Preparation device for superfine metal powder

Abstract

The utility model discloses a preparation device of superfine metal powder, which comprises a feeder, an evaporation channel assembly, a first evaporation channel and a first non-transferred arc plasma gun, and further comprises a plurality of evaporation channels which are communicated front and back, and the axes of the evaporation channels are not on the same straight line. The head end of each evaporation channel is connected with at least one non-transferred arc plasma gun; the foremost evaporation channel of the multiple evaporation channels communicates with the tail end of the first evaporation channel, the axes of the foremost evaporation channel and the first evaporation channel are not on the same straight line, and the tail end of the last evaporation channel communicates with a superfine metal powder collector. A channel body of each evaporation channel is made of a high-temperature-resistant material or a metal material with a cooling interlayer; a heat preservation layer is arranged on the outer wall of each evaporation channel; and the superfine metal powder collector and all the non-transferred arc plasma guns are communicated with the working medium gas circulating device. The non-transferred arc plasma arc gun can be effectively utilized, and evaporation preparation of the metal powder with the particle size smaller than 10 micrometers can be carried out with high efficiency and low cost.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of metal powder preparation, specifically to a preparation device of superfine metal powder. BACKGROUND

[0002] Metal powder is an important industrial raw material and is widely used in various fields. With the continuous application of metal powder in downstream technologies, metal powder preparation technology is also updated and iterated, and is constantly improving. One direction of process development is the development of superfine metal powder preparation technology with smaller particle size. Superfine metal powder generally refers to metal powder with a particle size of less than 10 μm, and is also described as nano to micron powder, i.e. metal powder with a particle size of 1 nm-10 μm.

[0003] Currently, the preparation of superfine metal powder mainly has the following methods.

[0004] Firstly, chemical method, which uses chemical reaction to obtain target material powder. The particle size of the prepared powder can reach within 10 μm. However, the powder obtained by chemical method is mostly irregular in shape, such as dendritic shape, and it is difficult to prepare spherical powder. Moreover, chemical reaction can only be used for the preparation of one or a few kinds of material powder, which is harsh on material selection. At the same time, the environmental pollution problem caused by chemical method is also more serious, thus limiting its more extensive application.

[0005] Secondly, physical method, which mainly includes ball milling method, atomization method and vapor condensation method. Ball milling method requires a large amount of time cost to prepare superfine metal powder, and impurities are easily introduced during the ball milling process. The obtained powder is mostly irregular in shape, thus it does not meet the needs of industrial development. Atomization method is widely used in the field of metal powder preparation, but the particle size of the prepared metal powder is mostly above 20 μm, and the yield of superfine metal powder with a particle size of less than 10 μm is very low. Therefore, the production cost is greatly increased, which limits its development. Vapor condensation method is one of the main methods for preparing superfine metal powder. Compared with other preparation methods of existing technology, the yield of superfine metal powder is relatively high, the powder sphericity is relatively good and the impurity content is relatively low, but it still needs to be improved.

[0006] Similar ultra-fine metal powder preparation methods are described in the invention patent application with application publication number CN102211197A and the invention patent application with application publication number CN105057688A, both of which use a plasma transferred arc as a heating source to heat the raw material placed in a high-temperature evaporation crucible until evaporation, and then pass through a particle controller to determine the target particle size of the powder and finally collect it. This method uses a high-temperature evaporation crucible to place the raw material, and the crucible needs to be able to withstand temperatures above the boiling point of the raw material to ensure smooth evaporation. For high-melting-point metal materials, it is almost impossible to find a suitable crucible, so the use of the crucible greatly limits the selection of raw materials for this method.

[0007] For example, the invention patent application with application publication number CN111977659A discloses a nano-silicon powder production device, which consists of multiple non-transferred arc plasma torches to form a plasma arc ring. The raw material in the form of coarse powder enters the plasma arc ring and is evaporated, and then the powder with the target particle size is collected. Although this technical solution avoids the use of crucibles and expands the range of materials that can be prepared into powder, it still has several shortcomings: first, the effective evaporation area is limited to the plasma arc ring. As a beam of ultra-high temperature gas, the plasma arc ring has a very high gas pressure. During the feeding process, it is inevitable that some of the raw materials will be bounced off the outer edge of the plasma arc ring and cannot enter the arc ring. Given that the temperature of the plasma arc ring is highest in the central region and gradually decreases outward in the axial and radial directions, the raw materials that enter the outer layer of the arc ring or do not enter the arc ring are at risk of not being completely evaporated, and only the raw materials that enter the inner layer of the arc ring can be completely evaporated, thereby resulting in a low evaporation efficiency. Second, the direction of the plasma arc ring jet is consistent with the direction of the raw material falling, which causes the raw materials entering the arc ring to be accelerated in the direction of the arc ring jet, thereby shortening the residence time of the raw materials in the arc ring. A short evaporation time also leads to incomplete evaporation of the raw materials, further reducing the evaporation efficiency. Third, the evaporated vapor usually moves upward and easily condenses into clumps when it encounters the cold feeding pipe and the plasma torch part above, and even blocks the feeding pipe. Fourth, the evaporated vapor generally grows into large particles through subsequent collisions. In this process, the vapor needs to remain in a gaseous state, and the larger the space for collision and growth, the longer the time, and the larger the particle size of the particles obtained. Since the heating area of the plasma arc ring is very limited, the evaporated vapor is quickly cooled after leaving the heating area of the arc ring, making it difficult to maintain a gaseous state for a long time, and thus unable to continue to grow. Therefore, the powder prepared by this process is mostly nano-powder with a particle size of less than 100 nm, which is not suitable for the preparation of metal powder with a particle size of 100 nm to 10 μm. Fifth, the tolerance for raw materials is low, and it can usually only be a powder with a particle size of several tens of microns, increasing the material crushing cost.

[0008] For example, the patent application with the publication number CN116511512A discloses a preparation device for plasma atomized spherical metal powder, which obtains micron-sized metal powder by crushing through the characteristics of high temperature and super high speed of non-transferred arc, but the yield of ultrafine powder obtained by evaporation is not high due to the extremely short contact time of liquid with the non-transferred arc.

[0009] As can be seen from the above discussion, the preparation of ultrafine metal powder by vapor condensation is still the preferred solution at present, but the use of crucibles needs to be avoided, and how to use the non-transferred arc plasma gun to prepare ultrafine metal powder by evaporation with high efficiency and low cost has become a technical problem to be solved in the technical field. Practical new type content

[0010] The technical problem to be solved by the present application is to provide a preparation device for ultrafine metal powder which can effectively utilize the non-transferred arc plasma gun and prepare metal powder with a particle size of less than 10 microns by evaporation with high efficiency and low cost.

[0011] The technical solution of the present application is to provide a preparation device for ultrafine metal powder, which comprises a feeder and an evaporation channel assembly. The evaporation channel assembly comprises a first evaporation channel, one end of the first evaporation channel is connected to at least one first non-transferred arc plasma gun, and the outlet end of the outlet pipe of the feeder is located in the plasma arc of the first non-transferred arc plasma gun. The evaporation channel assembly further comprises a plurality of evaporation channels which are in communication with each other and have different axis lines. The first end of each evaporation channel is connected to at least one non-transferred arc plasma gun. The first evaporation channel is in communication with the last evaporation channel and has different axis lines. The last evaporation channel is connected to a collector for ultrafine metal powder. The channel body of each evaporation channel is made of high-temperature-resistant material or metal material with a cooling layer. Each evaporation channel is provided with a heat preservation layer on the outer wall. The collector for ultrafine metal powder and all non-transferred arc plasma guns are in communication with a working medium gas circulation device.

[0012] After adopting the above structure, the preparation device for ultrafine metal powder has the following advantages:

[0013] The present application overcomes the defect that the temperature of the non-transferred arc gradually decreases with the increase of the distance after being sprayed out, increases the high-temperature area of the non-transferred arc and forces the metal raw material to move in the high-temperature area for a long time, effectively utilizes the non-transferred arc plasma arc gun, and prepares metal powder with a particle size of less than 10 microns by evaporation with high efficiency and low cost:

[0014] The multiple evaporation channels, which are connected in series and have different axes, and the first channel, and the non-transferred arc plasma gun, ensure that all the metal raw materials entering the outlet of the discharge pipe are heated and evaporated into gas, greatly reducing the waste of raw materials and the production cost.

[0015] The respective evaporation channels in the evaporation channel assembly force the plasma arc of the respective non-transferred arc plasma gun to be injected in the respective evaporation channel, and the metal raw materials are heated by the non-transferred arc in the constrained space of the respective evaporation channel, which can maximize the use of the high temperature of the non-transferred arc and improve the heating efficiency. Even if the feeding speed is fast, the evaporation efficiency can be guaranteed to be high, which greatly improves the evaporation efficiency.

[0016] The heating of the channel by the plasma arc of the respective non-transferred arc plasma gun and the heat preservation of the channel by the heat preservation layer on the respective outer wall ensure that the temperature in the constrained space of the evaporation channel can be maintained above the melting point of the metal raw materials, so that the raw materials remain in a liquid or gaseous state. The metal vapor collides and grows during movement in the multiple interconnected evaporation channels. The more the number of channels, the more frequent the collision, and the larger the final powder particle size. Therefore, the particle size of the ultra-fine metal powder can be adjusted by adjusting the number of evaporation channels and their matched non-transferred arc plasma guns, or adjusting the temperature of the plasma arc of the non-transferred arc plasma gun, to meet the needs of evaporation preparation of ultra-fine metal powder with a particle size of 1 nm to 10 μm in different particle size ranges.

[0017] In addition, since the metal vapor in each evaporation channel always moves in the direction of the respective non-transferred arc plasma gun and has no room to turn back, the condensation and clogging of metal vapor around the outlet pipe of the feeder are prevented, effectively ensuring the long-term stable operation of the preparation device itself.

[0018] In addition, all the metal raw materials entering the multiple evaporation channels of the evaporation channel assembly can be fully heated and completely evaporated, so that metal powder, metal wire or molten metal liquid can be selected according to the physical and chemical properties and cost of different raw materials, which greatly expands the material range of the metal powder that can be prepared by the ultra-fine metal powder preparation device, and further reduces the production cost.

[0019] Further, the axis of the outlet pipe of the feeder is perpendicular to the axis of the first evaporation channel and the axis of the first non-transferred arc plasma gun. With the above structure, the evaporation efficiency of the first non-transferred arc plasma gun on the metal raw material entering the evaporation channel from the outlet end of the outlet pipe is further improved, the condensation and clogging of metal vapor around the outlet pipe of the feeder can be basically avoided, and the selection range of the metal raw material is further expanded to further reduce the production cost.

[0020] Further, the axes of the two adjacent evaporation channels are perpendicular to each other. With the above structure, the gaseous evaporation of the metal raw material entering the plurality of evaporation channels in the evaporation channel assembly is more complete, the raw material waste is further reduced, and the evaporation efficiency of the metal raw material is further improved.

[0021] Further, the feeder is a vertical feeder, the first evaporation channel is a horizontal and circular evaporation channel, and the first non-transferred arc plasma gun is a non-transferred arc plasma gun arranged at the outer end of the first evaporation channel and used for evaporating the metal raw material at the outlet end of the outlet pipe of the feeder and sending the evaporated metal raw material to the second evaporation channel through the first hot gas flow. With the above structure, the evaporation effect on the metal raw material entering the first evaporation channel is better, the evaporation efficiency of the metal raw material is further improved, the condensation and clogging of metal vapor around the outlet pipe of the feeder can be completely avoided, and the selection range of the metal raw material is further expanded to further reduce the production cost.

[0022] Further, the second evaporation channel is a vertical and circular evaporation channel, the second non-transferred arc plasma gun is a non-transferred arc plasma gun arranged at the top end of the second evaporation channel and used to continuously evaporate the metal raw material sent from the first evaporation channel and send the evaporated metal raw material to the third evaporation channel through a second hot gas flow; the third evaporation channel is a horizontal and circular evaporation channel, the third non-transferred arc plasma gun is a non-transferred arc plasma gun arranged at the outer end of the third evaporation channel and used to continuously evaporate the metal raw material sent from the second evaporation channel and send the evaporated metal raw material to the collector of the ultra-fine metal powder or the next evaporation channel through a third hot gas flow. It is understood that the temperature of the plasma arc of the second non-transferred arc plasma gun and the temperature of the plasma arc of the third non-transferred arc plasma gun can be lower than the temperature of the plasma arc of the first non-transferred arc plasma gun, that is, the metal raw material in the second evaporation channel and the third evaporation channel can exist in liquid state and gas state (i.e. vapor state) at the same time, so as to facilitate the collision between liquid and liquid or the collision between liquid and vapor state to grow, and if the third evaporation channel is connected with the next evaporation channel (such as the fourth evaporation channel) at the end, the metal raw material evaporated in the third evaporation channel can be in liquid state and gas state at the same time; of course, if the third evaporation channel is the last evaporation channel, the metal raw material evaporated in the third evaporation channel is completely in vapor state, so as to ensure high evaporation efficiency and the diversity of the shape of the metal raw material. After the above structure is adopted, the gaseous evaporation of the metal raw material entering the plurality of evaporation channels of the evaporation channel assembly is more complete, the inclusiveness of the metal raw material in molten liquid state, powder state or filament state is better, the waste of raw materials is further reduced, the evaporation efficiency of the metal raw material is further improved, and the evaporation preparation of the nanoscale ultra-fine metal powder is more suitable.

[0023] Further, the evaporation channel assembly further comprises a fourth evaporation channel: the next evaporation channel of the third evaporation channel is the fourth evaporation channel, the fourth evaporation channel is a vertical and circular evaporation channel, the fourth non-transferred arc plasma torch is arranged at the top end of the fourth evaporation channel and continues to evaporate the metal raw material sent from the third evaporation channel and sends the evaporated metal raw material to the collector of the ultra-fine metal powder or the next evaporation channel through the fourth hot gas flow. It is not difficult to understand that the temperature of the plasma arc of the fourth non-transferred arc plasma torch can be lower than the temperature of the plasma arc of the first non-transferred arc plasma torch, that is, the metal raw material in the fourth evaporation channel can exist in liquid state and gas state (i.e. vapor state) at the same time, so as to facilitate the collision between liquid and liquid or the collision between liquid and vapor state to grow up, and if the fourth evaporation channel is connected with the next evaporation channel such as the fifth evaporation channel at the end, the metal raw material evaporated in the fourth evaporation channel can be in liquid state and gas state at the same time; of course, if the fourth evaporation channel is the last evaporation channel, the metal raw material evaporated in the fourth evaporation channel is completely in vapor state, so as to ensure high evaporation efficiency and the diversity of the shape of the metal raw material. After the above structure is adopted, the gaseous evaporation of the metal raw material entering the multiple evaporation channels of the evaporation channel assembly is more complete and thorough, the waste of raw materials is further reduced, the production cost is further reduced, the evaporation efficiency of the metal raw material is further improved, and it is more suitable for the evaporation preparation of the ultra-fine metal powder with a particle size of 10 μm and a particle size greater than that of the third evaporation channel outlet after cooling.

[0024] Further, the evaporation channel assembly further comprises a fifth evaporation channel: the next evaporation channel of the fourth evaporation channel is the fifth evaporation channel, the fifth evaporation channel is a horizontal and circular evaporation channel, the fifth non-transferred arc plasma gun is arranged at the outer end of the fifth evaporation channel and is used for continuously evaporating the metal raw material sent by the fourth evaporation channel and sending the evaporated metal raw material to the collector of the ultra-fine metal powder or the next evaporation channel through the fifth hot gas flow. It is also not difficult to understand that the temperature of the plasma arc of the fifth non-transferred arc plasma gun can be lower than the temperature of the plasma arc of the first non-transferred arc plasma gun, that is, the metal raw material in the fifth evaporation channel can exist in liquid state and gas state (vapor state) at the same time, so as to facilitate the collision of liquid state and liquid state or the collision of liquid state and vapor state to grow, and if the next evaporation channel (such as the sixth evaporation channel) is also connected to the end of the fifth evaporation channel, the metal raw material evaporated in the fifth evaporation channel can be in liquid state and gas state at the same time; of course, if the fifth evaporation channel is the last evaporation channel, the metal raw material evaporated in the fifth evaporation channel is completely in the vapor state, so as to ensure the high evaporation efficiency and the diversity of the shape of the metal raw material. After the above structure is adopted, the gaseous evaporation of the metal raw material entering the multiple evaporation channels of the evaporation channel assembly is more complete and thorough, the waste of raw materials is further reduced, the production cost is further reduced, the evaporation efficiency of the metal raw material is further improved, and the ultra-fine metal powder with a particle size of less than 10 μm and greater than the particle size of the fourth evaporation channel after cooling at the outlet is more suitable for evaporation preparation.

[0025] Further, the end of the third evaporation channel or the fourth evaporation channel or the fifth evaporation channel is fixed with a separation plate of the evaporation channel and the collector of the ultra-fine metal powder, the center hole of the separation plate is the outlet of the metal raw material in the vapor state of the third evaporation channel or the fourth evaporation channel or the fifth evaporation channel, and the edge of the separation plate has a plurality of gas through holes for the cooling gas to pass into the collector of the ultra-fine metal powder. After the above structure is adopted, the evaporation of the metal raw material and the cooling and collection of the metal powder are separated by the separation plate, the two are less interfered, and the negative influence of the gas pressure fluctuation and the gas flow movement of the cooling and collection part on the metal raw material evaporation process and the metal raw material particle cooling and collision growth process is greatly reduced.

[0026] Further, the axes of all the non-transferred arc plasma guns in the evaporation channel assembly are on the same straight line with the axes of the evaporation channels. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a structure schematic view of the preferred embodiment of the ultra-fine metal powder preparation device.

[0028] Figure 2 is Figure 1 is an enlarged structure schematic view of A in FIG.

[0029] Figure 3 is Figure 1 Enlarged structural schematic view of B in the middle.

[0030] Figure 4 is Figure 1 Enlarged structural schematic view of C in the middle.

[0031] Figure 5 is Figure 1 Enlarged structural schematic view of D in the middle.

[0032] Figure 6 is Figure 1 Enlarged structural schematic view of the right view of the partition plate in the middle.

[0033] The figure shows:

[0034] 1, feeder, 11, outlet pipe, 111, outlet end;

[0035] 2, evaporation channel assembly, 21, first evaporation channel, 22, first non-transferred arc plasma gun, 221, first plasma arc, 222, first hot gas flow, 23, channel body, 24, heat preservation layer, 25, second evaporation channel, 26, second non-transferred arc plasma gun, 261, second plasma arc, 262, second hot gas flow, 27, third evaporation channel, 28, third non-transferred arc plasma gun, 281, third plasma arc, 282, third hot gas flow;

[0036] 3, collector, 31, rapid cooling channel, 32, filter structure;

[0037] 4, partition plate, 41, center hole, 42, gas via hole;

[0038] 5, working medium gas circulating device, 51, gas inlet pipeline, 52, gas pump, 53, gas outlet pipeline;

[0039] 6, shell;

[0040] 7, metal raw material;

[0041] 8, superfine metal powder. DETAILED DESCRIPTION

[0042] The specific embodiments of the utility model will be further described below in combination with the drawings. It needs to be declared here that the description of these specific embodiments is used to help understanding the utility model, but does not constitute the limitation of the utility model. In addition, the technical features involved in each specific embodiment of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0043] As Figure 1 , Figure 1 ,Figure 2 , Figure 3 , Figure 4 and Figure 5 as shown in FIGS. 10A and 10B.

[0044] The utility model discloses the preparation device of superfine metal powder's preferred embodiment, including feeder 1 and evaporation passage subassembly 2, evaporation passage subassembly 2 includes first evaporation passage 21, and the first evaporation passage 21 one end is called first non -transferred arc plasma gun 22 of outer end or first end sealing connection has at least a branch, and feeder 1 outlet pipe 11's export end 111 is located in the first non -transferred arc plasma gun 22's first plasma arc 221.The cross section of first evaporation passage 21 can be circular, and the cross section of other evaporation passages described below can also be circular.It is not difficult to understand that the cross section of prior art non -transferred arc plasma gun is generally circular.The feeder 1 described can be the metal liquid feeder of molten metal liquid of prior art by vertical metal smelting chamber, metal liquid tank, heat preservation cover and intermediate frequency induction wire, cooling water sandwich and conical cylinder.Each non -transferred arc plasma gun is communicated with energy source such as power supply, water supply structure and gas supply structure.The non -transferred arc plasma gun described includes the first non -transferred arc plasma gun 22, the second non -transferred arc plasma gun 26, the third non -transferred arc plasma gun 28 described below, and also can include the fourth non -transferred arc plasma gun and the fifth non -transferred arc plasma gun described below and the like.Non -transferred arc plasma gun is also called non -transferred arc plasma torch.The first end of each place described below is at least a branch, preferably one, which can also be two or three branches with the same horizontal axis (the vertical described below refers to the same vertical plane).It is not difficult to understand that if two or three, the axis intersects in the passage to form a plasma arc or arc torch.The above details can be found in the invention patent application with the application publication number CN116511512A and the title of preparation device of plasma atomized spherical metal powder.Of course, the feeder 1 described can also use different feeders 1 according to different metal raw material forms, such as the metal powder feeder of prior art for feeding metal powder in addition to the above metal liquid feeder, and the metal wire feeder of prior art for conveying metal wire.Feeders 1 are also called feeders.In addition, the high-temperature-resistant materials described below can be graphite, ceramics and tungsten, etc. of prior art.The metal material containing cooling sandwich described below can be carbon steel of prior art, with a cooling sandwich in the carbon steel, such as a cooling water sandwich or a cooling gas sandwich.The heat insulation material described below can use rock wool and glass wool in mineral wool, or expanded perlite or micro-nano thermal insulation foaming cement, etc.The working gas described below can be one of nitrogen, argon, hydrogen, ammonia, helium and other gases of prior art.The working gas circulating device 5 described below is also called a working gas circulation system.It is not difficult to understand that the working gas circulating device 5 is a closed system, which can be composed of an inlet pipe 51, a gas pump 52 and an outlet pipe 53 connected to each other, and can be connected to the working gas cylinder through a gas pipe, and a valve can be provided on the gas pipe.The valve of the working gas cylinder is opened when the working gas circulating device 5 needs original gas or subsequent gas supply.The collector 3 described below generally also includes a filter structure 32.The above is the prior art.

[0045] The utility model discloses the following invention points.

[0046] The preferred embodiment of the preparation device of superfine metal powder of the utility model, the evaporation subassembly 2 still includes multiple evaporation channels that are communicated front and back and whose axis is not on the same straight line, and the first end of multiple evaporation channels all has at least one non-transferred arc plasma gun. It is not difficult to understand that the multiple evaporation channels described herein refer to multiple evaporation channels other than the first evaporation channel 21, such as the second evaporation channel 25, the third evaporation channel 27, etc. The first evaporation channel such as the second evaporation channel 25 is communicated with the first evaporation channel 21 at the end and the axis is not on the same straight line, and the end of the last evaporation channel such as the third evaporation channel 27 is communicated with the collector 3 of superfine metal powder 8. The channel body 23 of each evaporation channel is made of high-temperature-resistant material or metal material with cooling interlayer. The outer wall of the channel body 23 of each evaporation channel is provided with a heat preservation layer 24. The collector 3 of superfine metal powder 8 and all non-transferred arc plasma guns are communicated with the working medium gas circulating device 5. The channel body 23 can be a circular ring channel body 23.

[0047] The axis of the outlet pipe 11 of the feeder 1 is preferably perpendicular to the axis of the first evaporation channel 21 and the axis of the first non-transferred arc plasma gun 22. It is not difficult to understand that the angles between them can also be obtuse, such as 100°, or acute, such as 80°, which can also achieve the technical effects of the utility model.

[0048] The axes of the two adjacent evaporation channels in the evaporation channel subassembly 2 are preferably perpendicular to each other. For example, the axis of the first evaporation channel 21 is perpendicular to the axis of the second evaporation channel 25, and the axis of the second evaporation channel 25 is perpendicular to the axis of the third evaporation channel 27. It is also not difficult to understand that the angles between them can also be obtuse, such as 100°, or acute, such as 80°, which can also achieve the technical effects of the utility model.

[0049] The axis of the non-transferred arc plasma gun installed at the first end of each evaporation channel is preferably on the same straight line as the axis of the evaporation channel. For example, the axis of the first non-transferred arc plasma gun 22 is on the same straight line as the axis of the first evaporation channel 21. For another example, the axis of the second non-transferred arc plasma gun 26 is on the same straight line as the axis of the second evaporation channel 25, and the axis of the third non-transferred arc plasma gun 28 is on the same straight line as the axis of the third evaporation channel 27. Of course, the axis of the non-transferred arc plasma gun at the first end of each evaporation channel can also be not on the same straight line as the axis of the evaporation channel, which can also achieve the technical effects of the utility model.

[0050] The feeder 1 is preferably a vertical feeder 1, such as the molten metal feeder 1 described above. The first evaporation channel 21 is preferably a horizontal and circular evaporation channel, with the outlet end 111 of the feeder 1 outlet pipe 11 located within the plasma arc of the first non-transfer arc plasma gun 22, such as the first plasma arc 221. The first non-transfer arc plasma gun 22 is preferably located at the outer end of the first evaporation channel 21 and used to evaporate the metal raw material at the outlet end 111 of the feeder 1 outlet pipe 11, and the non-transfer arc plasma gun that delivers the evaporated metal raw material 7 to the second evaporation channel 25 via the first hot gas flow 222. The outer end of the first evaporation channel 21 is as follows: Figure 6 The left end is shown. The evaporated metal raw material 7 generally includes liquid metal raw material 7 and gaseous metal raw material 7, i.e., vapor state.

[0051] The second evaporation channel 25 is preferably a vertical and circular evaporation channel. The second non-transfer arc plasma gun 26 is installed and connected to... Figure 1 The second evaporation channel 25 is shown at its top, and the metal raw material 7 from the first evaporation channel 21 continues to evaporate and is then transported by the second hot air stream 262 to the non-transfer arc plasma gun in the third evaporation channel 27. The third evaporation channel 27 is preferably a horizontally oriented, circular evaporation channel. The third non-transfer arc plasma gun 28 is preferably located at the outer end of the third evaporation channel 27, and is used to continue evaporating the metal raw material 7 from the second evaporation channel 25 and transporting it by the third hot air stream 282 to the collector 3 or the next evaporation channel. The outer end of the third evaporation channel 27 is shown as... Figure 1 The left end is shown.

[0052] The beginning of the plurality of evaporation channels, such as Figure 1 As shown, the first end of the first evaporation channel 21 can be the left end, the first end of the second evaporation channel 25 can be the top end, and the first end of the third evaporation channel 27 can be the left end.

[0053] like Figure 1 As shown, the end of the horizontally oriented third evaporation channel is fixed with a partition plate 4, such as the third evaporation channel 27, and the collector 3 for the ultrafine metal powder 8, by multiple screws. The central hole 41 of the partition plate 4 is the outlet for the gaseous or vaporized metal raw material 7 of the third evaporation channel 27. The edge of the partition plate 4 has several gas through holes 42 for the working fluid cooling gas to pass through and enter the collector 3 for the ultrafine metal powder 8. The ultrafine metal powder 8 can also be referred to as metal powder particles.

[0054] like Figure 1 As shown, the multiple evaporation channels of the evaporation channel assembly 2 may also be provided with a shell 6 outside the insulation layer 24, such as a steel shell 6.Figure 1 The middle shell 6 is drawn in single line. The shell 6 can be attached to the partial insulation layer 24 of the evaporation channels, such as the first evaporation channel 21, the second evaporation channel 25, the third evaporation channel 27, the fourth evaporation channel and the fifth evaporation channel. The shell 6 can also be attached to the partial insulation layer 24 of the evaporation channels as shown in the middle with a gap. Figure 1 The partial insulation layer 24 can also be called insulation body or insulation structure.

[0055] Figure 1 The quick cooling channel 31, the collector 3, the filter structure 32, the gas inlet pipe 51, the gas pump 52 and the gas outlet pipe 53 are drawn in single line. As mentioned above, the working gas circulation device 5 includes the gas inlet pipe 51, the gas pump 52 and the gas outlet pipe 53, and can also include a gas cylinder and a gas pipe and a valve connected to the gas cylinder.

[0056] As shown in the middle, the end of the first hot gas flow 222 of the first evaporation channel 21 is located in the second plasma arc 261 of the second non-transferred arc plasma gun 26. The end of the second hot gas flow 262 of the second evaporation channel 25 is located in the third plasma arc 281 of the third non-transferred arc plasma gun 28. The third hot gas flow 282 of the third evaporation channel 27 passes through the center hole 41 of the partition plate 4 into the quick cooling channel 31, and the superfine metal powder 8 after quick cooling is collected by the collector 3. Figure 1

[0057] Alternatively, the evaporation channel assembly can further include a fourth evaporation channel: the next evaporation channel of the third evaporation channel is the fourth evaporation channel, the fourth evaporation channel is a vertical and circular evaporation channel, and the end of the third hot gas flow of the third evaporation channel can be located in the fourth plasma arc of the fourth non-transferred arc plasma gun. The fourth non-transferred arc plasma gun is a non-transferred arc plasma gun arranged at the top end of the fourth evaporation channel and continues to evaporate the metal raw material sent by the third evaporation channel and sends the evaporated metal raw material to the collector of the superfine metal powder or the next evaporation channel through the fourth hot gas flow. If the end of the fourth evaporation channel is connected to the collector, the fourth hot gas flow of the fourth evaporation channel can pass vertically through the center hole of the partition plate into the quick cooling channel, and the superfine metal powder after quick cooling is collected by the collector.

[0058] ​Or, the evaporation channel assembly can further include a fifth evaporation channel: the next evaporation channel of the fourth evaporation channel is the fifth evaporation channel, the fifth evaporation channel is a horizontal and circular evaporation channel, and the end of the fourth hot gas flow of the fourth evaporation channel can be located in the fifth plasma arc of the fifth non-transferred arc plasma torch. The fifth non-transferred arc plasma torch is arranged at the outer end of the fifth evaporation channel, and continuously evaporates the metal raw material sent by the fourth evaporation channel and sends the evaporated metal raw material to the collector of the ultra-fine metal powder or the next evaporation channel through the fifth hot gas flow. If the end of the fifth evaporation channel is connected to the collector, the fifth hot gas flow of the fifth evaporation channel can pass through the central hole of the partition plate horizontally into the rapid cooling channel, and the ultra-fine metal powder after rapid cooling is collected by the collector.

[0059] The axis of the third evaporation channel and the axis of the fourth evaporation channel can be perpendicular to each other, and the axis of the fourth evaporation channel and the axis of the fifth evaporation channel can be perpendicular to each other. The axis of the fourth non-transferred arc plasma torch and the axis of the fourth evaporation channel can be on the same straight line, and the axis of the fifth non-transferred arc plasma torch and the axis of the fifth evaporation channel can be on the same straight line. The fourth evaporation channel and the fifth evaporation channel can be continued on the basis of Figure 1 Figure 1 The first end of the fourth evaporation channel can be a top end, and the first end of the fifth evaporation channel can be a left end.

[0060] The structure diagrams of the above three paragraphs are not shown.

[0061] It is not difficult to understand that, according to the need for larger particle size preparation, the ultra-fine metal powder preparation device can further include a vertical sixth evaporation channel and a horizontal seventh evaporation channel, etc. If there is a vertical sixth evaporation channel, the partition plate is fixed at the end of the vertical channel body of the sixth evaporation channel, and the rest of the structure, i.e. the flow direction of the hot gas flow, can be referred to the above description of the fourth evaporation channel. If there is a horizontal seventh evaporation channel, the partition plate is fixed at the end of the horizontal channel body of the horizontal seventh evaporation channel, and the rest of the structure, i.e. the flow direction of the hot gas flow, can be referred to the above description of the fifth evaporation channel.

[0062] It is not difficult to understand that the non-transferred arc plasma torch connection, i.e. fixed or removable fixed, such as directly fixed by screws or fixed by screws through flanges. Of course, because the entire ultra-fine metal powder preparation device is a sealed body with internal communication. Therefore, generally, a sealing structure is provided, but in production practice, the sealing between the non-transferred arc plasma torch and the first end of the evaporation channel is not very strict. The sealing is generally sealed by a sealing ring, such as a graphite or fluorine rubber ring.

[0063] The above parts or structures or quantities not marked in the figure are not shown in the figure, and some parts are not marked in the figure. The drawings are only schematic, and if there is any inconsistency between the drawings and the written description or between the drawings themselves, the written description shall prevail.

[0064] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can be variously changed and modified. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An apparatus for producing ultrafine metal powder, comprising a feeder and an evaporation channel assembly, the evaporation channel assembly comprising a first evaporation channel, one end of the first evaporation channel being connected to at least one first non-transferred arc plasma gun, an outlet end of an outlet tube of the feeder being located within a plasma arc of the first non-transferred arc plasma gun; characterized in that: The evaporation channel assembly further comprises a plurality of evaporation channels which are in communication with each other and have axes not in the same straight line, and at least one non-transferred arc plasma gun is connected to the head end of each evaporation channel; the first evaporation channel is in communication with the end of the first evaporation channel and has an axis not in the same straight line with the axis of the first evaporation channel; the end of the last evaporation channel is in communication with a collector of superfine metal powder; the channel body of each evaporation channel is made of high-temperature-resistant material or metal material with a cooling interlayer; a heat preservation layer is arranged on the outer wall of each evaporation channel; the collector of superfine metal powder and all non-transferred arc plasma guns are in communication with a working medium gas circulating device.

2. The apparatus for producing ultrafine metal powder according to claim 1, wherein: The axis of the outlet pipe of the feeder is perpendicular to the axes of the first evaporation channel and the first non-transferred arc plasma gun.

3. The apparatus for producing ultrafine metal powder according to claim 2, wherein: The axes of two adjacent evaporation channels are perpendicular to each other.

4. The apparatus for producing ultrafine metal powder according to claim 3, wherein: The feeder is a vertical feeder, the first evaporation channel is a horizontal circular evaporation channel, and the first non-transferred arc plasma gun is arranged at the outer end of the first evaporation channel and used for evaporating the metal raw material at the outlet end of the outlet pipe of the feeder and sending the evaporated metal raw material to the second evaporation channel through the first hot gas flow.

5. The apparatus for producing ultrafine metal powder according to claim 4, wherein: The second evaporation channel is a vertical circular evaporation channel, the second non-transferred arc plasma gun is arranged at the top end of the second evaporation channel and used for continuously evaporating the metal raw material sent from the first evaporation channel and sending the evaporated metal raw material to the third evaporation channel through the second hot gas flow; the third evaporation channel is a horizontal circular evaporation channel, and the third non-transferred arc plasma gun is arranged at the outer end of the third evaporation channel and used for continuously evaporating the metal raw material sent from the second evaporation channel and sending the evaporated metal raw material to the collector of superfine metal powder or the next evaporation channel through the third hot gas flow.

6. The apparatus for producing ultrafine metal powder according to claim 5, wherein: The evaporation channel assembly further comprises a fourth evaporation channel: the next evaporation channel of the third evaporation channel is the fourth evaporation channel, the fourth evaporation channel is a vertical circular evaporation channel, and the fourth non-transferred arc plasma gun is arranged at the top end of the fourth evaporation channel and used for continuously evaporating the metal raw material sent from the third evaporation channel and sending the evaporated metal raw material to the collector of superfine metal powder or the next evaporation channel through the fourth hot gas flow.

7. The apparatus for producing ultrafine metal powder according to claim 6, wherein: The evaporation channel assembly further comprises a fifth evaporation channel: the next evaporation channel of the fourth evaporation channel is the fifth evaporation channel, the fifth evaporation channel is a horizontal circular evaporation channel, and the fifth non-transferred arc plasma gun is arranged at the outer end of the fourth evaporation channel and used for continuously evaporating the metal raw material sent from the fourth evaporation channel and sending the evaporated metal raw material to the collector of superfine metal powder or the next evaporation channel through the fifth hot gas flow.

8. The apparatus for producing ultrafine metal powder according to claim 7, wherein: A partition plate is fixed on the end of the channel body of the third, fourth or fifth evaporation channel, and the center hole of the partition plate is the outlet of the third, fourth or fifth evaporation channel for the metal raw material in vapor state, and the edge of the partition plate has a plurality of gas through holes for the working cooling gas to enter the collector of the ultra-fine metal powder.

9. The apparatus for producing ultrafine metal powder according to claim 1, wherein: The axis of all the non-transferred arc plasma guns in the evaporation channel assembly is in line with the axis of the evaporation channel where the non-transferred arc plasma gun is located.

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