Analysis on the Classification and Working Principle of Explosion-proof Surveillance Camera
Gasket & Ring,Stub End,Pipe Nipple Group Steel Pipe Engineering Co., Ltd. , http://www.hbsteelpipes.com
Currently, there are three types of explosion-proof cameras on the market: 'intrinsically safe type; positive pressure type; flameproof type 'intrinsically safe' type, which starts from limiting the energy in the circuit. The camera's internal control parameters reduce the potential spark energy to a After ignition of the specified gas mixture energy, the temperature of the wire and the surface of the element heating is limited to the ignition temperature of the specified gas mixture. All circuits inside the camera are intrinsically safe circuits that do not ignite the prescribed explosive atmosphere by any spark or any thermal effect that is produced under standard conditions (including normal operation and specified fault conditions). Type 'cameras are relatively expensive and are rarely seen on the market.
The 'positive pressure type' explosion-proof type is to maintain continuous air or inert gas in the camera to restrict the flammable mixture from entering the camera through the housing.
The most common type of explosion-proof camera on the market today is a 'flameproof type' explosion protection type, in which the components of the camera that may ignite an explosive gas mixture are all enclosed in a single enclosure whose enclosure can withstand any joint or structural clearance through the enclosure. The flammable mixture that penetrates into the interior of the enclosure explodes internally without damage, and does not cause ignition of the external explosive atmosphere formed by one or more gases or vapours. Place parts of the camera that may produce sparks, arcs, and dangerous temperatures into a flameproof enclosure that isolates 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, an explosive gas mixture may be present inside. When the explosion occurs, the enclosure can withstand the explosion pressure generated without damage, and at the same time, the gap between the shell structure can cool the flame and reduce the flame. The speed of flame propagation or termination of the acceleration chain prevents flames or dangerous flame products from igniting the external explosive atmosphere through explosion-proof gaps, thereby achieving the goal of flameproofing. Therefore, many of these flameproof enclosures are the main security companies, such as Shenzhen Wanwan. Cheng Technology Co., Ltd.
In fact, there are almost the same elements needed to produce an 'explosion' and 'burn'. Three conditions must be met at the same time. First, there must be explosive or flammable substances; second, there must be flammable substances, mainly in the air. Oxygen; third, there is also a source of ignition (such as sparks, arcs, and dangerous temperatures, etc.) that provide the energy necessary to ignite the mixture. Only if these three conditions exist at the same time will there be the possibility of an explosion. If any of these conditions is not met, there will be no burning or explosion. In the mines, chemical plants, military factories, arsenals, oil fields, oil depots and other dangerous goods production or storage, the first two conditions are basically met, and the third condition is the cameras introduced by the contractor because of the sealing performance of ordinary cameras. It is impossible to prevent the inflammable gas from entering the body, and the electronic components of ordinary cameras may generate sparks, arcs, and dangerous temperatures during normal operation. Therefore, the combustible gas entering the casing is encountered, and thus the installed camera is not only unsafe. The original intention was to become a 'time bomb'. The real explosion-proof camera manufacturing principle is also nothing more than to make the above three conditions not available at the same time, it really played the role of explosion-proof.
As people's safety awareness gradually increases, the field of application of anti-explosion-proof cameras should be wider and wider in theory, but in fact, the amount of explosion-proof cameras is not very large. Why?
1. The most important reason is cost. The price of an explosion-proof camera is a lot higher than that of an ordinary camera with the same parameters. Domestic engineering companies and users do not have a high degree of acceptance of these high-priced products. They still need time to cultivate and change their consumer attitudes and awareness, which greatly restricts the popularity of explosion-proof cameras.
2. The second reason is that there is not enough awareness of the need for 'explosion protection'.
3. The third reason is that the surrounding facilities are not enough 'explosion-proof'. Even if an explosion-proof camera is not equipped with explosion-proof back-end equipment or professional construction, it will not be able to exert the effect of explosion-proof. For example, explosion-proof heads are not used, or the transmission wires are exposed and there are potential safety hazards.