe of the temperature controller, which plays a role in relieving the impact force of the metal liquid when the metal liquid passes through for the first time, and gradually melts during the continuous flow of the metal liquid, gradually increasing the flow rate of the metal liquid without affecting the material of the metal powder made from the metal liquid. There are flowing liquid and gas refrigeration media in the atomization chamber to cool and solidify the atomized metal liquid into powder and transport it out.

[0009] The reflux circulation part is composed of a reflux pipe (10), a liquid outlet pipe (11) and a reflux trough (12) of the molten metal. The reflux pipe is a right-angled bend pipe made of silicon carbide or silicon nitride ceramic material. A heater is installed outside the pipe and wrapped with an insulation layer. The inlet of the reflux pipe is perpendicular to the liquid distributor pipe and is connected to it by a flange. The outlet is connected to the liquid outlet pipe by a flange. A reflux trough is placed at the lower end of the outlet of the liquid outlet pipe. The outlet of the liquid outlet pipe is higher than the height of the reflux trough and cannot extend into the reflux trough. The inner diameter of the reflux pipe is less than 36% of the inner diameter of the liquid distributor pipe and greater than 25% of the inner diameter of the liquid distributor pipe. The total height of the pipeline that vertically transports the molten metal connected to the reflux pipe is lower than the pressure head of the ceramic pump that can transport homogeneous molten metal.

[0010] The emergency plug (15) is cylindrical and made of a fragile non-metallic material that is resistant to high temperature and heat shock. A hole is opened at one end to dig out a hollow cylindrical cavity. The outer diameter of one end of the hole is embedded in the upper port of the pipette or the emergency discharge pipe and bonded with an inorganic adhesive. The cylindrical cavity part in the emergency plug is located at the outer end of the pipe mouth, and a circle of grooves (22) are carved between the bottom of the cavity and the pipe mouth. In an emergency, the emergency plug of the pipette is knocked open along this groove, and the metal liquid in the pipette falls back into the metal pool; in an emergency, the emergency plug of the emergency discharge pipe is knocked open along this groove, and the metal liquid in the pipeline and pump in the device flows into the emergency pool along the emergency discharge pipe. The support frame of the emergency plug at the lower end of the emergency discharge pipe should have a pressure higher than the delivery pressure of the ceramic pump. When the emergency plug needs to be knocked open, the support frame should be removed first.

[0011] The present invention includes a method of operating the device:

[0012] When the device is used, according to the working temperature of the metal liquid atomization, turn on the heaters of the pipeline and ceramic pump to gradually increase the temperature. After setting the temperature of the thermostat, heat the pipeline and ceramic pump to a temperature where the metal liquid does not solidify when passing through, and then start the ceramic pump to input the metal liquid for pressurized spray atomization. Most of it passes through the straight pipe of the liquid distribution pipe and the thermostat into the atomizer, and is atomized into droplets in the atomization chamber. There are flowing liquid and gas refrigeration media in the atomization chamber, which cools down the atomized metal liquid, solidifies it into powder and transports it out. Part of the metal liquid enters the liquid outlet pipe through the reflux pipe and flows into the reflux tank.

[0013] Adjust the temperature of the thermostat to change the temperature and viscosity of the molten metal, adjust the droplet size of the molten metal atomization, and change the particle size and particle size distribution of the prepared metal powder. The heat exchanger of the thermostat can solidify the molten metal in this part by cooling down so that the molten metal cannot pass through the thermostat but circulates through the reflux pipe. After repairing, replacing, cleaning, etc. the atomizer and atomization chamber, the solidified metal in the thermostat tube is melted by gradually increasing the temperature and then atomized.

[0014] To stop the atomization operation, first quickly adjust the temperature of the temperature controller below the solidification temperature of the molten metal. The molten metal solidifies in the pipeline of the temperature controller, aborting the atomization. Then stop the operation of the ceramic pump to discontinue the delivery of the molten metal. Remove the support frame and break off the emergency plug at the lower end of the emergency discharge pipe along the groove. The molten metal in the device pump and pipeline is discharged into the emergency tank through the emergency discharge pipe. Replace the emergency discharge pipe before the next startup. The solidified metal in the temperature controller melts when heated during the next startup.

[0015] If a fault occurs where the ceramic pump cannot stop running, quickly adjust the temperature of the temperature controller below the solidification temperature of the molten metal, causing the molten metal to solidify in the pipeline of the temperature controller. At the same time, break off the emergency plug at the upper end of the liquid suction pipe along the groove, allowing external air to communicate with the liquid suction pipe. The molten metal inside the pipe flows downward into the molten metal pool and no longer enters the feed pipe. At the same time, remove the support frame and break off the emergency plug at the lower end of the emergency discharge pipe along the groove. The molten metal in the device pump and pipeline is discharged into the emergency tank through the emergency discharge pipe.

[0016] The device of the present invention solves the safety problem of preparing metal powders by pressurized atomization of molten metal with a high-temperature resistant ceramic pump. Compared with other atomization powder-making methods, it is easier to operate, has higher safety, lower energy consumption, higher production efficiency, significantly increased single-unit production capacity of the device, large-scale production of some high-melting-point metal powders, and reduced investment and production costs per unit production scale. Description of the Drawings

[0017] Appendix Figure 1 Schematic Diagram of the Device Structure

[0018] Appendix Figure 2 Schematic Diagram of the Temperature Controller with a Through Diameter and a Slow-Melting Thin Sheet

[0019] Appendix Figure 3 Schematic Diagram of the Reduced-Diameter Temperature Controller

[0020] Appendix Figure 4 Schematic Diagram of the Emergency Plug

[0021] Specific Application Examples

[0022] Example 1: Using this device to atomize molten aluminum above 700 °C to produce aluminum powder

[0023] 1. The metal liquid pool contains molten aluminum at a temperature of 750 °C. The liquid suction pipe of the device is a three-way pipe made of silicon nitride, and the upper emergency plug is made of talc. The feed pipe, ceramic pump, liquid distribution pipe, return pipe, and emergency discharge pipe are made of silicon carbide. The diameter of the return pipe is 30% of the diameter of the liquid distribution pipe. The total height of the liquid distribution pipe connecting the return pipe and vertically transporting the molten metal pipe is 2 m. The emergency plug at the lower end of the emergency discharge pipe is made of mullite and is supported by a support frame. The liquid outlet pipe is made of silicon nitride. The inner pipe of the temperature controller is of reduced diameter and made of silicon nitride. The atomizer is of Laval tube type, and the atomization chamber is filled with flowing nitrogen. The coupling of the ceramic pump is connected to a chain drive device with chain refrigeration. The liquid suction pipe, feed pipe, ceramic pump, liquid distribution pipe, return pipe, liquid outlet pipe, emergency discharge pipe, and atomizer are all connected by flanges.

[0024] 2. Start the heater to heat the pipeline and the ceramic pump to 660 °C, and set the temperature of the temperature controller to 700 °C.

[0025] 2. Start the ceramic pump to generate a suction pressure at the inlet end of the pump. The molten aluminum is sucked into the pump through the liquid suction pipe and enters the pump through the feed pipe. Most of it passes through the straight pipe of the liquid distribution pipe, enters the atomizer through the temperature controller, and is dispersed into liquid droplets in the atomization chamber under the pressure of the pump. It is condensed into solid particles by the flowing nitrogen to prepare and transport the powder of molten aluminum. Part of the molten metal enters the liquid outlet pipe through the return pipe and flows into the return tank.

[0026] 3. Adjust the temperature of the temperature controller to 800 °C to increase the temperature of the molten aluminum, reduce the viscosity of the molten aluminum, and reduce the particle size and increase the fineness of the prepared aluminum powder.

[0027] 4. Adjust the temperature controller so that the temperature of the primary heat exchanger is 550 °C and that of the secondary heat exchanger is 350 °C. The molten aluminum solidifies in the corresponding pipe of the secondary heat exchanger, and the molten aluminum cannot pass through and all flows into the return tank through the return pipe and the liquid outlet pipe. Replace the atomizer connected after the temperature controller. After replacement, gradually increase the temperature of the temperature controller to above 700 °C, and the solidified molten aluminum in the secondary heat exchanger gradually melts and enters the atomizer for atomization after passing through.

[0028] 5. Stop the atomization operation. First, quickly adjust the temperature of the temperature controller to below 300 °C, and the molten aluminum solidifies in the temperature controller pipeline to abort the atomization. Then stop the operation of the ceramic pump to abort the transportation of the molten aluminum. Remove the support frame and break the emergency plug at the lower end of the emergency discharge pipe along the groove. The molten aluminum in the pump and pipeline of the device is discharged into the emergency tank through the emergency discharge pipe. Replace the emergency discharge pipe to prepare for the next start.

[0029] 6. In case of a failure where the ceramic pump cannot stop running, quickly adjust the temperature of the thermostat to below 200°C. The molten aluminum solidifies in the thermostat pipeline and cannot enter the atomizer and the atomization chamber. At the same time, break off the emergency plug at the upper end of the liquid suction pipe along the groove, so that the external air communicates with the liquid suction pipe, and the molten aluminum in the pipe flows downward into the molten metal pool and no longer enters the feed pipe. At the same time, remove the support frame and break off the emergency plug at the lower end of the emergency discharge pipe along the groove. The molten aluminum in the device pump and pipeline is discharged into the emergency tank through the emergency discharge pipe.

[0030] Example 2: Using this device to atomize molten metal copper at about 1200°C to produce metal copper powder

[0031] 1. There is molten metal copper at a temperature of 1200°C in the molten metal pool. The liquid suction pipe of the device is a three-way pipe made of silicon carbide, and the upper emergency plug is made of mullite. The feed pipe, ceramic pump, liquid distribution pipe, return pipe, liquid outlet pipe, and emergency discharge pipe are made of silicon carbide. The diameter of the return pipe is 30% of the diameter of the liquid distribution pipe. The total height of the liquid distribution pipe connecting the return pipe and vertically transporting the molten metal pipe is 1m. The emergency plug at the lower end of the emergency discharge pipe is made of mullite and is supported by a support frame. The inner pipe of the thermostat is of through-hole type and made of silicon carbide, and pure copper slow-melting thin sheets are installed inside the pipe. The atomizer is a hollow spiral nozzle, and the atomization chamber is filled with sprayed pure water. The coupling of the ceramic pump is connected to a chain drive device with chain refrigeration. The liquid suction pipe, feed pipe, ceramic pump, liquid distribution pipe, return pipe, liquid outlet pipe, emergency discharge pipe, and atomizer are all connected by flanges.

[0032] 2. Start the heater to raise the temperature of the pipeline and the ceramic pump to 1100°C, and set the temperature of the thermostat to 1200°C.

[0033] 2. Start the ceramic pump to generate an adsorption pressure at the inlet end of the pump. The molten metal copper is sucked into the pump through the liquid suction pipe and enters the pump through the feed pipe. Most of it passes through the straight pipe of the liquid distribution pipe, enters the atomizer through the thermostat, and is dispersed into copper droplets in the atomization chamber under the pressure of the pump, and is condensed into copper microparticles by pure water. The prepared copper powder is transported out by water flow. Part of the molten metal enters the liquid outlet pipe through the return pipe and flows into the return tank.

[0034] 4. Adjust the thermostat. The temperature of the first-stage heat exchanger is 750°C, and the second-stage heat exchanger is 350°C. The molten copper solidifies in the corresponding pipe of the second-stage heat exchanger and cannot pass through, and all flows into the return tank through the return pipe and the liquid outlet pipe. Replace the atomizer connected after the thermostat. After replacement, gradually raise the temperature of the thermostat to above 1200°C. The solidified copper in the second-stage heat exchanger gradually melts, and the molten aluminum enters the atomizer for atomization after passing through.

[0035] 5. Normally stop the atomization operation, first quickly adjust the temperature of the thermostat to below 800℃, the copper liquid solidifies in the thermostat pipe to stop atomization; then stop the operation of the ceramic pump to stop the copper liquid transportation; remove the support frame, knock off the emergency plug at the lower end of the emergency discharge pipe along the groove, install the pump, and put the copper liquid in the pipe into the emergency tank through the emergency discharge pipe; replace the emergency discharge pipe to prepare for the next start.

[0036] 6. If the ceramic pump cannot stop running, quickly adjust the temperature of the thermostat to below 700℃. The copper liquid will solidify in the thermostat pipe and cannot enter the atomizer and atomization chamber. At the same time, knock off the emergency plug at the upper end of the suction pipe along the groove, so that the external air is connected to the suction pipe, and the copper liquid in the pipe flows downward into the metal liquid pool and no longer enters the feed pipe. At the same time, remove the support frame and knock off the emergency plug at the lower end of the emergency discharge pipe along the groove, and put the copper liquid in the pump and pipe into the emergency tank through the emergency discharge pipe.

Claims

1. A device for preparing metal powder by spraying high-temperature metal liquid under pressure using a high-temperature ceramic pump, characterized in that The device consists of an infusion pressurization part, a temperature control atomization part, and a reflux circulation part. The infusion pressurization part consists of a metal liquid pool, a liquid suction pipe, a feed pipe, and a ceramic pump; the temperature control atomization part consists of a liquid distribution pipe, a temperature controller, an atomizer, an atomization chamber, an emergency discharge pipe, a support frame, and an emergency tank; the reflux circulation part consists of a reflux pipe, a liquid outlet pipe, and a reflux tank of the metal liquid; emergency plugs are installed at the upper port of the liquid suction pipe and the lower port of the emergency discharge pipe; the device has the following operation methods: (1) Start the atomization device. First, according to the working temperature of the metal liquid atomization, open the pipeline and the heater of the ceramic pump to gradually increase the temperature and set the temperature of the thermostat. Then start the ceramic pump to suck in the metal liquid and transport most of the metal liquid through the liquid distribution pipe straight pipe through the thermostat into the atomizer to be atomized and condensed into powder in the atomization chamber; part of the metal liquid enters the liquid outlet pipe through the reflux pipe and flows into the reflux tank; (2) adjusting the temperature controller to change the temperature of the molten metal flowing through, thereby changing the temperature and viscosity of the molten metal and changing the particle size and particle size distribution of the prepared metal powder; (3) Lower the temperature of the thermostat to cool down and solidify the molten metal at that location. No molten metal passes through and cools down. Replace, clean, and repair the atomizer and atomization chamber, then adjust the thermostat to heat up, melt, and solidify the metal before atomizing. (4) Stop the device atomization. First, quickly adjust the temperature of the thermostat to below the solidification temperature of the molten metal. The molten metal solidifies in the thermostat pipe to stop atomization. Then stop the ceramic pump to interrupt the molten metal delivery. Remove the support frame and knock off the emergency plug at the lower end of the emergency discharge pipe. The pump and the molten metal in the pipe of the device are put into the emergency tank through the emergency discharge pipe. Replace the emergency discharge pipe before the next start. The solidified metal in the thermostat will heat up and melt when it is started next time. (5) If the ceramic pump cannot be shut down, the temperature controller is lowered to solidify the molten metal at that location. At the same time, the emergency plug at the upper end of the suction tube is knocked off along the groove, and the molten metal in the tube returns to the molten metal pool and no longer enters the feed pipe. At the same time, the support frame is removed and the emergency plug at the lower end of the emergency discharge pipe is knocked off along the groove. The molten metal in the pump and pipeline is placed into the emergency tank through the emergency discharge pipe.

2. According to claim 1, the device for preparing metal powder by spraying high-temperature molten metal under pressure using a high-temperature resistant ceramic pump is characterized in that The suction pipe, feed pipe, ceramic pump, dispensing pipe, reflux pipe, liquid outlet pipe and emergency discharge pipe are all made of silicon nitride or silicon carbide ceramic materials. The feed pipe, ceramic pump, dispensing pipe, reflux pipe and emergency discharge pipe are all equipped with heaters and wrapped with insulation layers.

3. According to claim 1, the device for preparing metal powder by spraying high-temperature molten metal under pressure using a high-temperature resistant ceramic pump is characterized in that The inner diameter of the reflux pipe is less than 36% of the inner diameter of the dispensing pipe and greater than 25% of the inner diameter of the dispensing pipe; the total height of the pipeline for vertically conveying molten metal connected to the reflux pipe is lower than the pressure head of the ceramic pump that can convey homogeneous molten metal.

4. According to claim 1, the device for preparing metal powder by spraying high-temperature molten metal under pressure using a high-temperature resistant ceramic pump is characterized in that The emergency plug is made of a fragile non-metallic material that is resistant to high temperature and heat shock. The emergency plug on the upper end of the suction tube is located at the highest end of the metal liquid pipeline, and the emergency plug on the emergency discharge pipe is located at the lowest end of the metal liquid pipeline.

5. According to claim 1, the device for preparing metal powder by spraying high-temperature molten metal under pressure using a high-temperature resistant ceramic pump is characterized in that The inner tube of the temperature controller is made of silicon carbide or silicon nitride ceramics, and the inner diameter of the tube can be a full diameter or a reduced diameter shape; a slow-melting sheet made of the same material as the molten metal can be placed in the tube to relieve the impact of the molten metal when it passes through for the first time, and gradually melt it in the continuous flow of the molten metal, gradually increasing the flow rate of the molten metal without affecting the material of the powder made of the molten metal.

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