In the process of using the boiler exhaust fan, the ventilation effect is mainly achieved by exhausting indoors or outdoors. The flow of air around the human body can promote the evaporation of body fluids, and the exhaust fan plays a role of natural cooling, thereby avoiding the uncomfortable reaction caused by poor ventilation such as stuffiness, odor, dust, and soot. The exhaust fan achieves ventilation by exhausting air indoors or outdoors. The working principle of the exhaust fan is that the input electric power drives the fan impeller to rotate through the motor to achieve the suction or exhaust effect on the gas. The fan is composed of components such as the air inlet impeller casing motor. The motor is used to convert the electric power into mechanical power to drive the impeller to rotate the air inlet. The smooth flow of gas into the impeller is to transfer the kinetic energy of the rotation to the gas.
The general operating conditions of the boiler exhaust fan are low-speed exhaust. However, in some projects, the working conditions are manual low and high speed exhaust. When the two-speed fan is used as the exhaust fan, the thermal relay operates when the fan motor is overloaded. The main circuit power is cut off by the contactor. If overload protection is installed, the overload protection can be applied to the alarm signal.
Boiler exhaust fans are generally installed at the downwind opening, and there should be no obstructions within 3~5 meters around the exhaust vents. In the practical application of industrial plants, the negative pressure exhaust fans are usually installed in one side of the plant, the air inlet is on the other side of the plant, and the air is convectively blown from the air inlet to the negative pressure fan. During this process, the doors and windows near the negative pressure exhaust fan remain closed, and forced air is compensated into the workshop by the door and window on the side of the intake port.