Controlling Explosive Gases Artificially in hazardous l […]
Controlling Explosive Gases Artificially in hazardous locations (we call industrial sites with the three conditions required for an explosion to be called hazardous locations) to create a space with no explosive gas, and install the instrument in it. Pressure Type Explosion Protection Method. The working principle is: in a sealed box, it is filled with clean gas or inert gas that does not contain explosive gas, and the pressure inside the box is slightly higher than the pressure outside the box, and the meter is installed in the box. Commonly used in explosion-proof analytical instruments and positive pressure-type instrument cabinets that place computers, PLCs, operation stations or other instruments on site.
Controlling the scope of the explosion artificially limits the explosion to a limited local extent so that explosions in that area do not cause a wider range of explosions. Typical representative is explosion-proof explosion-proof method Exd. The working principle is: Designing a sufficiently rugged housing for the instrument, strictly designing, manufacturing and installing all interfaces in accordance with the standard, so that the explosion occurring in the housing will not cause the explosion of hazardous gas (explosive gas) outside the housing. The design and manufacturing specifications for flameproof explosion protection methods are extremely stringent and the operating procedures for installation, wiring, and maintenance are also very strict. This method determines that the explosion-proof electrical equipment and instruments are often very heavy and the operation must be powered off, but in many cases it is also an effective method.
Controlled detonation source stainless steel case Artificially eliminates the source of detonation and eliminates sparks sufficient to detonate and eliminates the surface temperature rise sufficient to detonate, typically represented by the intrinsically safe explosion protection method. The working principle is: using the safety barrier technology, the electric energy provided to the field instrument is limited to a safety range that can neither generate enough sparks to detonate, nor produce a surface temperature rise enough to detonate the instrument. In accordance with international standards and national standards of China, intrinsically safe explosion-proof methods ensure the explosion-proof safety of hazardous sites when any failure of the equipment connected to the safety zone side of the safety barrier occurs (not exceeding 250V). Ex ia class intrinsically safe devices do not explode an explosive gas mixture during normal operation, failure, or failure. Therefore, this method is a safe and reliable method of explosion protection.