Lighting lamps are indispensable electrical appliances in our life and work, and the same is true for explosion-proof electrical appliances. The reason why explosion-proof electrical appliances can be built is inseparable from the word safety, and it can be applied to all walks of life and production and processing. Therefore, this type is relatively complicated. How many types of explosion-proof lamps are there?
There are five types of explosion-proof lamps, which are the following five types:
One of the explosion-proof electrical equipment structures means that the equipment has a sufficiently strong shell that can withstand the impact of 1.5 times the maximum explosion pressure generated by the internal explosive gas mixture and not less than 3.5×10pa.
Ensure no deformation or damage, no permanent deformation, and have a certain structural gap to allow the ejected combustion products to cool down to a temperature lower than the self-ignition temperature of the external explosive mixture through a certain flange length, so as to achieve the purpose of explosion protection.
Increased safety type:
One of the explosion-proof electrical equipment structures refers to the adoption of a series of safety measures on the equipment, such as using high-quality insulating materials, reducing temperature rise, increasing electrical clearances, and improving the quality of wire connections.
Make it impossible to generate sparks, arcs or dangerous temperatures to the maximum extent, or use effective protective components so that the sparks, arcs or temperatures generated cannot ignite explosive mixtures, so as to achieve the purpose of explosion protection.
Positive pressure type:
One of the structures of explosion-proof electrical equipment, which refers to inflating the inside of the equipment to ensure that the pressure of the internal protective gas is higher than that of the surrounding, to prevent the explosive mixture from entering the casing, or to pass a sufficient amount of protective gas through the casing to reduce the concentration of the internal explosive mixture below the lower explosion limit .
Under normal circumstances, there must be no ventilation dead space that affects safety inside the electrical equipment. During normal operation, the air pressure at the air outlet or the inflation air pressure must not be lower than a certain value, otherwise an alarm will be issued immediately or the power will be cut off.
Sparks and arcs inside the equipment are not allowed to blow out from any gap or air outlet. The use of the positive pressure structure has nothing to do with the level of explosive substances, and it is mostly used in equipment with easily damaged internal components or large electrical equipment, or electrical equipment with self-ignition points of T4 and T5 that are difficult to make into other explosion-proof structures.
Electrical equipment that will not ignite the surrounding explosive mixture under normal operating conditions, and generally does not cause ignition failures, is called non-sparking type.
During normal processing and production, explosive and flammable substances that can produce dust clouds or dust layers, when mixed with air to a certain concentration, this environment must choose a “dust-tight” enclosure to prevent dust from entering the enclosure. Inside. Because the electrical components in the shell may generate arcs and sparks ignite dust to form an explosion.
Explosion-proof lamps have different design categories in different workplaces and safety requirements.