Jet mill equipment for preparing neodymium iron boron metal powder

Abstract

The invention relates to the technical field of neodymium iron boron powder preparation, in particular to jet mill equipment for preparing neodymium iron boron metal powder. According to the device, the pneumatic device provides pneumatic power, materials are fed from the feeder and then enter the grinding chamber to be ground into fine powder, the fine powder is discharged from the grinding discharging port, filtered through the grinding filtering device and enters the cyclone separator to be subjected to superfine powder separation, and the fine powder is collected into the discharging barrel; the powder which does not meet the collection standard is recycled through a filtering device; in the device, whether neodymium iron boron metal powder is left or not can be observed through a transparent protective cover of the grinding and filtering device, if yes, the device can be conveniently disassembled to take out the left neodymium iron boron metal powder, then the grinding and filtering device is installed, and therefore safe operation of the device is guaranteed.

Description

Technical Field

[0001] The invention discloses a jet milling device for preparing NdFeB metal powder. Background Art

[0002] Sintered NdFeB permanent magnet materials are widely used in permanent magnetic field devices and equipment such as electroacoustic and telecommunications, motors, instruments, nuclear magnetic resonance, magnetic levitation and magnetic sealing due to their excellent properties of high remanence, high coercive force and high magnetic energy product. They are particularly suitable for manufacturing various high-performance and complex-shaped products, and have become an indispensable key basic supporting material in many modern industrial technologies.

[0003] At present, when sintering NdFeB magnets, qualified NdFeB magnets are generally prepared through processes such as batching, smelting, hydrogen crushing of NdFeB castings, airflow grinding, pressing and sintering. Among them, in the process of airflow grinding, airflow grinding is a processing method that uses high-speed airflow to grind the surface of the material. It uses the high-speed rotating flow field generated by the airflow to make the material continuously rotate, collide and rub in the airflow to achieve the purpose of grinding, thereby producing fine powder. However, in the process of airflow grinding, the NdFeB metal powder remains in the pipeline after grinding, which affects the connection parts of the pipeline joints and has the risk of overpressure powder spraying ignition. In particular, the ultrafine powder produced (fine powder with particles below 2um) is easy to catch fire and must be safely recycled and disposed of. Summary of the invention

[0004] In order to overcome the above-mentioned shortcomings, the purpose of the present invention is to provide a jet mill equipment for preparing NdFeB metal powder. The air pressure device provides air pressure power. The material is put into the feeder and then enters the grinding chamber to be ground into fine powder. The fine powder comes out from the grinding outlet and is filtered by the grinding filter device, and enters the cyclone separator for ultrafine powder separation. The fine powder is collected in the discharge barrel, and the powder (ultrafine powder) that does not meet the collection standard is recovered through the filtering device.

[0005] The technical solution of the present invention to solve the technical problem is: A jet mill for preparing NdFeB metal powder, comprising a feeder for feeding, a grinder for grinding, a cyclone separator for separating ultrafine powder, a filter device for collecting ultrafine powder and a gas pressure device for providing nitrogen as a power pressure, which are connected in sequence; a discharge barrel for collecting fine powder is arranged directly below the cyclone separator; the feeder is connected to the grinder through a feeding pipe, and a feeding motor is connected to a spiral structure arranged in the feeding pipe; the grinder comprises a grinding chamber, a grinding discharge port is arranged on the side wall of the grinding chamber, the grinding discharge port is connected to one end of a separation tube through a grinding filter device, and the other end of the separation tube is connected to the cyclone separator, the grinding filter device comprises a filter rod, a filter housing and a protective cover, the two ends of the filter housing are respectively connected to the grinding discharge port and the separation tube, the filter rod is fixedly connected to the filter housing, the protective cover is composed of two transparent semicircular transparent plates that are mutually buckled, and the protective cover is detachably connected to the filter housing.

[0006] As an improvement of the present invention, a feeding port is provided on the top of the feeder, and the feeding port is connected to a feeding hose. A connecting head slot is provided at one end of the feeding hose. A high-pressure water hose is clamped on the connecting head slot and fixed by a first clamp. The other end of the feeding hose is sleeved with a manual butterfly valve, and the manual butterfly valve is connected to the connecting head slot of the feeding port by a second clamp.

[0007] As a further improvement of the present invention, an oxygen exhaust pressure reducing valve is provided at the oxygen exhaust interface of the feeding port.

[0008] As a further improvement of the present invention, the cyclone separator is connected to a pneumatic hammer base, and the pneumatic hammer is connected to the pneumatic hammer base.

[0009] As a further improvement of the present invention, a pneumatic pressure reducing valve is provided on the air supply pipe of the pneumatic hammer.

[0010] As a further improvement of the present invention, an audible and visual alarm device is provided at the bottom of the cyclone separator, and the audible and visual alarm device includes a power supply module, a radio frequency conductance material level switch, an electromagnetic relay, a power cord, and an audible and visual alarm. The power cord is electrically connected to the power supply module, and the power module supplies power to the radio frequency conductance material level switch. The output end of the radio frequency conductance material level switch is electrically connected to the electromagnetic relay, and the electromagnetic relay is electrically connected to the audible and visual alarm.

[0011] As a further improvement of the present invention, the sampler is connected to the bottom of the cyclone separator, the sound and light alarm device is located between the sampler and the cyclone separator, the upper end and the lower end of the sampler are respectively provided with a sampling inlet and a sampling outlet, the diameter of the middle part of the sampler is larger than the sampling inlet and the sampling outlet, an arc-shaped baffle is vertically connected to the inner wall of the sampler, and a sampling hole for a sampling spoon to pass through is provided on the arc-shaped baffle.

[0012] As a further improvement of the present invention, the sorting motor is connected to the sorting wheel arranged in the grinding chamber, the particle size of the fine powder ground in the grinding chamber is 2um~5um, and the separated ultrafine powder is particles below 2um.

[0013] As a further improvement of the present invention, the filtering device includes four filter barrels connected in parallel, the discharge ports of the filter barrels are connected to the discharge barrels, and the feed ports of the filter barrels are connected to the air pressure device.

[0014] As a further improvement of the present invention, the air pressure device includes a low-pressure tank, a compressor, a high-pressure tank and a cold dryer connected in sequence, and the cold dryer is connected to the side nozzle and the bottom nozzle of the grinding chamber.

[0015] In the present invention, the air pressure device provides air pressure power, the material is put into the feeder, and then enters the grinding chamber to be ground into fine powder, the fine powder comes out from the grinding outlet, is filtered by the grinding filter device, enters the cyclone separator for ultrafine powder separation, and the fine powder is collected in the discharge barrel, and the powder (ultrafine powder) that does not meet the collection standard is recovered by the filtering device; in the present invention, it can be observed through the transparent protective cover of the grinding filter device whether there is any residual NdFeB metal powder. If so, it can be easily disassembled to take out the residual NdFeB metal powder, and then the grinding filter device is installed, thereby ensuring the safe operation of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For ease of explanation, the present invention is described in detail with reference to the following preferred embodiments and the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the operation of the present invention; Figure 2 It is a partial schematic diagram of the present invention; Figure 3 is a schematic diagram of a grinding and filtering device of the present invention; Figure 4 It is a connection schematic diagram of the feeding port of the present invention; Figure 5 It is a connection diagram of the pneumatic hammer of the present invention; Figure 6 A schematic diagram of the arc-shaped baffle of the present invention being arranged in a sampler; Figure markings: 1-feeder, 11-feeding pipe, 12-feeding motor, 13-feeding port, 14-feeding hose, 15-high-pressure water hose, 16-first clamp, 17-manual butterfly valve, 18-second clamp, 19-oxygen exhaust pressure reducing valve, 2-grinder, 21-grinding chamber, 22-grinding discharge port, 23-grinding filter device, 24-filter rod, 25-filter housing, 26-protective cover, 27-side nozzle, 28-bottom nozzle, 3-cyclone separator, 31-pneumatic hammer base, 32-pneumatic hammer, 33-air supply pipe, 34-pneumatic pressure reducing valve, 35-sound and light alarm device, 36-sampler, 37-arc baffle, 4-filter device, 41-filter barrel, 5-air pressure device, 51-low-pressure tank, 52-compressor, 53-high-pressure tank, 54-cold dryer, 6-discharge barrel. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] like Figures 1 to 6 As shown, a jet mill device for preparing NdFeB metal powder of the present invention comprises a feeder 1 for feeding, a grinder 2 for grinding, a cyclone separator 3 for separating ultrafine powder, a filtering device 4 for collecting ultrafine powder and a gas pressure device 5 for providing nitrogen as a power pressure, which are connected in sequence, wherein a discharge barrel 6 for collecting fine powder is arranged directly below the cyclone separator 3.

[0021] In the present invention, the feeder 1 is connected to the grinder 2 through the feeding pipe 11, and the feeding motor 12 is connected to the spiral structure arranged in the feeding pipe 11. The feeding motor 12 works by controlling the weight. Further, when the grinding chamber 21 is lower than 69kg, the feeding motor 12 works, and when it is higher than 70kg, it stops.

[0022] In the present invention, the sorting motor is connected to the sorting wheel arranged in the grinding chamber 21, and the material is ground into fine powder in the grinding chamber 21. The fine powder of 2um~5um will be recovered by the discharge barrel 6, and the ultrafine powder below 2um will be recovered by the filtering device 4, and then other process treatments will be carried out.

[0023] In the present invention, the air pressure device 5 provides air pressure power, the material is fed from the feeder 1, and then enters the grinding chamber 21 to be ground into fine powder, the fine powder comes out from the grinding outlet 22, is filtered by the grinding filter device 23, enters the cyclone separator 3 for ultrafine powder separation, and the fine powder is collected in the discharge barrel 6, and the powder (ultra-fine powder) that does not meet the collection standard is recovered through the filter device 4.

[0024] In the present invention, the grinder 2 includes a grinding chamber 21, and a grinding discharge port 22 is arranged on the side wall of the grinding chamber 21. The grinding discharge port 22 is connected to one end of the separation tube through a grinding filter device 23, and the other end of the separation tube is connected to the cyclone separator 3, wherein the grinding filter device 23 includes a filter rod 24, a filter shell 25 and a protective cover 26, and the two ends of the filter shell 25 are respectively connected to the grinding discharge port 22 and the separation tube, the filter rod 24 is fixedly connected in the filter shell 25, and the protective cover 26 is composed of two transparent semicircular transparent plates that are buckled with each other, and the protective cover 26 is detachably connected to the filter shell.

[0025] Because the grinding chamber 21 is a concentrated collection area for fine powder, there is a large amount of ultra-fine NdFeB metal powder inside it. Due to the characteristics of NdFeB metal powder, the finer the powder, the easier it is to oxidize and catch fire. Therefore, if the operation is improper during maintenance / repair and disassembly, an explosion accident is very likely to occur; moreover, the outlet area of ​​the grinding chamber 21 generally uses a PVC steel wire hose or other soft connection, and the soft connection is usually fastened with a reinforced clamp. The powder-containing grinding gas causes great wear on the soft connection, so the soft connection needs to be replaced regularly and the disassembly frequency is relatively high.

[0026] In the present invention, it is possible to observe whether there is any residual NdFeB metal powder (such as ultrafine powder) through the transparent protective cover 26 of the grinding and filtering device 23. If there is, the residual NdFeB metal powder can be easily disassembled and taken out, and then the grinding and filtering device 23 can be installed, thereby ensuring the safe operation of the present invention, improving the rapid decomposition ability of the grinding and filtering device 23 when it is disassembled, and reducing the risk of explosion.

[0027] In the present invention, a feeding port 13 is provided on the top of the feeder 1, and the feeding port 13 is connected to a feeding hose 14, one end of the feeding hose 14 is provided with a connector slot, a high-pressure hose 15 is clamped on the connector slot and fixed by a first clamp 16, the other end of the feeding hose 14 is sleeved with a manual butterfly valve 17, and the manual butterfly valve 17 is connected to the connector slot of the feeding port 13 by a second clamp 18; an oxygen exhaust pressure reducing valve 19 is provided at the oxygen exhaust interface of the feeding port 13, specifically, a DN100 connector The joint slot is connected to the high-pressure resistant water hose, and then fixed with the first clamp to form a connecting feeding hose 14. One end of the feeding hose 14 is connected and assembled with the DN100 manual butterfly valve 17; the DN100 connector on the other side of the manual butterfly valve 17 is connected to the DN100 connector slot of the feeding port 13 with a clamp, and an oxygen exhaust pressure reducing valve 19 is added to the front section of the oxygen exhaust interface at the connection of the feeding port 13 to reduce the air pressure (100-200kpa is recommended). The principle is to reduce the pressure as much as possible to avoid the risk of powder leakage caused by high pressure.

[0028] In the present invention, a pneumatic hammer base 31 is connected to the cyclone separator 3, a pneumatic hammer 32 is connected to the pneumatic hammer base 31, and a pneumatic pressure reducing valve 34 is provided on the air supply pipe 33 of the pneumatic hammer 32. Specifically, the pneumatic hammer base 31 is welded to the outer metal pipe of the cyclone separator, the pneumatic hammer 32 is installed on the pneumatic hammer base 31, and a pneumatic pressure reducing valve 34 is added to the air supply pipe 33 of the pneumatic hammer 32 to control the pressure within a reasonable range (recommended 200-300kpa) to achieve normal use and control the purpose of knocking loss. In the present invention, an audible and visual alarm device 35 is provided at the bottom of the cyclone separator 3, and the audible and visual alarm device 35 includes a power module, a radio frequency admittance level switch, an electromagnetic relay, a power line, and an audible and visual alarm. The power line is electrically connected to the power module, and the power module supplies power to the radio frequency admittance level switch. The output end of the radio frequency admittance level switch is electrically connected to the electromagnetic relay, and the electromagnetic relay is electrically connected to the audible and visual alarm. Specifically, the DC24V power supply outputs voltage to the radio frequency admittance level switch, and the output end of the radio frequency admittance level switch is connected to the electromagnetic relay as a relay. The relay then controls the 220V AC power to connect the audible and visual alarm. When the radio frequency admittance level switch detects the material level, it will feedback a signal to the intermediate relay, and the intermediate relay will then connect the audible and visual alarm to trigger an alarm.

[0029] In the present invention, since powder material is prone to sticking and remaining in the cyclone separator 3, a pneumatic hammer 32 and a material level detection and alarm device are added to reduce the powder material sticking phenomenon and improve the ability to identify the residue inside the pipeline.

[0030] In the present invention, the sampler 36 is connected to the bottom of the cyclone separator 3, the sound and light alarm device 35 is located between the sampler 36 and the cyclone separator 3, the upper end and the lower end of the sampler 36 are respectively provided with a sampling inlet and a sampling outlet, the diameter of the middle part of the sampler 36 is larger than the sampling inlet and the sampling outlet, the arc baffle 37 is vertically connected to the inner wall of the sampler 36, and the arc baffle 37 is provided with a sampling hole for the sampling spoon to pass through; specifically, the arc baffle 37 is installed on the inner wall of the sampler 36, and the sampling spoon needs to pass through the arc baffle 37 to move, so the arc baffle 37 needs to cut a hole of about 20 mm at the moving trajectory of the sampling spoon to facilitate normal sampling operation.

[0031] In the present invention, the filtering device 4 includes four filter barrels 41 connected in parallel, the discharge port of the filter barrel 41 is connected to the discharge barrel 6, the feed port of the filter barrel 6 is connected to the air pressure device 5, the air pressure device 5 includes a low-pressure tank 51, a compressor 52, a high-pressure tank 53 and a cold dryer 54 connected in sequence, and the cold dryer 54 is connected to the side nozzle 27 and the bottom nozzle 28 of the grinding chamber 21; the function of the cold dryer 54 is to cool and dry the nitrogen, the low-pressure tank 51 is for nitrogen buffering to ensure pressure stability, and the compressor 52 is for compressing nitrogen.

[0032] The present invention provides an embodiment, which includes a feeder 1 for feeding, a grinder 2 for grinding, a cyclone separator 3 for separating fine powder, a filtering device 4 for collecting fine powder, and a gas pressure device 5 for providing nitrogen as a power pressure, which are connected in sequence. A discharge barrel 6 for collecting fine powder is arranged directly below the cyclone separator 3. The feeder 1 is connected to the grinder 2 through a feeding pipe 11. The feeding motor 12 is connected to a spiral structure arranged in the feeding pipe 11. The sorting motor is connected to a sorting wheel arranged in the grinding chamber 21. The gas pressure device 5 includes a low-pressure tank 51, a compressor 52, a high-pressure tank 53 and a cold dryer 54 connected in sequence. The top of the feeder 1 is provided with a feeding port 13, and the feeding port 13 is provided. The port 13 is connected to the feeding hose 14, one end of the feeding hose 14 is provided with a connector slot, the high-pressure water hose 15 is clamped on the connector slot and fixed by a first clamp 16, the other end of the feeding hose 14 is sleeved with a manual butterfly valve 17, and the manual butterfly valve 17 is connected to the connector slot of the feeding port 13 through a second clamp 18; an oxygen exhaust pressure reducing valve 19 is provided at the oxygen exhaust interface of the feeding port 13, the grinder 2 includes a grinding chamber 21, and a grinding discharge port 22 is provided on the side wall of the grinding chamber 21, the grinding discharge port 22 is connected to one end of the separation tube through a grinding filter device 23, and the other end of the separation tube is connected to the cyclone separator 3, the grinding filter device 23 includes a filter rod 24, a filter housing 25 and a protective The filter housing 25 is provided with a protective cover 26, and the two ends of the filter housing 25 are respectively connected to the grinding discharge port 22 and the separation tube. The filter rod 24 is fixedly connected to the filter housing 25. The protective cover 26 is composed of two transparent semicircular transparent plates that are buckled with each other. The protective cover 26 is detachably connected to the filter housing; the cyclone separator 3 is connected to a pneumatic hammer base 31, and a pneumatic hammer 32 is connected to the pneumatic hammer base 31. A pneumatic pressure reducing valve 34 is arranged on the air supply pipe 33 of the pneumatic hammer 32. An audible and visual alarm device 35 is arranged at the bottom of the cyclone separator 3. The audible and visual alarm device 35 includes a power module, a radio frequency admittance material level switch, an electromagnetic relay, a power line, and an audible and visual alarm. The power line is electrically connected to the power module, and the power module supplies the radio frequency admittance material The level switch is powered, the output end of the RF admittance level switch is electrically connected to the electromagnetic relay, and the electromagnetic relay is electrically connected to the sound and light alarm; the sampler 36 is connected to the bottom of the cyclone separator 3, and the sound and light alarm device 35 is located between the sampler 36 and the cyclone separator 3. The upper and lower ends of the sampler 36 are respectively provided with a sampling inlet and a sampling outlet, and the diameter of the middle part of the sampler 36 is larger than the sampling inlet and the sampling outlet. The arc baffle 37 is vertically connected to the inner wall of the sampler 36, and the arc baffle 37 is provided with a sampling hole for the sampling spoon to pass through; the filtering device 4 includes four filter barrels 41 connected in parallel, the discharge port of the filter barrel 41 is connected to the discharge barrel 6, and the feed port of the filter barrel 6 is connected to the low-pressure tank 51.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A jet mill for preparing NdFeB metal powder, characterized in that: It comprises a feeder for feeding, a grinder for grinding, a cyclone separator for separating ultrafine powder, a filtering device for collecting ultrafine powder and a pneumatic device for providing nitrogen as a power pressure, which are connected in sequence; a discharge barrel for collecting fine powder is arranged directly below the cyclone separator; the feeder is connected with the grinder through a feeding pipe, and the feeding motor is connected with a spiral structure arranged in the feeding pipe; the grinder comprises a grinding chamber, a grinding discharge port is arranged on the side wall of the grinding chamber, the grinding discharge port is connected with one end of a separation tube through a grinding filtering device, and the other end of the separation tube is connected with the cyclone separator, the grinding filtering device comprises a filter rod, a filter housing and a protective cover, the two ends of the filter housing are respectively connected with the grinding discharge port and the separation tube, the filter rod is fixedly connected in the filter housing, the protective cover is composed of two transparent semicircular transparent plates that are buckled with each other, and the protective cover is detachably connected to the filter housing.

2. A jet mill for preparing NdFeB metal powder according to claim 1, characterized in that: A feeding port is provided on the top of the feeder, which is connected to a feeding hose. A connector slot is provided at one end of the feeding hose. A high-pressure water hose is clamped on the connector slot and fixed by a first clamp. The other end of the feeding hose is sleeved with a manual butterfly valve, and the manual butterfly valve is connected to the connector slot of the feeding port by a second clamp.

3. The jet mill for preparing NdFeB metal powder according to claim 2, characterized in that: An oxygen exhaust pressure reducing valve is arranged at the oxygen exhaust interface of the feeding port.

4. The jet mill for preparing NdFeB metal powder according to claim 1, characterized in that: The cyclone separator is connected with a pneumatic hammer base, and the pneumatic hammer is connected to the pneumatic hammer base.

5. The jet mill for preparing NdFeB metal powder according to claim 4, characterized in that: A pneumatic pressure reducing valve is arranged on the air supply pipe of the pneumatic hammer.

6. The jet mill for preparing NdFeB metal powder according to claim 1, characterized in that: An audible and visual alarm device is provided at the bottom of the cyclone separator, and the audible and visual alarm device includes a power supply module, a radio frequency admittance level switch, an electromagnetic relay, a power cord, and an audible and visual alarm. The power cord is electrically connected to the power supply module, and the power module supplies power to the radio frequency admittance level switch. The output end of the radio frequency admittance level switch is electrically connected to the electromagnetic relay, and the electromagnetic relay is electrically connected to the audible and visual alarm.

7. The jet mill for preparing NdFeB metal powder according to claim 6, characterized in that: The sampler is connected to the bottom of the cyclone separator, the sound and light alarm device is located between the sampler and the cyclone separator, the upper end and the lower end of the sampler are respectively provided with a sampling inlet and a sampling outlet, the diameter of the middle part of the sampler is larger than the sampling inlet and the sampling outlet, an arc-shaped baffle is vertically connected to the inner wall of the sampler, and a sampling hole for a sampling spoon to pass through is provided on the arc-shaped baffle.

8. The jet mill for preparing NdFeB metal powder according to claim 1, characterized in that: The sorting motor is connected to the sorting wheel arranged in the grinding chamber. The particle size of the fine powder ground in the grinding chamber is 2um~5um, and the ultrafine powder separated is less than 2um.

9. The jet mill for preparing NdFeB metal powder according to claim 1, characterized in that: The filtering device comprises four filter barrels connected in parallel, the discharge ports of the filter barrels are connected to the discharge barrels, and the feed ports of the filter barrels are connected to the air pressure device.

10. The jet mill equipment for preparing NdFeB metal powder according to claim 1, characterized in that: The air pressure device comprises a low-pressure tank, a compressor, a high-pressure tank and a cold dryer which are connected in sequence, and the cold dryer is communicated with the side nozzle and the bottom nozzle of the grinding chamber.

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