Electrothermal installations. Induction and dielectric heating plants

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Encyclopedia of radio electronics and electrical engineering / Electrician

Section 7. Electrical equipment of special installations

Electrothermal installations. Induction and dielectric heating plants

Free technical library

Encyclopedia of radio electronics and electrical engineering / Rules for the installation of electrical installations (PUE)

Comments on the article

7.5.50. The equipment of induction and dielectric heating installations with transformers, motor-generator, thyristor and ion converters or lamp generators and capacitors is installed, as a rule, in separate rooms or, in justified cases, directly in the workshop in the process flow of production of categories D and D according to building codes and rules; the building structures of these separate rooms must have fire resistance limits not lower than the values \u7.5.22b\u10bgiven in XNUMX for in-shop furnace (including converter) substations with an amount of oil in them less than XNUMX tons.

7.5.51. To improve the use of transformers and converters, capacitor banks should be installed in the inductor circuits. To facilitate tuning into resonance, capacitor banks in installations with a stabilized frequency, as a rule, should be divided into two parts - constantly on and adjustable.

7.5.52. The mutual arrangement of the elements of installations, as a rule, should provide the shortest length of current conductors of resonant circuits in order to reduce active and inductive resistances.

7.5.53. For high-medium frequency circuits, as indicated in 7.5.33, it is recommended to use coaxial cables and conductors. The use of cables with steel armor and wires in steel pipes for circuits with an increased average frequency of up to 10 kHz is allowed only if the cores of one cable or wires in one pipe are used for forward and reverse current directions. The use of cables with steel armor (with the exception of special cables) and wires in steel pipes for circuits with a frequency of more than 10 kHz is not allowed.

Cables with steel armor and wires in steel pipes used in industrial, high-medium or low-frequency electrical circuits must be laid so that the armor and pipes do not heat up from an external electromagnetic field.

7.5.54. To protect installations from damage when the crucible of induction furnaces (of any frequency) is “burned through” and in case of violation of the insulation of high-medium, high and ultra-high frequency networks relative to the body (ground), an electrical protection device with an action on a signal or shutdown is recommended.

7.5.55. Engine-generators with frequency settings of 8 kHz or more must be equipped with idle speed limiters that turn off the excitation of the generator during long pauses between work cycles, when stopping the engine-generators is impractical.

To improve the time loading of high-medium and high-frequency generators, it is recommended to use the "standby" mode where it is allowed by the technology conditions.

7.5.56. High-frequency induction and dielectric heating installations must have shielding devices to limit the level of electromagnetic field strength at workplaces to the values determined by the current sanitary rules.

7.5.57. In dielectric heating drying chambers (high-frequency dryers) using vertical grid electrodes, the grids on both sides of the passages must be grounded.

7.5.58. The doors of the units of high-frequency induction and dielectric heating units must be equipped with a lock, in which the door can be opened only when the voltage of all power circuits is turned off.

7.5.59. The width of workplaces at control panels should be at least 1,2 m, and at the heating devices of melting furnaces, heating inductors (for induction heating) and working capacitors (for dielectric heating) - at least 0,8 m.

7.5.60. Motor-generator frequency converters operating with a noise level above 80 dB must be installed in electrical machine rooms that provide noise reduction to levels permitted by current sanitary standards.

To reduce the vibration of engine-generators, vibration damping devices should be used to ensure compliance with the requirements of sanitary standards for the level of vibration.

See other articles Section Rules for the installation of electrical installations (PUE).

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Machine for thinning flowers in gardens 02.05.2024

In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers. ... >>

Advanced Infrared Microscope 02.05.2024

Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

Random news from the Archive

Good cholesterol protects against sepsis 01.04.2022

"Good cholesterol" refers to high-density lipoproteins, or HDL - large molecular complexes of lipids and proteins. The more of them, the less "bad cholesterol" in the blood, that is, low and very low density lipoproteins. "Bad cholesterol" increases the likelihood of atherosclerosis, "good" - reduces, in fact, that's why they are called that.

Lipoproteins carry lipids from place to place, from tissue to tissue, and as such they influence various physiological processes - not only lipid metabolism, but also, for example, immunity. Researchers at the University of Kentucky and the University of Michigan noticed that patients with sepsis generally have lower "good cholesterol" levels than healthy people, and the lower the level, the worse the clinical prognosis.

Sepsis, or blood poisoning, is an inflammatory response to a bacterial infection. Inflammation can be so severe that it will disable some organs and lead to death. Experiments with mice confirmed that HDL levels are associated with septic inflammation: animals that were known to be low in them were more likely to get sepsis when bacterial infection. It is likely that HDL somehow helps control the inflammatory response so that it does not turn into damage.

By increasing the level of "good cholesterol", you can cope with sepsis that has already begun. High-density lipoproteins have synthetic analogues that act in the same way as real HDL; clinical studies show that such analogues are quite effective in preventing cardiovascular diseases.

One of these analogs was injected into mice with sepsis, after which the inflammation in them subsided, the internal organs (for example, the kidneys) began to work better, and in general the mice were more likely to survive. It is possible that analogues of "good cholesterol" can be used in humans.

Other interesting news:

▪ Mice eat birds

▪ Unmanned passenger Boeing

▪ How to protect yourself from sea robbers

▪ More and more carbon dioxide

▪ Smart toothbrush ISSALEXA

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Visual illusions. Article selection

▪ peace pipe article. Popular expression

▪ article What is the height of the highest peak of the Earth? Detailed answer

▪ seismograph article. Children's Science Lab

▪ article KV regenerator. Encyclopedia of radio electronics and electrical engineering

▪ article The use of airlifts in wind turbines. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews