Atomization device, atomization method and application

Abstract

The invention provides an atomization device, an atomization method and application, and belongs to the technical field of atomization. The device comprises an acoustic vortex generation system used for generating a vortex ultrasonic field; and the liquid supply system is used for conveying an atomizing medium into the vortex ultrasonic field. The vortex ultrasonic field is generated through the sound vortex generation system, the vortex ultrasonic field has the ultrasonic standing wave field atomization capacity and the centrifugal atomization capacity at the same time to atomize the atomization medium, and the ultrasonic vortex atomization device has wide application prospects in the fields of common liquid atomization, metal powder preparation and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of atomization, and in particular to an atomization device, an atomization method and applications thereof based on a vortex ultrasonic field. Background Art

[0002] The general ultrasonic atomization technology is to directly contact the liquid to be atomized with the high-frequency vibrating surface. The liquid oscillates on the ultrasonic vibrating surface, breaks and separates, and is atomized. This contact ultrasonic atomization technology is simple and direct, but it also has some inevitable limitations, such as contamination of the atomized liquid, cavitation corrosion of the vibrating end surface, and can only process low-temperature liquids. To overcome these shortcomings, non-contact ultrasonic atomization is a very promising development direction.

[0003] At present, non-contact ultrasonic atomization technology is mainly non-contact ultrasonic standing wave field atomization technology. This technology uses an ultrasonic vibration end and a reflection end placed oppositely, or two ultrasonic vibration ends placed oppositely, to generate a strong standing wave field, and the liquid is flattened, oscillated, broken, and atomized at the sound pressure node. In 1991, Lierke et al. first proposed a non-contact ultrasonic atomization method using a transmitter end and a reflection end placed oppositely, and applied for an ultrasonic standing wave atomization device for molten metal atomization. In 1996, K. Bauckhage et al. first proposed the use of an ultrasonic standing wave field with dual transmitter ends to atomize the liquid, and obtained spherical tin powder of 10-20μm. Since then, scientists have also improved the non-contact ultrasonic standing wave field atomization technology by changing the shape of the transducer end face and using multiple pipes to input fluid. Domestic research on non-contact atomization started relatively late. Harbin Institute of Technology conducted research on ultrasonic standing wave atomization, conducted theoretical analysis on the characteristics of the acoustic field, established an overall solution for the ultrasonic standing wave atomization system, and conducted atomization experiments on glycerol and aqueous solutions. By establishing an acoustic field simulation model and a droplet atomization model that couples the acoustic field with two-phase flow, the droplet breakup mechanism and critical conditions were analyzed, and the influence of various parameters on the droplet atomization process was studied. In addition, they also proposed a molten metal ultrasonic standing wave non-contact atomization powder making device and method. However, to this day, the atomization capacity of the ultrasonic standing wave field is still relatively low, and its application range is extremely limited.

[0004] Recent studies have shown that under certain conditions, sound waves can form a vortex sound field carrying orbital angular momentum, and its wavefront changes in a spiral shape about the center of zero field intensity. In a gas medium, the vortex sound field can not only suspend high-density objects but also drive the suspended objects to rotate at high speed. In view of this, the vortex ultrasonic field has both the ability of ultrasonic standing wave field atomization and the ability of centrifugal atomization. Summary of the invention

[0005] In view of this, in order to solve the technical problem that the atomization ability of the ultrasonic standing wave field in the prior art is still low, in the first aspect, the present invention provides an atomization device, which utilizes an acoustic vortex generating system to generate a vortex ultrasonic field, and utilizes the vortex ultrasonic field which has both the ultrasonic standing wave field atomization ability and the centrifugal atomization ability to atomize the atomization medium. The atomization can be carried out efficiently and has broad application prospects in the fields of ordinary liquid atomization and metal powder making.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An atomizing device, comprising:

[0008] An acoustic vortex generating system for generating a vortex ultrasonic field;

[0009] The liquid supply system is used to deliver atomized medium into the vortex ultrasonic field.

[0010] Preferably, the acoustic vortex generating system comprises an ultrasonic generating component and a vortex field acoustic atomization component connected to the ultrasonic generating component;

[0011] The ultrasonic generating assembly includes a signal generator, a power amplifier and an electroacoustic transducer;

[0012] The power amplifier amplifies the signal output by the signal generator to drive the electroacoustic transducer to work;

[0013] The vortex field acoustic atomization component includes an ultrasonic vibration end, which is connected to the electroacoustic transducer. The transmitting end of the ultrasonic vibration end is rotationally symmetrically arranged around the same point and the same axis in space, and is used to transmit ultrasonic waves that are superimposed in the area surrounded by the ultrasonic vibration end to form the vortex ultrasonic field.

[0014] Preferably, the phases of the electroacoustic transducers change in sequence in a counterclockwise or clockwise direction, and the phase differences between adjacent electroacoustic transducers are equal.

[0015] Preferably, the number of the ultrasonic vibration ends is at least 3, which are arranged in an array and operate at the same frequency.

[0016] Preferably, the number of the ultrasonic vibration ends is 4, and each of the ultrasonic vibration ends passes through a circular hole on the constraining pipe and enters into the internal area surrounded by the constraining pipe.

[0017] Preferably, it also includes a vacuum system for controlling the vacuum degree and / or a temperature control system for controlling the atomization temperature.

[0018] Preferably, the atomizing medium is one of water, oil and metal liquid.

[0019] Preferably, a collection system is also included.

[0020] In a second aspect, the present invention provides an atomization method of the atomization device, comprising the following steps:

[0021] Step (1), the acoustic vortex generating system generates a vortex ultrasonic field;

[0022] Step (2), the liquid supply system sends the atomized medium into the vortex ultrasonic field for atomization.

[0023] In a third aspect, the present invention provides the application of the above-mentioned atomization device and / or the above-mentioned atomization method in the fields of general liquid atomization and metal liquid powder making.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention proposes for the first time a way and method for non-contact atomization of liquid medium using an acoustic vortex field. Since the vortex ultrasonic field has both the ability of ultrasonic standing wave field atomization and the ability of centrifugal atomization, the atomization efficiency of the atomized medium can be effectively improved. It not only has a good atomization effect on ordinary liquids, but also solves the problem of difficulty in obtaining fine powder of 50μm and below in the preparation of metal powder by traditional non-contact ultrasonic atomization, effectively optimizes the energy utilization rate, sphericity, particle size controllability, particle size range and other issues in the implementation process of existing powder making technology, and achieves the effect of greatly improving the anti-pollution and anti-oxidation properties in the powder making process, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0027] Figure 2 Schematic diagram of the formation of vortex ultrasonic field.

[0028] Figure 3 The atomization process of water droplets.

[0029] Figure 4 This is the atomized particle size and particle size distribution of water droplets.

[0030] Figure 5 This is the atomization process of glycerol droplets.

[0031] Figure 6 is the atomized particle size of glycerol droplets.

[0032] Figure 7 This is the SEM image and particle size distribution curve of pure tin (Sn, melting point 232°C) particles after atomization.

[0033] In the figure, 100, device body; 101, working chamber; 200, liquid supply system; 201, liquid container or melting crucible; 202, gas supply device; 2021, gas cylinder; 2022, air inlet pipe; 2023, gas regulating valve; 203, heating device; 300, ultrasonic generating component; 301, signal generator; 302, power amplifier; 303, electroacoustic transducer; 400, vortex field acoustic atomization component; 401, ultrasonic vibration end; 4011, first ultrasonic vibration end; 4012, second ultrasonic vibration end; 4013, third ultrasonic vibration end; 4014, fourth ultrasonic vibration end; 402, restraint pipeline; 500, collection system; 10, liquid to be atomized. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", "top / bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] like Figure 1-2 As shown, the present invention provides an atomizing device, comprising:

[0038] An acoustic vortex generating system is used to generate a vortex ultrasonic field, wherein the function of the acoustic vortex generating system is to generate an integer-order or fractional-order acoustic vortex;

[0039] The liquid supply system 200 is used to transport atomized medium into the vortex ultrasonic field, wherein the liquid supply system 200 can transport atomized liquid, including water, oil, melt, etc., to the center of the vortex acoustic field at a certain flow rate, where the melt refers to molten metal liquid.

[0040] like Figure 1 As shown, in the present invention, the liquid supply system 200 preferably delivers an atomized medium into the vortex ultrasonic field. The atomized medium is preferably a common liquid or a molten metal liquid, which is contained in a liquid container or a smelting crucible 201.

[0041] When the liquid supply system 200 transports ordinary liquid (such as water, oil and other liquids), the liquid supply system 200 preferably includes a liquid bottle and an air supply device 202. The liquid bottle is used to hold the liquid 10 to be atomized, and the air supply device 202 is connected to the liquid bottle to control the outflow rate of the liquid 10 to be atomized.

[0042] When the liquid supply system 200 conveys molten liquid (molten metal liquid), the liquid supply system 200 preferably includes a melting crucible, a gas supply device 202 and a heating device 203. The melting crucible is used to hold the molten liquid. The heating device 203 is arranged on the periphery of the melting crucible and is used to heat the melting crucible. The gas supply device 202 is connected to the melting crucible and is used to control the outflow rate of the molten liquid.

[0043] The device body 100 of the above-mentioned atomization device provided by the present invention preferably has an operating chamber 101, and the acoustic vortex generating system and the liquid supply system 200 are located in the operating chamber 101. The acoustic vortex generating system is preferably located below the liquid supply system 200 to ensure that the droplets fall directly into the center of the acoustic vortex field.

[0044] like Figure 1 As shown, the present invention provides an embodiment of an acoustic vortex generating system, wherein the acoustic vortex generating system comprises an ultrasonic generating component 300 and a vortex field acoustic atomization component 400 connected to the ultrasonic generating component 300;

[0045] The ultrasonic generating assembly 300 includes a signal generator 301, a power amplifier 302 and an electroacoustic transducer 303;

[0046] The power amplifier 302 amplifies the signal output by the signal generator 301 to drive the electroacoustic transducer 303 to work, preferably working at the same frequency, amplitude and waveform. The signal generator 301 is used to control the working frequency, amplitude, waveform, phase and other parameters of the electroacoustic transducer 303;

[0047] The vortex field acoustic atomization component 400 includes an ultrasonic vibration end 401, which is connected to the electroacoustic transducer 303. The transmitting end of the ultrasonic vibration end 401 is rotationally symmetrically arranged around the same point and the same axis in space, and is used to transmit ultrasonic waves that are superimposed in the area surrounded by the ultrasonic vibration end 401 to form the vortex ultrasonic field.

[0048] In the present invention, the phase of the electroacoustic transducer 303 changes in counterclockwise or clockwise direction, and the phase difference between adjacent electroacoustic transducers 303 is equal, preferably 2π or an integer multiple (or fractional multiple) of 2π divided by the number of electroacoustic transducers 303.

[0049] In the present invention, the number of the ultrasonic vibration ends 401 is at least 3, and they are arranged in an array and operate at the same frequency, preferably at the same frequency, amplitude and waveform.

[0050] In the present invention, the number of the ultrasonic vibration ends 401 is 4, and each of the ultrasonic vibration ends 401 passes through a circular hole on the constraint pipe 402 to enter the internal area surrounded by the constraint pipe 402, wherein the constraint pipe 402 is preferably placed outside the annular array of the ultrasonic vibration ends 401. Each ultrasonic vibration end 401 passes through a circular hole on the constraint pipe 402 to enter the internal area surrounded by the constraint pipe 402, wherein the constraint pipe 402 includes the transmitting end therein, thereby increasing the intensity of the vortex sound field.

[0051] like Figure 2 As shown, the area where the liquid 10 to be atomized is located is the area where the vortex ultrasonic field is formed.

[0052] In the present invention, the number of the transducers 1 is 4.

[0053] In the present invention, a vacuum system for controlling the vacuum degree and / or a temperature control system for controlling the atomization temperature are also included, and preferably a cooling component is also included. The temperature control component and the cooling component are preferably arranged on the periphery of the vortex field acoustic atomization component 400. The temperature control component is used to monitor the real-time temperature in the working chamber 101, to ensure the normal operation of the acoustic vortex generating system, and to make the acoustic field in a resonant state. The temperature control component can select a conventional temperature control component in the field, and there are no special requirements for this. The cooling component is used to cool the working chamber 101, and a conventional cooling component in the field can be selected, and there are no special requirements for this.

[0054] In the present invention, the atomizing medium is a liquid containing water, oil and metal melt.

[0055] The present invention further comprises a collection system 500, which is preferably located below the acoustic vortex generating system and is used to collect fine liquid droplets or metal fine powder.

[0056] The working chamber 101 of the atomization device provided by the present invention is preferably connected to an inert gas cylinder 2021 to ensure that the working chamber 101 is an inert gas protective environment.

[0057] In a second aspect, the present invention provides an atomization method of the atomization device, comprising the following steps:

[0058] Step (1), the acoustic vortex generating system generates a vortex ultrasonic field;

[0059] Step (2), the liquid supply system 200 delivers the atomized medium into the vortex ultrasonic field for atomization. The temperature, flow rate, atmosphere, etc. at the center of the vortex ultrasonic field can be controlled by the temperature control component, the gas supply device 202, and the inert gas cylinder 2021, etc.

[0060] In a third aspect, the present invention provides the application of the above-mentioned atomization device and / or the above-mentioned atomization method in the fields of general liquid atomization and metal liquid powder making.

[0061] The technical solution of the present invention is clearly described in detail below in conjunction with specific embodiments.

[0062] Example 1

[0063] The liquid 10 to be atomized is pure water and glycerin, neither of which needs to be heated. The liquid supply system 200 mainly includes a liquid bottle and a gas supply device 202. The gas supply device 202 includes a gas cylinder 2021, an air inlet pipe 2022, and a gas regulating valve 2023. The gas cylinder 2021 provides high-pressure gas, generally an inert gas, and the gas regulating valve 2023 controls the gas flow rate. A numerically controlled gas flow meter can be selected for this part. The gas flow rate changes with the type of droplets. The inert gas enters the liquid bottle through the air inlet pipe 2022. Under the action of pressure, the droplets flow out from the small holes at the bottom of the liquid bottle and enter the acoustic vortex field.

[0064] If the liquid 10 to be atomized is pure water, the collecting system 500 is a glass sheet coated with silicone oil; if the liquid 10 to be atomized is glycerol, the collecting system 500 is a dry glass sheet, both of which are placed directly below the atomization position.

[0065] The specific implementation steps are as follows:

[0066] Step 1: Pour pure water or glycerin into a liquid container, and place the collection system 500 below the vortex field acoustic atomization assembly 400.

[0067] Step 2: Turn on the ultrasonic atomization system. First, input relevant control parameters on the signal generator 301. The frequencies used in this specific embodiment are all 23kHz, the amplitudes are all 20Vpp, the waveforms are all sine waves, and the number of electroacoustic transducers 303 is selected to be 4, namely the first electroacoustic transducer, the second electroacoustic transducer, the third electroacoustic transducer and the fourth electroacoustic transducer, which correspond to controlling 4 ultrasonic vibration ends 401 respectively, and the four ultrasonic vibration ends 401 are respectively named as the first ultrasonic vibration end 4011, the second ultrasonic vibration end 4012, the third ultrasonic vibration end 4013 and the fourth ultrasonic vibration end 4014. The phase of the first electric energy transducer is 0°, the phase of the second electroacoustic transducer is 90°, the phase of the third electroacoustic transducer is 180°, and the phase of the fourth electroacoustic transducer is 270°; the four-way signal is amplified by the power amplifier 302 after output, and the four-way amplification voltage is adjusted to 600V; the electroacoustic transducer 303 converts the electrical signal into a vibration signal, which is emitted from the ultrasonic vibration end with an end face diameter of 10mm, generating an acoustic vortex field in the array enclosed area; the constraint pipe 402 has a diameter of 18.9mm and is placed outside the transducer array.

[0068] Step 3: Turn on the gas supply device 202. Nitrogen is provided by the gas cylinder 2021 of the gas supply device 202, and the gas flow is controlled by the gas regulating valve 2023. The gas flow of pure water is about 500 sccm, and the gas flow of glycerol is about 1000 sccm. The nitrogen gas enters the liquid bottle through the inlet pipe 2022.

[0069] Step 4: Under the action of pressure, the droplet 10 is dropped into the acoustic vortex field at a flow rate of 2 μL / s, and is broken into atomization under the action of the acoustic field.

[0070] Step 5: The atomized droplets fall freely in the confinement pipe 402 and are collected by the collection system 500 at the bottom of the working chamber 101 .

[0071] The specific implementation results are as follows:

[0072] Figure 3-4 The whole process of atomization of water droplets and glycerin is shown respectively. Figure 5-6 The particle size and distribution of water droplets and glycerol after atomization are shown respectively. The spreading diameter of water droplets is normally distributed, concentrated in 20-40μm, and the spreading diameter of glycerol is larger than that of water droplets.

[0073] Example 2

[0074] Solid pure tin alloy is solid at room temperature and needs to be heated and melted. The liquid supply system 200 includes a smelting crucible, a gas supply device 202 and a heating device 203, and requires a cooling component, a temperature control component and an inert gas protection environment. The smelting crucible is used to hold solid metal or molten metal liquid. The heating device 203 includes a transformer and a resistance wire, which is connected to the transformer and wound around the periphery of the smelting crucible for heating the smelting crucible. The temperature control component and the cooling component are placed on the periphery of the constraint pipe 402 of the vortex field acoustic atomization component 400. The working chamber 101 is an inert gas protection environment. The collection system 500 is a funnel-shaped container, which is placed below the constraint pipe 402 and is used to collect metal fine powder after being crushed and atomized by the acoustic vortex field.

[0075] Specific implementation steps:

[0076] Step 1: Place solid pure tin metal in a melting crucible, and fill the working chamber 101 with high-purity inert gas to ensure that the pressure in the working chamber 101 is less than or equal to 1 MPa. The collection system 500 is placed below the vortex field acoustic atomization assembly 400.

[0077] Step 2: Turn on the heating device 203 and set the transformer voltage to 10V.

[0078] Step 3: Turn on the temperature control component to monitor the temperature change of the vortex field acoustic atomization component 400 in real time. When the temperature is higher than 60°C, turn on the cooling component to ensure that the temperature of the vortex field acoustic atomization component 400 is between 20 and 60°C.

[0079] Step 4: Turn on the ultrasonic atomization system, which is the same as step 2 in specific embodiment 1.

[0080] Step 5: After the metal in the smelting crucible is melted, turn on the gas supply device 202. The principle and use steps of the gas supply device 202 are the same as those of step 3 in specific embodiment 1. Nitrogen is provided by the gas cylinder 2021 of the gas supply device 202, and the gas flow rate is controlled to be about 800 sccm through the gas regulating valve 2023. The nitrogen gas enters the liquid container through the gas inlet pipe 2022.

[0081] Step 6: Under the action of pressure, the metal droplet 10 drips into the acoustic vortex field at a flow rate of 2 μL / s, and is broken into atomization under the action of the acoustic field.

[0082] Step 7: The atomized metal droplets fall freely in the confinement pipe 402 , cool naturally and solidify into metal powder with high sphericity and small particle size, and are collected by the collection system 500 at the bottom of the working chamber 101 .

[0083] Specific implementation results:

[0084] Figure 7The SEM image and particle size distribution curve of pure tin metal particles after being atomized by the acoustic vortex field are shown, and it is found that the particles are mainly spherical. The particle diameter is also normally distributed, mainly concentrated in 30-40μm.

[0085] The above are only preferred specific implementations of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and improved concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An atomizing device, characterized in that: include: An acoustic vortex generating system for generating a vortex ultrasonic field; The liquid supply system is used to deliver atomized medium into the vortex ultrasonic field.

2. An atomizing device according to claim 1, characterized in that: The acoustic vortex generating system comprises an ultrasonic generating component and a vortex field acoustic atomization component connected to the ultrasonic generating component; The ultrasonic generating assembly includes a signal generator, a power amplifier and an electroacoustic transducer; The power amplifier amplifies the signal output by the signal generator to drive the electroacoustic transducer to work; The vortex field acoustic atomization component includes an ultrasonic vibration end, which is connected to the electroacoustic transducer. The transmitting end of the ultrasonic vibration end is rotationally symmetrically arranged around the same point and the same axis in space, and is used to transmit ultrasonic waves that are superimposed in the area surrounded by the ultrasonic vibration end to form the vortex ultrasonic field.

3. An atomizing device according to claim 2, characterized in that: The phases of the electroacoustic transducers change in sequence in a counterclockwise or clockwise direction, and the phase differences between adjacent electroacoustic transducers are equal.

4. The atomizing device according to claim 2, characterized in that: The number of the ultrasonic vibration ends is at least 3, which are arranged in an array and operate at the same frequency.

5. The atomizing device according to claim 3, characterized in that: The number of the ultrasonic vibration ends is 4, and each of the ultrasonic vibration ends passes through a circular hole on the constraining pipe and enters into the internal area surrounded by the constraining pipe.

6. The atomizing device according to claim 1, characterized in that: It also includes a vacuum system for controlling the vacuum degree and / or a temperature control system for controlling the atomization temperature.

7. An atomizing device according to any one of claims 1 to 6, characterized in that: The atomizing medium is a liquid containing water, oil and metal melt.

8. An atomizing device according to claim 7, characterized in that: Also includes a collection system.

9. An atomization method of an atomization device according to any one of claims 1 to 8, characterized in that: The steps include: Step (1), the acoustic vortex generating system generates a vortex ultrasonic field; Step (2), the liquid supply system sends the atomized medium into the vortex ultrasonic field for atomization.

10. Application of an atomization device according to any one of claims 1 to 8 and / or an atomization method according to claim 9 in the fields of general liquid atomization and metal liquid powder making.

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