[ Huaqiang Security Network News ] Explosion-proof cameras should be known to everyone, as the name suggests, it can prevent explosions. However, many engineers hold the ordinary riot camera to tell Party A exactly. The power supply for the camera is 12V weak, and it will not catch fire and explode. I can't judge with ignorance, but he certainly doesn't know much about the conditions that the "explosion" should have. 
In fact, the "explosion" and the "burning" required elements are similar. It is necessary to have three conditions at the same time: first, there must be explosive substances or flammable substances; second, there must be combustion-supporting substances, mainly in the air. Oxygen; third, there is also a source of ignition (such as sparks, arcs, and dangerous temperatures) that provides the energy necessary to ignite the mixture. Only when these three conditions exist simultaneously can the possibility of explosion occur. If any one of the conditions is not available, there will be no burning or explosion.
In the mine, the first two conditions are basically available. The third condition comes from the camera introduced by the engineering company. Because the sealing performance of the ordinary camera is impossible to prevent the combustible gas from entering the body, the electronic components of the ordinary camera are in normal operation. It is possible to generate sparks, arcs and dangerous temperatures, so that the flammable gas entering the casing is encountered, so that the installed camera not only fails to be safe, but also becomes a "time bomb".
The real explosion-proof camera manufacturing principle is nothing more than to make the above three conditions different, only to really play the role of explosion-proof, the earliest explosion-proof camera, the "intrinsically safe" explosion-proof type.
The "intrinsically safe type" starts with the energy in the limiting circuit. The internal vibration of the camera is reduced by the reliable control circuit parameters to the energy of the specified gas mixture. The heating temperature of the wire and the component surface is limited to the specified gas mixture. Under the ignition temperature. All circuits inside the camera are intrinsically safe circuits that do not ignite the specified explosive atmosphere under any standard specified conditions (including normal operation and specified fault conditions). The type of camera is relatively expensive and is rarely seen on the market.
Of course, there has also been a "positive pressure type" explosion-proof type in which continuous air is kept in the camera or filled with an inert gas to restrict the flammable mixture from entering the inside of the camera through the casing. As for the cameras that use the "oil-immersed" and "filled sand" explosion-proof models, the security market has also appeared, but the number is very small.
The most common explosion-proof camera on the market today is a "explosion-proof" explosion-proof type, which encloses all components of the camera that may ignite the explosive gas mixture in a casing that can withstand any joint or structural clearance through the casing. The flammable mixture that penetrates into the interior of the enclosure explodes internally without damage and does not cause an external igniting of an explosive atmosphere formed by one or more gases or vapors. The components of the camera that may generate sparks, arcs, and dangerous temperatures are placed in an explosion-proof enclosure that separates the interior of the camera from the surrounding environment. There is a gap in the flameproof enclosure. Due to the respiration of the electrical equipment and the gas permeation, there may be an explosive gas mixture inside. When it explodes, the outer casing can withstand the explosion pressure generated without damage, and the outer structure gap can cool the flame and reduce The flame spread speed or terminate the acceleration chain, so that the flame or dangerous flame products can not ignite the external explosive environment through the explosion-proof gap, so as to achieve the purpose of explosion-proof, so many of them use this kind of flame-proof casing as the main security enterprise.
Therefore, explosion-proof cameras are used in very dangerous places. Our country is very clear in the definition of explosion-proof grades for dangerous places. It means that there is a fire caused by the presence of flammable and explosive gases, vapors, liquids, flammable dust or flammable fibers. Or a place where the explosion is dangerous. Typical hazardous locations, such as the environment formed during the production, processing, and storage of explosive materials in the petrochemical industry, underground coal mines (working environments resulting from the continuous infiltration of methane gas from coal seams).
In the mine, the first two conditions are basically available. The third condition comes from the camera introduced by the engineering company. Because the sealing performance of the ordinary camera is impossible to prevent the combustible gas from entering the body, the electronic components of the ordinary camera are in normal operation. It is possible to generate sparks, arcs and dangerous temperatures, so that the flammable gas entering the casing is encountered, so that the installed camera not only fails to be safe, but also becomes a "time bomb".
The real explosion-proof camera manufacturing principle is nothing more than to make the above three conditions different, only to really play the role of explosion-proof, the earliest explosion-proof camera, the "intrinsically safe" explosion-proof type.
The "intrinsically safe type" starts with the energy in the limiting circuit. The internal vibration of the camera is reduced by the reliable control circuit parameters to the energy of the specified gas mixture. The heating temperature of the wire and the component surface is limited to the specified gas mixture. Under the ignition temperature. All circuits inside the camera are intrinsically safe circuits that do not ignite the specified explosive atmosphere under any standard specified conditions (including normal operation and specified fault conditions). The type of camera is relatively expensive and is rarely seen on the market.
Of course, there has also been a "positive pressure type" explosion-proof type in which continuous air is kept in the camera or filled with an inert gas to restrict the flammable mixture from entering the inside of the camera through the casing. As for the cameras that use the "oil-immersed" and "filled sand" explosion-proof models, the security market has also appeared, but the number is very small.
The most common explosion-proof camera on the market today is a "explosion-proof" explosion-proof type, which encloses all components of the camera that may ignite the explosive gas mixture in a casing that can withstand any joint or structural clearance through the casing. The flammable mixture that penetrates into the interior of the enclosure explodes internally without damage and does not cause an external igniting of an explosive atmosphere formed by one or more gases or vapors. The components of the camera that may generate sparks, arcs, and dangerous temperatures are placed in an explosion-proof enclosure that separates the interior of the camera from the surrounding environment. There is a gap in the flameproof enclosure. Due to the respiration of the electrical equipment and the gas permeation, there may be an explosive gas mixture inside. When it explodes, the outer casing can withstand the explosion pressure generated without damage, and the outer structure gap can cool the flame and reduce The flame spread speed or terminate the acceleration chain, so that the flame or dangerous flame products can not ignite the external explosive environment through the explosion-proof gap, so as to achieve the purpose of explosion-proof, so many of them use this kind of flame-proof casing as the main security enterprise.
Therefore, explosion-proof cameras are used in very dangerous places. Our country is very clear in the definition of explosion-proof grades for dangerous places. It means that there is a fire caused by the presence of flammable and explosive gases, vapors, liquids, flammable dust or flammable fibers. Or a place where the explosion is dangerous. Typical hazardous locations, such as the environment formed during the production, processing, and storage of explosive materials in the petrochemical industry, underground coal mines (working environments resulting from the continuous infiltration of methane gas from coal seams).
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