Liquid drop generating device

Abstract

The invention provides a liquid drop generating device which comprises a liquid storage tank and a Venturi tube, the Venturi tube is located below the liquid storage tank, an inlet section of the Venturi tube is located on the upper portion and isolated from the liquid storage tank, and the inlet section is connected with an air inlet; a needle cylinder is arranged on the inner side of the venturi tube, the upper end of the needle cylinder is communicated with the liquid storage tank, and the lower end of the needle cylinder is located at a throat pipe of the venturi tube and connected with a rotary needle core sprayer. According to the liquid drop generating device, monodisperse liquid drops can be formed at a time, the production rate is high, and the method is simple and practical; in addition, the requirement for external environment factors is not high, the device can be used in severe environments such as high temperature, high pressure and strong light, and the universality is high.

Description

Technical Field

[0001] The invention belongs to the technical field of droplet preparation, and in particular relates to a droplet generating device. Background Art

[0002] With the continuous development of modern machinery, the refinement of oil affects the performance of high-precision mechanical equipment. The movement, deformation, secondary breakage and evaporation of droplets are particularly important for the design of high-precision equipment. There is a greater demand for research on small droplets, and a group of droplet generators with simpler structures and controllable droplet sizes are needed.

[0003] Existing droplet generating devices, such as a droplet generator disclosed in the Chinese patent document with application number CN201710470257.7, work on the principle that the capillary generates droplets that affect photoelectric induction, causing the high-voltage plates on both sides to carry a pulse voltage, causing the droplets to fall. However, the device is greatly affected by the light environment and cannot be used normally in a strong light environment. Another example is a droplet generator disclosed in the Chinese patent document with application number CN201410236750.9, which works on the principle that a motor controls a retractable cam to control the inner and outer control rods to squeeze out the droplets. Although the droplet size and initial test speed can be adjusted, it can only be used at room temperature and pressure, and cannot generate droplets at high temperature and high pressure. Therefore, its applicable occasions are greatly limited. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a droplet generating device to improve the versatility of the working environment of the droplet generating device.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A droplet generating device, comprising:

[0007] Fluid storage tank;

[0008] The venturi tube is located below the liquid storage tank, the inlet section is above and isolated from the liquid storage tank, and the inlet section is connected to the air inlet;

[0009] The upper end of the syringe is connected with the liquid storage tank, and the lower end is located at the throat of the venturi tube and is connected with a rotating needle core nozzle.

[0010] Furthermore, the syringe is arranged along the central axis of the Venturi tube.

[0011] Furthermore, the inner diameters of the syringe and the rotating needle core nozzle are 0.21 to 0.6 mm.

[0012] Furthermore, the top end of the rotating needle core nozzle is 2 to 8 mm lower than the lower end of the throat pipe.

[0013] Furthermore, the inner diameter of the throat is 2 to 4 mm.

[0014] Furthermore, the needle core in the rotating needle core nozzle extends into the liquid storage tank, passes through the upper end of the liquid storage tank, and is connected to the motor.

[0015] Furthermore, a centering bracket is provided in the liquid storage tank to support the needle core.

[0016] Furthermore, there are four air inlets, which are evenly distributed around the outside of the inlet section; during operation, two of the opposite air inlets supply air continuously and steadily, and the other two opposite air inlets spray compressed gas in a pulsed form.

[0017] Furthermore, a liquid replenishing port and a metering pump are provided on the side wall of the liquid storage tank.

[0018] Furthermore, a collecting plate is provided below the rotating needle core nozzle.

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

[0020] (1) The present invention provides a droplet generating device that can form monodisperse droplets in one go, with a high production rate and a simple and practical method. It is mainly based on the interaction between the Weissenberg effect and the Venturi effect. First, liquid is supplied to the nozzle (throat position) through the Weissenberg effect. This effect usually occurs in non-Newtonian fluids. Under the action of external forces, the fluid will exhibit special elastic and viscous behaviors. Then, the Venturi effect is used to generate a low-pressure area near the nozzle, which will accelerate the flow of the fluid and form a negative pressure at the nozzle outlet. The result of the combined action of these two effects is the formation of a stable liquid cone at the nozzle. Due to the effect of fluid dynamics, this liquid cone will break at a certain frequency under specific conditions to form droplets of uniform size. This breakup frequency can be precisely controlled to ensure the consistency and accuracy of the droplets during the printing process. Finally, these discrete droplets are ejected in a predetermined manner to complete a high-quality printing task.

[0021] (2) The droplet particle size and generation rate of the droplet generating device of the present invention are controllable, and can form monodisperse droplets with a larger size range.

[0022] (3) The droplet generating device of the present invention has low requirements for external environmental factors and can be used in harsh environments such as high temperature, high pressure, strong light, etc., and has strong versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a structural diagram of a droplet generating device of the present invention;

[0024] Figure 2 It is a partial enlarged view of the throat portion of the liquid generating device of the present invention.

[0025] Reference numerals:

[0026] 1-motor; 2-centering bracket; 3-liquid storage tank; 4-air inlet;

[0027] 5-syringe; 6-rotating needle core nozzle; 7-collection plate; 8-throat;

[0028] 9-needle core; 10-venturi tube; 11-metering pump; 12-fluid filling port. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, examples of the illustrated embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0030] like Figure 1 and Figure 2 The droplet generating device shown comprises a liquid storage tank 3. The liquid storage tank 3 is arranged vertically, and a venturi tube 10 is connected to the lower end of the liquid storage tank 3; wherein the inlet section of the venturi tube 10 is at the top, and the diffusion section is at the bottom; a partition is arranged between the inlet section and the liquid storage tank 3 to isolate them. A syringe 5 is arranged along the central axis of the inner side of the venturi tube 10. The upper end of the syringe 5 is an inlet, and is connected to the liquid storage tank 3 through a trumpet-shaped opening; the lower end of the syringe 5 extends to the throat 8 of the venturi tube 10, and is connected to a rotating needle core nozzle 6.

[0031] The inner diameter (diameter) of the syringe 5 and its rotating needle core nozzle 6 is required to be 0.21-0.6 mm. The top of the rotating needle core nozzle 6 is slightly lower than the lower end of the throat 8, and the specific size requirement is 2-8 mm. The inner diameter (diameter) of the throat 8 is 2-4 mm.

[0032] A motor 1 is provided at the top of the outer side of the liquid storage tank 3. The needle core 9 in the rotating needle core nozzle 6 passes through the top of the liquid storage tank 3 and is connected to the motor 1, and is driven to rotate by the motor 1. A centering bracket 2 is also provided in the liquid storage tank 3. A bearing is provided on the centering bracket 2 for auxiliary support of the needle core 9 to ensure that the needle core 9 can always run at the center axis position.

[0033] A liquid replenishing port 12 and a metering pump 11 are provided on the side wall of the liquid storage tank 3 for replenishing liquid to the liquid storage tank 3 in a quantitative manner.

[0034] The side wall of the inlet section of the venturi tube 10 is evenly surrounded by four air inlets 4 around the central axis; when working, two of the opposite air inlets 4 continuously and steadily supply air, and the other two opposite air inlets 4 spray compressed gas into the inlet section in a pulsed form.

[0035] A collecting plate 7 is placed below the rotating needle core nozzle 6 to collect the generated monodisperse droplets.

[0036] When the above-mentioned droplet generating device is working, the motor 1 drives the needle core 9 to rotate, and the solution in the liquid storage tank 3 gathers toward the needle tip under the Weissenberg effect to form droplets. In order to reduce the droplet formation time, the present invention is based on the Venturi tube principle: on the one hand, a pair of air inlets 4 are used to continuously supply gas, and the flow rate of the air flow increases in the process from the inlet section to the throat section, so that the gas generates a negative pressure area at the bottom of the throat 8, thereby producing an adsorption effect on the solution at the rotating needle core nozzle 6; and when the solution at the rotating needle core nozzle 6 gathers to a certain extent, another pair of air inlets 4 are used to instantaneously introduce compressed gas, so that a stronger negative pressure is instantaneously generated at the bottom of the throat 8, causing the solution to drip, completing a cycle of monodisperse droplet production. The compressed gas is continuously supplied in the form of pulses, and droplets are continuously generated with the pulse frequency.

[0037] The formation speed and particle size of monodisperse droplets are related to the injection pressure of the solution in the liquid storage tank 3, the properties of the solution, and the rotation speed of the needle core 9. The particle size of the monodisperse droplets can be controlled by adjusting the injection pressure of the metering pump 11. The droplet generation speed can be controlled by adjusting the rotation speed of the needle core 9 and the pulse frequency of the compressed gas.

[0038] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are 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 should not be understood as a limitation on the present invention.

[0039] The present invention is not limited to the above-mentioned embodiments. Any obvious improvement, substitution or deformation that can be made by those skilled in the art without departing from the essential content of the present invention belongs to the protection scope of the present invention.

Claims

1. A droplet generating device, characterized in that: include: Liquid storage tank (3); A venturi tube (10) is located below the liquid storage tank (3), with an inlet section at the top and isolated from the liquid storage tank (3), and the inlet section is connected to the air inlet (4); The syringe (5) has an upper end connected to the liquid storage tank (3) and a lower end located at the throat (8) of the venturi tube (10) and connected to a rotating needle core nozzle (6).

2. The droplet generating device according to claim 1, characterized in that: The needle cylinder (5) is arranged along the central axis of the Venturi tube (10).

3. The droplet generating device according to claim 1, characterized in that: The inner diameters of the syringe (5) and the rotating needle core nozzle (6) are 0.21 to 0.6 mm.

4. The droplet generating device according to claim 1, characterized in that: The top end of the rotating needle core nozzle (6) is 2 to 8 mm lower than the lower end of the throat pipe (8).

5. The droplet generating device according to claim 1, characterized in that: The inner diameter of the throat (8) is 2 to 4 mm.

6. The droplet generating device according to claim 1, characterized in that: The needle core (9) in the rotating needle core spray head (6) extends into the liquid storage tank (3), passes through the upper end of the liquid storage tank (3), and is connected to the motor (1).

7. The droplet generating device according to claim 6, characterized in that: A centering bracket (2) is provided in the liquid storage tank (3) to support the needle core (9).

8. The droplet generating device according to claim 1, characterized in that: The air inlets (4) are provided with four air inlets (4), which are evenly distributed around the outside of the inlet section; when working, two of the air inlets (4) opposite to each other continuously and steadily supply air, and the other two air inlets (4) opposite to each other spray compressed gas in a pulsed form.

9. The droplet generating device according to claim 1, characterized in that: The side wall of the liquid storage tank (3) is provided with a liquid replenishing port (12) and a metering pump (11).

10. The droplet generating device according to claim 1, characterized in that: A collecting plate (7) is provided below the rotating needle core nozzle (6).

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