A method and apparatus for measuring the level of a crucible

Abstract

The application relates to the technical field of nano metal production, and particularly discloses a method for measuring the liquid level height of a crucible and a device for measuring the liquid level height of the crucible. The method comprises the following steps: a cooling jacket is arranged outside the crucible, cooling water is introduced, and the crucible and the cooling jacket are weighed by a sensor after the water quantity is stabilized to obtain a weight value a; the equipment is operated, metal raw materials are evaporated and reduced, and a real-time weight value c is obtained; the residual liquid surface height of the crucible is calculated according to the formula: residual liquid surface height = ((c-a) / liquid metal density) / crucible bottom area, and the feeding time is determined according to the residual liquid surface height. The device for measuring the liquid level height of the crucible comprises a vacuum container, the vacuum container is provided with a crucible and a weighing sensor, and the crucible is arranged above the weighing sensor. The application has the effect of accurately determining the feeding time when metal powder is prepared.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of nanometer metal production, and in particular to a method for measuring the liquid level height of a crucible and a device for measuring the liquid level height of a crucible. BACKGROUND

[0002] The electric arc method is one of the commonly used methods for producing nanometer metal powder, and the core of the method is to melt and evaporate the metal raw material in the crucible by using the high temperature generated by the electric arc, and the metal vapor generated is condensed to form the required powder. When continuously producing in this high-temperature vacuum environment, the metal melt is continuously evaporated and consumed, and the liquid level gradually decreases, so the raw material needs to be replenished in time to ensure the continuity of the process and the quality of the powder.

[0003] Due to the extremely high temperature in the crucible and the evaporation of metal powder in the vacuum cavity, it is difficult to observe and judge the feeding time with the naked eye. Currently, the commonly used technologies include measuring the liquid level height by using ultrasonic or laser distance sensors, but the structure of the vacuum container, the possible inclination of the liquid surface, and the radiation and reflection interference generated by the high-temperature metal liquid surface will all affect the transmission, reception and analysis accuracy of the ultrasonic or laser signal, resulting in unreliable measurement results.

[0004] Therefore, there is an urgent need to develop a new method and device that can overcome the high temperature, vacuum and metal vapor interference, and realize relatively reliable and relatively accurate measurement of the relative height of the molten metal liquid level in the crucible, so as to accurately judge the feeding time and ensure the continuous and efficient operation of the nanometer metal powder production. SUMMARY

[0005] In order to accurately judge the feeding time when producing metal powder, the application provides a method for measuring the liquid level height of a crucible and a device for measuring the liquid level height of a crucible.

[0006] In a first aspect, the application provides a method for measuring the liquid level height of a crucible, which adopts the following technical solution:

[0007] A method for measuring the liquid level height of a crucible, comprising the following steps:

[0008] Q1, a cooling jacket is arranged outside the crucible, cooling water is introduced, and after the water quantity is stabilized, the crucible and the cooling jacket are weighed by a sensor to obtain a weight value a;

[0009] Q2, metal raw material is added to the crucible to obtain a weight value b;

[0010] Q3, the equipment is operated, the metal raw material is evaporated and reduced, and a real-time weight value c is obtained;

[0011] Q4, according to the formula, the remaining height of the liquid surface = ((c-a) ÷ liquid metal density) ÷ crucible bottom area, the remaining height of the liquid surface in the crucible is calculated;

[0012] Q5, judging the feeding time according to the remaining height of the liquid surface.

[0013] By adopting the technical scheme, the weight change of the metal raw material is obtained through the weight change difference of the equipment, so that the change height of the liquid surface is indirectly measured, the feeding time is judged, the problems of distance, angle and reflection which are dependent on the ultrasonic wave and laser measurement method are avoided, and the feeding time is accurately judged when the metal powder is made.

[0014] Optionally, in the Q1 step, the flow rate of the cooling water is 10-20 L / min.

[0015] Optionally, in the Q2 step, the total height of the liquid surface in the crucible after feeding = (b-a) ÷ liquid metal density ÷ crucible bottom area.

[0016] Optionally, the sensor is provided with a plurality of sensors, and the weight value a, the weight value b and the real-time weight value c are all the sum of the readings of the plurality of sensors.

[0017] By adopting the technical scheme, the plurality of sensors are used for weighing, and the accuracy of the data can be improved.

[0018] In a second aspect, the application provides a crucible liquid level height measuring device, which adopts the following technical scheme:

[0019] A crucible liquid level height measuring device, comprising a vacuum container, wherein the vacuum container is provided with a crucible and a weighing sensor, the crucible is placed above the weighing sensor, and a second cooling jacket is sleeved on the crucible.

[0020] Optionally, a first cooling jacket is sleeved on the weighing sensor, a first water inlet pipe is arranged on one side of the first cooling jacket, and a first water outlet pipe is arranged on the other side of the first cooling jacket.

[0021] By adopting the technical scheme, the weighing sensor is protected by water cooling, and the service life of the sensor is increased.

[0022] Optionally, a second water inlet pipe is arranged on one side of the second cooling jacket, and a second water outlet pipe is arranged on the other side of the second cooling jacket.

[0023] Optionally, a plurality of guide plates are arranged in the second cooling jacket, and the plurality of guide plates are arranged at intervals.

[0024] Optionally, a guide opening is arranged on each guide plate, and the guide openings on the adjacent two guide plates are located on opposite sides of the crucible.

[0025] By adopting the technical scheme, the cooling water flows fully in the second cooling jacket due to the arrangement of the guide plates, and the cooling effect on the crucible is improved.

[0026] Optionally, the surface roughness of the contact surface of the weighing sensor and the first cooling jacket is not greater than 0.025 μm, and the surface roughness of the contact surface of the first cooling jacket and the weighing sensor is not greater than 0.025 μm.

[0027] By adopting the above technical solution, the contact surfaces of the weighing sensor and the first cooling jacket are as smooth as possible, thereby reducing the friction between the weighing sensor and the first cooling jacket and reducing the influence of the friction on the reading of the weighing sensor.

[0028] In summary, the present application has at least one of the following beneficial technical effects:

[0029] 1. The weight change of the metal raw material is obtained by the difference in the weight change of the device, thereby indirectly measuring the change height of the liquid level, so as to determine the feeding time, and avoid the problems of distance, angle and reflection which are dependent on the ultrasonic and laser measurement methods, thereby realizing accurate determination of the feeding time when the metal powder is made;

[0030] 2. The weighing sensor is protected by water cooling, thereby prolonging the service life of the sensor;

[0031] 3. The flow guide plate is arranged to make the cooling water flow fully in the second cooling jacket, thereby improving the cooling effect on the crucible. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a structural schematic diagram of a crucible liquid level height measuring device in the embodiment of the present application.

[0033] Explanation of reference signs: 1, vacuum container; 2, crucible; 3, weighing sensor; 4, support shaft; 5, first cooling jacket; 6, support rod; 7, first water inlet pipe; 8, first water outlet pipe; 9, second cooling jacket; 10, second water inlet pipe; 11, second water outlet pipe; 12, electrically conductive pipe; 13, flow guide plate; 14, flow guide opening. DETAILED DESCRIPTION

[0034] The following will be described in detail in combination with the accompanying drawings. Figure 1 The present application will be further described in detail.

[0035] Embodiment 1

[0036] The embodiment of the present application discloses a crucible liquid level height measuring device.

[0037] Reference will be made to the drawings Figure 1The application discloses a kind of crucible liquid level height measuring device, including vacuum container 1 and crucible 2, vacuum container 1 is sealed inside and in vacuum state, crucible 2 is located in vacuum container 1.There is weighing sensor 3 in vacuum container 1, weighing sensor 3 is located at the bottom of vacuum container 1.Weighing sensor 3 includes support shaft 4, support shaft 4 is vertically arranged at the top of weighing sensor 3.The surface roughness of the side wall of support shaft 4 is not more than 0.025 μm.In the embodiment, the number of weighing sensor 3 is four, and the support shaft 4 is located at the four corners of the bottom of the crucible 2.

[0038] With reference to Figure 1 There is first cooling jacket 5 in vacuum container 1, first cooling jacket 5 is sleeved on four support shafts 4, for cooling weighing sensor 3.The bottom of first cooling jacket 5 is provided with four support rods 6, and the four support rods 6 are located at the four corners of first cooling jacket 5, and the four support rods 6 are fixedly connected with first cooling jacket 5.One end of the four support rods 6 is placed at the bottom of vacuum container 1.

[0039] With reference to Figure 1 One side of first cooling jacket 5 is provided with first water inlet pipe 7, and the other side of first cooling jacket 5 is provided with first water outlet pipe 8.One end of first water inlet pipe 7 penetrates the side wall of first cooling jacket 5, first water inlet pipe 7 is sealingly connected with first cooling jacket 5, and the inside of first water inlet pipe 7 is communicated with the inside of first cooling jacket 5.The end of first water inlet pipe 7 away from first cooling jacket 5 penetrates the bottom of vacuum container 1, and first water inlet pipe 7 is sealingly connected with vacuum container 1.One end of first water outlet pipe 8 penetrates the side wall of first cooling jacket 5, first water outlet pipe 8 is sealingly connected with first cooling jacket 5, and the inside of first water outlet pipe 8 is communicated with the inside of first cooling jacket 5.The end of first water outlet pipe 8 away from first cooling jacket 5 penetrates the bottom of vacuum container 1, and first water outlet pipe 8 is sealingly connected with vacuum container 1.

[0040] With reference to Figure 1The second cooling jacket 9 is arranged on the crucible 2, and the side wall and the bottom of the crucible 2 are wrapped by the second cooling jacket 9. One end of the supporting shaft 4 is in contact with the bottom of the second cooling jacket 9. One side of the second cooling jacket 9 is provided with a second water inlet pipe 10, and the other side of the second cooling jacket 9 is provided with a second water outlet pipe 11. One end of the second water inlet pipe 10 penetrates the side wall of the second cooling jacket 9, and the second water inlet pipe 10 is in sealed connection with the second cooling jacket 9. The inside of the second water inlet pipe 10 is in communication with the inside of the second cooling jacket 9. The end of the second water inlet pipe 10 away from the second cooling jacket 9 penetrates the bottom of the vacuum container 1, and the second water inlet pipe 10 is in sealed connection with the vacuum container 1. One end of the second water outlet pipe 11 penetrates the side wall of the second cooling jacket 9, and the second water outlet pipe 11 is in sealed connection with the second cooling jacket 9. The inside of the second water outlet pipe 11 is in communication with the inside of the second cooling jacket 9. The end of the second water outlet pipe 11 away from the second cooling jacket 9 penetrates the bottom of the vacuum container 1, and the second water outlet pipe 11 is in sealed connection with the vacuum container 1. The second water inlet pipe 10 and the second water outlet pipe 11 are flexible metal hoses.

[0041] With reference to Figure 1 One side of the second cooling jacket 9 is provided with a conductive pipe 12. In the embodiment, the conductive pipe 12 is located below the second water outlet pipe 11. One end of the conductive pipe 12 is fixedly connected with the conductive connection port of the second cooling jacket 9, and the other end of the conductive pipe 12 penetrates the bottom of the vacuum container 1, and the conductive pipe 12 is in sealed connection with the vacuum container 1. In the embodiment, the conductive pipe 12 is a braided soft copper bar.

[0042] With reference to Figure 1 A plurality of flow guide plates 13 are arranged in the second cooling jacket 9. The flow guide plates 13 are arranged around the crucible 2, and the two sides of the flow guide plates 13 are fixedly connected with the side wall of the second cooling jacket 9. The flow guide plates 13 are horizontally arranged, and the plurality of flow guide plates 13 are arranged in the vertical direction at equal intervals. The flow guide plates 13 are provided with flow guide ports 14. The flow guide ports 14 are openings in the vertical direction, and the flow guide ports 14 on the adjacent two flow guide plates 13 are located on the opposite sides of the crucible 2.

[0043] The application example discloses a crucible liquid level height measurement method.

[0044] Application example 1

[0045] The application example 1 is implemented in the crucible liquid level height measurement device disclosed in the embodiment, and includes the following steps.

[0046] S1, the first cooling jacket 5 is passed into cooling water through the first water inlet pipe 7, and the second cooling jacket 9 is passed into cooling water through the second water inlet pipe 10, the flow rate is kept at 10L / min, after the water amount in the first cooling jacket 5 and the second cooling jacket 9 is stable, the reading of the weighing sensor 3 is read, the sum of the readings of the four weighing sensors 3 is calculated, and is recorded as weight A, in the application example, weight A=20kg;

[0047] S2, the metal raw material is added into the crucible 2, in the application example, the metal raw material is blocky iron, the reading of the weighing sensor 3 is read, the sum of the readings of the four weighing sensors 3 is calculated, and is recorded as weight B, in the application example, weight B=45kg;

[0048] S3, the metal powder is made by the arc method, the metal raw material is melted into liquid state, then evaporates and reduces, the liquid surface height drops, the reading of the weighing sensor 3 is continuously read, the sum of the readings of the four weighing sensors 3 is calculated, and is recorded as real-time weight C;

[0049] S4, according to the formula, the remaining height of the liquid surface=total height-liquid surface drop height= ((C-A) ÷ liquid metal density) ÷ crucible bottom area, the remaining height of the liquid surface in the crucible 2 is calculated, when the remaining height of the liquid surface is close to 3cm, the metal raw material is started to be supplemented;

[0050] In the application example, the liquid density of the metal raw material is 7.138g / cm3, the radius of the crucible 2 is 15cm, when the real-time weight C is close to 3xpi x 15 2 x 7.138+20000=35129g≈35.2kg, the metal raw material is started to be supplemented.

[0051] Application example 2

[0052] The application example 2 is carried out in the crucible liquid level height measuring device disclosed in the embodiment, and includes the following steps:

[0053] S1, the first cooling jacket 5 is passed into cooling water through the first water inlet pipe 7, and the second cooling jacket 9 is passed into cooling water through the second water inlet pipe 10, the flow rate is kept at 20L / min, after the water amount in the first cooling jacket 5 and the second cooling jacket 9 is stable, the reading of the weighing sensor 3 is read, the sum of the readings of the four weighing sensors 3 is calculated, and is recorded as weight A, in the application example, weight A=25kg;

[0054] S2, the metal raw material is added into the crucible 2, in the application example, the metal raw material is blocky iron, the reading of the weighing sensor 3 is read, the sum of the readings of the four weighing sensors 3 is calculated, and is recorded as weight B, in the application example, weight B=45kg;

[0055] S3, the metal powder is made by arc method, the metal raw material is melted into liquid state, then evaporates and reduces, the liquid level drops, the weighing sensor 3 readings are continuously read, the sum of the readings of the four weighing sensors 3 is calculated, and is recorded as real-time weight C;

[0056] S4, according to the formula, the remaining height of the liquid level = total height - liquid level drop height = ((C-A) ÷ liquid metal density) ÷ crucible bottom area, the remaining height of the liquid level in the crucible 2 is calculated, when the remaining height of the liquid level is close to 3cm, the metal raw material is started to be replenished;

[0057] In the application example, the liquid density of the metal raw material is 7.138g / cm3, the radius of the crucible 2 is 12cm, when the real-time weight C is close to 3×π×12 2 ×7.138+25000=34683g≈34.6kg, the metal raw material is started to be replenished.

[0058] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, therefore: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for measuring the liquid level height in a crucible, characterized in that, Includes the following steps: Q1. Set a first cooling jacket outside the sensor and a second cooling jacket outside the crucible. Pass cooling water through the jacket. After the water flow stabilizes, weigh the crucible and the second cooling jacket through the sensor to obtain the weight value a. Q2. Add the metal raw material into the crucible to obtain the weight value b; Q3. When the equipment is working, the metal raw material evaporates and decreases, and the real-time weight value c is obtained. Q4. According to the formula, the remaining height of the liquid surface = (ca) ÷ density of liquid metal) ÷ ​​bottom area of ​​crucible, calculate the remaining height of the liquid surface in the crucible; Q5. Determine the timing of feeding based on the remaining liquid level.

2. The method for measuring the liquid level height in a crucible according to claim 1, characterized in that: In step Q1, the flow rate of cooling water is 10-20 L / min.

3. The method for measuring the liquid level height in a crucible according to claim 1, characterized in that: In step Q2, the total height of the liquid level in the crucible after feeding is equal to ((ba) ÷ liquid metal density) ÷ crucible bottom area.

4. The method for measuring the liquid level height in a crucible according to claim 1, characterized in that: The sensor is provided in multiple ways, and the weight value a, weight value b and real-time weight value c are all the sum of the readings of multiple sensors.

5. A crucible liquid level height measuring device, used in the crucible liquid level height measuring method according to any one of claims 1-4, characterized in that: It includes a vacuum container (1), a crucible (2) and a weighing sensor (3) are provided inside the vacuum container (1), the crucible (2) is placed above the weighing sensor (3), and a second cooling jacket (9) is fitted on the crucible (2).

6. The crucible liquid level measuring device according to claim 5, characterized in that: The weighing sensor (3) is fitted with a first cooling jacket (5), and a first water inlet pipe (7) is provided on one side of the first cooling jacket (5), and a first water outlet pipe (8) is provided on the other side of the first cooling jacket (5).

7. The crucible liquid level measuring device according to claim 5, characterized in that: The second cooling jacket (9) has a second water inlet pipe (10) on one side and a second water outlet pipe (11) on the other side.

8. The crucible liquid level height measuring device according to claim 5, characterized in that: The second cooling jacket (9) is provided with a plurality of guide plates (13), which are spaced apart.

9. The crucible liquid level measuring device according to claim 8, characterized in that: The guide plate (13) is provided with a guide port (14), and the guide ports (14) on two adjacent guide plates (13) are located on opposite sides of the crucible (2).

10. The crucible liquid level measuring device according to claim 5, characterized in that: The surface roughness of the contact surface between the weighing sensor (3) and the first cooling jacket (5) is not greater than 0.025 μm.

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