Advantages centrifugal fan: cooling, precipitation effect is obvious positive outlet axial fan, ventilation time is short; Disadvantages: high energy consumption; ventilation timing was bad prone to condensation. Conclusion: In order to cool down for the purpose of ventilation, the application of axial fans safe, efficient, energy-efficient ventilation retarder; centrifugal fan application in order for the purpose of ventilation in precipitation. Part of the connection D30K2-12 type axial fan can be used as pipe in the middle of the pipe, used in chemical, paper and other factories sixty degrees below the air transportation and a variety of motor harmful gases. The fan impeller diameter divided by its NO4,5,6,7,8,9 axial fans, 10,11.2. Hebei machine number eight axial fans, number of leaves have four, six two kinds of blade mounting angle can be made 15 degrees, 20 degrees, 25 degrees axial fan, 30-degree four. Motor mounted on the upper duct with adjustable motor base plate supporting the motor, and can adjust the center distance. All use of V-belt drives, bearing box fixed in the central duct sealing protective tube and the dielectric isolation. Fans generally use steel welded, can request a special production at the time of ordering if the transport corrosive, flammable gas. Axial fan production, rich ventilation equipment (certified), Liaocheng, Shandong Dezhou axial fan provided by rich ventilation plant. Dezhou Plumper ventilation plant (www.frtfsb.com) (www.frtfsb.com) is a leader in Dezhou, fans, ventilation equipment, over the years, the company implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum limits to meet customer needs. Rich ventilation equipment in leadership with the staff warmly welcome all inquiries negotiations to create rich, ventilation a better future.