Axial formulas of locomotives. H2O2 - what is this substance

Electric transmissions on diesel locomotives.

1. DC when the generator and electric motors DC; transmission is simple and high efficiency.

2. AC-DC when the synchronous generator AC, and DC electric motors; rectifier installation required; used on diesel locomotives with a power of more than 3000 kW, since with such power the DC generator would have larger dimensions and the sparking under the brushes on the commutator would increase.

3. AC-AC, when the generator and electric motors are alternating current; AC electric machines are simpler in design, more reliable in operation, and easier to repair; movement speed is controlled by changing the frequency of alternating current, so special frequency converters are required; used on some experimental diesel locomotives.

6.3. Gas turbine locomotive– when fuel (oil, fuel oil) is burned in the fire boxes of a gas turbine engine, a powerful flow of hot gases hits the blades of the gas turbine, the shaft of which is connected to electric generator, from which electrical voltage is supplied to electric motors, which rotate the wheel pairs through gears. There is a compressor for supplying air to the combustion chambers and for diluting hot gases having a temperature of about 2000 o C, so that a mixture of gases and air arrives at the turbine blades at a temperature of no more than 800 o C (otherwise the turbine blades will not withstand the heat resistance). For now, the gas turbine locomotives are designed as prototypes.

6.4. Electric locomotive– when serving electrical voltage along a contact wire and rail suspended above the railway track and with its corresponding transformation into electric motors, which transmit rotation to the wheel pairs through gears. Depending on the supplied voltage, electric locomotives are divided into DC electric locomotives with a rated voltage in the contact network of 3000 V and AC electric locomotives with a rated voltage in the contact network of 25,000 V, and dual-power electric locomotives capable of operating both from a DC contact network with a voltage of 3000 V. V, and from an AC contact network with a voltage of 25,000 V.

The axial formula determines the number of locomotive sections, the number and type of bogies, the method of transmitting traction and braking forces, the number of driving and runner wheel pairs, and the presence of an individual or group drive.

For example: 2 (2 о +2 о) or 2 о +2 о +2 о +2 о – an eight-axle locomotive with four articulated biaxial bogies (sign “+”), wheel pairs have an individual drive (sign “0”) – this is axial formula of the VL8 electric locomotive. The TEM 7 diesel locomotive has an axle formula of 2 o +2 o -2 o +2 o – an eight-axle locomotive with two separate (sign “-”) four-axle bogies, consisting of two paired two-axle ones. For the diesel locomotive 3TE10M - 3 (3 о -3 о) - the locomotive is three-section, each section has two three-axle non-articulated bogies. For the electric locomotive VL15 and electric locomotive VL85 - 2(2 о -2 о -2 о) - the locomotive is two-section, each section has three biaxial non-articulated bogies, the wheel pairs have an individual drive. If the bogies are not articulated, then the traction and braking forces from the wheel sets are transmitted to the train through the bogie frames to the body frame and then through the automatic couplers.

For non-bogie locomotives, the axle formula sequentially lists the number of runner and driving wheel pairs. For example, for a steam locomotive 1-3-1 or for a diesel locomotive TGM23 0-3-0 there are no running wheel sets; the three driving wheel sets have a group drive.

The formula for the basis of life - water - is well known. Its molecule consists of two hydrogen atoms and one oxygen, which is written as H2O. If there is twice as much oxygen, you will get a completely different substance - H2O2. What is this and how will the resulting substance differ from its “relative” water?

H2O2 - what is this substance?

Let's look at it in more detail. H2O2 is the formula of hydrogen peroxide, Yes, the same one that is used to treat scratches, white. Hydrogen peroxide H2O2 - scientific.

For disinfection, use a three percent peroxide solution. In pure or concentrated form, it causes chemical burns to the skin. A thirty percent peroxide solution is otherwise called perhydrol; Previously, it was used in hairdressers to bleach hair. The skin burned by it also turns white.

Chemical properties of H2O2

Hydrogen peroxide is a colorless liquid with a “metallic” taste. It is a good solvent and easily dissolves in water, ether, and alcohols.

Three and six percent peroxide solutions are usually prepared by diluting a thirty percent solution. When storing concentrated H2O2, the substance decomposes with the release of oxygen, so it should not be stored in tightly sealed containers to avoid an explosion. As the peroxide concentration decreases, its stability increases. You can also add H2O2 to it to slow down the decomposition various substances, for example, phosphoric or salicylic acid. To store solutions of high concentration (more than 90 percent), sodium pyrophosphate is added to peroxide, which stabilizes the state of the substance, and aluminum vessels are also used.

H2O2 in chemical reactions can be both an oxidizing agent and a reducing agent. However, more often peroxide exhibits oxidizing properties. Peroxide is considered to be an acid, but a very weak one; salts of hydrogen peroxide are called peroxides.

as a method of producing oxygen

The decomposition reaction of H2O2 occurs when the substance is exposed to high temperature (more than 150 degrees Celsius). As a result, water and oxygen are formed.

Reaction formula - 2 H2O2 + t -> 2 H2O + O2

The oxidation state of H in H 2 O 2 and H 2 O = +1.
Oxidation state of O: in H 2 O 2 = -1, in H 2 O = -2, in O 2 = 0
2 O -1 - 2e -> O2 0

O -1 + e -> O -2
2 H2O2 = 2 H2O + O2

The decomposition of hydrogen peroxide can also occur at room temperature if a catalyst is used ( chemical substance, accelerating the reaction).

In laboratories, one of the methods for producing oxygen, along with the decomposition of bertholite salt or potassium permanganate, is the decomposition reaction of peroxide. In this case, manganese (IV) oxide is used as a catalyst. Other substances that accelerate the decomposition of H2O2 are copper, platinum, and sodium hydroxide.

History of the discovery of peroxide

The first steps towards the discovery of peroxide were taken in 1790 by the German Alexander Humboldt, when he discovered the transformation of barium oxide into peroxide when heated. That process was accompanied by the absorption of oxygen from the air. Twelve years later, scientists Tenard and Gay-Lussac conducted an experiment on burning alkali metals with excess oxygen, resulting in sodium peroxide. But hydrogen peroxide was obtained later, only in 1818, when Louis Thénard studied the effect of acids on metals; a low amount of oxygen was necessary for their stable interaction. Conducting a confirmatory experiment with barium peroxide and sulfuric acid, the scientist added water to them, hydrogen chloride and ice. After a short time, Tenar discovered small frozen drops on the walls of the container with barium peroxide. It became clear that this was H2O2. Then they gave the resulting H2O2 the name “oxidized water.” This was hydrogen peroxide - a colorless, odorless, difficult-to-evaporate liquid that dissolves other substances well. The result of the interaction of H2O2 and H2O2 is a dissociation reaction, peroxide is soluble in water.

An interesting fact is that the properties of the new substance were quickly discovered, allowing it to be used in restoration work. Tenar himself, using peroxide, restored a painting by Raphael that had darkened with time.

Hydrogen peroxide in the 20th century

After a thorough study of the resulting substance, it began to be produced on an industrial scale. At the beginning of the twentieth century, electrochemical technology for the production of peroxide, based on the process of electrolysis, was introduced. But the shelf life of the substance obtained by this method was short, about a couple of weeks. Pure peroxide is unstable, and for the most part it was produced in a thirty percent concentration for bleaching fabrics and in a three or six percent concentration for household needs.

Scientists fascist Germany used peroxide to create rocket engine liquid fuel, which was used for defense purposes in World War II. As a result of the interaction of H2O2 and methanol/hydrazine, powerful fuel was obtained, on which the aircraft reached speeds of more than 950 km/h.

Where is H2O2 used now?

in medicine - for treating wounds;
V pulp and paper industry the bleaching properties of the substance are used;
in the textile industry, natural and synthetic fabrics, furs, and wool are bleached with peroxide;
as rocket fuel or its oxidizer;
in chemistry - to produce oxygen, as a foaming agent for the production of porous materials, as a catalyst or hydrogenating agent;
for the production of disinfectants or cleaning agents, bleaches;
for bleaching hair (this is an outdated method, since hair is severely damaged by peroxide);

Hydrogen peroxide can be successfully used to solve various household problems. But only three percent hydrogen peroxide can be used for these purposes. Here are some ways:

To clean surfaces, you need to pour peroxide into a container with a spray bottle and spray it on contaminated areas.
To disinfect objects, they need to be wiped with an undiluted H2O2 solution. This will help cleanse them of harmful microorganisms. Washing sponges can be soaked in water with peroxide (1:1 ratio).
To bleach fabrics, add a glass of peroxide when washing white items. You can also rinse white fabrics in water mixed with a glass of H2O2. This method restores whiteness, protects fabrics from yellowing and helps remove stubborn stains.
To combat mold and mildew, mix peroxide and water in a 1:2 ratio in a container with a spray bottle. Spray the resulting mixture onto contaminated surfaces and after 10 minutes clean them with a brush or sponge.
You can renew darkened grout in tiles by spraying peroxide onto required areas. After 30 minutes, you need to thoroughly rub them with a stiff brush.
To wash dishes, add half a glass of H2O2 to a full basin of water (or a sink with a closed drain). Cups and plates washed in this solution will shine clean.
To clear toothbrush, you need to dip it in an undiluted three percent peroxide solution. Then rinse under strong running water. This method disinfects hygiene items well.
To disinfect purchased vegetables and fruits, you should spray a solution of 1 part peroxide and 1 part water on them, then rinse them thoroughly with water (can be cold).
At your summer cottage, using H2O2 you can fight plant diseases. You need to spray them with a peroxide solution or soak the seeds shortly before planting in 4.5 liters of water mixed with 30 ml of forty percent hydrogen peroxide.
To revive aquarium fish, if they were poisoned by ammonia, suffocated when the aeration was turned off, or for another reason, you can try placing them in water with hydrogen peroxide. You need to mix three percent peroxide with water at the rate of 30 ml per 100 liters and place lifeless fish in the resulting mixture for 15-20 minutes. If they do not come to life during this time, then the remedy did not help.

Even as a result of vigorously shaking a bottle of water, a certain amount of peroxide is formed in it, since the water is saturated with oxygen during this action.

Fresh fruits and vegetables also contain H2O2 until they are cooked. When heating, cooking, frying and other processes with accompanying high temperature destroyed large number oxygen. This is why cooked foods are considered not so healthy, although some vitamins remain in them. Freshly squeezed juices or oxygen cocktails served in sanatoriums are useful for the same reason - due to saturation with oxygen, which gives the body new strength and cleanses it.

Danger of peroxide when ingested

After the above, it may seem that peroxide can be specifically taken orally, and this will benefit the body. But this is not true at all. In water or juices, the compound is found in minimum quantities and is closely related to other substances. Taking “unnatural” hydrogen peroxide internally (and all peroxide purchased in a store or produced as a result chemical experiments independently, cannot in any way be considered natural; moreover, it has too high a concentration compared to natural) can lead to consequences dangerous to life and health. To understand why, we need to turn again to chemistry.

As already mentioned, under certain conditions, hydrogen peroxide breaks down and releases oxygen, which is an active oxidizing agent. can occur when H2O2 collides with peroxidase, an intracellular enzyme. The use of peroxide for disinfection is based on its oxidizing properties. So, when a wound is treated with H2O2, the released oxygen destroys living pathogenic microorganisms that have entered it. It has the same effect on other living cells. If you treat intact skin with peroxide and then wipe the treated area with alcohol, you will feel a burning sensation, which confirms the presence of microscopic damage after peroxide. But when applying peroxide externally at a low concentration of some kind noticeable harm the body will not.

It’s another matter if you try to take it orally. That substance, which can damage even relatively thick skin on the outside, gets onto the mucous membranes digestive tract. That is, chemical mini-burns occur. Of course, the released oxidizing agent - oxygen - can also kill harmful microbes. But the same process will happen with the cells of the food tract. If burns as a result of the action of the oxidizing agent are repeated, then atrophy of the mucous membranes is possible, and this is the first step on the path to cancer. The death of intestinal cells leads to the body's inability to absorb nutrients, this explains, for example, weight loss and the disappearance of constipation in some people who practice “treatment” with peroxide.

Separately, it is necessary to say about this method of using peroxide, such as intravenous injections. Even if for some reason they were prescribed by a doctor (this can only be justified in case of blood poisoning, when there are no other suitable drugs available), then under medical supervision and with strict dosage calculations, there are still risks. But in such extreme situation this will be a chance for recovery. Under no circumstances should you prescribe hydrogen peroxide injections to yourself. H2O2 poses a great danger to blood cells - red blood cells and platelets, since it destroys them when it enters the bloodstream. In addition, a fatal blockage of blood vessels by the released oxygen can occur - a gas embolism.

Safety precautions for handling H2O2

Keep out of the reach of children and disabled persons. The lack of odor and distinct taste makes peroxide especially dangerous for them, since large doses can be taken. If the solution gets inside, the consequences of use can be unpredictable. You should consult a doctor immediately.
Peroxide solutions with a concentration of more than three percent cause burns if they come into contact with the skin. The burn area needs to be washed a large number water.

Do not allow the peroxide solution to get into your eyes, as it may cause swelling, redness, irritation, and sometimes painful sensations. First aid before contacting a doctor is to wash the eyes generously with water.
Store the substance in such a way that it is clear that it is H2O2, that is, in a container with a sticker to avoid accidental use not for the intended purpose.
Storage conditions that prolong its life are a dark, dry, cool place.
Hydrogen peroxide should not be mixed with any liquids other than clean water, including chlorinated tap water.
All of the above applies not only to H2O2, but also to all preparations containing it.