The mixed-flow fan's pressure coefficient and flow coefficient, along with its linear connection method, are suitable for pressurization, air supply, exhaust, and general ventilation in civil and industrial building duct systems. In high-rise buildings and other structures requiring fire smoke exhaust systems, as positive-pressure supply fans for smoke-proof stairwells and vestibules, they can maintain the necessary positive pressure in the stairwell and vestibule during fires, ensuring safe evacuation of personnel. The SWF mixed-flow fan is available in single-speed and double-speed models, allowing adjustment of the installation angle, blade count, and speed variation to meet different operational requirements.