The explosion-proof principle of explosion-proof ventilators is to prevent potential sparks, arcs, and dangerous temperatures during operation, thus ensuring that they do not ignite the surrounding explosive atmosphere. The drive motor of the explosion-proof ventilator is an explosion-proof motor. The impeller and casing are made of matching materials that meet explosion-proof requirements. When the ventilator impeller is made of aluminum alloy, the inlet chamber and casing must be made of carbon steel. When the ventilator impeller is made of steel, the inlet ring and rivets of the centrifugal ventilator must be made of brass or aluminum. When using other materials, materials that do not produce sparks when rotating and stationary parts rub against each other should be selected.
Structurally, the ventilator requires that rotating parts and adjacent stationary parts avoid rubbing against each other to prevent sparks. The ventilator impeller should undergo an overspeed test, operating at a speed not less than 110% of the maximum operating speed for at least 2 minutes. The impeller should be balanced. Within the rated speed and specified flow range, the deviation between the measured aerodynamic performance and the specified aerodynamic performance of the ventilator should meet the requirements. The A-weighted sound level (Las) of the ventilation fan at its optimal efficiency operating point should comply with the requirements of JB/T 8690.
