WO2021118490A1

WO2021118490A1 - A new unit to charge spray droplets with static electricity produced by turbo atomizers in the pesticide application

Info

Publication number: WO2021118490A1
Application number: PCT/TR2020/050295
Authority: WO
Inventors: Ali BAYAT; Kemal AMAYA
Original assignee: Cukurova Universitesi
Current assignee: Cukurova Universitesi
Priority date: 2019-12-13
Filing date: 2020-04-08
Publication date: 2021-06-17
Anticipated expiration: 2022-06-13

Abstract

This invention relates to a new system that creates an electrical field between static-charged pesticide droplets and target tree parts (leaves, bodies and branches), enabling the sprayed droplets to reach the target directly.

Description

A NEW UNIT TO CHARGE SPRAY DROPLETS WITH STATIC ELECTRICITY PRODUCED BY TURBO ATOMIZERS IN THE PESTICIDE APPLICATION TECHNICAL FIELD

The invention relates to a new system that creates an electrical field between static-charged agricultural pesticide droplets and target tree parts (leaves and branches), enabling the sprayed droplets to reach the target directly. BACKGROUND

Turbo atomizers are widely used in the application of pesticides to fruit trees and vineyards. In applying pesticides to fruit trees, it is more difficult to manage the droplets by mechanical methods than field crops, as the tree crown geometric measurements are quite different, the gaps between and above the rows and the droplets directed to the target are under the influence of gravitational force along their long trajectory. Since fruit trees and vineyards to be sprayed are higher than turbo atomizer, due to this, the droplets produced by pressure in classic type turbo atomizers are transported to the target surfaces with the air current provided by an atomizer fan. However, the airspeed used, tree height, the spaces on the rows and the pesticide success vary depending on the vegetative period of the tree. In other words, droplets leaving the nozzle form drops track according to the air jet profile of the assisted airflow created by the fan on the machine, but only the leaves on the droplet trajectory are exposed to the pesticide. In this case, the under surface of the leaves is not exposed to the pesticide. Due to the pesticide drifting away from fruit trees and inadequate machine efficiency, more pesticides are always sprayed than necessary. One of the most effective methods for producing lower pesticide consumption than traditional pesticide spraying methods on turbo atomizers is the electrostatic charging of spray droplets to be delivered to the target. Electrostatic forces on the spray droplets create an electrical attraction between these droplets and the plant. This electrical attraction not only increases the ratio of droplets reaching on the plant but the pesticides also reach the under surface of the leaves, allowing control of the pests and diseases on the under leaf surfaces.

Although many kinds of research have been conducted on electrostatic spraying of liquids, electrostatic has been applied to limited models of sprayers offered to the market. The main reasons for this are the difficulties in the design of the electrostatically charged sprayers, some physical and electrical properties of the sprayed liquid and the various effects depending on the characteristics of the target plant. The design in the available invention US5039019 (A) has been developed for liquid paint applications in the industrial field and developed for liquid with different physical electrical properties (e.g. higher surface tension and lower conductivity than water) than spray liquids used in agricultural treatments. The charging method on the available invention is intended to charge paint droplets produced from a rotating disc with static electricity, so they cannot be applied to the hydraulic nozzles on turbo atomizers used in pesticide applications.

In the available invention US5039019 (A), for charging paint droplets exiting from the rotary disc nozzle, it used pins which have short ends extend through in a semi-conductor ring, which has insulated outer surfaces. However, in the unit we have developed, the ring performs a homogeneous charging throughout the entire body of the spray nozzle electrode. Also, in the patent US5039019 (A), paint drops leaving the rotary disc can be neutralized by wetting. However, in the system we have developed, droplets do not neutralize by wetting as high-speed airflow passes between the droplet cloud and the ring electrode. Thus, the electrode will stay dry and the droplets are charged with a higher charge to mass ratio with a more efficient charging.

While the high voltage used in patent US5039019 (A) is 60-100 kV, the charging voltage in the system we developed is 5-10 kV, it contains less risk in terms of human safety and the insulation of the high voltage can be made at lower costs.

Although some systems that charge spray droplets with electrostatic are available on the market, they can only be applied to machines with radial fans which can produce very high air velocity. However, although the air velocity is high in machines with radial fans, the low airflow rate of this type of fan reduces the demand for such machines. Manufacturers prefer classic type turbo atomizers due to high airflow rate. However, a significant part of the material sprayed in these machines does not reach the target. However, the electrostatic charging system, which has been developed and can be easily adapted to the existing spray system of classical type turbo atomizers, ensures a more effective application of pesticides. This system can be adapted directly onto the existing nozzles without making any mechanic modification to the spray unit of the turbo atomizers. BRIEF DESCRIPTION OF THE INVENTION

As a result of intensive use of pesticides product, soil and water pollution occur with increasing pesticides. One of the ways to reduce this pollution caused by pesticides used for plant protection purposes in agriculture is to ensure that the sprayed pesticide reaches the target surfaces with certainty and to ensure less pesticide consumption in the unit area.

Turbo atomizers (air assisted orchard sprayer) are widely used in the application of pesticides to orchards and vineyards. In this type of sprayers, the liquid pesticide droplets are produced by the pressure provided by a pump in the hydraulic nozzles and the resulting droplets are carried to the tree with the airflow provided by an axial fan on the sprayer. In applications with classic type turbo atomizers, only a small part of the total spray amount deposits on the target, while the rest is a chemical that causes plenty of environmental problems. In applications with classical turbo atomizers, especially the skirts of the tree crown are exposed to more pesticides, while the upper parts of the tree crown and the inner parts of the tree crown are exposed to fewer pesticides. This is considered as an undesirable pesticide distribution. In addition, the high-speed airflow carrying the droplets in classical type turbo sprayers causes some droplets to deviate from the target without allowing them to deposits on the tree as there is no additional force such as the electrostatic force that diverts the drops from the carrier air track. However, gratitude to our present invention, an electrostatic force effecting on the droplet changes the track of the droplet, allowing it to deposits on the target leaf surfaces (Figure 1). This new design with electrostatic charging, which can be adapted on conventional type turbo atomizers, will be made more effective in turbo atomizers, which are widely used in tree spraying, but have low pesticide retention efficiency and too much pesticide loss.

LIST OF FIGURES

Figure 1. A new unit that charges droplets with electrostatic in the application of pesticides with turbo atomizers Figure 2. Isometric view of a fan housing of the invention

Figure 3. Front view of fan housing /rear view of sprayer

Figure 4. Partial Cross-section B-B View of Fan housing

Figure 5. Isometric view of the electrostatic charging unit

Figure 6. Front view of the electrostatic charging unit of the invention Figure 7. Side partial section a-a view of the electrostatic charging unit

The numbers given in the figures correspond to:

1. Fan Hosing.

2. Electrostatic Charging Unit.

3. Fan Protective Cage.

4. Fan Air Director

5. Fan

6. Spray Liquid Hose

7. Spray Liquid Hose Inlet

8. Static Charging Cage

9. Air Holes surrounding the electrode

10. Electrostatic Electrode

11. High Voltage Cable

12. Spray Liquid Inlet

13. Spray Nozzle Body

14. Nozzle Orifice

15. High-Speed Air Duct Through Static Charging Cage DETAILED DESCRIPTION OF THE INVENTION

The present invention charges droplets produced by standard type turbo atomizers used in fruit trees and vine with static electricity. Thus, an electrical attraction field is formed between the static electrically charged droplets and the tree parts. A force equal to Coulomb tensile force (F=drop charge x electric field strength) is applied to the droplets charged with static electricity, this force overcomes the gravitational force (G=m.g) and allows the droplets to reach the targeted surfaces, not the ground. Thus, under surface of leaves that cannot be reached by the classical spraying method are also exposed to the pesticides. So that a better pesticide deposit is provided and pesticide consumption is decreased. In this invention, a ring-shaped electrostatic electrode (10) located at the tip of the nozzle is placed on the existing nozzle to charge the droplets with static electricity. In order to prevent sprayed and electrostatically charged droplets from depositing on the ring electrode (10), a high-velocity air flow is sent to the ring electrode (10) from the air holes (9) which are opened in a cage (8) and surround the electrostatic electrode (10). Thus, charged droplets are more stable on the target and environmental pollution is prevented as pesticide wastage will be reduced. This invention shall be applicable to all turbo atomizer with an axial fan-produced and offered to the market by many manufacturers.

This invention consists of parts of fan housing (1), electrostatic charging unit (2), fan protection cage (3), fan air director (4), fan (5), spray liquid tube (6), spray liquid tube inlet (7), static charging cage (8), air holes surrounding the electrode (9), electrostatic electrode (10), high voltage cable (11 ), spray fluid inlet (12), spray nozzle body (13), nozzle orifice (14), high-speed air duct (15) high-speed air duct through static charging cage.

The unit, which charges the droplets with static electricity, is placed on the nozzle body (13) located on the back part of the turbo atomizer, this unit charges the droplets exiting from the nozzles by induction charging. The high voltage used in the charging operation is provided from a DC source providing voltage from the battery on the tractor. The droplets from each nozzle on the atomizer are charged with a ring electrode (10) made of nickel and its base is designed as a frustum of a cone. The connection form of the charging electrode (10) to be used in electrostatic charging on the nozzle is provided in Figure 5.

Air venture cage (8) provides high-speed air flow over the ring electrode (10) through the holes ( 9) in a cage (8) surrounding the electrode (10) in order to prevent the droplets which are sprayed and opposite to the ring electrode (10) from sticking to the ring electrode (10).

The 12 V DC current taken from the tractor battery is primarily supplied to a high voltage source, the resulting high voltage is transmitted by the High Voltage Cable (11 ) to the electrostatic electrode (10) surrounding the nozzle body of the turbo atomizer (13). The Electrostatic Electrode (10) is contained in a venturi-shaped static charging cage (8) and a base which has a frustum of a cone shape which allowed to air to pass in high-speed through the Holes surrounding the electrode (9).

The electrostatic electrode (10) charge the liquid droplets formed in the nozzle body (13) with the opposite charge, allowing the droplets to be charged, thereby also causing an opposite charge in the plant. The charged droplets would be attracted by opposing charged plants.

Claims

1. A system which charges droplets with static electricity in the turbo atomizers used in fruit and vineyard spraying characterizes by comprising;

- A static charging cage (8) in the form of the venturi surrounding the electrostatic electrode (10) to prevent wetting the electrostatic electrode (10) with the opposite droplets,

- Air holes (9) in the static charge cage (8) that surrounds the electrode that delivers high-speed airflow, on the electrostatic electrode (10),

- Electrostatic electrode (10) in a nickel-shaped ring form for charging droplets by the induction method,

- The high-voltage cable (11 ), which transmits the current from the tractor battery to the electrostatic electrode (10).