An explosion-proof fan is a type of industrial ventilation fan that helps to prevent fires and explosions in commercial and industrial applications where certain types of dust, gases, vapors, or particles are present. Since industrial fans have metal blades and housing, there are many ways a spark can ignite in around metal, dust, and fumes. Here is one scenario: A metal object could hit a fan blade, causing a spark. The spark is then ignited by fumes.
A fan company cannot promise that fans will be completely explosion-proof, but this type of fan is made to minimize accidents caused when metal, sparks, and fibers (or fumes) interact. In fact, a better name for them would be spark- and explosion-resistant. Nevertheless, an explosion-proof fan has an electrical motor that is contained in a specially-designed housing to prevent combustion.
Explosion-proof fans are classified into three categories: Types A, B, and C.
- Type A blower fans are constructed so that all materials that contact the air stream are spark-resistant, nonferrous metals (aluminum or brass).
- Type B fans have a nonferrous wheel and rubbing ring at the motor shaft entrance to the fan housing.
- Type C have nonferrous plates inside the fan housing.