Pulse-adjustable electric field coupling enhanced DBD powder efficient treatment device

Abstract

The invention relates to a pulse-adjustable electric field coupling enhanced DBD powder efficient treatment device. A reactor shell of a quartz glass reactor is provided with a plurality of tungsten rod fixing holes used for fixing tungsten rods; the tungsten rods are exposed from the left side and the right side of the quartz glass reactor and are staggered in the reactor shell to form an interdigital electrode structure; efficient powder surface modification is achieved at low cost, the treatment efficiency is improved, and the cost is reduced; in addition, the pulse width and frequency of the device are adjustable, plasma parameters can be flexibly adjusted according to different powder materials and modification requirements, the treatment effect is further improved, and accurate regulation and control of powder surface modification are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of powder processing, and in particular to a pulse-adjustable electric field coupling enhanced DBD powder high-efficiency processing device. Background Art

[0002] Plasma is the fourth state of matter besides solid, liquid and gas. It is a macroscopic quasi-neutral mixed particle group composed of a large number of charged particles and neutral particles, accounting for more than 99% of the matter in the universe. It can be divided into high-temperature plasma and low-temperature plasma. High-temperature plasma particles are almost completely ionized, the temperature of electrons and ions is similar, and it is in a complete thermodynamic equilibrium state; low-temperature plasma is a non-equilibrium plasma, which has a low degree of ionization, a large difference in the temperature of electrons and ions and is close to room temperature, rich in a large number of active particles, and has active physical and chemical properties. It can process sample surfaces at room temperature, so it is widely used in many fields such as material surface modification, thin film growth, and medical disinfection.

[0003] As a promising method for material surface modification and management, low-temperature plasma technology is also used for surface treatment of powders. The plasma method relies on the large number of high-energy active particles in the plasma to cause a series of complex physical and chemical reactions between it and the powder reactants, thereby achieving effective modification of the powder. This method has the advantages of high efficiency, low temperature, easy activation, selectivity and high conversion rate in powder modification treatment. In addition, the depth of plasma treatment on the surface of the material is only a very thin layer on the surface (a few nanometers to tens of nanometers), which will not affect the inherent properties of the material itself. It is an application technology that conforms to the trend of scientific development, energy conservation, and green environmental protection.

[0004] The methods for generating plasma usually include dielectric barrier discharge, sliding arc discharge, glow discharge, etc. Among them, dielectric barrier discharge (DBD) is to insert an insulating medium into the discharge space between two metal electrodes, and the gas molecules between the electrodes are ionized and accelerated under the action of a strong electric field, and finally an ionization channel running through the entire space is generated. The method of generating plasma by dielectric barrier discharge has the advantages of simple device, easy occurrence, stable discharge, etc., and is one of the most widely used methods in practical applications of plasma.

[0005] The DBD with common parallel plate electrode structure can prevent the discharge from turning into arc or spark discharge because the barrier medium limits the growth of discharge current. However, in most cases, DBD discharge is uneven, with many micro-discharges controlled by positive and negative streamers. A large number of bright filaments can be seen macroscopically. The "memory effect" of surface charge fixes the filaments in the discharge gap, resulting in uneven discharge and limiting the application of plasma. In addition, traditional DBD plasma is only generated between two parallel plate electrodes. Due to the limitation of plasma space, it is difficult to achieve ideal results when processing irregular samples. Summary of the invention

[0006] To this end, the present invention provides a pulse-adjustable electric field coupling enhanced DBD powder efficient processing device to solve the technical problems in the background technology.

[0007] To achieve the above-mentioned object, the present invention provides a pulse adjustable electric field coupling enhanced DBD powder efficient processing device, comprising a quartz glass reactor, wherein a plurality of first tungsten rod fixing holes for fixing a first tungsten rod are provided on the left side of a reactor shell of the quartz glass reactor, and a same number of second tungsten rod fixing holes for fixing a second tungsten rod are provided on the right side; the first tungsten rod and the second tungsten rod are exposed from the left side and the right side of the quartz glass reactor respectively, and are staggeredly distributed inside the reactor shell to form an interdigitated electrode structure; the right end of the quartz glass reactor is connected to the copper rod by An air inlet fixed plug, the left end of which is connected to an air outlet fixed plug via a copper rod; the right end of the copper rod contacts the inner surface of the first groove of the air inlet fixed plug, and the left end contacts the inner surface of the second groove (802) of the air outlet fixed plug to complete the hard connection; a first through-hole conductive slip ring is fixed on the long outer wall of the air inlet part of the air inlet fixed plug, and a second through-hole conductive slip ring and a third through-hole conductive slip ring are respectively fixed on the long outer wall of the air outlet fixed plug, and a wire reserved hole is provided; the copper rod is connected to the wire through the wire reserved hole and is connected to the second excitation power supply through the second through-hole conductive slip ring.

[0008] The wire leading out of the second tungsten rod is connected to the ground electrode through the first via-hole conductive slip ring; the wire leading out of the first tungsten rod is connected to the first excitation power supply through the third via-hole conductive slip ring.

[0009] The left end of the air outlet fixing plug is connected with a rotating motor, and the parameters of the rotating part are adjusted by the rotation speed of the rotating buckle on the rotating motor.

[0010] The lengths of the first tungsten rod fixing hole and the second tungsten rod fixing hole are smaller than the length of the quartz glass reactor.

[0011] It also includes a signal generator, an oscilloscope, a high-voltage probe and a current coil. The signal generator is used to generate a power signal with a specific phase difference. The oscilloscope is used to collect voltage and current waveforms during the experiment. The high-voltage probe can directly measure the high-voltage signal. The current coil is used for current blocking, tuning and frequency selection.

[0012] The first excitation power supply and the second excitation power supply are high-frequency AC power supplies or nanosecond pulse power supplies.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention utilizes active particles in the plasma generated by DBD to react chemically with the surface of powder particles, thereby forming a stronger chemical bond. Compared with physical modifications such as mechanical mixing, the interfacial bonding force can be significantly enhanced, and the risk of film shedding can be reduced. In view of the environmental pollution problem caused by chemical plating when treating powder, the present device utilizes the pollution-free characteristics of low-temperature plasma treatment to make the entire treatment process more environmentally friendly. In view of the problems that the atomic layer deposition equipment is expensive and the coating rate is low, the present device adopts DBD technology to achieve efficient powder surface modification at a lower cost, improve the processing efficiency and reduce the cost. In view of the problem that the existing drum DBD device has low efficiency when treating powder by surface discharge, the present device enhances the plasma discharge effect by a three-electrode structure and electric field coupling technology, thereby improving the powder processing efficiency. In addition, the pulse width and frequency of the present device are adjustable, and the plasma parameters can be flexibly adjusted according to different powder materials and modification requirements, further improving the processing effect, and realizing precise regulation of powder surface modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The figure is a schematic diagram of the overall structure of a pulse-adjustable electric field coupling-enhanced DBD powder efficient processing device of the present invention.

[0016] Figure 2 Schematic diagram of plasma treatment of powder materials.

[0017] Figure 3 It is a partial schematic diagram of the reactor of the plasma device involved in the present invention.

[0018] Figure 4 Schematic diagram of the oblique section of the three-electrode structure.

[0019] Figure 5 Schematic diagram of the electrode part of the device.

[0020] Figure 6 Schematic diagram of the air intake fixing plug.

[0021] Figure 7 Schematic diagram of the air outlet fixing plug.

[0022] Figure 8 Schematic diagram of through-hole conductive slip ring.

[0023] Fig. 9 Schematic diagram of a rotating motor.

[0024] Explanation of reference numerals: 1. first excitation power supply; 2. second excitation power supply; 3. signal generator; 4. oscilloscope; 5. high voltage probe; 6. rotating motor; 601. rotating buckle; 701. first through-hole conductive slip ring; 7011. fixing part of the first through-hole conductive slip ring; 7012. electrical signal transmission part of the first through-hole conductive slip ring; 7013. rotating part of the first through-hole conductive slip ring; 702. second through-hole conductive slip ring; 703. third through-hole conductive slip ring; 8. air outlet fixing plug; 801. fixing part of the air outlet fixing plug; 802. second groove; 803. outlet Gas port; 804. Wire reserved hole; 9. Inlet fixing plug; 901. Fixing part of the inlet fixing plug; 902. Inlet part; 903. Internal inlet hole; 904. First groove; 10. Quartz glass reactor; 1001. First tungsten rod fixing hole; 1002. Second tungsten rod fixing hole; 1003. Reactor shell; 11. First tungsten rod; 12. Second tungsten rod; 13. Copper rod; 14. Mixing chamber; 15. Flowmeter; 16. One-way valve; 17. First high-pressure gas cylinder; 18. Second high-pressure gas cylinder; 19. Coal quality bottle; 20. Anti-backflow bottle; 21. Current coil. DETAILED DESCRIPTION

[0025] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments.

[0026] like Figure 2 As shown, a pulse adjustable electric field coupling enhanced DBD powder efficient processing device comprises a quartz glass reactor 10, wherein a plurality of first tungsten rod fixing holes 1001 for fixing a first tungsten rod 11 are provided on the left side of a reactor shell 1003 of the quartz glass reactor 10, and a same number of second tungsten rod fixing holes 1002 for fixing a second tungsten rod 12 are provided on the right side; the first tungsten rod 11 and the second tungsten rod 12 are exposed from the left side and the right side of the quartz glass reactor 10 respectively, and are staggeredly distributed inside the reactor shell 1003 to form an interdigital electrode structure;

[0027] The lengths of the first tungsten rod fixing hole 1001 and the second tungsten rod fixing hole 1002 are smaller than the length of the quartz glass reactor 10 .

[0028] In this embodiment, the quartz glass material has good insulation performance and high temperature resistance, which can effectively prevent the surface barrier discharge from being transformed into arc discharge, thereby ensuring the stability of plasma discharge.

[0029] In this embodiment, the interdigital electrodes are made of tungsten. During the experiment, the interdigital electrodes are required to have strong electron emission capability, no melting at high temperature, high strength, low loss, long service life, and convenient use under working conditions. Metal tungsten rods have the advantages of high melting point of 3410°C, high boiling point of 5900°C, high strength of 850-1100MPa, low thermal conductivity and low volatility at high temperature. When high voltage is applied to the tungsten electrode, it can be heated to a very high temperature, thereby generating a large amount of electron emission and a very high current density. Therefore, tungsten rods are selected as interdigital electrodes.

[0030] In this embodiment, the shape of the interdigitated electrode is finger-like, and a plurality of interdigitated fingers are evenly distributed on the inner wall of the drum. The spacing between adjacent interdigitated fingers is between 4-6 mm. The length of the hole is 90 mm, and the length of the entire reactor is 100 mm, leaving a 10 mm margin. The advantage of this design is that plasma will be generated in an area with a length of 90 mm, which is a large area, has high energy utilization efficiency, and will not cause damage to the air outlet fixed plug 8 and the air inlet fixed plug 9.

[0031] In this embodiment, the copper rod 13 is connected to the high-voltage electrode, and the material is copper. Because copper has good electrical conductivity and high electrical conductivity, it can effectively reduce the resistance loss of the electrode during operation, reduce energy consumption, and improve the efficiency of electric energy utilization; at the same time, copper has good thermal conductivity, which can quickly conduct and dissipate the heat generated by the electrode during operation, avoiding the electrode from being affected by local overheating and affecting its performance and service life; and copper has excellent ductility and is easy to process into various shapes and sizes, which is convenient for installation and adaptation in the device, and can meet the experimental device's requirements for the convenience of electrode use. The diameter of the copper rod ranges from 5-8mm, and its length (90mm) is close to that of the drum reactor (length is 100mm), almost running through the entire drum, but slightly shorter than the drum length.

[0032] The right end of the quartz glass reactor 10 is connected to the air inlet fixed plug 9 through the copper rod 13, and the left end is connected to the air outlet fixed plug 8 through the copper rod 13; the right end of the copper rod 13 contacts the inner surface of the first groove 904 of the air inlet fixed plug 9, and the left end contacts the inner surface of the second groove 802 of the air outlet fixed plug 8 to complete the hard connection; the first through-hole conductive slip ring 701 is fixed on the long outer wall of the air inlet part 902 of the air inlet fixed plug 9, and the second through-hole conductive slip ring 702 and the third through-hole conductive slip ring 703 are respectively fixed on the long outer wall of the air outlet fixed plug 8, and a wire reserved hole 804 is provided; the copper rod 13 is connected to the second excitation power supply 2 through the wire reserved hole 804 through the second through-hole conductive slip ring 702; the second tungsten rod 12 is connected to the ground electrode through the first through-hole conductive slip ring 701; the first tungsten rod 11 is connected to the first excitation power supply 1 through the third through-hole conductive slip ring 703.

[0033] The left end of the air outlet fixed plug 8 is connected to a rotating motor 6 , and the rotation speed of the rotating buckle 601 on the rotating motor 6 is used to adjust the parameters of the rotating part.

[0034] In this embodiment, the first through-hole conductive slip ring 701 can be divided into a fixed part 7011, an electrical signal transmission part 7012, and a rotating part 7013; driven by the rotating motor 6, the rotor of part 7011 will drive the reactor 10 to rotate, while part 7013 is tightly fixed to the horizontal plane of the test bench through a fixed support clamp to remain stationary; 7012 is the part for transmitting electrical signals, and the tungsten rod, the copper rod and part 7012 are connected by wires to transmit electrical signals. The wire on the side close to the reactor will rotate synchronously with 7011 and the reactor, and there will also be a corresponding part 7012 on the other side of the slip ring, but the wire on the other side is stationary. The advantage of this design is that it can achieve the purpose of rotation during the experiment and connect the electrical signal to the reactor.

[0035] The device also includes a signal generator 3, an oscilloscope 4, a high-voltage probe 5 and a current coil 21. The signal generator 3 is used to generate a power signal with a specific phase difference, the oscilloscope 4 is used to collect voltage and current waveforms during the experiment, the high-voltage probe 5 can directly measure the high-voltage signal, and the current coil 21 is used for current blocking, tuning and frequency selection. The first excitation power supply 1 and the second excitation power supply 2 are high-frequency AC power supplies or nanosecond pulse power supplies.

[0036] When the device is working, a certain flow rate of gas is introduced, so that the gas enters the reaction device and the powder is continuously tumbled and stirred in the drum reactor as it rotates. The introduction of inert gas can reduce the breakdown field strength of the atmospheric pressure DBD. The discharge area of ​​the device adopts a drum cylindrical shape design. The outstanding feature of this reactor configuration is its simple construction method. When the air flow passes through, this construction method will lead to a relatively low pressure drop, and there is no need for too much wall thickness, thereby reducing the cost of the reactor. In addition, the signal generator of this device has a pulse adjustable function, which can adjust the frequency and width of the pulse according to the processing requirements, so as to accurately control the discharge characteristics of the plasma and optimize the processing effect of the powder. At the same time, through the electric field coupling technology, the generation and maintenance of plasma are enhanced, and the processing intensity and efficiency are improved.

Claims

1. A pulse adjustable electric field coupling enhanced DBD powder efficient processing device, characterized in that: The invention comprises a quartz glass reactor (10), wherein a reactor shell (1003) of the quartz glass reactor (10) is provided with a plurality of first tungsten rod fixing holes (1001) for fixing a first tungsten rod (11) on the left side, and a second tungsten rod fixing holes (1002) for fixing a second tungsten rod (12) on the right side; the first tungsten rod (11) and the second tungsten rod (12) are exposed from the left side and the right side of the quartz glass reactor (10) respectively, and are staggeredly distributed inside the reactor shell (1003) to form an interdigitated electrode structure; the right end of the quartz glass reactor (10) is connected to an air inlet fixing plug (9) through a copper rod (13), and the left end is connected to an air outlet fixing plug through a copper rod (13) (8); the right end of the copper rod (13) contacts the inner surface of the first groove (904) of the air inlet fixed plug (9), and the left end contacts the inner surface of the second groove (802) of the air outlet fixed plug (8) to complete the hard connection; a first through-hole conductive slip ring (701) is fixed on the long outer wall of the air inlet part (902) of the air inlet fixed plug (9), and a second through-hole conductive slip ring (702) and a third through-hole conductive slip ring (703) are respectively fixed on the long outer wall of the air outlet fixed plug (8), and a wire reserved hole (804) is provided; the wire connected to the copper rod (13) passes through the wire reserved hole (804) and is connected to the second excitation power source (2) through the second through-hole conductive slip ring (702).

2. The pulse adjustable electric field coupling enhanced DBD powder efficient processing device according to claim 1, characterized in that: The wire connected to the second tungsten rod (12) is connected to the ground electrode through the first through-hole conductive slip ring (701); the wire connected to the first tungsten rod (11) is connected to the first excitation power supply (1) through the third through-hole conductive slip ring (703).

3. The pulse adjustable electric field coupling enhanced DBD powder efficient processing device according to claim 2, characterized in that: The left end of the air outlet fixed plug (8) is connected to a rotating motor (6), and the parameters of the rotating part are adjusted by the rotation speed of the rotating buckle (601) on the rotating motor (6).

4. The pulse adjustable electric field coupling enhanced DBD powder efficient processing device according to claim 3, characterized in that: The lengths of the first tungsten rod fixing hole (1001) and the second tungsten rod fixing hole (1002) are smaller than the length of the quartz glass reactor (10).

5. The pulse adjustable electric field coupling enhanced DBD powder efficient processing device according to claim 4, characterized in that: The device also comprises a signal generator (3), an oscilloscope (4), a high-voltage probe (5) and a current coil (21); the signal generator (3) is used to generate a power supply signal with a specific phase difference; the oscilloscope (4) is used to collect voltage and current waveforms during the experiment; the high-voltage probe (5) can directly measure the high-voltage signal; and the current coil (21) is used for current blocking, tuning and frequency selection.

6. The pulse adjustable electric field coupling enhanced DBD powder efficient processing device according to claim 5, characterized in that: The first excitation power source (1) and the second excitation power source (2) are high-frequency AC power sources or nanosecond pulse power sources.

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