CN202684094U - Device for preparing metal powder - Google Patents

Abstract

The utility model relates to a metal powder preparation device, comprising an atomization furnace, a heater, a cooler, an atomization chamber, an atomizer, a pneumatic classifier, an intermediate warehouse, a screening funnel, a sieve machine, a dust collector, a balance tank, Tube and tube heat exchangers, vacuum obtaining equipment, control systems, infusion tubes, conduits, pipelines, gas pipelines, pneumatic butterfly valves and solenoid valves, etc. The use includes atmosphere preparation, metal smelting, infusion, centrifugal atomization, pneumatic classification, mechanical sieving, gas purification and cooling, etc. After the metal is melted and processed, it is poured on the atomizer for centrifugal atomization to form powder, and the powder is pneumatically The classifier is classified, and the classified coarse powder is mechanically screened to obtain the finished powder. The fine powder is sent to the dust collector by the airflow for dust removal and purification. The purified gas is accelerated by the high-pressure centrifugal fan, and after heat exchange through the tube-and-tube heat exchanger Re-engage in atomization and grading. The device of the utility model can continuously produce spherical powder below -320 mesh, and the oxygen content is ≤80ppm.

Description

A metal powder preparation device

technical field

The utility model relates to a metal powder preparation device, which applies the integrated technology of metal melting, powder atomization and powder classification to the powder preparation in the powder industry, and belongs to the technical field of metal powder preparation.

Background technique

High-performance functional powder material is a kind of powder material that is directly used by utilizing the inherent physical and chemical characteristics of the material itself. It has excellent physical properties such as good fluidity, large specific surface area, and uniform composition, as well as excellent chemical properties. It can effectively improve the performance of the material and reduce the production cost, so it has high requirements for the preparation technology. Especially in the case of global resource and energy shortages, all kinds of high-tech products are developing in the direction of lightweight, miniaturization and multi-functional integration, which has rapidly increased the demand for high-performance functional powder materials. , automobile manufacturing, biomedical, national defense and military and other fields have been widely used. The main characteristics of high-performance non-ferrous metal powders are small, spherical, low-oxygen, narrow particle size, etc., which can only be obtained by using advanced atomization technology. This sets technical barriers, increases the added value of products, and obtains high monopoly profits. As a result, a large number of high-performance metal powders and products need to be imported, which seriously restricts the development of high-tech industries such as automobiles, electronics, and aerospace fields. Therefore, it is of great practical significance to develop high-performance non-ferrous metal powders and improve the preparation and processing technology level of non-ferrous metal powders.

The preparation technology of high-performance functional powder materials is derived from traditional powder manufacturing technology, but traditional technologies, such as gas atomization, water atomization, atomization, etc., have problems such as short continuous preparation time and insufficient powder quality, which cannot meet high Performance requirements for functional powder materials.

With the development of high technology, metal powder has been developed into a functional or structurally functional integrated material by utilizing the physical characteristics of metal powder itself, such as good fluidity, large specific surface area, and uniform composition. And this change in the use form of materials will not only bring revolutionary changes in the performance and cost of the final product, but also meet the development needs of many high-tech fields. For example, the miniaturization and multi-functionalization of electronic appliances and communication products have promoted the development of packaging and interconnection of integrated circuits from traditional welding to surface mount technology, and high-grade powdered soldering materials have become the most critical materials for surface mount technology. Therefore, metal powder has been widely used as a high-performance new material in various departments such as electronic information, electromechanical, automobile, metallurgy, aerospace, aviation, transportation, and biomedicine.

At present, a series of atomization pulverization technologies have been developed internationally to meet the needs of atomization pulverization of different materials. U.S. Patent US4207040 proposes a method for preparing powder, but it belongs to intermittent powder preparation technology rather than an integrated technology. It is difficult to continuously prepare powder for a long time, and it is not conducive to ensuring the quality of powder; Chinese Patent 200410079654.4 and Chinese Patent 200410021160.0 have the same problems, and it is not conducive to obtaining a better powder shape, and it is difficult to ensure the control of the ultrafine powder content; US483892 provides a method for recycling the atomized gas, purifying the atomized gas, pressurizing it, and then It is converted into high-pressure gas and put into use. The disadvantage is that the processing cost is relatively high, which is not conducive to reducing product prices and improving product competitiveness. Advanced atomization technology is developed by integrating many core technologies and supporting technologies, and the atomization equipment is constantly developing in the direction of large-scale and integrated, so as to further reduce production costs, improve production efficiency, and increase product competitiveness. A trend in technological development.

Utility model content

The purpose of this utility model is to propose a high-efficiency, energy-saving, environmental-friendly and suitable preparation device for high-quality metal powder, aiming at the deficiencies of the existing technology and conforming to the development trend of powder technology.

To achieve the above object, the utility model takes the following technical solutions:

A metal powder preparation device, the device includes a smelting device, a heater, a cooler, an atomization chamber, an atomizer, a pneumatic classifier, an intermediate warehouse, a screening funnel, a sieve machine, a dust collector, a balance tank, and a tube changer. Heater, vacuum obtaining equipment, control system, infusion pipe, conduit, pipeline, gas pipeline, pneumatic butterfly valve and solenoid valve, etc., atomizer is installed in the atomization chamber, and the melting device is connected to the conduit installed on the atomizer through the infusion pipe , the infusion pipe is equipped with a heater and a cooler for liquid supply or stop liquid supply; the spray chamber is connected to the pneumatic classifier through a pipeline, and the inclined pipe of the pneumatic classifier is connected to the intermediate chamber through a pneumatic butterfly valve, and the intermediate chamber The pneumatic butterfly valve is connected to the screening funnel, and the screening funnel is connected to the screening machine; the pneumatic classifier is connected to the dust collector through the gas pipeline, and the dust collector is connected to the balance tank through the gas pipeline. The balance tank is equipped with a high-pressure centrifugal fan, and the balance tank passes the gas The pipe is connected to the tube heat exchanger, and the air outlet of the tube heat exchanger is connected to the return air pipe, which is then divided into two return air branches, one of which returns to the top of the atomization chamber, and the other returns to the secondary air return port of the pneumatic classifier. Vacuum acquisition equipment is connected to the return air duct.

The above-mentioned device forms a powder production device, including atmosphere preparation, metal smelting, infusion, atomization, floating powder settlement, pneumatic classification, mechanical screening, gas purification and cooling and other links.

The smelting device is a smelting furnace and/or an atomizing furnace, and the smelting furnace can be connected with the atomizing furnace through a liquid infusion pipe.

The atomizer is one of centrifugal atomizer, ultrasonic atomizer and gas atomizer.

The atomization chamber, tube heat exchanger, etc. are all equipped with cooling devices, and the cooling method is usually water cooling or air cooling, preferably water cooling.

The pneumatic classifier is a squirrel cage centrifugal classifier, and the rotating speed of the squirrel cage is in the range of 200~3000rpm. The sieve machine is a mechanical sieve.

The described dust collector is a pneumatic principle mode, and its typical structure is a cyclone dust collector, or it is a filtration principle mode, and its typical structure is a bag filter and a filter element filter.

The dust collector is preferably a combination of two or more dust collectors, including one or more of the pneumatic principle mode dust collector and the filtration principle mode dust collector, which are connected in series through gas pipelines. Two or more dust collectors are connected in series through gas pipelines, which preferably include at least one pneumatic principle mode dust collector and at least one filtration principle mode dust collector.

When using the device of the present invention to prepare metal powder, it includes process steps such as atmosphere preparation, metal melting, melt transportation, atomization, floating powder settlement, pneumatic classification, mechanical screening, gas purification, gas driving, and gas cooling; The chamber is vacuumed and inflated to prepare the atmosphere; metals (including elemental metals and alloys) are melted in the smelting device to form a metal melt, and the metal melt is poured into the atomizer in the atomization chamber through the infusion tube and the catheter, and passed through The atomizer is atomized to form a mist, and the mist droplets fly, cool, and solidify in the atomization chamber to form powder, and the powder is sent to the pneumatic classifier for classification; the coarse powder after pneumatic classification enters the screening funnel through the intermediate chamber In the process, mechanical sieving is carried out through a sieve machine to obtain finished powder; the fine powder after pneumatic classification is sent to the dust collector by air flow for dust removal and purification, and the purified gas enters the balance tank, which is accelerated by the high-pressure centrifugal fan and passed through the tube After heat exchange, the heat exchanger is divided into two paths, one path returns to the atomization chamber, and the other path enters the pneumatic classifier.

Integrate the atmosphere preparation, metal melting, melt conveying, powder atomization, floating powder settlement, powder classification, gas cooling, purification and circulation process in metal powder preparation, and the metal powder preparation process (powdering process) is in a closed environment The gas in the system is recycled, and the formed powder is transferred from the closed system to the screening funnel through the intermediate bin. The utility model maximizes the continuity of the metal powder preparation process.

The metals are Sn, Pb, Bi, Sb, Ag, Cu, In, Zn, Al, Si, Ga, Ge, B, C, P, Ni, Ti, Cr, Mn, rare earth and other elements or their alloys. The smelting device is a smelting furnace and/or an atomizing furnace, and the smelting furnace can be connected with the atomizing furnace through a liquid infusion pipe.

Before the molten metal enters the atomizer, it needs to pass through a heater and a cooler for heating or cooling the molten metal, so as to control or stop the liquid supply of the molten metal.

When the atmosphere is prepared, the gas used for the inflation is one or more of nitrogen, argon, helium, hydrogen, ammonia, air and oxygen.

During atomization, the system environment atmosphere pressure in the atomization chamber is 0-50KPa.

During atomization, the oxygen content in the atomization area of the atomization chamber is generally in the range of 10-1000 ppm.

When atomizing, the atomization temperature of the metal melt is 20~180°C higher than the melting point of the metal.

The powder is fed into the pneumatic classifier by gravity and pneumatic conveying (under the action of air flow).

The pneumatic classifier can be a squirrel cage centrifugal classifier, and the rotation speed of the squirrel cage is usually in the range of 200~3000rpm.

After heat exchange through the tube heat exchanger, it is divided into two paths, one path returns to the top of the atomization chamber, and the floating powder in the atomization area is taken away, and the path enters the secondary air return port of the pneumatic classifier.

The control system of the utility model is controlled by PLC, and the precise supply of the melt is controlled by the air pressure method, and the stability of the powder particle size control is improved; the floating ultrafine powder is taken away in time by the return air of the atomization tank, and the dust concentration in the atomization area is reduced. , so that it is beneficial to increase the ratio of spherical powder and form a fine structure of powder; the utility model removes the ultrafine powder through pneumatic classification, and then performs mechanical screening to ensure the screening accuracy and reduce the oxygen content of the powder; in this utility model In the new model, processes such as atmosphere preparation, metal melting, melt conveying, atomization, floating powder settlement, pneumatic classification, mechanical screening, gas purification, gas drive, and gas cooling are scientifically and effectively integrated, so that each process link can be effectively connected. Realize the integration of powder production, shorten the process flow, reduce the transfer links, improve the automation of equipment, improve production efficiency and powder quality, and enable continuous powder production, and because the powder preparation is carried out in a closed environment, the gas circulation Therefore, environmental pollution is minimized, the production environment is greatly improved and emissions are minimized, and the environmental protection of powder production is realized.

The device of the utility model can be used for atomizing Sn, Pb, Bi, Sb, Ag, Cu, In, Zn, Al, Si, Ga, Ge, B, C, P, Ni, Ti, Cr, Mn, rare earth, etc. Elements and their alloys can continuously produce spherical powders below -320 mesh, and the oxygen content is less than or equal to 80ppm.

The utility model will be further described below through the accompanying drawings and specific embodiments, but it does not mean that the protection scope of the utility model is limited.

Description of drawings

Figure 1 is a schematic diagram of the structure of a metal powder preparation device.

Figure 2 is a scanning electron micrograph of SnAg ₃ Cu _0.5 powder (25-38 microns).

Figure 3 is the laser particle size distribution of SnAg ₃ Cu _0.5 powder (25~38 microns).

Figure 4 is a scanning electron micrograph of SnBi58 powder (25-62 microns).

Figure 5 is the laser particle size distribution of SnBi58 powder (25-62 microns).

Explanation of main reference signs:

Melting Furnace 1 Infusion Tube 2, 4

Atomization Furnace 3 Conduit 5

Atomizer 6, 7 Spray chamber 8

Control system 9 Pipeline 10

Pneumatic butterfly valve 11, 14, 19, 22, 32, 36 Return air branch 12, 13

Pneumatic classifier 15 return air duct 16

Gas pipeline 17, 29, 31, 34 Classifier inclined pipe 18

Solenoid valve 20, 23 Intermediate chamber 21

Screening funnel 24 Mechanical sieve 25

Powder collection tank 26 Powder collection tank 28

Dust collector 27, 30 Balance tank 33

Tube and tube heat exchanger 35 Vacuum obtaining equipment 37

Heater 38 Cooler 39

Detailed ways

As shown in Figure 1, it is a structural schematic diagram of the metal powder preparation device of the present invention. The metal powder preparation device of the present utility model comprises a melting furnace 1, an atomizing furnace 3, infusion tubes 2, 4 and a conduit 5, a heater 38, a cooler 39, an atomization chamber 8, atomizers 6, 7, and pneumatic classification Device 15, intermediate warehouse 21, screening funnel 24, mechanical sieve 25, dust collector 27, 30, balance tank 33, tube heat exchanger 35, vacuum obtaining equipment 37, control system 9, pipeline 10, gas pipeline 17, 29 , 31, 34, pneumatic butterfly valves 11, 14, 19, 22, 32, 36 and solenoid valves 20, 23 and other equipment.

The atomization chamber 8, the tube-and-tube heat exchanger 35 and other devices are all equipped with cooling devices, and the cooling methods are usually water cooling or air cooling, preferably water cooling. The dust collectors 27 and 30 can be in the pneumatic principle mode, and the typical structure is a cyclone dust collector; the dust collectors 27 and 30 can be in the filtration principle mode, and the typical structures are bag filter and filter element filter; the dust collectors 27 and 30 are preferably in the pneumatic principle mode Combination with filter principle mode. The smelting furnace 1 is an optional configuration, or only the atomizing furnace 3 can be equipped. The system is equipped with a vacuum obtaining device 37, which is a general-purpose device, so that the system has the ability to obtain vacuum. Above-mentioned devices are linked successively by Fig. 1 and formed closed system, and screening funnel 24, mechanical sieve 25 are the devices that are connected with atmospheric environment, and they are connected with closed system by intermediate storehouse 21.

The smelting device can use a resistance heating furnace or an induction heating furnace. Generally, whether it is a vacuum furnace is determined by the characteristics of the metal to be smelted and the product requirements. For high-end products, vacuum smelting is generally used. One smelting device can be selected, that is, only the atomization furnace 3 is used. The smelting furnace 1 is connected to the atomization furnace 3 through the infusion tube 2, and the atomization furnace 3 is connected to the conduit 5 of the atomization chamber 8 through the infusion tube 4, and the heater 38 and the cooler 39 are installed on the infusion tube 4, and the liquid is supplied by The heater 38 heats the infusion tube 4 to 30-200°C higher than the melting point of the alloy. If the infusion is to be stopped, cool the infusion tube 4 to 20-150°C lower than the alloy melting point through the cooler 39 to solidify the melt in the infusion tube 4, thus playing a closed role.

The atomization chamber 8 is one of the main devices of the utility model, and the atomizer 6 is installed in it, and the atomizer 6 is a kind of in a centrifugal atomizer, an ultrasonic atomizer and a gas atomizer. The atomization chamber 8 is connected to the pneumatic classifier 15 through the pipeline 10. The pneumatic classifier 15 is usually a squirrel-cage centrifugal classifier. 21 is docked with a screening funnel 24 through a pneumatic butterfly valve 22, and the screening funnel 24 is connected to a mechanical screen 25. The pneumatic classifier 15 is connected to the dust collector through the pipeline 17. The dust collector is a pneumatic principle mode, and the typical structure is a cyclone dust collector, or a filter principle mode, and the typical structure is a bag filter and a filter element filter. It can be used alone, but it is generally used in combination. Preferably, two dust collectors are connected in series through gas pipelines, which is a combination of pneumatic principle mode and filtration principle mode dust collector. In this embodiment, two dust collectors are selected, the dust collector 27 is a pneumatic dust collector, such as a cyclone separator, the dust collector 30 is a filter dust collector, such as a bag filter or other filter elements, and the pneumatic classifier 15 is connected to the dust collector 27 (cyclone separator), and then connected to dust collector 30 (element filter or bag filter). After the dust remover 30, a balance tank 33 is connected, and the balance tank 33 is an air pressure balance device with a high-pressure centrifugal fan inside to provide power to the gas to pressurize the gas to speed up. The tube heat exchanger 35 is connected after the balance tank 33 to cool the gas. The tube heat exchanger 35 can also be installed in other positions on the gas pipeline, but it is preferably installed after the balance tank 33 . The air outlet of the tube heat exchanger 35 is connected to the return air duct 16, and then divided into two return air branches, one return air branch 12 returns to the top of the atomization tank, and the other return air branch 13 returns to the pneumatic classifier 15 for the second return tuyere. A vacuum obtaining device 37 is connected to the return air duct 16 of the closed system. The pneumatic classifier 15, the dust collectors 27, 30, the balance tank 33, and the tube heat exchanger 35 are connected through gas pipelines 17, 29, 31, 34 respectively.

The above-mentioned device forms a powder production device, including atmosphere preparation, metal smelting, infusion, atomization, floating powder settlement, pneumatic classification, mechanical screening, gas purification, driving and cooling and other links.

When using the device of the utility model to prepare metal powder, it includes atmosphere preparation, metal smelting, melt transportation, atomization, floating powder settlement, pneumatic classification, mechanical screening, gas purification, gas drive, gas cooling and other links. Before entering the atomization, the system atmosphere preparation and metal smelting must be completed. First, the atomization chamber is evacuated and inflated to prepare the atmosphere; after the metal is melted and processed in the smelting furnace 1, it is connected to the atomization furnace 3 through the infusion tube 2, and then through the infusion The tube 4 and the conduit 5 pour the molten metal onto the atomizer 6, which forms a mist through the action of the atomizer 6, and the mist droplets fly, cool, and solidify in the atomization chamber 8 to form a powder. Under the action of the air, it is sent to the pneumatic classifier 15 for classification, and the coarse powder after pneumatic classification is transferred out of the closed system through the intermediate bin 21 and enters the screening funnel 24 to be sieved by the mechanical sieve 25, and mechanically sieved to the powder collection tank 26 to obtain the finished product powder; the fine powder after pneumatic classification is sent to the dust collector 27, 30 by the air flow for dust removal and purification, the separated and purified dust is collected in the powder collection tank 28, and the purified gas enters the balance tank 33 and is driven by a high-pressure centrifugal fan to obtain Accelerate, after further heat exchange through the tube heat exchanger 35, it is divided into two paths, one path returns to the atomization chamber 8, the other path enters the pneumatic classifier 15, and participates in atomization and classification again.

Before the atomization, the atmosphere should be prepared, that is, the whole system is evacuated by the vacuum obtaining device 37 . The degree of vacuum depends on the properties of the metal (or alloy) and the properties of the powder. For example, the degree of activity of the metal (or alloy), the particle size distribution of the powder, and the oxygen content of the powder determine the degree of vacuum to be achieved in the atmosphere preparation. Generally, it is not higher than 2000Pa. When the vacuum degree reaches the requirement, fill in the required gas, generally use one or more of nitrogen, argon, helium, hydrogen, ammonia, air, oxygen, usually use nitrogen as the main gas, and add no more than 10 at the same time. % of other gases, the specific gas to be used depends on the characteristics of the alloy and the requirements of the powder. During the atomization process, the internal pressure of the system is generally charged to 0~50KPa. On the one hand, this is the need of the melt atomization process, and on the other hand, it can also avoid the oxygen increase of the system. The maintenance of the system pressure is automatically controlled by the control system 9 according to the setting, and the automatic deflation and inflation device is used as the end effector. Using a known process, the metal is smelted and purified in the smelting furnace according to the designed distribution ratio, and then the melt is supplied from the smelting furnace 1 through the infusion tube 2 to the atomization furnace 3 by using the known infusion process, and then through the infusion tube 4. The furnace 3 flows into the conduit 5 in the atomization chamber 8, and continues to flow downwards to be supplied to the atomizer 6 for atomization. The atomizer 6 is one of centrifugal atomizer, ultrasonic atomizer and gas atomizer.

Furnace melting 1 is an optional configuration in the utility model, so it is not necessary. Melt conveying is carried out by known technology, which can use gravity to drive the melt to flow, and can also be driven by air pressure, and its control technology is well known to those in the industry. An atomizer 6 is installed in the atomization chamber 8 to accelerate and disperse the melt poured on its upper surface to form mist droplets, which fly, cool and solidify into powder in the atomization chamber 8 . The temperature field in the atomization area will have an important impact on the atomization, higher or lower will affect the powder shape and particle size distribution, so it is necessary to obtain and maintain an ideal temperature field through control. The control of the temperature field in the atomization area of the utility model is realized through the control of the cooling of the atomization chamber 8, the temperature of the return air at the top of the tank, the temperature of the melt, and the flow rate. The cooling of the atomization chamber 8 is controllable, and the cooling intensity is adjusted by monitoring the temperature of the atomization area. Similarly, the cooling intensity of the tube heat exchanger 35 is adjusted so that the gas is properly cooled, and the output of the tube heat exchanger 35 is controlled. Wind temperature, thus helping to obtain the ideal temperature field in the atomization area; the influence of melt temperature and flow rate on the temperature field in the atomization area is also obvious, but its adjustable range is small, and the control of the temperature field in the atomization area can play a role Supporting role. Oxygen content will have an extremely important impact on the morphology and particle size distribution of the powder. Lower oxygen content will cause the metal droplets to lack sufficient spheroidization driving force, resulting in the powder forming a polyhedral shape or sticking to each other to form cohesive powder or even snowflake powder. , and a higher oxygen content in the atomization zone will lead to more oxides on the surface of the metal droplets, which will affect the spheroidization of the droplets and lead to an increase in special-shaped powder. Only when the oxygen content in the atomization zone is maintained in a suitable range , the presence of oxygen can become the ideal driving force for the spheroidization of droplets, which is conducive to the formation of powders with better sphericity and smoother surface. The oxygen content in the atomization area is generally in the range of 10~1000ppm, which needs to be determined according to the metal characteristics, powder particle size and oxygen content requirements. In order to maintain the stability of the oxygen content in the atomization process, the control system 9 has an oxygen analyzer and an automatic oxygen supply device. The powder falls under the action of gravity and the return air from the top of the tank, collects at the powder outlet of the spray chamber, and is transported to the pneumatic classifier 15 through the pipeline under the action of air flow for classification. There will always be a certain concentration of floating powder in the atomization area. The existence of floating powder will increase the number of cohesive powder. Therefore, it is necessary to reduce the concentration of floating powder in the atomization area as much as possible. For this reason, the utility model introduces return air at the top of the atomization chamber. The floating powder is taken away forcibly, so as to achieve the purpose of improving the powder morphology and refining the microstructure of the powder. Pneumatic classifier 15 usually adopts squirrel cage centrifugal classifier (centrifugal squirrel cage classifier), and the rotation speed of squirrel cage is usually in the range of 200~3000rpm, preferably 500~1500rpm. The specific process should be optimized according to the properties of powder alloy and powder particle size distribution . The coarse powder after pneumatic classification is transferred out of the closed system through the intermediate bin 21 and enters the screening funnel 24 to wait for mechanical screening, and the finished powder is obtained through mechanical screening. Mechanical screening generally uses commercially available rotary vibrating screens, which are equipped with ultrasonic vibrations to enhance the screening effect. There are pneumatic butterfly valves 19 and 22 at the inlet and outlet of the intermediate chamber 21, and the intermediate chamber 21 is also equipped with air intake and air discharge solenoid valves 20. Controlled by the control system 9, the two butterfly valves 19 and 22 are opened and closed in turn, and are coordinated with the air pressure. The transfer of powder can be realized by adjusting with the atmosphere. The ultra-fine powder after pneumatic classification is sent to the dust remover 27, 30 for dust removal and purification by the air flow, and the dust in the gas is removed by the action of the dust remover 27, 30 to make the gas pure, and the purified gas enters the balance tank 33, Driven by a high-pressure centrifugal fan to obtain boosting acceleration, after further heat exchange through the tube heat exchanger 35, it is divided into two paths, one path returns to the top of the atomization chamber 8, and the other path enters the secondary air return port of the pneumatic classifier 15 to participate in the atomization again with grading. The distribution of these two paths of gas is controlled by butterfly valves 11 and 14 to adjust its flow. This constitutes a gas circulation closed channel, which can realize atmosphere preparation, powder atomization, pneumatic classification, gas purification, cooling and circulation. After the powder is transferred out of the circulation system, it will be sieved by a sieve machine to produce finished powder. The whole process can be carried out continuously.

The metals used in the utility model are elements such as Sn, Pb, Bi, Sb, Ag, Cu, In, Zn, Al, Si, Ga, Ge, B, C, P, Ni, Ti, Cr, Mn, rare earth or their alloy. Before the molten metal enters the atomizer, it can also pass through heaters and coolers to heat or cool the molten metal to control or stop the liquid supply of the molten metal. When atomizing, the atomization temperature of the metal melt is 20~180°C higher than the melting point of the metal.

The utility model integrates the atmosphere preparation, metal melting, melt transportation, powder atomization, floating powder settlement, powder classification, gas cooling, purification and circulation process in the metal powder preparation, and the metal powder preparation process (powder making process) in It is carried out in a closed environment, the gas in the system is recycled, and the formed powder is transferred from the closed system to the screening funnel through the intermediate warehouse. The utility model maximizes the continuity of the metal powder preparation process.

Example 1

Atomized SnAg ₃ Cu _0.5 . The system is evacuated to 50Pa, filled with nitrogen and 100ppm oxygen to 40KPa to prepare for atomization. Add Sn, Ag, and Cu into the vacuum melting furnace 1 according to the designed ratio, and then smelt at 330°C after vacuuming and inflating. The turntable is driven to rotate at a speed of 50000rpm for atomization, and the oxygen content in the atomization chamber 8 is stabilized at 100ppm. Under the action of gravity and airflow, the powder enters the centrifugal classifier for classification, and the centrifugal classifier cage rotates at 750rpm. The coarse powder separated by the centrifugal classifier is transferred through the intermediate bin 21, transferred out from the closed system to the screening funnel 24, and then sieved by the rotary vibrating sieve to obtain the finished powder (see Figure 2 for the powder morphology photo, and Figure 3 for the particle size distribution ). The ultra-fine powder enters the dust collector 27, 30 with the airflow, and the dust collector 27, 30 is a combination of the cyclone separator 27 and the bag filter 30. Most of the ultra-fine powder is settled in the cyclone separator 27, and a small amount enters the bag filter 30 is filtered and collected. After the gas is purified, it passes through the tube heat exchanger 35 for heat exchange, and then is divided into two paths, one path returns to the top of the atomization chamber 8 to participate in atomization, and the other path returns to the centrifugal classifier 15 to participate in classification. The atomization chamber 8 and the tube heat exchanger 35 are cooled by water, and the air volume distribution of the atomization chamber 8 and the centrifugal classifier is controlled by butterfly valves 11 and 14 .

Example 2

Nebulized SnBi58. The system is evacuated to 50Pa, filled with nitrogen and 80ppm oxygen to 30KPa to prepare for atomization. Add Sn and Bi into the vacuum melting furnace 1 according to the designed ratio, smelt at 200°C after vacuuming and inflating, and pour the melt into the atomizing furnace 3 after purification treatment, and then supply the atomizer through the infusion channel, the mist The atomizer adopts an ultrasonic atomizer with a vibration frequency of 60KHz to atomize the melt, and the oxygen content in the atomization chamber 8 is stabilized at 80ppm. The powder enters the centrifugal classifier 15 under the action of gravity and airflow for classification, and the centrifugal classifier cage rotates at a speed of 500 rpm. The coarse powder separated by the centrifugal classifier passes through the transfer of the intermediate bin 21, and is transferred from the closed system to the screening funnel 24, and then sieved by the rotary vibrating screen 25 to obtain the finished powder (see Figure 4 for the powder morphology photo, and see Figure 4 for the particle size distribution. 5). The superfine powder enters the dust collectors 27 and 30 along with the air flow, and the dust collectors 27 and 30 are a combination of a cyclone dust collector 27 and a cartridge filter 30. Most of the superfine powder is settled in the cyclone dust collector 27, and a small amount enters the filter element filter 30 to be filtered and collected. After the gas is purified, it passes through the tube heat exchanger 35 to exchange heat, and then divides into two paths, and returns to the mist all the way. The top of the chamber 8 participates in atomization, and all the way back to the centrifugal classifier 15 to participate in classification. The atomization chamber 8 and the tube heat exchanger 35 are cooled by water, and the air volume distribution between the atomization chamber 8 and the centrifugal classifier 15 is controlled by butterfly valves 11 and 14 .

Example 3

Atomized SnAg _0.3 Cu _0.7 . The system is evacuated to 80Pa, filled with nitrogen, 60ppm oxygen and 1% hydrogen to 50KPa to prepare for atomization. Add Sn, Ag, and Cu into the vacuum melting furnace 1 according to the designed proportion, smelt at 310°C after vacuuming and inflating, and pour the melt into the atomizing furnace 3 after purification treatment, and then supply gas atomization through the infusion channel The atomizer is atomized at a pressure of 2Mpa, and the oxygen content in the atomization chamber 8 is stable at 60ppm. Under the action of gravity and airflow, the powder enters the centrifugal classifier for classification, and the rotation speed of the cage of the centrifugal classifier is 550rpm. The coarse powder separated by the centrifugal classifier passes through the transfer of the intermediate bin 21, and is transferred out of the closed system to the screening funnel 24, and then sieved by a rotary vibrating sieve to obtain the finished powder (the powder particle size is less than 45 microns, and the proportion of 20-36 microns powder reaches 60%, oxygen content 60ppm). The ultra-fine powder enters the dust collector 27, 30 with the airflow, and the dust collector 27, 30 is a combination of the cyclone separator 27 and the bag filter 30. Most of the ultra-fine powder is settled in the cyclone separator 27, and a small amount enters the bag filter 30 is filtered and collected. After the gas is purified, it passes through the tube heat exchanger 35 for heat exchange, and then is divided into two paths, one path returns to the top of the atomization chamber 8 to participate in atomization, and the other path returns to the centrifugal classifier 15 to participate in classification. The atomization chamber 8 and the tube heat exchanger 35 are cooled by water, and the air volume distribution of the atomization chamber 8 and the centrifugal classifier is controlled by butterfly valves 11 and 14 .

Example 4

Atomized SnAg _1.0 Cu _0.5 . The system is evacuated to 100Pa, filled with nitrogen and 200ppm oxygen to 20KPa to prepare for atomization. Add Sn, Ag, and Cu into the vacuum melting furnace 1 according to the designed ratio, and then smelt at 300°C after vacuuming and inflating. The turntable is driven to rotate at a speed of 60000rpm for atomization, and the oxygen content in the atomization chamber 8 is kept at 200ppm. Under the action of gravity and airflow, the powder enters into the centrifugal classifier for classification, and the cage speed of the centrifugal classifier is 950rpm. The coarse powder separated by the centrifugal classifier passes through the transfer of the intermediate bin 21, and is transferred out of the closed system to the screening funnel 24, and then sieved by a rotary vibrating sieve to obtain the finished powder (the powder particle size is less than 45 microns, and the proportion of 20-36 microns powder reaches 65%, oxygen content 70ppm). The ultra-fine powder enters the dust collector 27, 30 with the airflow, and the dust collector 27, 30 is a combination of the cyclone separator 27 and the bag filter 30. Most of the ultra-fine powder is settled in the cyclone separator 27, and a small amount enters the bag filter 30 is filtered and collected. After the gas is purified, it passes through the tube heat exchanger 35 for heat exchange, and then is divided into two paths, one path returns to the top of the atomization chamber 8 to participate in atomization, and the other path returns to the centrifugal classifier 15 to participate in classification. The atomization chamber 8 and the tube heat exchanger 35 are cooled by water, and the air volume distribution of the atomization chamber 8 and the centrifugal classifier is controlled by butterfly valves 11 and 14 .

Example 5

Atomized SnBi ₃₀ Cu _0.5 . The system is evacuated to 120Pa, filled with nitrogen and 300ppm oxygen to 25KPa to prepare for atomization. Add Sn, Bi, and Cu to the vacuum melting furnace 1 according to the designed ratio, and then smelt at 236°C after vacuuming and inflating. After purification, the melt is poured into the atomizing furnace 3, and then supplied to the atomizer through the infusion channel - Turntable, the motor drives the turntable to rotate at a speed of 50000rpm for atomization, so that the melt is atomized, and the oxygen content in the atomization chamber 8 is stabilized at 300ppm. The powder enters the centrifugal classifier 15 under the action of gravity and airflow for classification, and the centrifugal classifier cage rotates at 450rpm. The coarse powder separated by the centrifugal classifier passes through the transfer of the intermediate bin 21, and is transferred from the closed system to the screening funnel 24, and then sieved by the rotary vibrating screen 25 to obtain the finished powder (the proportion of 20-45 micron powder reaches 95%, the oxygen content 35ppm). The ultrafine powder enters the dust collector 27 with the airflow, and the dust collector 27 is a cyclone dust collector. The ultra-fine powder is settled in the cyclone dust collector 27, and the gas is purified and then passed through the tube heat exchanger 35 for heat exchange, and then divided into two paths, one path returns to the top of the atomization chamber 8 to participate in atomization, and the other path returns to the centrifugal classifier Participate in grading in 15. The atomization chamber 8 and the tube heat exchanger 35 are cooled by water, and the air volume distribution between the atomization chamber 8 and the centrifugal classifier 15 is controlled by butterfly valves 11 and 14 .

The device of the utility model can be used for atomizing Sn, Pb, Bi, Sb, Ag, Cu, In, Zn, Al, Si, Ga, Ge, B, C, P, Ni, Ti, Cr, Mn, rare earth and other elements And its alloys can continuously produce spherical powders below -320 mesh, and the oxygen content is less than or equal to 80ppm.

Claims (10)

1. A metal powder preparation device, characterized in that it includes a smelting device, a heater, a cooler, an atomization chamber, an atomizer, a pneumatic classifier, an intermediate warehouse, a screening funnel, a sieve machine, a dust collector, and a balance tank , tube heat exchanger, vacuum obtaining equipment, control system, infusion tube, conduit, pipeline, gas pipeline, pneumatic butterfly valve and electromagnetic valve, atomizer is installed in the atomization chamber, and the smelting device is installed on the atomizer through the infusion tube The infusion tube is connected with a heater and a cooler. The atomization chamber is connected with the pneumatic classifier through the pipeline. The funnel is docked, and the screening funnel is connected to the screen machine; the pneumatic classifier is connected to the dust collector through the gas pipeline, and the dust collector is connected to the balance tank through the gas pipeline. The balance tank is equipped with a high-pressure centrifugal fan, and the balance tank exchanges heat with the tubes through the gas pipeline. The air outlet of the tube heat exchanger is connected to the return air duct, and then divided into two return air branches, one way returns to the top of the atomization chamber, and the other returns to the secondary return air outlet of the pneumatic classifier, which is connected to the return air duct There are devices for obtaining vacuum. 2. The metal powder preparation device according to claim 1, characterized in that: the melting device is a melting furnace or an atomizing furnace. 3. The metal powder preparation device according to claim 1, characterized in that: the melting device is a melting furnace and an atomizing furnace, and the melting furnace is connected to the atomizing furnace through an infusion tube. 4. The metal powder preparation device according to claim 1, characterized in that: the atomizer is a centrifugal atomizer, an ultrasonic atomizer or a gas atomizer. 5. The metal powder preparation device according to claim 1, characterized in that: the atomization chamber and the tube heat exchanger are equipped with cooling devices, and the cooling method is water cooling or air cooling. 6. The metal powder preparation device according to claim 1, characterized in that: the pneumatic classifier is a squirrel-cage centrifugal classifier, and the sieve machine is a mechanical sieve. 7. The metal powder preparation device according to claim 6, characterized in that: the squirrel cage rotating speed of the squirrel cage centrifugal classifier is 200~3000rpm. 8. The metal powder preparation device according to claim 1, characterized in that: the dust collector is a pneumatic principle mode dust collector or a filtration principle mode dust collector. 9. The metal powder preparation device according to claim 8, characterized in that: the pneumatic principle mode dust collector is a cyclone dust collector, and the filtration principle mode dust collector is a bag filter or a filter element filter. 10. The metal powder preparation device according to claim 9, characterized in that: the dust collector is a combination of two or more, including one or more of the pneumatic principle mode dust collector and the filtration principle mode dust collector A plurality of them are connected in series through gas pipelines.

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