Continuous grading and separating device for micro-nano composite powder

Abstract

A continuous grading separation device for micro-nano composite powder comprises two or more fluidized beds connected in series, and a solid-liquid separation assembly is arranged between every two adjacent fluidized beds. A second liquid inlet of the solid-liquid separation assembly is connected with a liquid outlet of the liquid inlet side fluidized bed, a solid discharge port is connected with a first liquid inlet of the liquid outlet side fluidized bed, a liquid phase discharge port is connected with a nano-filtration assembly through a liquid return pipe, the nano-filtration assembly is connected with a liquid storage device, and the liquid storage device is connected with a first liquid inlet of the fluidized bed. The continuous grading and separating device for the micro-nano composite powder can simultaneously realize integrated, automatic and continuous treatment of separation and grading, and is particularly suitable for the micro-nano composite powder consisting of nano powder with the particle size of less than 0.1 mu m and micron powder with the particle size of 1-200 mu m; compared with batch operation, the method has great advantages in treatment efficiency, classification efficiency, micro-nano separation efficiency and convenience, and the post-treatment efficiency and productivity are greatly improved.

Description

Technical Field

[0001] The utility model relates to the field of 3D printing powder preparation, and in particular to a device for continuous grading and separation of micro-nano composite powders. Background Art

[0002] Plasma spheroidization involves passing irregularly shaped micron-sized powders through a high-temperature plasma torch (~10,000°C) using a carrier gas, rapidly heating and melting the particles. Surface tension exerts on the molten particles, forming highly spherical droplets that solidify within a very short time, resulting in high-quality spherical micron-sized powders. Currently, this technology can be used to produce hundreds of spherical powders, including metals and composite metals, oxides, and nitrides. It is a commonly used raw material preparation technique for 3D printing.

[0003] However, the products prepared by plasma spheroidization need to be subjected to micro-nano separation and particle size classification before they can be directly used for 3D printing. The main reasons are:

[0004] 1) Micro-nano powder separation: Due to the high plasma temperature, the micron powder will be partially vaporized during the spheroidization process. The steam will condense into nano powder (1-500nm) during the subsequent powder collection process and adhere to the micron spherical powder. It needs to be further separated before it can be used;

[0005] 2) Micron particle size classification: Different 3D printing processes and application scenarios require different raw material powder particle sizes. For example, the selective laser melting process mainly uses 15-53μm particle size powders, the electron beam melting process uses 50-150μm particle size powders, and ultra-precision devices (such as tungsten gratings) use 1-20μm particle size powders. To achieve the graded utilization of micron powders, the industry generally uses screening and airflow classification methods.

[0006] At present, the separation and classification of wide-particle micro-nano composite powders produced after plasma spheroidization generally adopts a two-step intermittent post-processing process method of separation and classification. As a result, the entire post-processing time is 10-30 times the production time, which greatly limits production efficiency.

[0007] In view of this, it is particularly necessary to improve the separation and classification efficiency of wide-particle-size micro-nano composite powders. Utility Model Content

[0008] The purpose of the utility model is to provide a device for continuous grading and separation of micro-nano composite powders, which can improve the separation and grading efficiency of micro-nano composite powders.

[0009] The embodiment of the present utility model is achieved as follows:

[0010] In a first aspect, the present invention provides a device for continuous fractionation and separation of micro-nano composite powders, comprising two or more fluidized beds, each of which is provided with a first liquid inlet at the bottom, a discharge port, a feed port, and a liquid outlet being sequentially provided on the fluidized bed above the first liquid inlet, a distribution plate being provided on the first liquid inlet, and an ultrasonic vibration component being provided in the fluidized bed above the distribution plate;

[0011] The two or more fluidized beds are arranged in series, and a solid-liquid separation component is provided between two adjacent fluidized beds. The solid-liquid separation component is provided with a second liquid inlet, a solid discharge port and a liquid phase discharge port. The second liquid inlet is connected to the liquid outlet of the fluidized bed on the liquid inlet side, the solid discharge port is connected to the first liquid inlet of the fluidized bed on the liquid outlet side, and the liquid phase discharge port is connected to a nanofiltration component through a return liquid pipe. The nanofiltration component is connected to a liquid storage device, and the liquid storage device is connected to the first liquid inlet of the fluidized bed.

[0012] In an optional embodiment, the liquid phase discharge port of each solid-liquid separation component is connected to the inlet of the same nanofiltration component through a return pipe, and the liquid storage device is connected to the first liquid inlet corresponding to each fluidized bed through two or more infusion pipes, and each of the infusion pipes is provided with a pump body.

[0013] In an optional embodiment, among two or more fluidized beds arranged in series, the liquid outlet of the last fluidized bed along the material flow direction is connected to the inlet of the nanofiltration component through a liquid return pipe.

[0014] In an optional embodiment, each of the liquid return pipes is provided with a turbidity detection component.

[0015] In an optional embodiment, the fluidized bed includes a cone portion and a cylindrical portion located above the cone portion, the ratio of the height of the cone portion to the maximum diameter is 1-50, and the diameter of the cylindrical portion is 30 cm-60 cm.

[0016] In an optional embodiment, the angle between the side wall of the cone portion of the fluidized bed and the vertical direction is 5°-45°.

[0017] In an optional embodiment, the distribution plate is provided with through holes, and the opening rate of the distribution plate is 0.1%-5%.

[0018] In an optional embodiment, a feeder is connected to the feed port.

[0019] In an optional embodiment, there are 2-5 fluidized beds.

[0020] In an optional embodiment, there are three fluidized beds, wherein:

[0021] The angle between the side wall of the cone portion of the first-stage fluidized bed and the vertical direction is 15°-20°, the ratio of the height of the cone portion to the maximum diameter is 13-17, and the opening rate of the distribution plate is 1%-1.5%;

[0022] The angle between the side wall of the cone portion of the second-stage fluidized bed and the vertical direction is 13°-17°, the ratio of the height of the cone portion to the maximum diameter is 8-12, and the opening rate of the distribution plate is 1%-1.2%;

[0023] The angle between the side wall of the cone portion of the third-stage fluidized bed and the vertical direction is 8°-12°, the ratio of the height of the cone portion to the maximum diameter is 5-10, and the opening rate of the distribution plate is 0.8%-1%.

[0024] The beneficial effects of the embodiments of the present utility model are:

[0025] The continuous grading and separation device for micro-nano composite powders in the utility model can simultaneously realize integrated, automated and continuous separation and grading. Especially for micro-nano composite powders composed of nano powders below 0.1um and micron powders of 1-200um, it has great advantages over batch operations in terms of processing efficiency, grading efficiency and micro-nano separation efficiency, greatly improving the efficiency and production capacity of post-processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 It is a structural diagram of the present utility model.

[0028] Icons: 210-fluidized bed; 211-first liquid inlet; 212-discharge port; 213-first liquid outlet; 214-distribution plate; 215-feed port; 220-solid-liquid separation component; 221-second liquid inlet; 222-liquid phase outlet; 223-solid outlet; 230-nanofiltration component; 231-third liquid outlet; 232-third liquid inlet; 240-pump body; 250-liquid storage device; 251-liquid inlet; 260-ultrasonic vibration component; 270-turbidity detection component; 280-feeder. DETAILED DESCRIPTION

[0029] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0032] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the utility model product is typically placed when in use. These terms are intended solely to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0034] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0035] The utility model provides a device for continuous classification and separation of micro-nano composite powders, such as Figure 1 As shown, it includes two or more fluidized beds 210, each of which is provided with a first liquid inlet 211 at the bottom, and a discharge port 212, a feed port 215 and a liquid outlet are sequentially provided on the fluidized bed 210 above the first liquid inlet 211. A distribution plate 214 is provided on the first liquid inlet 211, and an ultrasonic vibration component is provided in the fluidized bed 210 above the distribution plate 214;

[0036] The two or more fluidized beds 210 are arranged in series, and a solid-liquid separation component 220 is provided between each adjacent fluidized bed 210. The solid-liquid separation component 220 is provided with a second liquid inlet 221, a solid discharge port 223 and a liquid phase discharge port 222. The second liquid inlet 221 is connected to the liquid outlet of the fluidized bed 210 on the liquid inlet side, the solid discharge port 223 is connected to the first liquid inlet 211 of the fluidized bed 210 on the liquid outlet side, and the liquid phase discharge port 222 is connected to the nanofiltration component 230 through a return liquid pipe. The nanofiltration component 230 is connected to a liquid storage device 250, and the liquid storage device is connected to the first liquid inlet 211 of the fluidized bed 210.

[0037] In an embodiment of the present invention, the discharge port 212 provided at the bottom of the fluidized bed 210 is used to recover the coarse-particle powder after separation, the solid-liquid separation component 220 can be a cyclone separator, and a pump body 240 can be provided at the liquid inlet 251 of the fluidized bed 210 to control the liquid inlet flow rate, and the pump body 240 can be a peristaltic pump.

[0038] The continuous grading and separation device for micro-nano composite powders in the utility model can simultaneously realize integrated, automated and continuous separation and grading. Especially for micro-nano composite powders composed of nano powders below 0.1um and micron powders of 1-200um, it has great advantages over batch operations in terms of processing efficiency, grading efficiency and micro-nano separation efficiency, greatly improving the efficiency and production capacity of post-processing.

[0039] In an optional embodiment, the liquid phase discharge port 222 of each solid-liquid separation component 220 is connected to the inlet of the same nanofiltration component 230 through a return liquid pipe, and the liquid storage device is connected to the first liquid inlet 211 corresponding to each fluidized bed 210 through more than two infusion pipes, and each of the infusion pipes is provided with a pump body 240.

[0040] In some embodiments, a nanofiltration assembly 230 may be installed only after the first-stage solid-liquid separation assembly 220. When the liquid turbidity at the liquid phase outlet 222 of the first-stage solid-liquid separation assembly 220 is extremely low, it indicates that the vast majority of the nanopowders within the fluidized bed 210 have been separated from the micron-sized powders and have flowed out (as indicated by a decrease in liquid turbidity). This allows for complete separation and recovery of the nanopowders from the micron-sized powders within the first-stage fluidized bed 210, thereby omitting the subsequent nanopowder separation operations after the solid-liquid separation assemblies 220 and fluidized bed 210. However, under industrial operating conditions, to ensure operational efficiency, it is difficult to completely recover the nanopowders within the first-stage fluidized bed 210. Therefore, some nanopowders may enter the next-stage fluidized bed 210 along with the fine-particle micron-sized powders for further separation and classification, until the final separation and recovery of the nanopowders is achieved in the final fluidized bed 210.

[0041] In some embodiments, each of the solid-liquid separation components 220 can be correspondingly provided with a nanofiltration component 230. In this case, multiple nanofiltration components 230 need to be provided and each nanofiltration component 230 needs to be controlled, and the powder in each of the nanofiltration components 230 needs to be collected. This increases the cost and is not conducive to the simplification of equipment control. Therefore, all solid-liquid separation components 220 are connected to the same nanofiltration component 230 to simplify the equipment.

[0042] In an optional embodiment, among two or more fluidized beds 210 arranged in series, the liquid outlet of the last fluidized bed 210 along the material flow direction is connected to the inlet of the nanofiltration component 230 through a liquid return pipe.

[0043] In an optional embodiment, each of the liquid return pipes is provided with a turbidity detection component 270 for detecting the turbidity of the liquid at the liquid phase outlet 222 of the solid-liquid separation component 220 and the liquid outlet of the last stage fluidized bed 210 .

[0044] In an optional embodiment, the fluidized bed 210 includes a conical portion and a cylindrical portion located above the conical portion, and the ratio of the height of the conical portion to the maximum diameter is 1-50, and more preferably 3-10; the diameter of the cylindrical portion is 30cm-60cm, which is conducive to improving the separation and classification efficiency.

[0045] In an optional embodiment, the angle between the cone sidewall of the fluidized bed 210 and the vertical direction is 5°-45°, more preferably 10-20°. This structure can reduce the fluid linear velocity, allowing micro-nano composite powders with a wide particle size range to be fluidized with a smaller amount of water.

[0046] In an optional embodiment, the distribution plate 214 is provided with through holes, and the opening rate of the distribution plate 214 is 0.1%-5%, more preferably 0.5-2%, which is beneficial to improving the fluidization effect of the fluid in the fluidized bed 210.

[0047] In an optional embodiment, the feed port 215 is connected to a feeder 280 , which is connected to the solid feed port 215 of the first-stage fluidized bed 210 , and is used to continuously feed the micro-nano composite powder into the first-stage fluidized bed 210 .

[0048] In an optional embodiment, there are 2-5 fluidized beds 210 .

[0049] In an optional embodiment, there are three fluidized beds 210, wherein:

[0050] The angle between the side wall of the cone portion of the first-stage fluidized bed 210 and the vertical direction is 15°-20°, the ratio of the height of the cone portion to the maximum diameter is 13-17, and the opening rate of the distribution plate 214 is 1%-1.5%;

[0051] The angle between the side wall of the cone portion of the second-stage fluidized bed 210 and the vertical direction is 13°-17°, the ratio of the height of the cone portion to the maximum diameter is 8-12, and the opening rate of the distribution plate 214 is 1%-1.2%;

[0052] The angle between the side wall of the cone portion of the third-stage fluidized bed 210 and the vertical direction is 8°-12°, the ratio of the height of the cone portion to the maximum diameter is 5-10, and the opening rate of the distribution plate 214 is 0.8%-1%.

[0053] Limiting the various parameters of the fluidized bed 210 is beneficial to improving the separation efficiency, classification efficiency and processing efficiency of the device for powders.

[0054] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0055] First embodiment

[0056] Reference Figure 1 An embodiment of the present invention provides a continuous graded separation device for micro-nano composite powders, comprising three fluidized beds 210 connected in series, a solid-liquid separation component 220 between each of the fluidized beds 210, a nanofiltration component 230, a pump body 240 and a liquid storage device 250.

[0057] The liquid storage device 250, the pump body 240, the fluidized bed 210, the solid-liquid separation component 220 and the nanofiltration component 230 are connected in sequence to form a circulation system.

[0058] Specifically, feeder 280 delivers micro-nano composite powder to feed port 215 of first-stage fluidized bed 210. Liquid from liquid storage device 250 is pumped into fluidized bed 210's first liquid inlet 211 via pump 240, separating the micro-nano composite powder under the countercurrent of gravity and the rising liquid. Ultrasonic vibration assembly 260 applies ultrasonic vibration to the liquid within fluidized bed 210, further promoting separation of the micro-nano composite powder. A distribution plate 214 with an open porosity of 0.1-5% is installed above first liquid inlet 211 within fluidized bed 210 to evenly distribute the water flow and thereby enhance the fluidization effect within fluidized bed 210.

[0059] The fluidized bed 210 has a discharge port 212 at the bottom and a first liquid outlet 213 at the top connected to the second liquid inlet 221 of the first-stage solid-liquid separation module 220. Liquid enters the first-stage solid-liquid separation module 220 from the fluidized bed 210 for solid-liquid separation. The liquid phase outlet 222 of the first-stage solid-liquid separation module 220 is connected to the third liquid inlet 232 of the nanofiltration module 230. The solid phase outlet 223 of the first-stage solid-liquid separation module 220 is connected to the feed port 215 of the second-stage fluidized bed 210, enabling the next stage of powder separation and classification. The first liquid outlet 213 of the final-stage fluidized bed 210 is directly connected to the third liquid inlet 232 of the nanofiltration module 230.

[0060] The continuous graded separation device for micro-nano composite powders also includes a turbidity detection component 270 for detecting the turbidity of the liquid at the liquid phase outlet 222 of the solid-liquid separation component 220 and the liquid outlet of the last-stage fluidized bed 210. The separation degree of the micro-nano composite powders is judged by the detection value, thereby achieving standardization and automation of the separation degree.

[0061] The third liquid outlet 231 of the nanofiltration component 230 is connected to the liquid inlet 251 of the liquid storage device 250 for recovering and recycling the liquid in the nanofiltration component 230 .

[0062] The fluidized bed 210 in this embodiment is preferably a conical fluidized bed 210, the inclination angle of its side wall to the vertical direction is 5-45 degrees, and the aspect ratio (ie, the ratio of the height to the maximum diameter) of the conical part of the fluidized bed 210 is 1-50.

[0063] In this embodiment, water is used to fluidize the micro-nano composite powder. In other embodiments of the present invention, other liquids may be used, and the present invention does not limit them.

[0064] The micro-nano composite powder continuous fractionation separation device of this embodiment can be used to separate micro-nano composite powders. The applicable micro-nano composite powders are composed of nanopowders below 0.1 μm and micron powders of 1-200 μm, including one or more of micro-nano composite metal powders, micro-nano composite metal alloy powders, micro-nano composite ceramic powders, and micro-nano composite nitride powders. The specific method includes:

[0065] (1) The micro-nano composite powder is continuously fed into the first-stage fluidized bed 210 through the feeder 280. The pump body 240 is turned on to allow water in the liquid storage device 250 to enter the fluidized bed 210 through the liquid inlet 251. The water flow rate is controlled to keep the micro-nano composite powder in a fluidized state. The vibrating rod of the ultrasonic vibration component 260 is placed in the water in the fluidized bed 210. The micro-nano composite powder begins to separate under the fluidization effect of the water flow and the ultrasonic vibration. At this time, a large amount of separated nanopowder is carried out of the fluidized bed 210 by the water and discharged from the liquid phase discharge port 222 of the solid-liquid separation component 220 together with the water after passing through the first-stage solid-liquid separation component 220.

[0066] (2) Setting the lower limit of water turbidity for the turbidity detection component 270. The turbidity detection component 270 is applied to the liquid phase discharge port 222 of the first-stage solid-liquid separation component 220. When the water turbidity detected by the water detection probe is lower than the lower limit set by the turbidity detection component 270, the turbidity detection component 270 emits a prompt sound, indicating that most of the nanopowders in the first-stage fluidized bed 210 have been separated from the micron powders and flowed out (manifested by a decrease in liquid turbidity). At this point, the water flow rate within the first-stage fluidized bed 210 is increased to the carryout velocity of the first-stage cut-off particle size, so that coarse micron powders larger than the cut-off particle size remain in the fluidized bed 210 and are subsequently discharged from the discharge port 212 of the fluidized bed 210. Fine micron powders smaller than the cut-off particle size, combined with water, form turbid water, which flows out of the liquid outlet of the fluidized bed 210 and enters the solid-liquid separation component 220 for solid-liquid separation. The separated solid phase powder enters the second-stage fluidized bed 210 through the solid discharge port 223. The separated liquid phase (a mixture of nanopowder and water) enters the nanofiltration component 230 for filtration and recovery of the nanopowder. The liquid filtered by the nanofiltration component 230 enters the liquid storage device 250 for recycling, while the nanopowder remains in the nanofiltration component 230.

[0067] (3) The solid separated in the first-stage solid-liquid separation component 220 is sent to the second-stage fluidized bed 210, and steps (1) and (2) are repeated to complete the second separation and classification of the micro-nano composite powder in the second-stage fluidized bed 210 and the second-stage solid-liquid separation component 220. The solid phase powder separated in the second-stage solid-liquid separation component 220 is sent to the third-stage fluidized bed 210 for the third separation of the micro-nano composite powder. At this time, the turbidity detection component 270 acts on the liquid at the liquid outlet of the third-stage fluidized bed 210 to indicate the separation of the micro-nano powder. The liquid phase (a mixed liquid composed of nano powder and water) flowing out of the third-stage fluidized bed 210 directly enters the nanofiltration component 230. The third-stage fluidized bed 210 is the last stage, mainly used for the separation of micron powder and nano powder in the last stage.

[0068] The powder in each stage of the fluidized bed 210 accumulates to a certain level and is discharged from the discharge port 212 . Powders of different particle sizes are obtained in each stage of the fluidized bed 210 .

[0069] The continuous grading and separation device for micro-nano composite powders in this embodiment can simultaneously realize integrated, automated, and continuous separation and grading. For micro-nano composite powders composed of nanopowders below 0.1 μm and micron powders of 1-200 μm, the processing efficiency can reach 1-50 kg / hour, the grading efficiency is greater than 85%, and the micro-nano separation efficiency is greater than 95%, which greatly improves the efficiency and production capacity of post-processing, and the efficiency is 3-10 times higher than that of batch operation.

[0070] Second embodiment

[0071] This embodiment provides a method for separation using the continuous fractionation and separation device for micro-nano composite powders described in Example 1:

[0072] Raw materials: Spherical tungsten powder (1-150 microns) obtained by plasma spheroidization. Fluidization experiments were conducted based on the desired particle size before implementation. The minimum fluidization velocity and carryout rate for tungsten powder with a particle size of 53 μm were 0.91 L / min and 4.8 L / min, respectively. For tungsten powder with a particle size of 15 μm, the minimum fluidization velocity and carryout rate were 0.27 L / min and 1.1 L / min, respectively.

[0073] Device parameters:

[0074] The first-stage fluidized bed 210 has a cone sidewall with an inclination angle of 20 degrees to the vertical direction, a height-to-diameter ratio of 15, a top diameter of 40 cm, and a distribution plate 214 with an opening rate of 1.5%.

[0075] The second-stage fluidized bed 210 has a cone sidewall with an inclination angle of 15 degrees to the vertical direction, a height-to-diameter ratio of 10, a top diameter of 40 cm, and a distribution plate 214 with an opening rate of 1%.

[0076] The inclination angle of the side wall of the cone portion of the third-stage fluidized bed 210 to the vertical direction is 10 degrees, the aspect ratio is 10, the opening rate of the distribution plate 214 is 1%, and the top diameter is 30 cm.

[0077] (1) 1-150 μm micro-nano composite tungsten powder is pumped into the first-stage fluidized bed 210 at a feed rate of 15 kg / h. The pump body 240 is turned on to allow water in the liquid storage device 250 to enter the fluidized bed 210 from the liquid inlet 251. The water flow rate is controlled to 1.8 L / min to fluidize the micro-nano composite powder. The vibrating rod of the ultrasonic vibration component 260 is placed in the water in the fluidized bed 210. The ultrasonic vibration component 260 is turned on and the power of the ultrasonic vibration rod is set to 4 kW. The micro-nano composite powder is clearly separated under the fluidization effect of the water flow and the stirring effect of the ultrasonic vibration. At this time, a large amount of separated nanopowder is carried out of the fluidized bed 210 by the liquid and enters the solid-liquid separation component 220, and then flows out with the liquid.

[0078] (2) The lower limit of the water turbidity of the water turbidity detection component 270 is set to 10NTU. When the water turbidity at the liquid phase outlet 222 of the first-stage solid-liquid separation component 220 detected by the water detection probe is lower than the lower limit set by the water turbidity detection component 270, the water turbidity detection component 270 emits a prompt sound. At this time, the fluid flow rate in the first-stage fluidized bed 210 is increased to 5L / min (slightly greater than the carry-out speed of powder with a particle size of 53 microns), so that powder with a particle size less than 53um is discharged from the fluidized bed 210 along with the water flow from the liquid outlet of the fluidized bed 210, and powder with a particle size greater than 53um will remain at the bottom of the fluidized bed 210. The liquid flowing out of the fluidized bed 210 enters the solid-liquid separation component 220 for solid-liquid separation. The solid powder in the solid-liquid separation module 220 enters the second-stage fluidized bed 210 through the solid discharge port 223. The nanopowder and water form a liquid phase and enter the nanofiltration module 230 through the liquid discharge port 222 of the solid-liquid separation module 220 for filtration and recovery. The liquid filtered by the nanofiltration module 230 enters the liquid storage device 250 for recycling, while the nanopowder remains in the nanofiltration module 230.

[0079] (3) The tungsten powder (<53 μm) in the first-stage solid-liquid separation component 220 is continuously discharged into the second-stage outflow bed, and the flow rate of the water in the fluidized bed 210 is controlled to 0.5 L / min, so that the powder is in a fluidized state. The vibration rod of the ultrasonic vibration component 260 is placed in the water in the fluidized bed 210, the ultrasonic vibration component 260 is turned on, and the power of the ultrasonic vibration rod is set to 3 kW. The micro-nano composite powder is further separated under the fluidization effect of the water flow and the stirring effect of the ultrasonic vibration. At this time, the separated nanopowder is carried out of the fluidized bed 210 by the liquid and enters the solid-liquid separation component 220, and then flows out with the liquid.

[0080] (4) The lower limit of the water turbidity of the water turbidity detection component 270 is set to 1NTU. When the water turbidity at the liquid phase outlet 222 of the second-stage solid-liquid separation component 220 detected by the water detection probe is lower than the lower limit set by the water turbidity detection component 270, the water turbidity detection component 270 emits a prompt sound. At this time, the flow rate in the second-stage fluidized bed 210 is increased to 1.3L / min (slightly greater than the carry-out speed of powder with a particle size of 15 microns), so that powder with a particle size of less than 15um is discharged from the fluidized bed 210 from the liquid outlet of the fluidized bed 210 along with the water flow, and powder with a particle size of 15-53um remains at the bottom of the fluidized bed 210. The liquid flowing out of the fluidized bed 210 enters the second-stage solid-liquid separation component 220 for solid-liquid separation. The solid powder in the solid-liquid separation module 220 enters the third-stage fluidized bed 210 through the solid discharge port 223 of the solid-liquid separation module 220. The nanopowder and water form a liquid phase and enter the nanofiltration module 230 through the liquid discharge port 222 of the solid-liquid separation module 220 for filtration and recovery. The liquid filtered by the nanofiltration module 230 enters the liquid storage device 250 for recycling, while the nanopowder remains in the nanofiltration module 230.

[0081] (5) The tungsten powder (<15um) in the second-stage solid-liquid separation component 220 is continuously discharged into the third-stage fluidized bed, and the fluid flow rate in the fluidized bed 210 is controlled to 0.4L / min so that the powder is in a fluidized state. The vibration rod of the ultrasonic vibration component 260 is placed in the water body in the fluidized bed 210, the ultrasonic vibration component 260 is turned on, and the power of the ultrasonic vibration rod is set to 3Kw. The micro-nano composite powder is further separated under the fluidization effect of the water flow and the stirring effect of the ultrasonic vibration. The lower limit of the water turbidity detection component 270 acting on the liquid outlet of the third-stage fluidized bed 210 is set to 1NTU. When the water turbidity detected by the water detection probe is lower than the lower limit set by the water turbidity detection component 270, the water turbidity detection component 270 emits a prompt sound. At this time, the separation and classification of all powders are completed.

[0082] (6) After the powder in each level of fluidized bed 210 accumulates to a certain extent, it is discharged from the discharge port 212 to obtain three powders with different particle sizes, which are dried in a N2 atmosphere at 80°C for 1 hour until they are completely dry.

[0083] After running for 2 hours, this embodiment processed a total of 30 kg of composite powder, of which:

[0084] The first-stage fluidized bed 210 obtained 5.6 kg of powder, of which 5.1 kg was powder larger than 53 μm and 0.5 kg was powder smaller than 53 μm after precise screening, with a classification efficiency of 91.1%.

[0085] The second-stage fluidized bed 210 obtained 11.2 kg of powder, of which powders with particle sizes of >53 um, 15-53 um, and <15 um were 0.3 kg, 11.2 kg, and 0.2 kg, respectively. The classification efficiency of the target product 15-53 um was 95.6%.

[0086] The third-stage fluidized bed 210 obtained 2.8 kg of powder, including 0.11 kg of powder >15 μm and 2.7 kg of target product <15 μm powder, with a classification efficiency of 96.4%.

[0087] The nanofiltration assembly 230 collected a total of 0.33 kg of powder. Observation showed that there was almost no nanopowder adhering to the surfaces of the three types of micron powders, indicating that the separation efficiency was greater than 98%.

[0088] Third embodiment

[0089] This embodiment provides a method for separation using the continuous fractionation and separation device for micro-nano composite powders described in Example 1:

[0090] Raw materials: Spherical niobium powder (3-100 microns) obtained by plasma spheroidization. Fluidization experiments were conducted based on the desired particle size. The minimum fluidization velocity and carryout rate for niobium powder with a cut-off particle size of 53 μm were 0.21 L / min and 1.9 L / min, respectively. For niobium powder with a cut-off particle size of 15 μm, the minimum fluidization velocity and carryout rate were 0.11 L / min and 0.39 L / min, respectively.

[0091] Device parameters:

[0092] The inclination angle of the cone side wall of the first-stage fluidized bed 210 to the vertical direction is 15 degrees, the aspect ratio is 15, the opening rate of the distribution plate 214 is 1%, and the top diameter of the fluidized bed 210 is 50 cm.

[0093] The inclination angle of the cone side wall of the second-stage fluidized bed 210 to the vertical direction is 15 degrees, the height-to-diameter ratio is 10, the opening rate of the distribution plate 214 is 1.2%, and the top diameter of the fluidized bed 210 is 60 cm.

[0094] The inclination angle of the cone side wall of the third-stage fluidized bed 210 to the vertical direction is 10 degrees, the aspect ratio is 5, the opening rate of the distribution plate 214 is 0.8%, and the top diameter of the fluidized bed 210 is 40 cm.

[0095] (1) 3-100 μm micro-nano composite niobium powder was pumped into the first-stage fluidized bed 210 at a feed rate of 25 kg / h. The pump body 240 was turned on to allow water in the liquid storage device 250 to enter the fluidized bed 210 through the liquid inlet 251. The water flow rate was controlled to 0.4 L / min to keep the micro-nano composite powder in a stable fluidized state. The vibrating rod of the ultrasonic vibration component 260 was placed in the water in the fluidized bed 210. The ultrasonic vibration component 260 was turned on and the power of the ultrasonic vibration rod was set to 5 kW. The micro-nano composite powder was clearly separated under the fluidization effect of the water flow and the stirring effect of the ultrasonic vibration. At this time, a large amount of separated nanopowder was carried out of the fluidized bed 210 by the liquid and entered the solid-liquid separation component 220, and then flowed out with the liquid.

[0096] (2) The lower limit of the water turbidity of the water turbidity detection component 270 is set to 5NTU. When the water turbidity at the liquid phase outlet 222 of the first-stage solid-liquid separation component 220 detected by the water detection probe is lower than the lower limit set by the water turbidity detection component 270, the water turbidity detection component 270 emits a prompt sound. At this time, the fluid flow rate in the first-stage fluidized bed 210 is increased to 2L / min (slightly greater than the carry-out speed of niobium powder with a particle size of 53 microns). At this time, powder with a particle size less than 53um is discharged from the fluidized bed 210 from the liquid outlet of the fluidized bed 210 along with the water flow, and powder with a particle size greater than 53um remains at the bottom of the fluidized bed 210. The liquid flowing out of the fluidized bed 210 enters the solid-liquid separation component 220 for solid-liquid separation. The solid powder in the solid-liquid separation module 220 enters the second-stage fluidized bed 210 through the solid discharge port 223. The nanopowder and water form a liquid phase and enter the nanofiltration module 230 through the liquid discharge port 222 of the solid-liquid separation module 220 for filtration and recovery. The liquid filtered by the nanofiltration module 230 enters the liquid storage device 250 for recycling, while the nanopowder remains in the nanofiltration module 230.

[0097] (3) The niobium powder (<53 μm) in the first-stage solid-liquid separator is continuously discharged into the second-stage effluent bed, and the flow rate of the water in the fluidized bed 210 is controlled to 0.15 L / min, so that the powder is in a fluidized state. The vibration rod of the ultrasonic vibration component 260 is placed in the water in the fluidized bed 210, and the ultrasonic vibration component 260 is turned on, and the power of the ultrasonic vibration rod is set to 3 kW. The micro-nano composite powder is further separated under the fluidization effect of the water flow and the stirring effect of the ultrasonic vibration. At this time, the separated nanopowder is carried out of the fluidized bed 210 by the liquid and enters the solid-liquid separation component 220, and then flows out with the liquid.

[0098] (4) The lower limit of the water turbidity of the water turbidity detection component 270 is set to 1NTU. When the water turbidity at the liquid phase outlet 222 of the second-stage solid-liquid separation component 220 detected by the water detection probe is lower than the lower limit set by the water turbidity detection component 270, the water turbidity detection component 270 emits a prompt sound. At this time, the fluid flow rate in the second-stage fluidized bed 210 is increased to 0.4L / min (slightly greater than the carry-out speed of powder with a particle size of 15 microns), so that powder with a particle size of less than 15um is discharged from the fluidized bed 210 from the liquid outlet of the fluidized bed 210 along with the water flow, and powder with a particle size of 15-53um remains at the bottom of the fluidized bed 210. The liquid flowing out of the fluidized bed 210 enters the second-stage solid-liquid separation component 220 for solid-liquid separation. The solid powder in the solid-liquid separation module 220 enters the third-stage fluidized bed 210 through the solid discharge port 223 of the solid-liquid separation module 220. The nanopowder and water form a liquid phase and enter the nanofiltration module 230 through the liquid discharge port 222 of the solid-liquid separation module 220 for filtration and recovery. The liquid filtered by the nanofiltration module 230 enters the liquid storage device 250 for recycling, while the nanopowder remains in the nanofiltration module 230.

[0099] (5) The niobium powder (<15um) in the second-stage solid-liquid separation component 220 is continuously discharged into the third-stage fluidized bed, and the fluid flow rate in the fluidized bed 210 is controlled to 0.15L / min so that the powder is in a fluidized state. The vibration rod of the ultrasonic vibration component 260 is placed in the water body in the fluidized bed 210, the ultrasonic vibration component 260 is turned on, and the power of the ultrasonic vibration rod is set to 3Kw. The micro-nano composite powder is further separated under the fluidization effect of the water flow and the stirring effect of the ultrasonic vibration. The lower limit of the water turbidity of the water turbidity detection component 270 acting at the liquid outlet of the third-stage fluidized bed 210 is set to 1NTU. When the water turbidity detected by the water detection probe is lower than the lower limit set by the water turbidity detection component 270, the water turbidity detection component 270 emits a prompt sound. At this time, the separation and classification of all powders are completed.

[0100] (6) After the powder in each level of fluidized bed 210 accumulates to a certain extent, it is discharged from the discharge port 212. The three powders with different particle sizes obtained are dried for 2 hours in a N2 atmosphere at 80°C until they are completely dry.

[0101] After running for 2 hours, this embodiment processed a total of 50 kg of composite powder, of which:

[0102] The first-stage fluidized bed 210 obtained 9.7 kg of powder, of which 9.0 kg was powder larger than 53 μm and 0.7 kg was powder smaller than 53 μm after precise screening, with a classification efficiency of 92.8%.

[0103] The second-stage fluidized bed 210 obtained 30.4 kg of powder, of which powders with particle sizes of >53 um, 15-53 um, and <15 um were 1.3 kg, 28.0 kg, and 1.1 kg, respectively. The classification efficiency of the target product 15-53 um was 92.1%.

[0104] The second-stage fluidized bed 210 obtained 8.3 kg of powder, including 0.41 kg of powder >15 μm and 7.8 kg of target product <15 μm powder, with a classification efficiency of 93.9%.

[0105] The nanofiltration assembly 230 collected a total of 1.14 kg of powder. Observation revealed that almost no nanopowder adhered to the surfaces of the three types of micron powders, indicating a separation efficiency greater than 98%.

[0106] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A device for continuous fractionation and separation of micro-nano composite powders, characterized in that: The invention comprises two or more fluidized beds, each of which is provided with a first liquid inlet at the bottom, a discharge port, a feed port and a liquid outlet being provided in sequence on the fluidized bed above the first liquid inlet, a distribution plate being provided on the first liquid inlet, and an ultrasonic vibration component being provided in the fluidized bed above the distribution plate; The two or more fluidized beds are arranged in series, and a solid-liquid separation component is provided between two adjacent fluidized beds. The solid-liquid separation component is provided with a second liquid inlet, a solid discharge port and a liquid phase discharge port. The second liquid inlet is connected to the liquid outlet of the fluidized bed on the liquid inlet side, the solid discharge port is connected to the first liquid inlet of the fluidized bed on the liquid outlet side, and the liquid phase discharge port is connected to a nanofiltration component through a return liquid pipe. The nanofiltration component is connected to a liquid storage device, and the liquid storage device is connected to the first liquid inlet of the fluidized bed.

2. The micro-nano composite powder continuous classification and separation device according to claim 1, characterized in that: The liquid phase discharge port of each solid-liquid separation component is connected to the inlet of the same nanofiltration component through a return pipe, and the liquid storage device is connected to the first liquid inlet corresponding to each fluidized bed through two or more infusion pipes, and each infusion pipe is provided with a pump body.

3. The continuous fractionation and separation device for micro-nano composite powders according to claim 2, characterized in that: Among the two or more fluidized beds arranged in series, the liquid outlet of the last fluidized bed along the material flow direction is connected to the inlet of the nanofiltration component through a liquid return pipe.

4. The continuous fractionation and separation device for micro-nano composite powders according to claim 2 or 3, characterized in that: Each of the liquid return pipes is provided with a turbidity detection component.

5. The continuous fractionation and separation device for micro-nano composite powders according to claim 1, characterized in that: The fluidized bed comprises a cone portion and a cylindrical portion located above the cone portion, the ratio of the height of the cone portion to the maximum diameter is 1-50, and the diameter of the cylindrical portion is 30 cm-60 cm.

6. The continuous fractionation and separation device for micro-nano composite powders according to claim 1, characterized in that: The angle between the side wall of the cone portion of the fluidized bed and the vertical direction is 5°-45°.

7. The continuous fractionation and separation device for micro-nano composite powders according to claim 1, characterized in that: The distribution plate is provided with through holes, and the opening rate of the distribution plate is 0.1%-5%.

8. The device for continuous fractionation and separation of micro-nano composite powders according to claim 1, characterized in that: The feed port is connected with a feeder.

9. The device for continuous fractionation and separation of micro-nano composite powders according to claim 1, characterized in that: There are 2 to 5 fluidized beds.

10. The device for continuous fractionation and separation of micro-nano composite powders according to claim 9, characterized in that: There are three fluidized beds, among which, The angle between the side wall of the cone portion of the first-stage fluidized bed and the vertical direction is 15°-20°, the ratio of the height of the cone portion to the maximum diameter is 13-17, and the opening rate of the distribution plate is 1%-1.5%; The angle between the side wall of the cone portion of the second-stage fluidized bed and the vertical direction is 13°-17°, the ratio of the height of the cone portion to the maximum diameter is 8-12, and the opening rate of the distribution plate is 1%-1.2%; The angle between the side wall of the cone portion of the third-stage fluidized bed and the vertical direction is 8°-12°, the ratio of the height of the cone portion to the maximum diameter is 5-10, and the opening rate of the distribution plate is 0.8%-1%.

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