pesticide spraying equipment

Abstract

This invention belongs to the field of agricultural equipment, specifically a pesticide spraying device. It includes a carrier with a pesticide tank connected to it. The tank is connected to a drive pump, which in turn is connected to an atomizing nozzle. The atomizing nozzle includes an atomizing chamber for atomizing the pesticide into droplets and a nozzle for spraying the droplets. An annular inner air chamber is formed on the outer wall of the nozzle. This inner air chamber is connected to an air supply mechanism and a bubble generating mechanism, where the bubble diameter is larger than the droplet diameter. An inner air curtain opening is formed at the bottom of the inner air chamber to create an annular air curtain that surrounds the droplet movement space. The annular air curtain gradually contracts towards the droplet movement space along the gas flow direction, causing the droplets to collide with the bubbles in the annular air curtain before reaching the crop. In this invention, the droplets are sprayed at a conventional speed, ensuring atomization effectiveness; the distance from the nozzle to the crop is a conventional distance, ensuring accurate pesticide delivery to the target area; and the splash rate is reduced, minimizing pesticide waste.

Description

Technical Field

[0001] This invention belongs to the field of agricultural equipment, and in particular to a pesticide spraying device. Background Technology

[0002] Existing pesticide spraying devices all include a tank, pump, and atomizing nozzle. Pesticides are atomized into fine droplets by the nozzle and sprayed onto the crop surface. Droplet size is generally negatively correlated with spray velocity; higher velocity results in greater shear force and finer droplets. Only fine droplets (50-150 μm) can evenly cover the crop surface; larger droplets are prone to rolling off. Currently, the spray velocity of traditional spraying devices is typically 10-20 m / s. When droplets reach the crop surface, they impact the crop, converting kinetic energy into deformation energy and rebound energy. At excessively high velocities, droplets break and splash; for example, at impact velocities >6 m / s, the splash rate can reach 25%-35%, leading to significant pesticide waste. The relationship between the velocity (v) of the droplets reaching the crop surface and the splash rate is approximately as follows: v = 2 m / s: splash rate < 5%; v = 4 m / s: splash rate 10%-15%; v = 6 m / s: splash rate 20%-25%; v = 8 m / s: splash rate 30%-40%; v = 10 m / s: splash rate 45%-55%. Therefore, during spraying, pesticide droplets are best sprayed at a higher velocity (10-20 m / s) and reach the crop at a lower velocity (less than 4 m / s). This ensures fine droplets, even spraying, and prevents waste caused by splashing. As droplets move, their speed gradually decreases due to air resistance. Therefore, increasing the distance between the nozzle and the crop can reduce the speed at which the droplets reach the crop surface. However, as the droplets move through the air, moisture continues to evaporate. The evaporation rate is related to the flight time and droplet diameter. If the flight path is too long, excessive evaporation of moisture can lead to pesticide crystallization and loss of effectiveness. Furthermore, the longer the droplets travel, the greater the drift distance caused by crosswinds, making it difficult for the pesticides to effectively reach the target area.

[0003] Patent application CN201911225565.9 discloses a wind curtain-type spray anti-drift device and method for a plant protection drone. It effectively reduces droplet drift by generating a wind wall to block external wind fields. Patent application CN201610211697.6 discloses a multi-atomization anti-drift sprayer. A secondary atomization structure inputs a fine air column into the reaction chamber, which collides again with small droplets, atomizing them into droplets. Simultaneously, air bubbles enter the droplets. After the droplets are sprayed out, the air bubbles rapidly burst under pressure difference, achieving tertiary atomization and obtaining an ideal atomization effect.

[0004] While existing technologies can reduce droplet drift by setting up air curtains and mixing air bubbles into droplets to promote multiple atomizations, they cannot solve the problem of severe splashing when droplets reach crops. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a pesticide spraying device that reduces the splashing of pesticide droplets when they reach crops and improves the utilization rate of pesticides.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows: a pesticide spraying device, including a carrier, a medicine tank is provided on the carrier, the medicine tank is connected to a drive pump, the drive pump is connected to an atomizing nozzle, and the atomizing nozzle includes an atomizing chamber for atomizing pesticide into droplets and a nozzle for spraying the droplets. The nozzle has an annular inner air chamber on its outer wall. The inner air chamber is connected to an air supply mechanism and a bubble generating mechanism for generating bubbles. The diameter of the bubbles is larger than the diameter of the droplets. The bottom of the inner air chamber has an inner air curtain opening for forming an annular air curtain. The annular air curtain surrounds the droplet movement space and gradually contracts towards the droplet movement space along the gas flow direction, so that the droplets collide with the bubbles in the annular air curtain before reaching the crop.

[0007] Furthermore, the outer wall of the inner air chamber is provided with an annular outer air chamber, and the bottom of the outer air chamber is provided with an outer air curtain opening for forming an annular outer air curtain; the inner air chamber and the outer air chamber are respectively connected to the air supply mechanism through a first air pipe and a second air pipe, and valves are provided on both the first air pipe and the second air pipe; a wind speed sensor and a controller are provided on the carrier, and the air supply mechanism, valves and wind speed sensor are all connected to the controller.

[0008] Furthermore, the bubble generation mechanism is used to generate microbubbles with a diameter of 50-500 μm; the volume of bubbles in the annular air curtain accounts for 10%-25% of the total volume of the annular air curtain; and the droplet size after atomization in the atomization chamber is 50-100 μm.

[0009] Furthermore, the air velocity ejected from the inner air curtain is 10-20 m / s, and the droplet velocity ejected from the nozzle is 10-20 m / s.

[0010] Furthermore, the inner air chamber is provided with an annular liquid distribution chamber, which is connected to a liquid storage chamber via a liquid supply pump. The liquid storage chamber contains bubble generating liquid. The bubble generating mechanism is an annular filter screen installed in the inner air curtain opening. The diameter of the filter pores of the annular filter screen is 20-200μm, and the annular filter screen slopes downward from its inner pores to its outer edge. The bottom of the liquid distribution chamber is connected to the edge of the inner pores on the upper surface of the annular filter screen through a liquid distribution channel.

[0011] Furthermore, the outer wall of the inner air curtain is provided with two insulating first mounting sleeves, and the side walls of the two first mounting sleeves are provided with annular negative electrodes. The negative electrodes are connected to a negative voltage power supply with a voltage of -5kV to -15kV, and the annular air curtain is located between the two negative electrodes. The nozzle outlet end is connected to an insulating second mounting sleeve, and the inner wall of the second mounting sleeve is provided with an annular positive electrode. The positive electrode is connected to a positive voltage power supply with a voltage of 5kV to 15kV.

[0012] Furthermore, the air supply mechanism is an air pump, and the air inlet of the air pump is equipped with a filter mechanism.

[0013] Furthermore, the carrier is a drone or a mobile vehicle.

[0014] The beneficial effects of the present invention are: 1. When spraying pesticides, the present invention can form an annular wind curtain outside the movement space of pesticide droplets. The annular wind curtain surrounds the movement space of the droplets and plays a certain role in blocking the wind, preventing the droplets from drifting away due to the influence of crosswinds after being sprayed.

[0015] 2. In this invention, the annular air curtain gradually contracts towards the droplet's movement space along the gas flow direction, forming a cone shape with its tip pointing downwards. If the droplets are sprayed vertically downwards, the annular air curtain flows downwards at an angle, ensuring that the droplets contact the annular air curtain close to the crop before reaching it. Because the annular air curtain contains air bubbles with a particle size larger than the droplets, the droplets collide and mix with the bubbles. The kinetic energy of the droplets decreases after the collision, reducing their velocity. Furthermore, the overall air resistance increases after the droplets and bubbles mix, further reducing the speed at which the droplets reach the crop, thus reducing splashing and pesticide waste.

[0016] This invention can simultaneously achieve the following effects: the droplets can be sprayed at the conventional speed to ensure atomization effect; the distance between the nozzle and the crop is also a conventional distance to ensure that the pesticide accurately reaches the target area; at the same time, it can reduce the splash rate and reduce pesticide waste. Attached Figure Description

[0017] Figure 1 This is a cross-sectional schematic diagram of the present invention; Figure 2 yes Figure 1 Enlarged schematic diagram of the medium-sized atomizing nozzle; Figure 3 This is an enlarged schematic diagram of the inner and outer air chambers; Reference numerals: 1—Carrier; 2—Medicine tank; 3—Drive pump; 4—Atomizing nozzle; 41—Atomizing chamber; 42—Nozzle; 43—Second mounting sleeve; 44—Positive electrode; 45—Positive pressure power supply; 46—Droplet movement space; 5—Inner air chamber; 51—Air supply mechanism; 52—Bubble generation mechanism; 53—Annular air curtain; 54—Inner air curtain opening; 55—Outer air chamber; 56—Valve; 57—Annular outer air curtain; 58—Outer air curtain opening; 59—First mounting sleeve; 510—Negative electrode; 511—Negative pressure power supply; 512—Liquid supply pump; 513—Filtering mechanism; 514—Liquid distribution chamber; 515—Liquid distribution channel; 6—Wind speed sensor; 7—Controller; 8—Liquid storage chamber. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] The pesticide spraying device of the present invention, such as Figures 1 to 3 As shown, it includes a carrier 1, which can be an aerial vehicle, such as a drone, specifically the drone carrier disclosed in the applicant's existing patent CN201922291972.1 - A Drone for Spraying Pesticides. The carrier 1 can also be a vehicle that travels on the ground, such as the vehicle body used in the applicant's existing patent CN202422711208.6 - Spraying Equipment and All-Terrain Spraying Vehicle.

[0020] The carrier 1 is equipped with a medicine tank 2, which is used to hold the prepared pesticide. A dosing port is located on the top of the medicine tank 2 for adding pesticide. The dosing port is equipped with a removable sealing cap to prevent external debris from falling into the medicine tank 2. The medicine tank 2 can be of various shapes, such as cylindrical or cuboid, and its outer wall is equipped with connecting plates, connecting columns, and other connecting components, allowing it to be detachably installed onto the carrier 1 using bolts or similar means.

[0021] The pesticide tank 2 is connected to a drive pump 3, and the drive pump 3 is connected to an atomizing nozzle 4. The drive pump 3 is connected to the bottom of the inner cavity of the pesticide tank 2 and is used to deliver the pesticide in the pesticide tank 2 to the atomizing nozzle 4. The atomizing nozzle 4 is used to atomize the pesticide into fine droplets and spray them out. Under normal circumstances, the spray direction of the atomizing nozzle 4 is downward.

[0022] The atomizing nozzle 4 includes an atomizing chamber 41 for atomizing pesticides into droplets and a nozzle 42 for spraying the droplets. An atomizing mechanism is installed inside the atomizing chamber 41. This mechanism can employ any existing technology, such as a centrifugal atomizing disc. The centrifugal atomizing disc is connected to a drive motor, which rotates the disc at 5000-15000 rpm. After the pesticide enters the disc, it forms a liquid film under centrifugal force. This film breaks into fine droplets with a diameter of 50-100 μm at the edge of the disc. The pesticide in the pesticide tank 2 is delivered to the atomizing chamber 41 by a drive pump 3 and then sprayed out through the nozzle 42 after atomization.

[0023] The outer wall of the nozzle 42 is provided with an annular inner air chamber 5, which surrounds the nozzle 42. The inner air chamber 5 is connected to an air supply mechanism 51 and a bubble generating mechanism 52 for generating bubbles. The air supply mechanism 51 can deliver outside air to the inner air chamber 5, specifically using an air pump. To prevent solid impurities in the air from entering the equipment, the air pump inlet is provided with a filter mechanism 513, which can filter out solid impurities in the air, specifically using conventional filter elements such as wire mesh. The bubble generating mechanism 52 generates bubbles with a diameter larger than the droplet diameter; specifically, the bubble generating mechanism 52 is used to generate microbubbles with a diameter of 50-500 μm. The droplet size after atomization in the atomization chamber 41 is 50-100 μm. The bubbles mix with the air in the inner air chamber 5. The bottom of the inner air chamber 5 has an inner air curtain opening 54 for forming an annular air curtain 53, which carries the bubbles. An annular air curtain 53 surrounds the droplet movement space 46, which is the space through which the droplets travel from the nozzle 42 to the crop. In this invention, the droplet movement space 46 is cylindrical. The center of the annular air curtain 53 coincides with the center of the droplet movement space 46, thus enclosing the droplet movement space 46. The annular air curtain 53 gradually contracts towards the droplet movement space 46 along the gas flow direction, forming a cone shape with its tip pointing downwards. As the droplets ejected from the nozzle 42 move downwards, the annular air curtain 53 tilts downwards, gradually intersecting with the droplet movement space 46. This allows the droplets to collide with air bubbles within the annular air curtain 53 before reaching the crop. In this invention, the upper diameter of the annular air curtain 53 is relatively large, meaning the distance from the annular air curtain 53 to the center of the nozzle 42 is relatively large. Therefore, a support can be installed on the outer wall of the nozzle 42 to mount the inner air chamber 5.

[0024] The working process of this invention is as follows: the bubble generating mechanism 52 generates microbubbles with a diameter of 50-500 μm, which enter the inner air chamber 5; the air supply mechanism 51 delivers outside air to the inner air chamber 5, where the microbubbles mix with the air and are then ejected from the inner air curtain opening 54, forming an annular air curtain 53. Simultaneously, the drive pump 3 delivers pesticide from the pesticide tank 2 to the atomization chamber 41, where it is atomized into tiny droplets with a particle size of 50-100 μm and then ejected from the nozzle 42. The distance between the nozzle 42 and the crop is a conventional distance. After the tiny droplets are ejected, they move towards the crop in the droplet movement space 46, while the annular air curtain 53 first surrounds the droplet movement space 46. When the droplets approach the crop, the annular air curtain 53 intersects with the droplet movement space 46, and the droplets collide with the bubbles in the annular air curtain 53. During the collision, the kinetic energy and speed of the droplets decrease. During the collision, some bubbles burst, some bubbles encapsulate droplets, and some bubbles are deflected by droplets. After the collision, droplets and bubbles form a mixed fluid that flows toward the crop. The increased air resistance of the mixture further reduces the speed at which droplets reach the crop, thereby reducing the splashing rate of droplets and minimizing pesticide waste.

[0025] While the annular air curtain 53 provides some protection against crosswinds, external crosswinds can affect its normal movement, potentially causing bubble separation within it. To more effectively mitigate the adverse effects of crosswinds, this invention provides an annular outer air chamber 55 on the outer wall of the inner air chamber 5. The bottom of the outer air chamber 55 has an outer air curtain opening 58 for forming an annular outer air curtain 57. The outlet direction of the outer air curtain opening 58 can be parallel to the injection direction of the nozzle 42. In a preferred embodiment, the outlet direction of the outer air curtain opening 58 deviates from the injection direction of the nozzle 42, making the annular outer air curtain 57 trumpet-shaped, and its diameter gradually increases along its flow direction. Using this annular outer air curtain 57, when horizontally flowing crosswinds reach it, it provides better force relief, preventing crosswinds from penetrating the annular outer air curtain 57 and reaching the annular air curtain 53.

[0026] The inner air chamber 5 and the outer air chamber 55 can each use different air sources. To reduce equipment costs and energy consumption, the inner air chamber 5 and the outer air chamber 55 are connected to the air supply mechanism 51 via a first air pipe and a second air pipe, respectively. Both the first and second air pipes are equipped with valves 56, which are solenoid valves. The air intake of the air supply mechanism 51 is divided into two parts: one part is delivered to the inner air chamber 5 via the first air pipe to form an annular air curtain 53, and the other part is delivered to the outer air chamber 55 via the second air pipe to form an annular outer air curtain 57. The valves 56 are used to regulate the air supply volume of the first and second air pipes. A wind speed sensor 6 and a controller 7 are installed on the carrier 1, and the air supply mechanism 51, valves 56, and wind speed sensor 6 are all connected to the controller 7. Wind speed sensor 6 is used to detect the wind speed in the external environment and transmits the detection signal to controller 7. Controller 7 adjusts the air intake flow rate of air supply mechanism 51 and the air flow rate of the second air pipe according to the detection result, so that when the external wind speed increases, the wind speed of the annular outer wind curtain 57 increases, and when the external wind speed decreases, the wind speed of the annular outer wind curtain 57 decreases. The wind speed of the annular wind curtain 53 remains stable.

[0027] When the number of bubbles in the annular air curtain 53 is small, the probability of droplet-bubble collision is low, and the droplet deceleration effect is average. When the number of bubbles is large, they may be too dense, leading to more bubbles colliding and breaking. Simultaneously, the annular air curtain 53 is more prone to turbulence, resulting in poor stability, and the bubble generation mechanism 52 consumes more energy. In this invention, the volume of bubbles in the annular air curtain 53 accounts for 10%-25% of the total volume of the annular air curtain 53, preferably 15%-20%, ensuring a high probability of collision between droplets and bubbles, achieving a good deceleration effect, while reducing the probability of bubbles colliding and breaking.

[0028] In this invention, the air velocity ejected from the inner air curtain 54 is 10-20 m / s to ensure the stability of the annular air curtain 53 shape. The droplet velocity ejected from the nozzle 42 is 10-20 m / s, which is the conventional ejection velocity. The air velocity ejected from the inner air curtain 54 is controlled by the air supply mechanism 51. The ejection velocity of the inner air curtain 54 is the same as or close to the ejection velocity of the nozzle 42. Because the bubbles in the annular air curtain 53 have a large diameter and are lightweight, they experience greater air resistance. Therefore, the velocity decay of the bubbles is greater than that of the droplets. When the droplets and bubbles meet, the velocity of the bubbles will be less than that of the droplets, thus slowing down the droplets.

[0029] The bubble generating mechanism 52 can be set independently and transports the generated bubbles to the inner air chamber 5 via airflow. To reduce the amount of bubble breakage during movement, the bubble generating mechanism 52 is set in the inner air curtain 54. Specifically, an annular liquid distribution chamber 514 is provided in the inner air chamber 5. The liquid distribution chamber 514 is connected to a liquid storage chamber 8 via a liquid supply pump 512. The liquid storage chamber 8 can be a container of various shapes and contains bubble generating liquid, which is used to generate bubbles. The bubble generating mechanism 52 is an annular filter screen set in the inner air curtain 54. The diameter of the filter pores of the annular filter screen is 20-200μm, and the annular filter screen slopes downward from its inner pores to its outer edge, that is, the annular filter screen is frustum-shaped. The bottom of the liquid distribution chamber 514 is connected to the edge of the inner hole on the upper surface of the annular filter screen through the liquid distribution channel 515. The liquid distribution channel 515 can be an annular notch set at the lower end of the liquid distribution chamber 514. In order to ensure that the bubble generating liquid is evenly distributed on the annular filter screen, a liquid distribution mechanism can be set in the liquid distribution chamber 514, such as an annular pipe. The bottom of the pipe is provided with a uniform liquid outlet to evenly transport the bubble generating liquid into the annular liquid distribution chamber 514.

[0030] When spraying pesticides, the supply pump 512 delivers the bubble-generating liquid from the storage chamber 8 to the distribution chamber 514. The bubble-generating liquid in the distribution chamber 514 flows along the distribution channel 515 to the upper end of the annular filter screen, and then flows downward under the action of gravity, thereby forming a liquid film on the upper surface of the annular filter screen. In this invention, the width of the annular filter screen is very small, and the bubble-generating liquid can be quickly dispersed on the annular filter screen. The air supply mechanism 51 provides flowing air to the inner air chamber 5. When the air passes through the annular filter screen, bubbles are generated, the principle of which is the same as that of a common bubble machine. The generated bubbles can be discharged with the air flow, forming an annular air curtain 53 carrying bubbles. The amount of bubbles generated is related to the supply amount of bubble-generating liquid. The more bubble-generating liquid supplied per unit time, the more bubbles there are. Therefore, the bubble content is controlled by controlling the flow rate of the supply pump 512. The diameter of the bubbles obtained by air passing through the annular filter is usually 1.5-3 times the diameter of the filter pores. The diameter of the filter pores of the annular filter is 20-200μm, which can produce microbubbles with the required size.

[0031] The bubble-generating liquid can be any existing aqueous solution capable of stably generating bubbles. Preferably, the bubble-generating liquid contains 92%-96% water by weight, 1%-3% alkyl glycosides as surfactants by weight, 2%-5% glycerol by weight, and 0.05-0.2% xanthan gum by weight. Alkyl glycosides are non-toxic and harmless and biodegradable, glycerol is safe and non-toxic, and xanthan gum is also a harmless component, meeting environmental protection requirements and not causing secondary pollution.

[0032] The outer wall of the inner air curtain 54 is provided with two insulating first mounting sleeves 59. Each of the two first mounting sleeves 59 has annular negative electrodes 510 on its sidewall. The negative electrodes 510 are connected to a negative voltage power supply 511 with a voltage of -5kV to -15kV. The annular air curtain 53 is located between the two negative electrodes 510. The outlet end of the nozzle 42 is connected to an insulating second mounting sleeve 43. The inner wall of the second mounting sleeve 43 has annular positive electrodes 44, which are connected to a positive voltage power supply 45 with a voltage of 5kV to 15kV. The first mounting sleeves 59 and the second mounting sleeve 43 can be ceramic bushings, providing insulation, voltage resistance, waterproofing, and leakage prevention, ensuring high-voltage safety and adapting to humid liquid environments. The negative electrodes 510 are two coaxial annular electrodes. The annular air curtain 53 passes through the gap between the two negative electrodes 510. When bubbles in the annular air curtain 53 pass through the negative electrodes 510, corona charging and contact induced charging occur, resulting in a surface charge density of 80 to 200 microcoulombs per square meter. The inner hole of the positive electrode 44 serves as a channel for atomized droplets. When droplets pass through the positive electrode 44, they acquire a positive charge of 1 to 3 millicoo per kilogram with a suitable charge-to-mass ratio. When the voltage is below 5 kV, the charge is insufficient, and the electrostatic attraction and charge neutralization effects are not significant. When the voltage is above 15 kV, air ionization discharge is likely to occur, causing energy loss and safety hazards.

[0033] When the bubble and droplet are uncharged, there are three possible scenarios when the droplet and bubble collide: When a droplet collides with a bubble at a high speed, its kinetic energy exceeds the bubble's surface energy, causing it to pierce the bubble and break into multiple smaller bubbles. In this case, some of the droplet's kinetic energy is consumed in the bubble bursting process, resulting in a decrease in its velocity.

[0034] When a droplet is encased in a bubble, and the droplet's velocity is moderate while the bubble diameter is significantly larger than the droplet's diameter, the droplet may embed itself inside the bubble without puncturing the bubble wall, forming a composite structure of bubble-encased droplet. The overall density of this composite structure is much lower than that of a pure droplet, resulting in significantly increased air resistance and further deceleration. Upon reaching the crop surface, the bubble bursts, and the droplet settles at an extremely low velocity.

[0035] When the droplet velocity is low or the surface tension of the bubble is high, the droplet cannot overcome the elastic resistance of the bubble after contacting it, and the bubble bounces the droplet away, separating the two. In this case, almost no momentum exchange occurs, the droplet velocity remains basically unchanged, and the deceleration effect is the worst.

[0036] It is evident that, among the three scenarios described above, bubble enveloping the droplet is most beneficial for slowing down the flow, followed by bubble bursting.

[0037] When bubbles and droplets become negatively charged and positively charged respectively, the following effects occur: 1. Bubbles and droplets can attract each other, increasing the probability of collision between droplets and bubbles, thus ensuring the deceleration effect of the droplets.

[0038] 2. The fundamental reason for the bubble's bounce when uncharged is that the droplet's kinetic energy is insufficient to overcome the bubble's surface energy, and the bubble's elastic restoring force pushes the droplet away. Electrostatic attraction provides the droplet with additional approach kinetic energy. The droplet and bubble begin to accelerate each other at a distance on the order of millimeters, and the relative velocity at the moment of contact is higher than in the uncharged state, significantly increasing kinetic energy and the probability of bubble breakage. Furthermore, the energy released during charge neutralization weakens the bubble's surface stability. The energy released during the neutralization of positive and negative charges at the contact interface acts on the bubble wall, reducing the local surface tension and elastic modulus, making the bubble more easily penetrated by the droplet rather than bounced away. Charge neutralization alters the interfacial wettability. The positive charge on the droplet surface and the negative charge on the bubble surface form a local electric field before contact. This electric field changes the wetting characteristics of the droplet-bubble interface, making the droplet more inclined to merge with the bubble rather than repel it. Therefore, when the bubble and droplet are respectively negatively and positively charged, the bubble bounce almost disappears, thus improving the deceleration effect on the droplet.

[0039] 3. When a positively charged droplet comes into contact with a negatively charged bubble, the opposite charges on their surfaces neutralize each other. This neutralization reaction follows the law of charge conservation, resulting in a neutral state where the positive and negative charges combine, releasing stored electrostatic energy. The amount of energy released depends on the charge and potential difference. Within the voltage parameters of this invention, the energy released in each neutralization is approximately 2 to 30 microjoules. Although this energy is small, it produces significant physicochemical effects when acting on the droplet surface. The energy release occurs precisely at the contact interface between the droplet and the bubble; this localized energy input temporarily reduces the free energy of the droplet surface, resulting in a decrease in surface tension.

[0040] Furthermore, the surface tension of a liquid originates from the unbalanced intermolecular forces acting on its surface molecules. When the energy released by charge neutralization acts on the droplet surface, it disrupts the ordered arrangement of surface molecules, temporarily weakening the intermolecular forces. Simultaneously, the energy release may cause a slight increase in local temperature, further reducing surface tension. At the same time, the charge density on the droplet surface decreases after charge neutralization. According to the principle of electrowetting, surface tension is inversely proportional to the square of the charge density; therefore, a reduction in charge also leads to a decrease in surface tension.

[0041] As can be seen, the present invention can effectively reduce the surface tension of droplets, making it easier for droplets to spread and wet crops when they reach them, thus further reducing the splashing rate.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pesticide spraying device, comprising a carrier (1), wherein a pesticide tank (2) is disposed on the carrier (1), the pesticide tank (2) is connected to a drive pump (3), and the drive pump (3) is connected to an atomizing nozzle (4), characterized in that: The atomizing nozzle (4) includes an atomizing chamber (41) for atomizing pesticides into droplets and a nozzle (42) for spraying the droplets. The outer wall of the nozzle (42) is provided with an annular inner air chamber (5). The inner air chamber (5) is connected to an air supply mechanism (51) and a bubble generating mechanism (52) for generating bubbles. The diameter of the bubbles is larger than the diameter of the droplets. The bottom of the inner air chamber (5) is provided with an inner air curtain opening (54) for forming an annular air curtain (53). The annular air curtain (53) surrounds the droplet movement space (46), and the annular air curtain (53) gradually contracts towards the droplet movement space (46) along the gas flow direction, so that the droplets collide with the bubbles in the annular air curtain (53) before reaching the crops. During the collision, the kinetic energy of the droplets decreases and the speed decreases. After the collision, the droplets and bubbles form a mixed fluid and flow towards the crops. The air resistance of the mixture increases, further reducing the speed of the droplets when they reach the crops, thereby reducing the splash rate of the droplets. The outer wall of the inner air curtain (54) is provided with two insulating first mounting sleeves (59). The side walls of the two first mounting sleeves (59) are provided with annular negative electrodes (510). The negative electrodes (510) are connected to a negative voltage power supply (511) with a voltage of -5kV to -15kV. The annular air curtain (53) is located between the two negative electrodes (510). The outlet end of the nozzle (42) is connected to an insulating second mounting sleeve (43). The inner wall of the second mounting sleeve (43) is provided with an annular positive electrode (44). The positive electrode (44) is connected to a positive voltage power supply (45) with a voltage of 5kV to 15kV. When the bubble passes through the negative electrode (510) in the annular air curtain (53), corona charging and contact induction charging occur; when the droplet passes through the positive electrode (44), it gains positive charge; when the positively charged droplet comes into contact with the negatively charged bubble, the opposite charges on their surfaces undergo a neutralization reaction, releasing the stored electrostatic energy. The energy release location is exactly at the contact interface between the droplet and the bubble. Local energy input will temporarily reduce the free energy of the droplet surface, which manifests as a decrease in surface tension. The bubble generating mechanism (52) is used to generate microbubbles with a diameter of 50-500μm; the volume of the bubbles in the annular air curtain (53) accounts for 10%-25% of the total volume of the annular air curtain (53); the droplet size after atomization in the atomization chamber (41) is 50-100μm. The air velocity ejected from the inner air curtain (54) is 10-20 m / s, and the droplet velocity ejected from the nozzle (42) is 10-20 m / s; The inner air chamber (5) is provided with an annular liquid distribution chamber (514). The liquid distribution chamber (514) is connected to a liquid storage chamber (8) through a liquid supply pump (512). The liquid storage chamber (8) is provided with bubble generating liquid. The bubble generating mechanism (52) is an annular filter screen provided in the inner air curtain (54). The diameter of the filter holes of the annular filter screen is 20-200μm, and the annular filter screen is inclined downward from its inner hole to its outer edge. The bottom of the liquid distribution chamber (514) is connected to the inner hole edge of the upper surface of the annular filter screen through the liquid distribution channel (515).

2. The pesticide spraying device of claim 1, wherein: The outer wall of the inner air chamber (5) is provided with an annular outer air chamber (55), and the bottom of the outer air chamber (55) is provided with an outer air curtain opening (58) for forming an annular outer air curtain (57); the inner air chamber (5) and the outer air chamber (55) are respectively connected to the air supply mechanism (51) through the first air pipe and the second air pipe, and valves (56) are provided on both the first air pipe and the second air pipe; the carrier (1) is provided with a wind speed sensor (6) and a controller (7), and the air supply mechanism (51), valves (56) and wind speed sensor (6) are all connected to the controller (7).

3. The pesticide spraying device of claim 1, wherein: The air supply mechanism (51) is an air pump, and the air inlet of the air pump is equipped with a filter mechanism (513).

4. The pesticide spraying device of claim 1, wherein: The carrier (1) is a drone or a mobile vehicle.

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