Electrostatic spraying ultrahigh-voltage induction charging device with preposed capacitor

Abstract

The invention relates to the field of agricultural plant protection, and particularly discloses an electrostatic spraying ultrahigh-voltage induction charging device with a preposed capacitor, which comprises a spraying system, an electrostatic generator, a high-voltage-resistant capacitor and a contact electrode, the electrostatic generator is connected with an upper polar plate of the high-voltage-resistant capacitor; a lower pole plate of the high-voltage-resistant capacitor is connected with the contact electrode; the contact electrode is arranged at the position, close to the nozzle, in the liquid medicine pipeline and is in direct contact with the spray liquid flow; and an induction charge electric field is formed between the upper polar plate of the high-voltage-resistant capacitor and the spray liquid flow. According to the electrostatic spraying ultrahigh-voltage induction charging device disclosed by the invention, induction charging can be performed on spraying liquid flow by using higher voltage, so that the charging capability of liquid drops is improved; in addition, the electrostatic spraying ultrahigh-pressure induction charging device can effectively prevent liquid drops from being reversely attracted to the induction electrode and wetting the nozzle, so that the charging stability is improved.

Description

Technical Field

[0001] The present invention relates to the field of agricultural plant protection, and particularly to an electrostatic spray ultra-high voltage induction charging device with a pre-positioned capacitor. Background Art

[0002] Electrostatic spraying of pesticide liquid is a common and efficient plant protection method, and its core lies in enhancing the deposition and coating effect of droplets on the plant surface through electrostatic force.

[0003] As Figure 2 shown, in a traditional electrostatic spray system, an induction electrode is usually arranged in the area where the spray liquid flow is ejected or preliminarily atomized, and the droplets are charged through the induction electric field. Specifically, the induction electrode and the spray liquid flow form a capacitor-like structure, with the induction electrode as the upper plate, the spray liquid flow as the lower plate, and air as the insulating medium in the middle, forming an electrostatic induction charging electric field, so that the droplets carry charges opposite in polarity to the induction electrode.

[0004] However, this method of post-positioning the capacitor (i.e., the spray liquid flow is atomized first and then charged) has the following inherent limitations: First, if the distance between the induction electrode and the spray liquid flow is relatively far, the induction electric field strength will be significantly attenuated; according to Coulomb's law, the electric field force is inversely proportional to the square of the distance. Therefore, as the distance increases, the induction electric field strength of the liquid will be significantly weakened, and the attraction of the weaker induction electric field to the charges in the spray liquid flow becomes smaller, resulting in the inability to effectively separate the positive and negative charges polarized and separated in the spray liquid flow, thereby reducing the charge amount of the droplets and further weakening the deposition efficiency of electrostatic spraying.

[0005] Second, if the induction electrode is too close to the nozzle, a relatively high voltage must be applied to ensure effective charging, which will cause the induction electric field strength between the spray liquid flow and the induction electrode to increase. As a result, under the action of the induction electric field, the molecules in the air medium will be ionized, making the originally insulating air medium become a conductive channel, and thus it is easy for the air medium to be broken down under the action of the strong induction electric field. After the air medium is broken down, the insulation performance is lost, forming a local conductive channel, which leads to the distortion of the electric field; after the droplets are charged, they carry charges opposite in polarity to the induction electrode, so they will be subjected to a strong reverse Coulomb attraction force, and under the action of this reverse Coulomb attraction force, they will be attracted back to the surface of the induction electrode and flow along the induction electrode, eventually wetting the nozzle.

[0006] After the surface of the nozzle is wetted by droplets, the local electric field is further distorted, that is, the electric field distribution near the nozzle becomes uneven, making the charging process of the spray liquid flow unstable, thus seriously reducing the charging consistency and reliability. At the same time, the droplets will lose some charges during the process of reverse Coulomb attraction and contacting the induction electrode, resulting in a decrease in the charge-mass ratio of the droplets, and ultimately affecting the charging intensity, atomization quality and deposition uniformity of the droplets.

[0007] In summary, due to problems such as limited electric field strength, easy breakdown of air medium, and reverse attraction of droplets to wet the nozzle, traditional induction charging methods usually can only use a charging voltage of about 1–8 kV, and cannot fully improve the charging ability of droplets, which limits the further improvement of the electrostatic spraying technology effect. Summary of the Invention

[0008] In order to overcome the deficiencies of the prior art, the present invention provides an electrostatic spraying ultra-high voltage induction charging device with a capacitor prepositioned. The electrostatic spraying ultra-high voltage induction charging device can use a larger voltage to inductively charge the spray liquid flow, increasing the charging ability of the droplets; in addition, the electrostatic spraying ultra-high voltage induction charging device can effectively prevent the droplets from being reversely attracted to the induction electrode and wetting the nozzle, thereby improving the charging stability.

[0009] The technical solution of the present invention to solve the above technical problems is: An electrostatic spraying ultra-high voltage induction charging device with a capacitor prepositioned, comprising a spraying system, an electrostatic generator, a high-voltage-resistant capacitor and a contact electrode. Among them, the electrostatic generator is connected to the upper plate of the high-voltage-resistant capacitor to provide electrostatic high voltage for the upper plate of the high-voltage-resistant capacitor; the lower plate of the high-voltage-resistant capacitor is connected to the contact electrode; the contact electrode is arranged inside the liquid medicine pipeline in the spraying system and close to the nozzle of the spraying system, and is in direct contact with the spray liquid flow; an induction charging electric field is formed between the upper plate of the high-voltage-resistant capacitor and the spray liquid flow.

[0010] Preferably, the spraying system includes a liquid storage tank, a diaphragm pump and a nozzle. Among them, the liquid storage tank, the diaphragm pump and the nozzle are connected through the liquid medicine pipeline; the liquid storage tank is used to store liquid medicine; the diaphragm pump is used to transport the liquid medicine to the nozzle through the liquid medicine pipeline for atomization.

[0011] Preferably, the distance between the contact electrode and the nozzle is less than or equal to 1 cm.

[0012] Preferably, the contact electrode adopts an annular structure, and the contact electrode is coaxially arranged with the liquid medicine pipeline.

[0013] Preferably, the contact electrode is made of brass.

[0014] Preferably, a solid insulating medium is provided in the high-voltage resistant capacitor.

[0015] Preferably, the solid insulating medium includes ceramics or epoxy resin.

[0016] Preferably, the positive electrode of the electrostatic generator is connected to the upper plate of the high-voltage resistant capacitor, and the negative electrode is grounded.

[0017] Preferably, the electrostatic generator provides electrostatic high voltage to the upper plate of the high-voltage resistant capacitor, so as to cause the upper plate of the high-voltage resistant capacitor to carry positive charge, while the lower plate of the high-voltage resistant capacitor carries negative charge. Under the polarization separation effect of electrostatic induction, the conductive ions in the spray liquid flow undergo directional migration, so as to cause the spray liquid flow to carry negative charge before atomization.

[0018] Preferably, the directional migration direction of the conductive ions is as follows: the negative charges in the spray liquid flow converge near the nozzle and the contact electrode, so as to cause the spray liquid flow near the nozzle and the contact electrode to carry negative charge; the positive charges in the spray liquid flow move away from the nozzle and the contact electrode, so as to cause the spray liquid flow far from the nozzle and the contact electrode to carry positive charge.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The upper plate in the high-voltage resistant capacitor in the electrostatic spray ultra-high voltage induction charging device of the present invention is connected to the upper plate of the electrostatic generator, and the lower plate is connected to the contact electrode. Moreover, an insulating medium with better insulating ability is adopted in the high-voltage resistant capacitor, thereby avoiding the high-voltage breakdown of the high-voltage resistant capacitor; based on the high-voltage resistant characteristics of the high-voltage resistant capacitor, the electrostatic spray ultra-high voltage induction charging device of the present invention can use a voltage of 10 - 40 kV or even higher to perform induction charging on the spray liquid flow, thereby enhancing the charging ability of the droplets, and further contributing to improving the electrostatic spray charging and coverage effect.

[0020] 2. The electrostatic spray ultra-high voltage induction charging device of the present invention adopts the method of pre-positioning the capacitor (induction electric field), so that the spray liquid flow can carry negative charge before being atomized. When the liquid flows through the area of the contact electrode, it is only affected by the electrostatic field induced by the upper plate of the high-voltage resistant capacitor. Therefore, the droplets can obtain stable negative charges (the upper plate is positive). When the spray liquid flow naturally sprays outwards, there will be no reverse attraction. At the same time, because the droplets themselves obtain a strong charge amount, this is beneficial to enhancing the subsequent deposition effect, thereby effectively avoiding the droplets being reversely attracted to the induction electrode and wetting the nozzle, and further improving the charging stability.

[0021] 3. The contact electrode of the electrostatic spraying ultra-high voltage induction charging device of the present invention is arranged inside the liquid medicine pipeline and close to the nozzle, ensuring the effective separation of positive and negative charges in the solution and the effectiveness of droplet charging. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the electrostatic spraying ultra-high voltage induction charging device of the present invention.

[0023] Figure 2 It is a schematic structural diagram of a traditional induction charging device.

[0024] In the figure: 1. Liquid storage tank; 2. Diaphragm pump; 3. Liquid medicine pipeline; 4. Nozzle; 5. Electrostatic generator; 6. High-voltage resistant capacitor; 7. Contact electrode; 8. Spray liquid flow; 9. Induction electrode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0026] See Figure 1 , the electrostatic spraying ultra-high voltage induction charging device with a capacitor in front of the present invention includes a spraying system, an electrostatic generator 5, a high-voltage resistant capacitor 6 and a contact electrode 7. Among them, The spraying system includes a liquid storage tank 1, a diaphragm pump 2 and a nozzle 4. Among them, the liquid storage tank 1, the diaphragm pump 2 and the nozzle 4 are connected through the liquid medicine pipeline 3; the liquid storage tank 1 is used for storing liquid medicine; the diaphragm pump 2 is used for transporting the liquid medicine to the nozzle 4 through the liquid medicine pipeline 3 for atomization; The electrostatic generator 5 is connected to the upper plate of the high-voltage resistant capacitor 6, and is used to provide electrostatic high voltage to the upper plate of the high-voltage resistant capacitor 6, with the negative electrode grounded; the high-voltage resistant capacitor 6 has a reliable insulating medium, so as to prevent the upper plate and the lower plate of the high-voltage resistant capacitor 6 from being broken down by high voltage. The lower plate of the high-voltage resistant capacitor 6 is connected to the contact electrode 7; the contact electrode 7 is arranged inside the liquid medicine pipeline 3 in the spraying system and close to the nozzle 4 of the spraying system, and is in direct contact with the spray liquid flow 8 to attract the charges in the spray liquid flow 8 that are opposite in polarity to the upper plate of the high-voltage resistant capacitor 6, so that when the spray liquid flow 8 is atomized to generate droplets, the droplets carry charges opposite in polarity to the upper plate of the high-voltage resistant capacitor 6, completing the droplet charging process; An induction charging electric field is formed between the upper plate of the high-voltage resistant capacitor 6 and the spray liquid flow 8.

[0027] In this embodiment, the contact electrode 7 must be installed close to the nozzle 4, and the distance is preferably within 1 cm. According to the polarization separation principle in induced charging: the formed induced charging electric field will attract opposite-polarity charges to accumulate near the nozzle 4, while the same-polarity charges will diffuse along the liquid medicine pipeline 3 towards the liquid storage tank 1 due to the repulsive force. Therefore, the contact electrode 7 shall not be placed far from the nozzle 4 or penetrate the entire liquid medicine pipeline 3. For example, if the contact electrode 7 extends along the conveying direction of the liquid medicine pipeline 3 or extends in the reverse direction, the flow path of the spray liquid flow 8 is long and the flow is disordered, resulting in the re-mixing of positive and negative charges, the failure of polarization separation, and thus the inability to effectively separate positive and negative charges, leading to a significant decrease in the charging ability.

[0028] In addition, the electrostatic generator 5 can provide an electrostatic high voltage of up to 10 - 40 kV or higher, depending on the ability of the insulating medium in the high-voltage-resistant capacitor 6 to prevent high-voltage breakdown. Among them, the high-voltage-resistant capacitor 6 can be selected from commercially available high-voltage-resistant capacitors 6 to achieve high-voltage breakdown prevention within the range of 10 - 50 kV; or the high-voltage-resistant capacitor 6 can be designed separately to increase the voltage application range of the electrostatic generator 5.

[0029] In this embodiment, the insulating medium of the high-voltage-resistant capacitor 6 in this embodiment can be selected from ceramics, epoxy resins, etc. Therefore, even if an ultra-high voltage (such as 40 - 60 kV) is applied, the insulating medium will not break down.

[0030] In addition, the structure and material of the contact electrode 7 can be optimized, such as adopting an annular structure, brass material, etc., to facilitate fixing inside the liquid medicine pipeline 3 and increase the contact area between the electrode and the liquid medicine.

[0031] See Figure 1 , the working principle of the electrostatic spray ultra-high voltage induced charging device with a capacitor prepositioned in the present invention is as follows: During operation, the electrostatic generator 5 provides electrostatic high voltage to the upper plate of the high-voltage-resistant capacitor 6. The lower plate of the high-voltage-resistant capacitor 6 is connected to the contact electrode 7 disposed inside the liquid medicine pipeline 3 and close to the nozzle 4, and the contact electrode 7 is in direct contact with the spray liquid flow 8 in the liquid medicine pipeline 3. Under the action of the electrostatic field, if the upper plate of the high-voltage-resistant capacitor 6 has a certain electric property (such as "+" electricity), then the lower plate of the high-voltage-resistant capacitor 6 is negatively charged. Under the polarization separation effect of electrostatic induction, the conductive ions in the spray liquid flow 8 migrate directionally. Among them, the negative charges in the spray liquid flow 8 gather near the nozzle 4 and the contact electrode 7, so as to make the spray liquid flow 8 near the nozzle 4 and the contact electrode 7 negatively charged, and the positive charges in the spray liquid flow 8 move away from the nozzle 4 and the contact electrode 7, so as to make the spray liquid flow 8 far from the nozzle 4 and the contact electrode 7 positively charged. In this way, it can be promoted that the spray liquid flow 8 is negatively charged before atomization. Therefore, when the spray liquid flow 8 at the nozzle 4 is atomized to generate droplets, the droplets are negatively charged, and thus the charging process of the droplets is completed.

[0032] In the above process, the contact electrode 7 must be placed close to the nozzle 4, rather than penetrating the liquid medicine pipeline 3 or the liquid storage tank 1. The contact electrode 7 is arranged close to the nozzle 4, so that the last section of the spray liquid flow 8 before spraying undergoes polarization separation directly in the strong electric field. Because the speed of the spray liquid flow 8 near the nozzle 4 gradually increases and contracts, it is extremely easy to form a complete and stable positive and negative charge separation structure here. After the spray liquid flow 8 is ejected from the nozzle 4, the charged droplets instantaneously break away from the liquid column, so that reverse attraction can be effectively avoided.

[0033] At this time, if the contact electrode 7 penetrates the entire liquid medicine pipeline 3 or is arranged inside the liquid storage tank 1, due to the long path and disordered flow of the spray liquid flow 8, the positive and negative charges will be mixed again, resulting in the failure of polarization separation and a significant decrease in the charging ability.

[0034] See Figure 2 , compared with the traditional method of placing the capacitor at the back, an induced charging electric field (capacitor electric field) is formed between the induction electrode 9 and the spray liquid flow 8. If the distance between them is too far, the charging effect will become worse; if the distance between them is too close, the charging voltage will be limited: if the voltage is too high, the charged droplets will be reversely attracted to the induction electrode 9 and wet the nozzle 4, causing the induced charging to start to change to contact charging, which makes the charging process unstable and the overall charging effect worse, reducing the charge-to-mass ratio of the droplets, which has been recorded in existing research papers. Therefore, restricted by this, the traditional electrostatic spray device with induced charging generally can only use a charging voltage of 1 - 8 kV, which seriously affects the further improvement of the charging efficiency.

[0035] In addition, in traditional induction charging, air between the induction electrode 9 and the spray liquid flow 8 is used as the insulating medium. However, when the voltage is too high, the air will be broken down. In the present invention, since the high-voltage resistant capacitor 6 contains a reliable insulating medium, the breakdown of the insulating medium caused by too high voltage can be avoided. Therefore, a higher charging voltage can be adopted to improve the charging ability.

[0036] In summary, by using the system solution of capacitor preposition (charging first and then atomizing), replacing the air medium with a high-voltage resistant insulating medium, and arranging the contact electrode 7 close to the nozzle 4, the present invention can effectively solve the problems of droplets being attracted in the reverse direction and the air medium being broken down by high voltage in the traditional induction charging method, and increase the threshold value of the charging voltage, thus helping to improve the induction charging effect.

[0037] Finally, by introducing the high-voltage resistant capacitor 6 between the electrostatic generator 5 and the contact electrode 7, and using the solid insulating medium in the high-voltage resistant capacitor 6 to replace the air medium used in the traditional induction charging method, the insulation voltage resistance performance is significantly improved, and the breakdown of the medium under the high-voltage electric field is effectively avoided. Since the induction electric field is constructed through the high-voltage resistant capacitor 6, potential isolation is achieved between the contact electrode 7 and the spray liquid flow 8, thus preventing the problem that the negatively charged droplets are attracted to the surface of the induction electrode in the reverse direction, avoiding the wetting of the nozzle 4 and the distortion of the charging electric field, and thus significantly improving the stability of droplet charging and the reliability of the spray system, enabling the induction charging to operate stably at a higher voltage and enhancing the operation effect of electrostatic spraying.

[0038] The above is the preferred embodiment of the present invention. However, the embodiments of the present invention are not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. An electrostatic spray ultra-high voltage induction charging device with a capacitor in front, characterized in that: It includes a spray system, an electrostatic generator, a high-voltage capacitor and a contact electrode, wherein the electrostatic generator is connected to the upper plate of the high-voltage capacitor to provide electrostatic high voltage to the upper plate of the high-voltage capacitor; the lower plate of the high-voltage capacitor is connected to the contact electrode; the contact electrode is arranged inside the liquid medicine pipeline in the spray system and close to the nozzle of the spray system, and is in direct contact with the spray liquid flow; an induced charging electric field is formed between the upper plate of the high-voltage capacitor and the spray liquid flow.

2. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 1, characterized in that: The spray system includes a liquid storage tank, a diaphragm pump and a nozzle, wherein the liquid storage tank, the diaphragm pump and the nozzle are connected through the liquid medicine pipeline; the liquid storage tank is used to store liquid medicine; and the diaphragm pump is used to transport the liquid medicine through the liquid medicine pipeline to the nozzle for atomization.

3. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 1, characterized in that: The distance between the contact electrode and the nozzle is less than or equal to 1 cm.

4. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 1, characterized in that: The contact electrode adopts an annular structure and is coaxially arranged with the drug solution pipeline.

5. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 1, characterized in that: The contact electrode is made of brass.

6. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 1, characterized in that: The high voltage capacitor is provided with a solid insulating medium.

7. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 6, characterized in that: The solid insulating medium includes ceramic or epoxy resin.

8. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 1, characterized in that: The positive electrode of the electrostatic generator is connected to the upper plate of the high-voltage capacitor, and the negative electrode is grounded.

9. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 1, characterized in that: The electrostatic generator provides electrostatic high voltage to the upper plate of the high-voltage capacitor to cause the upper plate of the high-voltage capacitor to be positively charged, while the lower plate of the high-voltage capacitor is negatively charged. Under the polarization separation effect of electrostatic induction, the conductive ions in the spray liquid flow migrate in a directional manner to cause the spray liquid flow to be negatively charged before it is atomized.

10. The capacitor-fronted electrostatic spray ultra-high voltage induction charging device according to claim 9, characterized in that: The directional migration direction of the conductive ions is as follows: the negative charges in the spray liquid flow gather near the nozzle and the contact electrode to cause the spray liquid flow near the nozzle and the contact electrode to be negatively charged; the positive charges in the spray liquid flow move in the direction away from the nozzle and the contact electrode to cause the spray liquid flow away from the nozzle and the contact electrode to be positively charged.

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