Principle and Selection of Explosion - proof Camera
As far as the explosion-proof camera itself is concerned, there is no essential difference between the photoelectric structure and the conventional industrial camera. Characterized in that the industrial camera is treated with one or more explosion-proof types so that it can be applied in a flammable and explosive field environment.
The early explosion-proof cameras were dominated by intrinsically safe and positive pressure. The intrinsically safe explosion-proof camera is characterized by intrinsically safe handling of the circuit of the camera, and the electrical line output or input is designed to control the energy below the energy that causes the hydrogen to ignite and cause it to cause no electricity in normal operation Sparks, arcs and high temperatures, so as to avoid detonating explosives. This type of explosion-proof camera structure unit cost is too high is the biggest drawback, in addition to the future is not conducive to the upgrade. Positive pressure type is the early US Department of explosion-proof camera products commonly used structure, the use of maintenance is very inconvenient, such as not careful maintenance, detonating the risk is quite large. This structure is currently seen in addition to a small number of Taiwan manufacturers are still manufacturing, the basic explosion-proof camera industry has been completely eliminated.
Explosion-proof electrical explosion-proof type, although more, but not all suitable for explosion-proof camera. Such as oil-filled, sand-filled, etc., in the explosion-proof camera is simply can not be used.
At present, the international mainstream of explosion-proof cameras is flameproof. Characterized in that a conventional conventional camera is placed in a specially made housing which has the effect of isolating the spark and arc generated from the electrical components in the shell from the explosive mixture outside the shell and capable of withstanding the explosive mixture entering the shell Electrical equipment sparks, arc detonated when the explosion pressure, and the shell is not destroyed; at the same time to prevent the shell of explosive products to the shell outside the explosive mixture of explosives, will not cause the explosive mixture outside the shell combustion and explosion. This is a flameproof shell of the camera is "explosion-proof explosion-proof camera." And this special shell called "explosion-proof shell", we usually call it "explosion-proof camera cover."
In other words, the explosion-proof explosion-proof camera is equal to "explosion-proof camera cover" + ordinary camera, lens. In this case, as long as the size is appropriate, engineers can freely choose the built-in camera, lens, while the cost is also reduced. For future maintenance, but also a lot of convenience, turn off the power can open the cover to remove the camera, lens.
This "explosion-proof camera cover" is usually made of high-strength stainless steel with anti-explosion pressure and impact, extremely strong. Good quality products in the wall thickness of more than 5MM, than the level of the anti-riot camera has gone beyond.
In many cases, stainless steel housings are superior to aluminum housings, such as corrosion resistance. Especially in the case of fire survivability is much better.
Give these two examples, mainly to illustrate the excellent quality of the explosion-proof camera's good viability, is not recommended to try this extreme environment. For the explosion-resistant environment, our usual practice is to thicken; corresponding to high temperature combustion environment also has a dedicated model.
In addition, the market there are so-called airtight explosion-proof protective cover, but in accordance with the requirements of this airtight shell is not free to remove, to ensure permanent air tightness. Such as disassembly, the seal must be re-airtight experiments. Taking into account the construction site is not airtight experimental conditions, this "thin skin stuffing" way of security is very questionable. Even if the factory is installed when the camera and do airtight experiments, after the maintenance is to open the shell, the permanent air tightness can not guarantee, very dangerous.