A thorough study of electrostatic spraying of liquids is incomplete without a look at the electrostatic discharge formula. This particular branch of applied science deals with the transfer of electric charge from an electrostatic body to an electrically conductive one. Electrostatic discharges are conducted through the application of strong electrical charges to systems where no current is present. The aim of this technique is to develop the use of static discharge systems for various applications in industries such as electronics, power generation, photovoltaic panels and hybrid cars.
Developing the electrostatic discharge system using aqueous solutions and inks for coating solid and non-solid surfaces respectively is the heart of this discipline. It uses the principle of direct and indirect current, which means that the charge of an electrostatic charge will be dependent on the difference in potential between the two systems. The term ‘discharge’ refers to the complete loss of charge from a fluid. The discharge may take the form of vaporization, loss of charge in some other chemical reaction or it can also be in the form of very high voltage output. It should be kept in mind that aqueous solutions and inks do not create a high voltage output by themselves; they are used only as a guide for the voltage.
A small gap is first opened in the liquid medium using a syringe gun. The high voltage generator is then connected across the gap and directed towards the electrostatic spraying nozzle. The syringe gun is then released so that the nozzle may spray a mixture of solution onto the charged plates. A nozzle may also be connected directly to the source of high voltage electricity so that the process can be reversed. In all these cases, it is important that the distance between the two terminals is not more than five millimeters from one another.
For the actual electrostatic spraying of liquids, a suitable solution may be mixed with the chemical being sprayed. This solution may be in the form of a foam, which can be sprayed on the charged surfaces. This foaming agent acts like a dynamic charge attracting particles such as dust, sand, etc., which are found on the surface of the metal objects. As time passes, the attraction of such particles with the static charge continues and thus the particles reach the end of the metal object. The length of this process depends upon the strength of the electrostatic charge and also the size of the particles being sprayed.
For electrostatic spraying of liquids at the input side of the electrohydrodynamic generator, a small hole with a small hole outlet is first pierced through the earthed object. The outlet of this small hole may be constructed so that the spray comes out from the opposite side of the nozzle as well. This way, the chemical being sprayed is directed to the area where it will have the least interaction with any liquid. A very strong current is then induced inside the electrohydrodynamic generator by means of this small hole outlet, and this current is sufficiently strong to induce electric discharges of very high voltage output, as well as to generate a huge electrostatic charge around the nozzle and the earthed object.
This electrostatic spraying apparatus is very efficient and produces a very good and steady stream of charge. The discharge produced by this electrostatic spraying device is about one volt per meter, but this depends on the input voltage that is provided. The output of this device is therefore far higher than the output of an ordinary electric shaver. The output of this electrostatic spraying apparatus is however, only effective when there is no contact between the electrostatic charge around the electrode and the particular area being charged.
Some types of electrostatic sprayers are connected with a panel. The panel has a coating or an outer coating that glows when the electrostatic sprayer discharges. This type of electrostatic sprayer is not as efficient as the one that is connected with a plastic membrane. This type of electrostatic spraying device uses two electrodes which are connected in series in such a way that the two electrodes are connected in series. This method gives better and more even distribution of charge.
This type of electrostatic spraying device produces the high voltage that is also capable of destroying electrically sensitive components. It is capable of doing this by inducing large amount of current in a very small amount of space. This high voltage generation is done by using a high power output device and a low voltage generator means producing fewer impulses. It is also a very fast discharge.