The friction resistance coefficient of the air duct is related to many factors, including: the diameter of the air duct, the shape and suspension quality of the air duct, the connection form of the air duct, etc. The friction resistance coefficient of the air duct during tunnel construction is , should be effectively measured during the tunnel construction process and at the same time guide the ventilation work on site. If the measured coefficient of friction resistance of the fan is high, the reasons must be. analyzed, improvements and adjustments must be made to ensure normal ventilation requirements during the tunnel construction process. The selection value of air duct friction coefficient can be obtained from the monograph “Ventilation and Dust Prevention in Tunnel Construction” by Professor Lai Diquan of Shij Railway Instituteiazhuang and consulting relevant books “Ventilation Safety”, but its value cannot be used as the actual wind pressure during tunnel construction on site. The coefficient of friction of the cylinder must be determined by on-site measurement. Otherwise, the calculated results will deviate significantly from the actual site, so the equipped fan and air duct equipment. cannot be used. The following is for reference only: friction resistance coefficient of 1200mm ventilation pipe = 0.00284 NS2/m4, friction resistance coefficient of 1000mm ventilation pipe = 0.0029 NS2/ m4.
Mining air ducts are divided into flexible air ducts and rigid metal air ducts according to different materials. Flexible air ducts are made of leather, plastic, canvas, rubber, etc. The rigid metal hair dryer is made of iron, steel, aluminum, etc. Among them, the driversIron air ducts are divided into ordinary iron air ducts and anti-return iron air ducts.
The iron air duct is therefore a rigid metal air duct. The function of the air duct is to connect ventilation equipment to extract and exhaust air and guide the air flow in a certain direction. pipe currently used in coal mines or tunnels. It is the most commonly used air guiding and air supply device in narrow tunnels and other places.