Fire hazard of hot particles and electrical sparks. Scheme, description

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Electrician

Fire hazard of hot particles and electrical sparks. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Electrical safety, fire safety

electric sparks и hot particles (drops of molten metal) are formed during a short circuit in the wiring, during electric welding and during the melting of the electrodes of electric incandescent lamps. The size of metal droplets during a short circuit and melting of the filament of electric incandescent lamps reaches 3 mm, and during electric welding - 5 mm.

The temperature of the electric arc during short circuits and electric welding can reach 4000 ° C, therefore, the arc will be the source of ignition of all combustible substances (even most metals at this temperature not only melt, but also evaporate).

The temperature of the metal droplets depends on the type of melted metal. It is equal to the melting point of this metal. The amount of heat that a metal drop is able to give off to a combustible medium during cooling depends on the free fall height of the drop, its volume (diameter) and mass, determined by the density of the molten metal, as well as its specific heat capacity.

The ignition of a combustible material on which a molten drop of metal has fallen depends on the self-ignition temperature of the material and the minimum required ignition energy. For example, for a combustible mixture, the minimum ignition energy is only 25 mlJ (millijoules). Sparks that occur during incomplete short circuits in electrical wiring and during electric welding are a great fire hazard.

Author: Korshevr N.G.

See other articles Section Electrical safety, fire safety.

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

Stress in dogs is associated with the emotional state of the owners 14.06.2019

Dogs reflect the emotional state of their owner. This conclusion was made by Swedish scientists from the University of Linköping.

In the course of the study, neurophysiologists proved the relationship between the level of stress in dogs and their owners. However, no inverse relationship was observed.

Several dozen Sheltie and Collie dogs, as well as their female owners, took part in the experiment. They measured the concentration of the hormone cortisol, which is produced by the body during strong experiences.

The dogs were also fitted with special collars capable of recording their level of physical activity. As a result, the study showed that the level of stress in animals is directly related to the condition of the hostesses.

Other interesting news:

▪ Artificial intelligence will be able to approach the capabilities of the human brain

▪ STM32L4P5/Q5 - STM32L4+ family in small packages

▪ Amazon Kindle e-book

▪ Seoul Semiconductor SunLike LED is the safest

▪ Copper foam battery

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Electric meters. Article selection

▪ article Express glasses repair. Tips for the home master

▪ article Which namesakes decided to become brothers? Detailed answer

▪ article Electrician for the maintenance and repair of alarm, centralization and blocking devices. Job description

▪ article Digital pump timer. Encyclopedia of radio electronics and electrical engineering

▪ article memory of a miner's lamp. 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