It has a drum structure. The small air inlet and outlet will accelerate the rate of air flow. It has a high pressure coefficient. In the case of same device number with general axial flow fans, the flow and pressure of it will be higher than those of general axial flow fans. Therefore, they are especially applicable to the place with a small room of pipeline installation. The fans may be extensively applied to industrial and mining enterprises, hotels, museums, gyms, and so on for pipeline pressurization, and air blowing and exhaust, and ventilation of high-rise and common buildings. The temperature of gas to be delivered shall be in the range of -20 to 80℃; and the  dust content in the gas shall not be more than 100mg/m3.