Counter rotating axial flow fan refers to a fan composed of impellers with two diameters in series, the hub ratio is the same, and the rotation direction is opposite. The rotational speed of two impellers is generally the same. Counter rotating axial flow fan refers to the fan composed of impellers with two diameters in series, the hub ratio is the same, and the rotation direction is opposite. The rotational speed of two impellers is generally the same. Counter rotating axial flow fan refers to the fan composed of impellers with two diameters in series, the hub ratio is the same, and the rotation direction is opposite. The rotational speed of two impellers is generally the same. Counter rotating axial flow fan refers to the fan composed of impellers with two diameters in series, the hub ratio is the same, and the rotation direction is opposite. The speed of the two impellers is generally the same.
