Plasma cutting: specifics, principle of operation, advantages and disadvantages
Plasma cutting is very often used in such industries, as shipbuilding, engineering, as well as in the manufacture of metal structures, communal sphere, etc.. P. exept this, plasma cutter is often used in a private workshop. With its help any material is quickly and qualitatively cut, conducting current, and some non-conductive materials - wood, stone and plastic.
Plasma cutting technology allows you to cut sheet metal and pipes, make a figured cut or make parts. The work is carried out using a high-temperature plasma arc. To create it, only the power source is required, air and cutter. That work was carried out easily enough, and the cut turned out smooth and beautiful, should be clarified, how the principle of operation of plasma cutting is carried out.
How plasma cutter is arranged
This device consists of the following elements:
- power supply;
- air compressor;
- plasma cutter or plasmatron;
- cable hose package.
The power supply for the plasma cutting device provides a certain current to the plasmatron. Is an inverter or transformer.
Inverters are quite light, in terms of energy consumption, inexpensive, but, able to cut blanks of small thickness. Because of this, they are used only in private workshops and small businesses. In inverter plasma cutters efficiency on 30% more, than in transformers and they have a better arc. They are often used for work in hard-to-reach places.
Transformers are much more massive, spend a lot of energy, but at the same time have less sensitivity to voltage drops, and with their help cut blanks of large thickness.
Plasma cutter is considered the main element of plasma cutting. Its main elements are:
- nozzle;
- cooler / insulator;
- channel, required for compressed air supply;
- electrode.
A compressor is required to supply air. The principle of operation of plasma cutting involves the use of protective and plasma-forming gases. For devices, which are designed for current to 200 And only compressed air is used for cooling, and to create plasma. They are able to cut blanks up to 50 mm
The cable hose package is used to connect the compressor, power supplies and plasmatron. The electric cable from the inverter or transformer begins to receive current to excite the electric arc, and compressed air is supplied through the hose, which is necessary for the occurrence inside the plasma plasmatron.
The principle of operation
When the ignition button is pressed, high frequency current is supplied from the power supply (inverter or transformer). As a result, another electric arc is formed inside the plasmatron, which temperature reaches 8 thousand. degrees. The column of this arc begins to fill the entire channel.
After the next arc, compressed air begins to enter the chamber. Breaking out of the pipe, it passes through an electric arc, heats up, while increasing in volume 50 or 100 times. in addition, air begins to ionize and ceases to be a dielectric, acquiring the ability to conduct current.
Plasmatron nozzle, narrowed down, compresses the air, creating a stream of it, which begins to break out of there with speed 2 – 3 m / s. At this point, the air temperature often reaches 30 thousand. degrees. This is how hot ionized air is plasma.
At that time, when the plasma begins to break out of the nozzle, it collides with the surface of the processed metal, the next arc at this point goes out, and ignites the cutting. It begins to heat the workpiece at the cut. As a result, the metal melts and a cut appears. On the metal surface, small particles of molten metal are formed, blown out of it by a stream of air. This is how the plasmatron works.
Advantages of plasma cutting
Metal cutting work is often carried out on site, in a workshop or shop. You can use autogen for this, but not everyone is happy with it. If the amount of work, associated with cutting metal, too big, and requirements, presented to the quality of the cut, very high, then you should think about it, to use a plasma cutter, have the following advantages:
- If the power is chosen correctly, then the plasma cutting machine allows in 10 times to increase productivity. This parameter allows the plasma cutter to yield only to an industrial laser installation, however, it significantly wins in cost. From an economic point of view, it is advisable to use a flame for cutting metal, having a thickness of up to 50 – 60 mm.
-
Versatility. Plasma is processed by means of plasma cutting, copper, steel, aluminum and other metals. You just need to choose the optimal power and set a specific air pressure.
- High quality cut. Plasma cutting machines are able to provide a minimum width of the cut and the edge without hardening, inflows and gratings practically without additional processing. in addition, such a point is quite important, that the heating zone of the material is several times smaller, than when using autogen. And since the thermal impact is minimal in the cutting area, even the deformation of the cut parts will be insignificant, even if they are small in thickness.
- There is no significant pollution of the environment. Economically, if there is a large amount of work, then plasma cutting is much more advantageous than oxygen or mechanical. In all other cases, materials are not taken into account, and the complexity of use.
Disadvantages of plasma cutting
There are also shortcomings in the work of plasma cutting. The first of them - the maximum allowable thickness of the cut is quite small, and at the most powerful units it seldom happens more 80 – 100 mm.
The next drawback is the rather strict requirements, presented for deviation from the perpendicularity of the cut. The angle of deviation should not be greater 10 – 50 degrees and it depends on the thickness of the part. If you go beyond these limits, then there is a significant expansion of the cut, which in turn causes rapid wear of consumables.
in addition, working equipment is quite complex, which makes it impossible to use two cutters at the same time, which are connected to one device.
Conclusion
The principle of operation of plasma cutting is quite simple. in addition, apparatus, which is used for this, has many advantages, several times more than the existing shortcomings. Properly covered, it will withstand a great deal of adverse conditions, then you can save a lot of time and get a quality result.
