Three Requirements for the Use of Exhaust Axial Fans in Smoke and Dust Concentration Monitoring Applications

Three Requirements for the Use of Exhaust Axial Fans in Smoke and Dust Concentration Monitoring Applications

In flue gas concentration monitoring systems, exhaust axial fans are primarily used for back-blowing dust analyzers. This ensures the cleanliness of the analyzer’s lens, enabling the analyzer to operate normally over the long term. Currently, there are many reverse-blow air sources used in the industry, such as exhaust axial fans and blowers. However, a drawback of exhaust axial fans is that analyzers may experience intermittent malfunctions when airflow is insufficient; blowers overcome this limitation. While there are many exhaust axial fans on the market today, few can meet the demands of harsh operating environments. Here is a brief overview of the requirements for exhaust axial fans. 1. Performance of Smoke Exhaust Axial Fans: Many fans currently on the market have low precision, which affects their initial performance. However, due to this lack of precision, the fans’ airflow becomes insufficient after a certain period of use, causing a significant decline in backwashing effectiveness. 2. Heat Resistance: Smoke exhaust axial fans are typically used near chimneys or installed within them. Temperatures in these areas generally rise. If the fan lacks sufficient heat resistance, it will be prone to damage. 3. Protection Rating: Under normal operating conditions, particle and dust levels tend to increase. If installed outdoors, will water affect the smoke exhaust axial fan? Therefore, if the protection rating is not high enough, the motor is prone to burning out. 1. What is the dynamic pressure of a fire smoke exhaust axial fan? This refers to the pressure generated by airflow. As long as air flows through the duct, a specific dynamic pressure exists. The energy of the gas, based on its flow rate C (m/s), is converted into pressure when the pressure rises, with no loss. Dynamic pressure is not only the kinetic energy per unit volume of the gas but also a force. Its function is to alter the velocity of the gas within the duct; dynamic pressure acts only in the direction of gas flow, which is always positive. Pd = ρ * C * C / 2, where ρ is the air mass density, in kg/m³. 2. What is the static pressure of a fire smoke exhaust axial fan? The pressure generated by the irregular motion of air molecules colliding with the pipe walls is called static pressure. In calculations, static pressure measured relative to absolute vacuum is called absolute static pressure. Static pressure measured relative to atmospheric pressure is called relative static pressure. In air conditioning, static pressure refers to relative static pressure. Static pressure is the potential energy per unit volume of a gas and represents the force exerted by compressed gas on the pipe walls. The absolute static pressure of gas within a duct can create positive pressure higher than the surrounding atmospheric pressure. Conversely, it can also create negative pressure lower than the surrounding atmospheric pressure. Gas exerts a force Pst parallel to the direction of gas flow on the surface of an object. Pst = p – pd² = pst² – pst₁ – pd₁ – p – the total pressure (PST) of the ventilator – the static pressure (PD) of the ventilator – the mechanical pressure of ventilation. 3. External residual pressure refers to: The concept of external residual pressure is typically derived from the external residual pressure provided in the manufacturer’s specifications. This represents the total pressure that can be delivered after accounting for the unit’s own pressure loss. Is the residual pressure outside the machine the total pressure or the static pressure? It is described as the static pressure outside the machine but can be understood as the total pressure outside the machine. In testing, dynamic pressure is typically considered to be 0. The concept of external residual pressure is not a standardized concept but rather the total pressure that the unit must deliver after accounting for its own pressure loss.