Static electricity in nature and technology

Static electricity in nature. Interesting Facts

1. For the first time, the electrification of liquids during crushing was seen at waterfalls in Switzerland in 1786. Since 1913 the phenomenon is called the balloelectric effect. The effect of electrification is observed not only at waterfalls in open areas, but also in caves.

Microscopic droplets of water and molecular complexes, which, when crushed, break away from the water surface and are carried into the environment, charge the air at the waterfalls.

The most significant effect of air electrification is observed at the largest waterfalls in the world - Iguassu on the border of Brazil and Argentina (height of water fall - 190 m, flow width - 1,500 m) and Victoria on the Zambezi river in Africa (height of water fall - 133 m, flow width -1600 m). At Victoria Falls, due to the crushing of water, an electric field of 25 kV / m arises.

When crushing fresh water, a negative charge passes into the air. Therefore, in the air at the waterfalls, the number of negative ions exceeds the number of positive ones.

At a small Uchan-Su waterfall in Crimea, the ratio of negative ions to the number of positive ions is 6.2.

2. Off the coast of the seas, air acquires a positive charge due to the spray of salt water. On the surface of the seas and oceans, water spray begins at a wind speed of more than 10 m / s, when scallops of foam appear on the waves. The ratio of positive charges to negative charges in the air over the Black and Azov Seas reaches 2.04 with a stormy sea, and 1.48 with swell.

3. The conqueror of the Jomolungma N. Tensing in 1953 in the area of ​​the southern saddle of this mountain peak at an altitude of 7.9 km above sea level at -30 ° C and a dry wind of up to 25 m / s observed strong electrification of ice-covered canvas tents, inserted one in another one. The space between the tents was filled with numerous electric sparks.

4. The movement of avalanches in the mountains on moonless nights is sometimes accompanied by a greenish-yellow glow, due to which the avalanches become visible. Typically, light phenomena are observed in avalanches moving on a snowy surface, and are not observed in avalanches sweeping over rocks. On the lakes of the Antarctic during the polar night, sometimes a glow occurs when breaking large masses of lake ice.

5. Lightning chooses the shortest path to the ground, so it ends up in buildings or trees. Tall buildings are equipped with metal strips (rods) along which an electric discharge goes into the ground. This is a lightning rod. Thunderstorm discharge goes to the ground and back along the same path.

This happens at such a rate that our eye sees only one flash. On its way, lightning heats the air, which, rapidly expanding, creates a sound wave. It causes thunderous peals. We hear them after we see lightning, as sound travels much more slowly than light.

Static electricity in technology. When electrifying bodies is good

Static electricity can be a faithful assistant to a person, if you study its laws and use them correctly. A technique is used in the technique, the essence of which is as follows.

The smallest solid or liquid particles of a material enter an electric field, where electrons and ions "settle" on their surface, that is, particles acquire a charge and then move under the influence of an electric field.

Depending on the purpose of the equipment, it is possible to control the movement of particles using electric fields in different ways in accordance with the necessary technological process. This technology has already made its way into various sectors of the national economy.

Painter without brush

Painted parts moving on a conveyor, for example, a car body, are positively charged, and a negative charge is imparted to the paint particles, and they rush to the positively charged part. The layer of paint on it is thin, uniform and dense.

Really charged dye particles of the same name repel each other - hence the uniformity of the staining layer. Particles dispersed by an electric field hit the product with force - hence the color density.

Paint consumption is reduced since it is deposited only on the part. The method of coloring products in an electric field is now widely used in our country.

Electric smoked meats

Smoking is the impregnation of a product with wood smoke. Smoke particles not only give the product a taste, but also protect them from spoilage.

With electric smoking, smoke particles are positively charged, and, for example, a fish carcass serves as a negative electrode. Charged smoke particles settle on the surface of the carcass and are partially absorbed by it. All electric smoking lasts several minutes. Before, smoking was considered a lengthy process.

Electric pile

In order to obtain a pile layer on any material in an electric field, it is necessary to ground the material, cover the surface with adhesive, and then pass a portion of the pile through a charged metal grid located above this surface. The villi quickly orient themselves in the field and, distributed evenly, settle on glue strictly perpendicular to the surface.

This is how you get suede or velvet-like coatings. It is easy to obtain a multi-colored pattern by preparing portions of a pile of different colors and several patterns, which are used to cover individual sections of the product alternately in the process of electro-teasing. So you can make multi-color carpets.

How to catch dust

Clean air is needed not only for people and particularly precise industries. All machines wear out prematurely due to dust, and their air cooling channels become clogged. In addition, dust often escaping with exhaust gases is a valuable raw material. Purification of industrial gases has become a necessity. Practice has shown that the electric field copes well with this.

In the center of the metal pipe, wire B is installed, which serves as one of the electrodes, the second is the walls of the pipe B. In the electric field, the gas in the pipe is ionized. Negative ions “stick” to the particles of smoke entering together with the gas through input A and charge them.

Under the influence of the field, these particles move to the pipe and settle on it, and the cleaned gas is sent to the outlet D. From time to time, the pipe is shaken and the trapped particles enter hopper G. Electric filters at large thermal power plants capture 99% of the ash contained in the exhaust gases .

Substance mixing

If the small particles of one substance are positively charged and the other negative, it is easy to obtain a mixture of them, where the particles are evenly distributed. For example, the bakery now does not have to do a lot of mechanical work to knead the dough.

The positively charged flour grains are fed into the chamber by air flow, where they meet negatively charged droplets of water containing yeast. Grains of flour and droplets of water, attracted to each other, form a homogeneous dough.

Many other examples of the beneficial uses of static electrification can be given. The technology based on this phenomenon is convenient: the flow of charged particles can be controlled by changing the electric field, and the whole process is easy to automate.