A high-frequency, high-power, high-flow ultrasonic atomization device

Abstract

The present invention provides a high-frequency, high-power, and high-flow ultrasonic atomization device. A high-frequency, high-power, and high-flow ultrasonic atomization device comprises a high-frequency ultrasonic transducer, a waveguide horn, and a multi-wavelength ultrasonic atomization disk connected in sequence from top to bottom, wherein the multi-wavelength ultrasonic atomization disk comprises a plurality of wave nodes with different thicknesses and different surface inclination angles with the axis of the multi-wavelength ultrasonic atomization disk, and the plurality of wave nodes are distributed in a ring shape from the center of the multi-wavelength ultrasonic atomization disk to the edge of the atomization disk. The present invention adopts a longitudinal wave transmission method, and in theory, the diameter of the multi-wavelength ultrasonic atomization disk can be increased by adding a plurality of half-wavelength wave nodes, so that the ultrasonic atomization area is multiplied. Under the condition of large-flow liquid input, the production capacity of several times or even ten times that of a conventional ultrasonic atomization device can be obtained. Under the condition of equal flow liquid input, the liquid is vibrated into a thinner film before atomization, and smaller atomized particles can be obtained.

Description

Technical Field

[0001] The invention relates to an atomizing device, in particular to a high-frequency and large-flow ultrasonic atomizing device. Background Art

[0002] Ultrasonic atomization powder making has been applied to certain extent in industry and people's daily life, such as pharmaceutical, food, SMT solder powder production in microelectronics industry, etc. Ultrasonic atomization has a good application basis in pharmaceutical, health, food and other aspects because it does not require additional atomization medium (such as gas, water, etc.). It is a clean and hygienic powder manufacturing method. Ultrasonic atomization is the most energy-saving powder atomization manufacturing method. The input atomization capacity of 5-100w is equivalent to the gas atomization with energy consumption of 3-5Kw and the water atomization capacity of 10-30Kw, and the energy saving effect is very significant.

[0003] However, this clean, hygienic and energy-saving atomization method needs to solve some key problems in order to achieve widespread industrial application:

[0004] 1. The problem of ultrasonic atomization of fine-particle powder. In addition to the physical properties of the atomized liquid itself (such as the temperature, viscosity, interfacial tension, adhesion and other characteristics of the liquid), the maximum particle size of the powder that can be produced by ultrasonic atomization is inversely proportional to the ultrasonic frequency used, that is, the higher the frequency, the finer the atomized powder particles. In the actual production of SMT solder powder, due to the limitations of process and equipment, the parameters of the atomized powder particle size and axial ultrasonic frequency (such as the device with a pointed ultrasonic atomization head published by the US invention patents No. 4402458 and No. 4978067) are as follows: the ultrasonic frequency is generally 35KHZ, and the median particle size of the powder is about 55 to 60 microns. In order to obtain fine-particle powder with a smaller particle size, a higher frequency ultrasonic atomization device is bound to be required.

[0005] 2. The production capacity problem of ultrasonic atomization. Axial ultrasonic atomization also faces the problem of very limited atomization circumference. Under normal circumstances, the diameter of the atomization area of ​​a 35KHZ frequency axial ultrasonic atomization device does not exceed 20mm, or the atomization circumference does not exceed 65mm. The efficiency of industrial application is very low and the value is not great. The US invention patent with patent number 5632445 discloses a radial half-wavelength ultrasonic atomization device operating at a frequency of 20KHZ. Through the standing wave symmetrical disc design, the axial ultrasonic vibration is transformed into a radial half-wavelength symmetrical atomization disc design, and the effective diameter of a single ultrasonic atomization is expanded to about 100mm, which is very helpful to effectively improve the atomization efficiency. However, it operates at a lower frequency and cannot solve the problem of fine particle powder.

[0006] 3. Design issues of ultrasonic atomization devices. In terms of the key technology development trend of large-flow fine-particle ultrasonic atomization, the available solutions are still high-frequency ultrasound and large-flow large-atomization disk design. However, in the atomization design, for the large-diameter disk design, the transducer is required to have a large output power under high-frequency working conditions, which greatly limits the design of high-frequency transducers with working frequencies greater than 35KHZ. Summary of the invention

[0007] The purpose of the present invention is to provide a high-frequency, high-power, and large-flow ultrasonic atomization device, which adopts a high-frequency ultrasonic design, has a larger ultrasonic atomization area, supports large-flow liquid input, and solves the problems described in the background technology.

[0008] The technical solution adopted by the present invention to solve its technical problem is:

[0009] A high-frequency, high-power, and high-flow ultrasonic atomization device comprises a high-frequency ultrasonic transducer, a waveguide horn, and a multi-wavelength ultrasonic atomization disk which are sequentially connected from top to bottom. The multi-wavelength ultrasonic atomization disk comprises a plurality of wave nodes with different thicknesses and different surface inclination angles to the axis of the multi-wavelength ultrasonic atomization disk. The plurality of wave nodes are distributed in a ring shape from the center of the multi-wavelength ultrasonic atomization disk to the edge of the multi-wavelength ultrasonic atomization disk.

[0010] Preferably, the relationship between the thickness of the node portion and the diameter of the disk where the node portion is located satisfies the following formula: Among them, f 0m is the ultrasonic frequency of the multi-wavelength ultrasonic atomizer disk, β 0m is the node value of the Bessel function, h m is the thickness of the node, r is the diameter of the disk where the node is located, E is the material elastic modulus of the multi-wavelength ultrasonic atomization disk, is the material density of the multi-wavelength ultrasonic atomization disk, and σ is the material Poisson’s ratio of the multi-wavelength ultrasonic atomization disk.

[0011] Preferably, the maximum thickness of the node portion is less than or equal to the diameter of the waveguide horn.

[0012] Preferably, a step portion is provided between adjacent node portions, a bending portion is provided at the end of the node portion located at the edge of the multi-wavelength ultrasonic atomization disk, and an angle between the bending portion and the front end of the node portion is 90-110°.

[0013] Preferably, the multi-wavelength ultrasonic atomization disk is a disk with a "human" shape in the axial cross section, and the thickness of the multi-wavelength ultrasonic atomization disk gradually decreases from the center to the edge of the disk.

[0014] Preferably, a heater is provided at the bottom of the multi-wavelength ultrasonic atomization disk, and the heater is a high-frequency induction heater.

[0015] Preferably, a liquid adding pipe is provided above the multi-wavelength ultrasonic atomization disk.

[0016] Preferably, the high-frequency ultrasonic transducer comprises a piezoelectric ceramic chip, a front cover plate and a rear cover plate, and the diameter of the piezoelectric ceramic chip is larger than the diameter of the output end of the front cover plate.

[0017] Preferably, the diameter of the waveguide horn is less than or equal to one quarter of the ultrasonic wave length of the high-frequency ultrasonic transducer.

[0018] Preferably, a rotating mechanism mounting portion for mounting a rotating mechanism is provided on the waveguide horn, and the rotating mechanism mounting portion is arranged at a distance from the input end of the waveguide horn that is one-quarter of the ultrasonic wave length of the high-frequency ultrasonic transducer.

[0019] The beneficial effects of the present invention are:

[0020] A high-frequency, high-power, and high-flow ultrasonic atomization device of the present invention increases the ultrasonic atomization operating frequency of a conventional device to a high-frequency range. The present invention adopts a longitudinal wave transmission method. In theory, the diameter of a multi-wavelength ultrasonic atomization disk can be increased by adding multiple half-wavelength node portions, so that the ultrasonic atomization area is multiplied. Under the condition of large-flow liquid input, the production capacity of several times or even ten times that of a conventional ultrasonic atomization device can be obtained. Under the condition of the same flow liquid input, the liquid is vibrated into a thinner film before being atomized, and smaller atomized particles can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0022] Figure 1 It is a main structural schematic diagram of the present invention;

[0023] Figure 2 This is a microscope view of the median particle size of the atomized powder of the liquid raw material SnBi58 in Example 1;

[0024] Figure 3 This is a test diagram of the median particle size of the atomized powder of the liquid raw material SnAgCu305 in Example 1;

[0025] Figure 4 This is a test diagram of the median particle size of the atomized powder of the liquid raw material SnAgCu305 in Example 1;

[0026] Figure 5 This is a test diagram of the median particle size of the atomized powder of the liquid raw material SnAgCu305 in Example 2;

[0027] Figure 6 This is a microscope view of the median particle size of the atomized powder of the liquid raw material SnAgCu305 in Example 2.

[0028] In the figure: 1. high-frequency ultrasonic transducer, 2. waveguide horn, 3. multi-wavelength ultrasonic atomization disk, 4. node portion, 5. heater, 6. liquid adding tube, 7. piezoelectric ceramic chip, 8. front cover plate, 9. rear cover plate, 10. rotating mechanism mounting portion, 11. step portion, 12. bending portion. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0030] In the present invention, unless otherwise specified, all parts and percentages are weight units, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art. The components or equipment in the following embodiments, unless otherwise specified, are universal standard parts or components known to those skilled in the art, and their structures and principles are known to those skilled in the art through technical manuals or conventional experimental methods.

[0031] Embodiment 1:

[0032] like Figure 1 A high-frequency, high-power, and high-flow ultrasonic atomization device is shown, comprising a high-frequency ultrasonic transducer 1, a waveguide horn 2, and a multi-wavelength ultrasonic atomization disk 3 connected in sequence from top to bottom. The multi-wavelength ultrasonic atomization disk comprises a plurality of wave nodes 4 having different thicknesses and having different surface inclination angles with the axis of the multi-wavelength ultrasonic atomization disk, and the plurality of wave nodes are distributed in a ring shape from the center of the multi-wavelength ultrasonic atomization disk to the edge of the multi-wavelength ultrasonic atomization disk.

[0033] Each node of the multi-wavelength ultrasonic atomizer is designed according to the half wavelength of the ultrasonic wave length of the high-frequency ultrasonic transducer. The relationship between the thickness of the node and the diameter of the disk where the node is located satisfies the following formula: Among them, f 0m is the ultrasonic frequency of the multi-wavelength ultrasonic atomizer disk, β 0m is the node value of the Bessel function, and the values ​​of the first node, the second node, the third node, and the fourth node are β 01 :3.196, β 02 :6.30, β 03 :9.43、β 04 :12.57,h mis the thickness of the node, r is the diameter of the disk where the node is located, E is the material elastic modulus of the multi-wavelength ultrasonic atomization disk, is the material density of the multi-wavelength ultrasonic atomizer disk, and σ is the material Poisson's ratio of the multi-wavelength ultrasonic atomizer disk. The thickness of the first node portion is the maximum initial thickness of the multi-wavelength ultrasonic atomizer disk, and the maximum thickness of the node portion is less than or equal to the diameter of the waveguide horn, and the diameter of the waveguide horn is less than or equal to one-fourth of the ultrasonic length of the high-frequency ultrasonic transducer. In this embodiment, the diameter of the waveguide horn is designed to be 24 mm.

[0034] The multi-wavelength ultrasonic atomizer disk is a disk with a "human"-shaped axial section. The thickness of the multi-wavelength ultrasonic atomizer disk gradually decreases from the center to the edge of the disk. The "human"-shaped structural design changes the ultrasonic wave from axial propagation to longitudinal propagation, which is the key design to change the ultrasonic wave propagation path.

[0035] The outer diameter of the multi-wavelength ultrasonic atomization disk of this embodiment is 220mm, and the number of nodes is 4. The first node is designed to be thicker, 23mm, to reduce the amplitude of the ultrasonic wave. The thickness of the first node to the fourth node gradually decreases, and each adjacent node is thinned by 2 to 5mm, so that the amplitude of the ultrasonic wave in transmission can be radially amplified step by step. A step portion 11 is provided between adjacent node portions to further amplify the ultrasonic amplitude. The fourth node portion is located at the edge of the multi-wavelength ultrasonic atomization disk, and its thickness is reduced to 2 to 4mm, so that the edge of the disk can have sufficient amplitude to enable ultrasonic atomization to continue smoothly. A bending portion 12 is provided at the end of the fourth node portion, and the bending portion and the front end of the fourth node portion have an angle of 90 to 110°. The bending portion forms an atomization working end, which functions to change the propagation direction of the ultrasonic wave and change the atomization working direction.

[0036] A heater 5 is provided at the bottom of the multi-wavelength ultrasonic atomization disk, and the heater is a high-frequency induction heater. For some raw materials to be atomized, they have a higher melting point, or their liquid state viscosity is higher, so they need to be atomized at a higher temperature. The diameter of the multi-wavelength ultrasonic atomization disk of this embodiment has a larger structural size and heat capacity than the conventional device, and the heater can heat the temperature of the multi-wavelength ultrasonic atomization disk to a level consistent with the input liquid temperature of the raw material to be atomized. The heating speed of the heating device using a resistance wire or a far-infrared method is slow, which will make the temperature of the multi-wavelength ultrasonic atomization disk uneven. Therefore, this embodiment uses a high-frequency induction heater as a heat source, and it is set in an area close to the bottom edge of the multi-wavelength ultrasonic atomization disk, which can keep the first wave node at a lower temperature and maintain the normal operation of the ultrasonic output. In this embodiment, the operating frequency of the multi-wavelength ultrasonic atomization disk at room temperature is about 42.5KHz, when the multi-wavelength ultrasonic atomization disk is heated to 260 degrees Celsius, its operating frequency is about 41KHz, and when the multi-wavelength ultrasonic atomization disk is heated to 300 degrees Celsius, its operating frequency is about 40.5KHz.

[0037] A liquid adding pipe 6 is provided above the multi-wavelength ultrasonic atomizing disk. The liquid adding pipe adds the liquid raw material to be atomized to the surface of the multi-wavelength ultrasonic atomizing disk. The introduction point of the liquid raw material can be between the first wave node and the fourth wave node. In order to fully disperse the liquid raw material, this embodiment chooses to set the liquid raw material introduction point at the position of the second wave node. It should be noted that the liquid adding pipe can be heated. For general liquid raw materials, it can be heated by 20 to 150 degrees Celsius based on the melting point temperature of the liquid raw material.

[0038] The high-frequency ultrasonic transducer includes a piezoelectric ceramic chip 7, a front cover plate 8 and a rear cover plate 9, and the diameter of the piezoelectric ceramic chip is greater than the diameter of the output end of the front cover plate. Conventional ultrasonic atomization devices all adopt a relatively easy-to-implement low-frequency ultrasonic design. When a low-frequency ultrasonic (<35KHz) design is adopted, due to the low frequency of the material and the long wavelength, it is easy to implement a larger-sized structural design, and the low-frequency ultrasonic transducer is also easy to implement a high-power design. Only two piezoelectric ceramic chips with a size of 45x5mm can obtain high power, but such a large-diameter ultrasonic transducer is prone to lateral vibration, and the ultrasonic longitudinal propagation loss is high, and it is not easy to obtain the longitudinal long-distance propagation of ultrasonic waves. This embodiment uses 4 small-size piezoelectric ceramic chips with a size of 35x4mm to make a high-frequency ultrasonic transducer with a frequency of 40KHz, and reduces the diameter of the output end of the front cover plate to 27mm, thereby improving the propagation efficiency of ultrasonic waves.

[0039] The waveguide horn has the following functions: transmitting the ultrasonic vibration energy output by the high-frequency ultrasonic transducer to the multi-wavelength ultrasonic atomization disk; carrying other functional mechanisms required by the ultrasonic atomization device; and thermally isolating the high-frequency ultrasonic transducer from the multi-wavelength ultrasonic atomization disk. The waveguide horn needs to be made of titanium alloy or high elastic modulus steel. This embodiment uses TC4 titanium alloy material.

[0040] The waveguide horn is provided with a rotating mechanism mounting portion 10 for mounting a rotating mechanism, and the rotating mechanism mounting portion is arranged at a distance of one quarter of the ultrasonic wave length of the high-frequency ultrasonic transducer from the input end of the waveguide horn. The function of the rotating mechanism is to further disperse the liquid raw material introduced into the surface of the multi-wavelength ultrasonic atomization disk. The position of the rotating mechanism mounting portion is set at the first one quarter ultrasonic wave length static node on the waveguide horn. The rotating mechanism mounting portion is pressed with a flexible sealing gasket, and the rotating mechanism is fixed thereon to drive the entire ultrasonic atomization device to rotate. In this embodiment, the rotation speed of the multi-wavelength ultrasonic atomization disk is controlled at 10 to 150 rpm.

[0041] The multi-wavelength ultrasonic atomization disk was heated to 180 degrees Celsius, and the liquid raw material SnBi58 to be atomized was introduced through the liquid adding tube. The atomization frequency was about 41.7KHz, the speed of the multi-wavelength ultrasonic atomization disk was controlled at 60rpm, and the flow rate of the liquid raw material was controlled at 40KG / H. The powder obtained after atomization looked like this under a microscope. Figure 2 As shown, the median particle size D50 of the powder is about 25 microns, which is much smaller than the 55-60 micron particle size powder produced by conventional devices.

[0042] The multi-wavelength ultrasonic atomization disk was heated to 260 degrees Celsius, and the liquid raw material SnAgCu305 to be atomized was introduced through the liquid adding tube. The atomization frequency was about 41KHz, the speed of the multi-wavelength ultrasonic atomization disk was controlled at 90rpm, and the flow rate of the liquid raw material was controlled at 50KG / H. The powder measurement results after atomization were as follows: Figure 3 As shown, the median particle size D50 is about 46 microns. The flow rate of the liquid raw material is controlled at 40KG / H. The powder measurement results after atomization are as follows Figure 4 As shown, the median particle size D50 is about 43 microns.

[0043] Example 2

[0044] A high-frequency, high-power, high-flow ultrasonic atomization device, the structural and technical features of which are the same as those of Example 1, except that:

[0045] This embodiment uses four small-sized piezoelectric ceramic chips of 20x3mm to manufacture a high-frequency ultrasonic transducer with a frequency of 55KHz, reduces the diameter of the output end of the front cover plate to 18mm, and designs the diameter of the waveguide horn to be 17mm.

[0046] The outer diameter of the multi-wavelength ultrasonic atomization disk of this embodiment is 168 mm, and the first wave node portion is designed to be thicker, which is 16 mm.

[0047] In this embodiment, the operating frequency of the multi-wavelength ultrasonic atomization disk at room temperature is about 57 KHz. When the multi-wavelength ultrasonic atomization disk is heated to 260 degrees Celsius, its operating frequency is about 55.7 KHz.

[0048] The multi-wavelength ultrasonic atomization disk was heated to 260 degrees Celsius, and the liquid raw material SnAgCu305 to be atomized was introduced through the liquid adding tube. The atomization frequency was about 55.7KHz, the speed of the multi-wavelength ultrasonic atomization disk was controlled at 90rpm, and the flow rate of the liquid raw material was controlled at 38KG / H. The powder measurement results after atomization were as follows: Figure 5 As shown under the microscope Figure 6 As shown, the median particle size D50 of the powder is about 39 microns.

[0049] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A high-frequency, high-power, high-flow ultrasonic atomization device, characterized in that: The high-frequency, high-power, and high-flow ultrasonic atomization device comprises a high-frequency ultrasonic transducer (1), a waveguide horn (2), and a multi-wavelength ultrasonic atomization disk (3) connected in sequence from top to bottom, wherein the multi-wavelength ultrasonic atomization disk comprises a plurality of wave node portions (4) having different thicknesses and having different surface inclination angles with respect to the axis of the multi-wavelength ultrasonic atomization disk, wherein the plurality of wave node portions are distributed in a ring shape from the center of the multi-wavelength ultrasonic atomization disk to the edge of the multi-wavelength ultrasonic atomization disk; the relationship between the thickness of the wave node portion and the diameter of the disk where the wave node portion is located satisfies the following formula, f 0m = β 0m 2 h m / 4πr 2 ·(E / 3ϱ(1-σ 2 )) 1 / 2 , where f 0m is the ultrasonic frequency of the multi-wavelength ultrasonic atomizer disk, β 0m is the node value of the Bessel function, h m is the thickness of the node portion, r is the diameter of the disk position where the node portion is located, E is the material elastic modulus of the multi-wavelength ultrasonic atomization disk, ϱ is the material density of the multi-wavelength ultrasonic atomization disk, and σ is the material Poisson's ratio of the multi-wavelength ultrasonic atomization disk; a step portion (11) is provided between adjacent node portions, and a bending portion (12) is provided at the end of the node portion located at the edge of the multi-wavelength ultrasonic atomization disk, and the angle between the bending portion and the front end of the node portion is 90-110°; the maximum thickness of the node portion is less than or equal to the diameter of the waveguide horn, and the diameter of the waveguide horn is less than or equal to one-fourth of the ultrasonic length of the high-frequency ultrasonic transducer.

2. A high-frequency, high-power, high-flow ultrasonic atomization device according to claim 1, characterized in that: The multi-wavelength ultrasonic atomization disk is a disk with a "human" shape in the axial cross section, and the thickness of the multi-wavelength ultrasonic atomization disk gradually decreases from the center to the edge of the disk.

3. The high-frequency, high-power, high-flow ultrasonic atomization device according to claim 1, characterized in that: A heater (5) is provided at the bottom of the multi-wavelength ultrasonic atomization disk, and the heater is a high-frequency induction heater.

4. The high-frequency, high-power, high-flow ultrasonic atomization device according to claim 1, characterized in that: A liquid adding pipe (6) is provided above the multi-wavelength ultrasonic atomization disk.

5. The high-frequency, high-power, high-flow ultrasonic atomization device according to claim 1, characterized in that: The high-frequency ultrasonic transducer comprises a piezoelectric ceramic chip (7), a front cover plate (8) and a rear cover plate (9), wherein the diameter of the piezoelectric ceramic chip is greater than the diameter of the output end of the front cover plate.

6. The high-frequency, high-power, high-flow ultrasonic atomization device according to claim 1, characterized in that: The waveguide horn is provided with a rotating mechanism mounting portion (10) for mounting the rotating mechanism, and the rotating mechanism mounting portion is arranged at a distance from the input end of the waveguide horn that is one quarter of the ultrasonic wave length of the high-frequency ultrasonic transducer.

Images