In the fan between the axial flow fan and the centrifugal fan, the mixed flow fan impeller causes the air to move both centrifugally and axially. The motion of air in the shell mixes axial flow and centrifugal motion, hence it is called "mixed flow". The wind pressure coefficient of mixed flow (oblique flow) fans is higher than that of axial flow fans, and the flow coefficient is larger than that of centrifugal fans, making them suitable for situations where both wind pressure and flow rate are "not too small". It fills the gap between the axial flow fan and the centrifugal fan. At the same time, it has the characteristics of simple and convenient installation.

The mixed flow fan combines the characteristics of axial flow and centrifugal fan, and its appearance is more like a traditional axial flow fan. The casing can have an open entrance, but more commonly, it has a right angled curved shape, allowing the motor to be placed outside the pipeline. The discharge shell slowly expands to reduce the velocity of air or gas flow and convert kinetic energy into useful static pressure. The SWF (B) series low-noise energy-saving mixed flow fan is a new type of fan between axial flow fan and centrifugal fan. They have the characteristics of high centrifugal fan pressure, large axial flow fan flow rate, high efficiency, good energy saving, low noise, and easy installation. The present invention has a novel design, compact structure, small volume, light weight, easy installation, a speed of less than 2000 revolutions per minute, a noise level of less than 75dB (A), and a noise level of less than 70dB (A) when the fan and pipeline are connected and installed in the air conditioning box. Low pressure centrifugal fans are widely used for ventilation and dust removal in industrial and civil buildings.

The fan is mainly composed of impeller, casing, imported slip ring, guide plate, motor and other components.. The impeller is welded to the hub through a twisted flat plate with radial acceleration characteristics. After dynamic balance inspection and overspeed test, it has good aerodynamic performance. The outer shell is circular and integrated with a silencer that has noise reduction function. The outlet is equipped with guide vanes, ensuring good airflow distribution and stable pressure. The HL3-2A [SWF (B)] series mixed flow ventilation fan is widely used for ventilation and high-temperature smoke exhaust in tunnels, underground garages, high-end civil buildings, metallurgy, factories, mines and other places. The HL3-2A [SWF (B)] series fan should not exceed 80 ℃ in conveying gas temperature, and anti riot mixed flow fans can be selected for special environments.

The performance of the fan is within the highest efficiency range. Divide it into five characteristics based on traffic. Choose based on the performance table. The performance of qualified fan products shall not exceed 5% of the total pressure at rated flow rate. The performance selection table is the performance under standard conditions. The standard atmospheric pressure is 101325 Pa, t=20， Relative temperature is 50% of the air state. The installation mode of the fan can be divided into vertical or horizontal.