Hydrogen storage alloy powder preparation equipment and powder preparation method

Abstract

The invention provides hydrogen storage alloy pulverizing equipment which comprises a feeding system, a material grinding system and a discharging pipeline, the feeding system is fixed to the top face of a rack table top through a fixing support, the material grinding system comprises a material grinding rolling barrel, a shell and a material grinding motor, the material grinding rolling barrel is installed in the shell in a crossing mode, the shell is fixed to the top face of the rack table top, and the material grinding motor is arranged in the shell. A feeding port of the grinding roller is communicated with a feeding pipeline of the feeding system, and a discharging pipeline is arranged on the bottom surface of the table board of the rack and is communicated with the interior of the shell. The invention further provides a hydrogen storage alloy powder preparation method. The hydrogen storage alloy powder preparation equipment is simple in structure and convenient to use; according to the hydrogen storage alloy powder preparation method, the hydrogen storage alloy powder preparation equipment is adopted for powder preparation, the method is simple and controllable, the hydrogen absorption and hydrogen desorption principle of the hydrogen storage alloy is utilized, the activation speed of the hydrogen storage alloy can be increased, and therefore the activation performance of the hydrogen storage alloy powder is improved.

Description

Technical Field

[0001] The invention relates to a hydrogen storage alloy powder making device and a powder making method. Background Art

[0002] Hydrogen storage alloy powder is the main material for the negative electrode of nickel-hydrogen batteries. It is an intermetallic compound that can react with hydrogen at a certain temperature and pressure to generate metal hydrides and can reversibly release hydrogen. The existing production processes of hydrogen storage alloys mainly include vacuum induction melting ingot casting and vacuum induction melting belt throwing. Both methods use a melting furnace to melt different metals under vacuum conditions through induction heating, and then pour and cool to form ingots or throw them into sheets. Hydrogen storage alloys are used in nickel-hydrogen batteries and need to be prepared into powders of corresponding requirements. According to national standards, the powder particle size is divided into type A wet powder, type B wet powder and dry powder. The particle size D50 of type A wet powder is required to be 38±5μm, the particle size D50 of type B wet powder is required to be 54±5μm, and the particle size D50 of dry powder is required to be 65±10μm. In the prior art, impact mills, air flow mills, ball mills, etc. are generally used for powder making. However, the use of impact mills and air flow mills for powder making has the problem of over-grinding during the powder making process because the material cannot be taken out by the fan in time, which will produce a large amount of ultrafine powder, which cannot be used and will clog the filter. When a ball mill is used for powder making, the material will adhere to the ball during the collision between the ball and the material, which is easy to cause material loss. Summary of the invention

[0003] The present invention aims to provide a hydrogen storage alloy powder making device with a simple structure and easy use, and also provides a hydrogen storage alloy powder making method. The method adopts the hydrogen storage alloy powder making device of the present invention to make powder, and the particle size of the prepared hydrogen storage alloy powder is better controllable.

[0004] The present invention is achieved through the following solutions:

[0005] A hydrogen storage alloy powder making device, comprising a feeding system, an abrasive system and a discharge pipe, wherein the feeding system comprises a feeding pipe, a feeding motor and a spiral conveying rod, one end of the feeding pipe is mounted on a feeding pipe fixing plate, a feeding port is arranged on the top surface of the feeding pipe, the spiral conveying rod is arranged in the feeding pipe and one end of the spiral conveying rod passes through the feeding pipe fixing plate and is connected to the motor shaft of the feeding motor, the feeding motor is mounted on the motor fixing plate, the feeding pipe fixing plate and the motor fixing plate are both fixed on the top of the fixing bracket, and the fixing bracket is fixed on the top surface of the frame table; the abrasive system comprises an abrasive drum, a shell and an abrasive motor, the abrasive drum is a cylindrical structure with closed ends and hollow inside, the abrasive drum The outer surface of the abrasive drum is provided with a plurality of through holes, the outer surface of the abrasive drum is covered with a screen, one end of the abrasive drum is provided with a connecting shaft, the other end of the abrasive drum is provided with a feeding port, the abrasive drum is installed in the shell across, and the feeding port and the connecting shaft on the abrasive drum are exposed from the corresponding ends of the shell respectively, the abrasive drum can rotate in the shell, the shell is provided with an air inlet port and a vacuum port, the shell is fixed on the top surface of the frame table, the feeding port of the abrasive drum is connected with the feeding pipe of the feeding system, the motor shaft of the abrasive motor is connected with the connecting shaft of the abrasive drum, and the abrasive motor is fixed on one side of the frame; the discharging pipe is provided on the bottom surface of the frame table and the discharging pipe is connected with the inside of the shell. The mesh size of the screen can be selected according to the process requirements. The hydrogen storage alloy material can be a hydrogen storage alloy ingot or a hydrogen storage alloy sheet. The way of connecting the motor shaft of the abrasive motor and the connecting shaft of the abrasive drum can be selected according to needs, for example, using a transmission belt to connect, installing a driving wheel on the motor shaft of the abrasive motor, installing a driven wheel on the connecting shaft of the abrasive drum, and installing a transmission belt on the driving wheel and the transmission wheel, so that the abrasive motor drives the abrasive drum to rotate.

[0006] Furthermore, the top of the fixed support is a plane that is tilted downward at a certain angle from the end away from the abrasive system to the end close to the abrasive system, and the feed pipe is parallel to the top of the fixed support. This design allows the hydrogen storage alloy material to enter the abrasive drum more conveniently from the feed pipe, and the tilt angle of the top of the fixed support can be adjusted and designed as needed.

[0007] Furthermore, a valve is provided on the discharge pipe.

[0008] Furthermore, a pressure gauge is provided on the housing, and the pressure gauge is used to measure the gas pressure value in the housing.

[0009] A method for preparing powder of a hydrogen storage alloy, using the above-mentioned hydrogen storage alloy powder preparing equipment to prepare powder, the specific steps are as follows:

[0010] (1) The housing is evacuated through the vacuum port of the housing of the abrasive system until the gas pressure value in the housing measured by the pressure gauge drops to a first pressure value; the evacuation time is related to the size of the housing and the evacuation efficiency of the evacuation device, etc. The specific evacuation time can be specifically calculated. In addition, considering the production efficiency, the evacuation time is generally controlled to be 20 to 40 minutes;

[0011] (2) adding hydrogen storage alloy material into the feed pipe from the feed port of the feed pipe, and starting the feed motor at the same time, the feed motor drives the spiral conveying rod to rotate, so that the hydrogen storage alloy material enters the abrasive drum;

[0012] (3) Start the abrasive motor, which drives the abrasive drum to rotate;

[0013] (4) hydrogen or a mixture of hydrogen and nitrogen is filled into the housing through an air inlet port of the housing of the abrasive system until the pressure value of the gas in the housing measured by the pressure gauge reaches a second pressure value, and during the rotation of the abrasive drum, the hydrogen storage alloy material and the hydrogen undergo a hydrogen absorption reaction, and after a certain period of hydrogen absorption reaction, the housing is evacuated through a vacuum port of the housing, so that the hydrogen or the mixture of hydrogen and nitrogen in the housing is evacuated out of the housing, until the pressure value of the gas in the housing measured by the pressure gauge drops to the first pressure value, and the hydrogen release reaction is completed at this time;

[0014] (5) Repeat step (4) several times to grind the hydrogen storage alloy material into hydrogen storage alloy powder; the number of times step (4) is repeated can be determined by measuring the mesh size of the screen on the outer side of the abrasive drum and taking into account the production efficiency. According to calculations, if the mesh size of the screen is 100 meshes, generally, the number of times step (4) is repeated is set to 5 to 8 times so that more than 80% of the hydrogen storage alloy material can be ground to the particle size required by the process; if the mesh size of the screen is 200 meshes, generally, the number of times step (4) is repeated is set to 10 to 15 times so that more than 80% of the hydrogen storage alloy material can be ground to the particle size required by the process;

[0015] (6) The hydrogen storage alloy powder falls from the through hole of the abrasive drum through the screen into the outer shell, and then flows out from the outer shell through the discharge pipe to the receiving device. The valve on the discharge pipe is controlled in an interval opening manner. The interval opening time of the valve can be adjusted and designed according to needs. Generally, the interval opening time of the valve is set to 1 to 2 minutes. By controlling the valve in this way, the influence of the valve opening on the gas entering the outer shell and the gas pressure value in the outer shell during vacuuming can be minimized.

[0016] Before the hydrogen storage alloy powder making equipment is put into operation, the air inlet port and the vacuum port of the outer shell of the abrasive system are connected to the gas supply device and the vacuum device accordingly.

[0017] Furthermore, the first pressure value is controlled to be 5-10 Pa, and the second pressure value is controlled to be 5-10 MPa.

[0018] Furthermore, the time of the hydrogen absorption reaction is controlled to be 15 to 25 minutes.

[0019] The hydrogen storage alloy powder making equipment of the present invention has a simple structure and is easy to use. The hydrogen storage alloy powder making equipment of the present invention utilizes the principle of hydrogen storage alloy absorbing and releasing hydrogen, and can quickly complete the powder making of hydrogen storage alloy. The powder making method using the hydrogen storage alloy powder making equipment of the present invention is simple and controllable. During the powder making process, powder with a particle size that meets the process requirements can flow out through the through holes of the abrasive drum through the screen in time and fall into the outer shell and flow out to the discharge pipe, which can better control the particle size of the hydrogen storage alloy powder and greatly reduce the proportion of powder with too small particle size caused by repeated crushing during the powder making process. Moreover, after the entire process step is completed, the hydrogen storage alloy material that has not yet reached the grinding particle size process requirement can continue to stay in the abrasive drum and perform the powder making step together with the next batch of hydrogen storage alloy materials. Since this method utilizes the principle of hydrogen storage alloy absorbing and releasing hydrogen, it can increase the activation speed of the hydrogen storage alloy, thereby improving the activation performance of the hydrogen storage alloy powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the hydrogen storage alloy powder making equipment in Example 1;

[0021] Figure 2 It is a schematic diagram of the structure of the feeding system in Example 1;

[0022] Figure 3 Schematic diagram of the structure of the abrasive drum in Example 1. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with embodiments and drawings, but the present invention is not limited to the description of the embodiments.

[0024] Example 1

[0025] A hydrogen storage alloy powder making device, such as Figure 1 As shown, it includes a feeding system 1, an abrasive system 2 and a discharge pipe 3, as shown in FIG. Figure 2As shown, the feeding system 1 includes a feeding pipe 11, a feeding motor 12 and a spiral conveying rod 13. One end of the feeding pipe 11 is mounted on a feeding pipe fixing plate 14. A feeding port 15 is arranged on the top surface of the feeding pipe 11. The spiral conveying rod 13 is placed in the feeding pipe 11 and one end of the spiral conveying rod 13 passes through the feeding pipe fixing plate 14 and is connected to the motor shaft of the feeding motor 12. The feeding motor 12 is mounted on a motor fixing plate 16. The feeding pipe fixing plate 14 and the motor fixing plate 16 are both fixed on the top of a fixing bracket 17. The top of the fixing bracket 17 is a plane inclined downward at a certain angle from one end away from the abrasive system 2 to one end close to the abrasive system 2. The feeding pipe 11 is parallel to the top of the fixing bracket 17. The fixing bracket 17 is fixed on the top surface of the frame 4 table; the abrasive system 2 includes an abrasive drum 21, a housing 22 and an abrasive motor 23, as shown in FIG. Figure 3 As shown, the abrasive drum 21 is a cylindrical structure with closed ends and a hollow interior. A plurality of through holes (not shown in the figure) are provided on the outer surface of the abrasive drum 21. The outer surface of the abrasive drum 21 is covered with a screen 24. The mesh number of the screen in this embodiment 1 is 100 meshes. A connecting shaft 211 is provided at one end of the abrasive drum 21, and a feed port 212 is provided at the other end of the abrasive drum 21. The abrasive drum 21 is installed across the housing 22, and the feed port 212 and the connecting shaft 211 on the abrasive drum 21 are exposed from the corresponding ends of the housing 22 respectively. The abrasive drum 21 can rotate in the housing 22. The housing 22 is provided with an air inlet port (not shown in the figure), a vacuum port 221 and a pressure gauge 25. The outer shell 22 is fixed on the top surface of the frame 4, the feed port 212 of the abrasive drum 21 is connected to the feed pipe 11 of the feed system 1, and the motor shaft of the abrasive motor 23 is connected to the connecting shaft 211 of the abrasive drum 21 through a transmission belt (the transmission belt is not shown in the figure), that is, a driving wheel 26 is installed on the motor shaft of the abrasive motor 23, and a driven wheel 27 is installed on the connecting shaft 211 of the abrasive drum 21. The transmission belt is installed on the driving wheel 26 and the transmission wheel 27, so that the abrasive motor drives the abrasive drum to rotate; the abrasive motor 23 is fixed on one side of the frame 4; the discharge pipe 3 is arranged on the bottom surface of the frame 4 and the discharge pipe 3 is connected to the inside of the outer shell 33, and a valve 5 is arranged on the discharge pipe 4.

[0026] Example 2

[0027] A hydrogen storage alloy powder making device, whose structure is similar to that of the hydrogen storage alloy powder making device in Example 1, except that: the mesh size of the sieve coated on the outer surface of the abrasive drum is 200 meshes.

[0028] Example 3

[0029] A method for preparing hydrogen storage alloy powder, using the hydrogen storage alloy powder preparing device as described in Example 1 to prepare powder. Before the hydrogen storage alloy powder preparing device is put into operation, the air inlet port and the vacuum port of the housing of the abrasive system are connected to the gas supply device and the vacuum device accordingly. The specific steps are as follows:

[0030] (1) starting the vacuum pumping device, and evacuating the inside of the shell of the abrasive system through the vacuum pumping port of the shell for 20 minutes, so that the gas pressure value in the shell measured by the pressure gauge drops to a first pressure value, and the first pressure value is controlled to be 10 Pa, and then closing the vacuum pumping device;

[0031] (2) adding hydrogen storage alloy material into the feed pipe from the feed port of the feed pipe, and starting the feed motor at the same time, the feed motor drives the spiral conveying rod to rotate, so that the hydrogen storage alloy material enters the abrasive drum;

[0032] (3) Start the abrasive motor, which drives the abrasive drum to rotate;

[0033] (4) hydrogen is filled into the shell through the air inlet port of the shell of the abrasive system until the gas pressure value in the shell measured by the pressure gauge reaches a second pressure value, the second pressure value is controlled to be 10 MPa, and the hydrogen storage alloy material reacts with hydrogen during the rotation of the abrasive drum. After 25 minutes of hydrogen absorption reaction, the vacuum pumping device is started, and the shell is vacuumed for 20 minutes through the vacuum pumping port of the shell, so that the hydrogen in the shell is extracted from the shell, so that the gas pressure value in the shell measured by the pressure gauge is reduced to the first pressure value, the first pressure value is controlled to be 10 Pa, at this time, the hydrogen release reaction is completed, and the vacuum pumping device is closed;

[0034] (5) repeating step (4) 5 times, so that the hydrogen storage alloy material is ground into hydrogen storage alloy powder;

[0035] (6) The hydrogen storage alloy powder falls into the outer shell from the through hole of the abrasive drum through the screen, and then flows out from the outer shell through the discharge pipe to the receiving device. The valve on the discharge pipe is controlled to open at intervals, and the interval opening time of the valve is 1 minute.

[0036] Example 4

[0037] A method for preparing powder of a hydrogen storage alloy, using the hydrogen storage alloy powder preparing device as described in Example 1 to prepare powder, wherein the steps are substantially the same as those of the method for preparing powder of a hydrogen storage alloy in Example 3, except that:

[0038] 1. In step (1), the vacuuming time is controlled to be 25 min, and the first pressure value is controlled to be 7 Pa;

[0039] 2. In step (4), the second pressure value is controlled to be 6 MPa, the time of hydrogen absorption reaction is controlled to be 20 min; the time of vacuuming is controlled to be 25 min, and the first pressure value is controlled to be 7 Pa;

[0040] 3. In step (5), step (4) is repeated 8 times;

[0041] 4. In step (6), the interval opening time of the valve on the material pipeline is 2 minutes.

[0042] Example 5

[0043] A method for preparing powder of a hydrogen storage alloy, using the hydrogen storage alloy powder preparing device as described in Example 2 for preparing powder, wherein the steps are substantially the same as those of the method for preparing powder of a hydrogen storage alloy in Example 3, except that:

[0044] 1. In step (1), the vacuuming time is controlled to be 40 min, and the first pressure value is controlled to be 5 Pa;

[0045] 2. In step (4), the gas filled into the housing of the abrasive system is a mixture of hydrogen and nitrogen, and the second pressure value is controlled to be 5 MPa; the time of hydrogen absorption reaction is controlled to be 23 min; the time of vacuuming is controlled to be 40 min, and the first pressure value is controlled to be 5 Pa;

[0046] 3. In step (5), repeat step (4) 10 times.

[0047] Example 6

[0048] A method for preparing powder of a hydrogen storage alloy, using the hydrogen storage alloy powder preparing device as described in Example 2 for preparing powder, wherein the steps are substantially the same as those of the method for preparing powder of a hydrogen storage alloy in Example 3, except that:

[0049] 1. In step (1), the vacuuming time is controlled to be 30 min, and the first pressure value is controlled to be 8 Pa;

[0050] 2. In step (4), the gas filled into the housing of the abrasive system is a mixture of hydrogen and nitrogen, and the second pressure value is controlled to be 8 MPa; the time of hydrogen absorption reaction is controlled to be 15 min; the time of vacuuming is controlled to be 30 min, and the first pressure value is controlled to be 8 Pa;

[0051] 3. In step (5), step (4) is repeated 15 times.

[0052] The grinding rate of the hydrogen storage alloy materials of Examples 3 to 6 was calculated. The calculation formula of the grinding rate is: grinding rate = (weight of the collected hydrogen storage alloy powder / weight of the hydrogen storage alloy material) × 100%. The calculation results are shown in Table 1:

[0053] Table 1 Grinding rate of hydrogen storage alloy materials of Examples 3 to 6

[0054] Example Example 3 Example 4 Example 5 Example 6 Grinding rate 82.35％ 96.85％ 83.23％ 97.14％

[0055] It can be seen from Table 1 that the grinding rate of the hydrogen storage alloy materials of Examples 3 to 6 reaches more than 80%.

Claims

1. A hydrogen storage alloy powder making device, characterized in that: It includes a feeding system, an abrasive system and a discharge pipe, wherein the feeding system includes a feeding pipe, a feeding motor and a spiral conveying rod, one end of the feeding pipe is mounted on a feeding pipe fixing plate, a feeding port is arranged on the top surface of the feeding pipe, the spiral conveying rod is placed in the feeding pipe and one end of the spiral conveying rod passes through the feeding pipe fixing plate and is connected to the motor shaft of the feeding motor, the feeding motor is mounted on the motor fixing plate, the feeding pipe fixing plate and the motor fixing plate are both fixed on the top of the fixing bracket, and the fixing bracket is fixed on the top surface of the frame table; the abrasive system includes an abrasive drum, an outer shell and an abrasive motor, the abrasive drum is a cylindrical structure with closed ends and a hollow interior, and the outer surface of the abrasive drum is A plurality of through holes are provided, and a screen is covered on the outer side surface of the abrasive drum. A connecting shaft is provided at one end of the abrasive drum, and a feeding port is provided at the other end of the abrasive drum. The abrasive drum is installed across the shell, and the feeding port and the connecting shaft on the abrasive drum are respectively exposed from the corresponding ends of the shell. The abrasive drum can rotate in the shell, and an air inlet port and a vacuum port are provided on the shell. The shell is fixed on the top surface of the frame table, and the feeding port of the abrasive drum is connected with the feeding pipe of the feeding system, and the motor shaft of the abrasive motor is connected with the connecting shaft of the abrasive drum, and the abrasive motor is fixed on one side of the frame; the discharging pipe is provided on the bottom surface of the frame table, and the discharging pipe is connected with the inside of the shell.

2. The hydrogen storage alloy powder making equipment according to claim 1, characterized in that: The top of the fixed bracket is a plane inclined downward at a certain angle from an end away from the abrasive system to an end close to the abrasive system, and the feed pipe is parallel to the top of the fixed bracket.

3. The hydrogen storage alloy powder making equipment according to claim 1, characterized in that: The discharge pipe is provided with a valve.

4. The hydrogen storage alloy powder making equipment according to any one of claims 1 to 3, characterized in that: The shell is provided with a pressure gauge.

5. A method for preparing hydrogen storage alloy powder, characterized in that: The hydrogen storage alloy powder making device as claimed in any one of claims 1 to 4 is used for powder making, and the specific steps are as follows: (1) evacuating the inside of the housing through a vacuum port of the housing of the abrasive system until a pressure gauge measures that the gas pressure value inside the housing drops to a first pressure value; (2) adding hydrogen storage alloy material into the feed pipe from the feed port of the feed pipe, and starting the feed motor at the same time, the feed motor drives the spiral conveying rod to rotate, so that the hydrogen storage alloy material enters the abrasive drum; (3) Start the abrasive motor, which drives the abrasive drum to rotate; (4) hydrogen or a mixture of hydrogen and nitrogen is filled into the housing through an air inlet port of the housing of the abrasive system until the pressure value of the gas in the housing measured by the pressure gauge reaches a second pressure value, and during the rotation of the abrasive drum, the hydrogen storage alloy material and the hydrogen undergo a hydrogen absorption reaction, and after a certain period of hydrogen absorption reaction, the housing is evacuated through a vacuum port of the housing, so that the hydrogen or the mixture of hydrogen and nitrogen in the housing is evacuated out of the housing, until the pressure value of the gas in the housing measured by the pressure gauge drops to the first pressure value, and the hydrogen release reaction is completed at this time; (5) repeating step (4) several times to grind the hydrogen storage alloy material into hydrogen storage alloy powder; (6) The hydrogen storage alloy powder falls from the through hole of the abrasive drum through the screen into the outer shell, and then flows out from the outer shell through the discharge pipe to the receiving device.

6. The method for preparing hydrogen storage alloy powder according to claim 5, characterized in that: The first pressure value is controlled to be 5-10 Pa, and the second pressure value is controlled to be 5-10 MPa.

7. The method for preparing hydrogen storage alloy powder according to claim 5 or 6, characterized in that: The time of the hydrogen absorption reaction is controlled to be 15 to 25 minutes.

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