CN211386912U - Laser evaporation multi-cavity nano powder preparation device - Google Patents

Abstract

The utility model relates to the technical field of nano-powder preparation, in particular to a laser evaporation multi-cavity nano-powder preparation device. At least two main chamber powder generating units are arranged; each main chamber powder generating unit is respectively connected to the vacuum main pipeline through its own vacuum branch pipeline, and the vacuum main pipeline is connected to the vacuum pump group system; each main chamber powder generating unit is respectively The main chamber powder generation units are connected to the main air intake pipe through their respective exhaust branch pipes, and each main chamber powder generation unit is connected to the main air intake pipe through their respective intake branch pipes; And the respective feeding control signal lines are connected to the laser generator and the control system. The utility model avoids mutual pollution in the powder preparation process, improves the purity of the powder, realizes the simultaneous preparation of a variety of powders with different components, realizes continuous production, greatly improves the production efficiency and reduces the cost.

Description

Laser evaporation multi-cavity nano-powder preparation device

technical field

The utility model relates to the technical field of nano-powder preparation, in particular to a laser evaporation multi-cavity nano-powder preparation device.

Background technique

Laser is an effective heat source for the preparation of nanoparticles. At present, this method has been used to initially achieve mass production. For example, Chinese patent application: A multi-source DC arc automated nano-powder production system and method (201410189518.4), but for large-scale industrialization There are still many technical problems in production, mainly in how to prepare nano-powders with high efficiency, low cost, high purity, no pollution and continuous production.

The existing nano-powder preparation equipment is mainly aimed at the generation, classification, capture and processing of nano-powder in a single cavity, that is, a single generation chamber. This single-cavity powder preparation equipment has the following defects:

1. Low production efficiency and high cost

At present, the single-chamber powder preparation equipment and process spend most of the time in the process of vacuum extraction, powder generation and processing, and vacuum maintenance during the cycle of vacuum extraction, vacuum maintenance and circulation. It takes 3 to 4 hours to vacuum the equipment, while the powder preparation time is less than 0.5 hours. The time for vacuum extraction and vacuum holding accounts for 50%-70%, while the actual powder production time is 15-20%. In other words, the production efficiency is low, and at the same time, due to the vacuum extraction and vacuum maintenance and repeated repetition of this process, a large amount of energy will be consumed, which will greatly increase the cost.

2. Low purity and cross contamination

Single-chamber powder preparation equipment and process, after the preparation of nano-powder of one material, if powder of other materials is prepared, there will be powder residues in copper crucibles, equipment connections and other places that cannot be removed, resulting in When preparing the next powder, there is mutual contamination between at least two powders, thereby reducing the purity of the nano-powder.

3. Unable to achieve continuous production in the true sense

The current single-chamber powder preparation equipment and process is limited by the size of the anode material, and there is a problem of insufficient continuity in the continuous feeding and supply of materials. At the same time, since the powder collection process requires repeated de-vacuuming and vacuuming processes, the operation time is relatively high. This method cannot achieve continuous production under the premise of ensuring product quality in large-scale industrial production. In the near future phase out.

Utility model content

The purpose of the present invention is to provide a continuous production method for multi-cavity metal nano-powders by laser evaporation, so as to solve the problems raised in the above background technology.

To achieve the above object, the utility model provides the following technical solutions:

The laser evaporation multi-cavity nano-powder preparation device is characterized in that at least two main-chamber powder generating units are arranged;

The powder generating units of each main chamber are respectively connected to the vacuum main pipeline through their respective vacuum branch pipelines, and the vacuum main pipeline is connected to the vacuum pump group system;

Each main chamber powder generating unit is connected to the exhaust main pipeline through respective exhaust branch pipes, and each main chamber powder generating unit is respectively connected to the intake main pipeline through respective intake branch pipes;

Each main chamber powder generating unit is connected to the laser generator and the control system through respective laser control signal lines and respective feed control signal lines;

The main chamber powder generating unit includes a main chamber and a laser device, the top of the main chamber is provided with a laser device, and the bottom of the main chamber is provided with a collection chamber;

An anode is set directly under the cathode, and a single metal or metal alloy target of the same composition or different composition is installed on the target holder of each independent cavity as the anode, and an automatic feeding device is arranged at the rear end of the anode to control the feeding of the anode. A cooling water device is arranged at the front end of the anode to cool the anode, and a gallium arsenide glass with a thickness of 3-5mm is sealed and installed at the opening on the inner wall of the cavity above the target.

The automatic feeding device is composed of a sealing rubber ring, a propelling screw, a servo motor and a transmission device. The cylindrical raw material rod with a conical protruding head and a conical pit at the tail is pushed into the main chamber gradually by the screw at a speed of 2mm/min. The servo motor is connected to the transmission device to provide the propulsion force of the propulsion screw. The raw material rod and the main chamber wall are sealed with a sealing rubber ring to ensure the vacuum degree inside the chamber.

Each of the vacuum branch pipes is respectively provided with a vacuum valve, each of the exhaust branch pipes is respectively provided with an exhaust valve, and each of the intake branch pipes is respectively provided with an intake valve. Each vacuum valve, exhaust valve and intake valve control the vacuum extraction, exhaust and intake of the respective main chambers respectively, so as to realize the separate control of the vacuum, exhaust and intake of each main chamber. The vacuum extraction, exhaust and intake of each main chamber are controlled by separate vacuum valve, exhaust valve and intake valve respectively. The main chambers are connected in parallel, and the components are individually controlled.

The front end of the anode is provided with a cooling water device. The cooling water device includes a support base, a cooling water pipe, and a cooling tank. The cooling tank is distributed inside the support base. The cooling water pipe is connected to the support base. The cooling water enters the cooling tank through the cooling water pipe. circulating flow. The circulating water is led out to the cooling system by the cooling water pipe, and the internal hollow structure design can realize the circulating flow of the internal circulating water. The switching of the cooling system is controlled by the condenser. The condensing system must be turned on before the equipment can be operated.

The main chamber is arranged as a cooling wall for cooling water circulation. The hollow cooling wall can significantly increase the cooling area, so as to achieve a better cooling effect on the overall cooling of the cavity and prolong the continuous working time of the equipment.

The upper end of the collection chamber is connected with the main chamber through a butterfly valve, the other end of the collection chamber is connected with a transition bin, and an observation window and collection gloves are also arranged on the collection chamber. After milling, open the butterfly valve to make the nano-powder fall into the collection chamber, use the collection gloves to collect the powder and put it into the transition bin. After taking out the powder, the transition bin is evacuated. The function of the transition chamber is to ensure the vacuum state of the main chamber and the collection chamber during the powder extraction process.

Compared with the prior art, the beneficial effects of the present utility model are:

1. The production efficiency is greatly improved and the cost is reduced

Multiple chambers use the same vacuum system at the same time. For a single chamber, the vacuum system does not need to be turned on and off repeatedly, which greatly reduces the time of vacuum pumping in production. In addition, the separate series connection of a single cavity can realize the overhaul and maintenance of a single equipment, and avoid large-scale production shutdown due to equipment damage. Production efficiency is increased by at least 30%, and production costs are reduced by at least 20%.

2. Realize continuous production

This multi-cavity continuous production process can achieve the production effect of continuous switching between different cavities and continuous evaporation of nano-powders in the industry, avoiding equipment shutdown due to damage and maintenance of a single cavity equipment. The production line-type equipment connection method can realize continuous production under the premise that the vacuum system can meet the continuous operation.

3. Simultaneous preparation of a variety of powders with different components

Multiple different independent cavities are independent of each other, and nano-powders with different compositions can be evaporated in different cavities, realizing the simultaneous preparation of different powders on one device.

4. Avoid mutual contamination in the powder preparation process and improve the purity of the powder

During the cleaning process of a single cavity equipment, it is not possible to efficiently clean the hidden places such as device connection ports and valves. Therefore, using a single cavity to prepare different types of powder will lead to cross-contamination of the powder and reduce the purity. In each independent cavity of this equipment, nano-powders of the same composition can be prepared, which prevents mutual contamination caused by preparing different powders in one cavity, and can improve the purity of the powders to 99.9%.

Description of drawings

Figure 1 is a schematic structural diagram of a laser evaporation multi-cavity nano-powder preparation device.

FIG. 2 is a schematic structural diagram of a powder generating unit in the main chamber in FIG. 1 .

In the picture: 1. Control system, 2. Exhaust main pipe, 3. Intake main pipe, 4. Exhaust branch pipe, 5. Exhaust valve, 6. Laser device, 7. Intake branch pipe, 8. Inlet Air valve, 9. Main chamber, 10. Automatic feeding device, 11. Vacuum valve, 12. Transition chamber, 13. Vacuum main pipeline, 14. Vacuum branch pipeline, 15. Laser control signal line, 16. Feeding control signal line, 17. Vacuum pump system, 18, Collection chamber, 19, Air outlet, 20, Cooling wall, 21, Crucible, 22, Support base, 23, Cooling water pipe, 24, Cooling tank, 25, Air inlet, 26, Cathode , 27, exhaust port, 28, butterfly valve, 29, observation window, 30, collection gloves, 31, anode, 32, gallium arsenide glass.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Example 1

As shown in Figure 1-2, the laser evaporation multi-chamber nano-powder preparation device is provided with at least two main chamber powder generation units; each main chamber powder generation unit is connected to the vacuum main chamber through its own vacuum branch pipes 14 Pipe 13, the main vacuum pipe is connected to the vacuum pump system 17; each main chamber powder generating unit is connected to the exhaust main pipe 2 through their respective exhaust branch pipes 4, and each main chamber powder generating unit is respectively through its respective intake air The branch pipe 7 is connected to the main intake pipe 3; each main chamber powder generating unit is connected to the control system 1 through respective feeding control signal lines; the main chamber powder generating unit includes a main chamber 9, a laser device 6 , a laser device is arranged at the top of the main chamber, a collection chamber 18 is arranged at the bottom of the main chamber; an anode 31 is arranged at the opposite position below the cathode, and a single component of the same composition or a different composition is installed on the target holder of each independent cavity. The metal or metal alloy target is the anode, the rear end of the anode is provided with an automatic feeding device 10 to control the feeding of the anode, the front end of the anode is provided with a cooling water device to cool the anode, and the thickness of the sealing installation at the opening on the inner wall of the cavity above the target is 3-5mm GaAs glass.

The automatic feeding device is composed of a sealing rubber ring, a propelling screw, a servo motor and a transmission device. The cylindrical raw material rod with a conical protruding head and a conical pit at the tail is pushed into the main chamber gradually by the screw at a speed of 2mm/min. The servo motor is connected with the transmission device to provide the propulsion force of the propulsion screw. The raw material rod and the main chamber wall are sealed with a sealing rubber ring to ensure the vacuum degree inside the chamber.

Each of the vacuum branch pipes is respectively provided with a vacuum valve 11 , each of the exhaust branch pipes is respectively provided with an exhaust valve 5 , and each of the intake branch pipes is respectively provided with an intake valve 8 . Each vacuum valve 11, exhaust valve 5 and intake valve 8 respectively control the vacuum extraction, exhaust and intake of the respective main chambers, so as to realize separate control of the vacuum, exhaust and intake of each main chamber. The vacuum extraction, exhaust and intake of each main chamber are controlled by separate vacuum valve 11, exhaust valve 5 and intake valve 8, respectively. The main chambers are connected in parallel, and the components are individually controlled.

The front end of the anode is provided with a cooling water device. The cooling water device includes a support base 22, a cooling water pipe 23, and a cooling tank 24. The cooling tank 24 is distributed inside the support base 22, and the cooling water pipe 23 is connected to the support base 22 for cooling. The water enters the cooling tank 24 through the cooling water pipe 23 and circulates. The circulating water is led out to the cooling system by the cooling water pipe 23, and the internal hollow structure design can realize the circulating flow of the internal circulating water. The switching of the cooling system is controlled by the condenser. The condensing system must be turned on before the equipment can be operated.

The main chamber is provided as a cooling wall 20 for cooling water circulation. The hollow cooling wall 20 can significantly increase the cooling area, so as to achieve a better cooling effect for the overall cooling of the cavity and prolong the continuous working time of the equipment.

The upper end of the collection chamber is connected with the main chamber through a butterfly valve 28 , the other end of the collection chamber is connected with a transition chamber, and an observation window and a collection glove 30 are also provided on the collection chamber. After the milling is completed, the butterfly valve 28 is opened to make the nano powder fall into the collection chamber, the powder is collected by the collection gloves 30 and then loaded into the transition bin, and the transition bin is evacuated after taking out the powder. The function of the transition chamber is to ensure the vacuum state of the main chamber and the collection chamber during the powder extraction process.

Example 2

Utilizing the device described in Embodiment 1 to realize the continuous production method of laser-evaporated multi-cavity metal nano-powders, the method includes the following steps:

(1) Place the target material: install a single metal or metal alloy target material of the same composition or different composition on the target material holder of each independent cavity as the anode, use the metal with a melting point higher than 3000 ℃ as the cathode, and the target material The opening on the inner wall of the upper cavity is sealed and installed with a thickness of 3-5mm gallium arsenide glass, and the gallium arsenide glass is cooled;

(2) Vacuuming: close the doors of each independent cavity, open the vacuum valve of each independent cavity, use a mechanical pump to evacuate all the cavities not higher than 10 ^-1 Pa, and then use a molecular pump to evacuate Above 10 ^-4 Pa, close the vacuum valve of each independent chamber;

(3) Filling with working gas: Open the inlet valve of each independent cavity, and enter the mixed gas of argon and hydrogen as working gas, the pressure of argon is 0.1 atmosphere, and the pressure of hydrogen is 0.2-0.3 atmosphere;

(4) Introducing the laser: Introduce the external laser light source into the cavity through the gallium arsenide glass, adjust the laser power to 300-400W and align the target material;

(5) Laser evaporation: increase the laser power to the target melting power: magnesium, aluminum, calcium, zinc 500-1500W, iron, cobalt, nickel 1500-2500W, molybdenum, niobium, tantalum 2500-3500W, by adjusting the laser power control, to change the evaporation efficiency of the anode η=P/P0, the range of η varies between 0.1-0.8 according to different metals: magnesium, aluminum, calcium, zinc 0.6-0.8, iron, cobalt, nickel 0.4- 0.6, molybdenum, niobium, tantalum 0.1-0.4;

(6) Forming powder: By controlling the flow of cooling water or placing a liquid nitrogen cooling tube in the cavity, the temperature gradient in the cavity is changed. The temperature between the laser and the target surface is 3000-5000K, and the cavity wall The temperature is 300K, the temperature gradient is 7000-14000K/m, the diameter of the nanoparticles is different under different temperature gradients, 7000-9000K/m, the particle size is 90-120nm, 9000-11000K/m, the particle size is 60-90nm, 110000-14000K/m, particle size is 30-60nm;

(7) Collection of metal nano-powders: The specific steps of collection of metal nano-powders are collection of passivated metal nano-powders: when any one of the anode targets is consumed, close the laser light source corresponding to the cavity, open the air valve, and send the Fill the cavity with 2%-5% air, then close the vent valve and let it stand for 4-6 hours, a 2-5nm thick oxide protective layer is formed on the metal/carbon surface, after passivation, open the vent valve to charge Enter the air to one atmospheric pressure, open the chamber door, and take out the powder;

(8) Change the target material: clean the cavity where the powder has been taken out, put the single metal or metal alloy target with the same composition as the target material put into the cavity as the anode, and close the cavity Body door, open the vacuum valve of the cavity, vacuum the cavity to a degree of vacuum not higher than 10 ^-4 Pa, close the vacuum valve of the cavity, open the air inlet valve of the cavity, and introduce argon gas The mixed gas with hydrogen is the working gas;

(9), continuous production: repeat the above-mentioned process steps (4)-(8) to realize continuous production.

Example 3

The steps of using the device described in Example 1 to realize the continuous production method of multi-cavity carbon nanopowder by laser evaporation are the same as those in Example 1, with the following differences:

In the step (1), the anode target material is a mixture of different types of carbon and catalyst, the carbon material is graphite, carbon black or activated carbon, the catalyst is a transition metal or yttrium oxide, and when the catalyst is a transition metal, the obtained carbon nanotubes are: Multi-walled carbon nanotubes, when the catalyst is yttrium oxide, the obtained carbon nanotubes are single-walled carbon nanotubes, and the atomic ratio of carbon atoms to metal atoms in the carbon material and catalyst mixture is 80-100;

In the step (7), the specific step of collecting carbon nano-powder is in-situ carbon nano-powder collection: when any one of the anode targets is consumed, close the arc in the cavity, fill with argon gas to an atmospheric pressure, and open the cavity The valve between the body and the processing chamber, the nano powder naturally settles into the collection tank of the processing chamber, and the sealed package can be taken out.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention may be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments are to be considered in all respects as exemplary and not restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description, and it is therefore intended that the All changes within the meaning and range of the required equivalents are embraced within the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described in terms of embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (5)

1. The laser evaporation multi-cavity nano powder preparation device is characterized in that at least two main cavity powder generation units are arranged;

each main chamber powder generating unit is respectively connected to a main vacuum pipeline (13) through a respective vacuum branch pipeline (14), and the main vacuum pipeline is connected to a vacuum pump unit system (17);

each main chamber powder generating unit is connected to the main exhaust pipeline (2) through a respective exhaust branch pipeline (4), and each main chamber powder generating unit is connected to the main intake pipeline (3) through a respective intake branch pipeline (7);

each main chamber powder generating unit is connected to the control system (1) through respective feeding control signal lines;

the main cavity powder generating unit comprises a main cavity (9) and a laser device (6), wherein the laser device is arranged at the top of the main cavity, and a collecting chamber (18) is arranged at the bottom of the main cavity;

an anode (31) is arranged at the positive position below the cathode, single metal or metal alloy targets with the same or different components are arranged on the target holders of the independent cavities to serve as the anode, an automatic feeding device (10) is arranged at the rear end of the anode to control feeding of the anode, a cooling water device is arranged at the front end of the anode to cool the anode, and gallium arsenide glass with the thickness of 3-5mm is hermetically arranged at an upper opening of the inner wall of the cavity above the target.

2. The apparatus for preparing laser evaporation multi-cavity nanopowder according to claim 1, wherein each vacuum branch conduit is provided with a vacuum valve (11), each exhaust branch conduit is provided with an exhaust valve (5), and each intake branch conduit is provided with an intake valve (8).

3. The laser evaporation multi-cavity nano powder preparation device according to claim 1, wherein a cooling water device is arranged at the front end of the anode, the cooling water device comprises a supporting base (22), cooling water pipes (23) and cooling tanks (24), the cooling tanks (24) are distributed inside the supporting base (22), the cooling water pipes (23) are connected with the supporting base (22), and cooling water enters the cooling tanks (24) through the cooling water pipes (23) to flow circularly.

4. The apparatus for preparing laser evaporation multi-cavity nanopowder according to claim 1, wherein the main chamber is provided as a cooling wall (20) for cooling water circulation.

5. The laser evaporation multi-cavity nano powder preparation device according to claim 1, wherein the upper end of the collection chamber is connected with the main chamber through a butterfly valve (28), the other end of the collection chamber is connected with a transition chamber, and the collection chamber is further provided with an observation window and collection gloves (30).

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