- Unidirectional vane axial fan for metro and tunnel
Fans shall be cylindrical vane axial fan with airfoil blade, directly driven by the motor.
- Reversible vane axial fan for metro and tunnel
Fans shall be cylindrical vane axial fan directly driven by the motor. Blades shall be completely symmetrical airfoil design and static guide vanes shall be set in the fan cylinder. Fans shall work as normal-reverse ventilation by changing rotate direction of the motor, with almost the same performance.
- Fan Casing
Fan casing should be constructed of continuously welded high quality steel plate, which shall be rolled to cylinder firstly and then wholly welded. Fan casing and motor support should be welded firmly as a whole to ensure enough strength and stiffness to bear dynamic load, meanwhile it should ensure manufacture precision of fan casing to make sure that the motor axis is identical with casing centerline.
Rotor blade should be optimized airfoil design, with asymmetrical airfoil for unidirectional fans and completely symmetrical airfoil for bidirectional fans to ensure almost the same performance between normal and reverse rotation.
Hub and blades should be casted in high strength aluminum alloy. Each blade must be tested by X ray to ensure a high quality for reliable running.
Blades should be fastened to hub with high strength bolts. Every impeller should be dynamically balanced.
Blade pitch should be adjustable in static state to meet different operating conditions.
Fairing should be streamlined design, made by pressure extruding by steel mould using high strength aluminum alloy. Fairing should be fastened to impeller by bolts and may be dismounted conveniently.
Anti surge device (only for impeller diameter over 1250 mm)
In order to prevent stall surge, fans should be set with mechanical anti surge device to ensure working without surge.
Motor should be squirrel cage asynchronous motor cooled by natural ventilation, standard product of totally enclosed type of damp heat, class H insulation, IP55. Motors are lubricated using grease by extended lubricating nipple on fan shell. Motor lead cables should extend to the junction box on the fan shell for easy wiring.
- Surface treatment
Surface of the fan should be treated with anticorrosion and antirust. It should be treated with paint （options：surface zinc plating or what specified by users）and the surface should be clean and smooth, without bubble, crinkle and spall faults to ensure long term anticorrosion.
- Smoke Removal Certification
Fans must pass testing according to GA211-2009《High Temperature Test Method for Fire Smoke Extraction Fan》by inspection agencies designated by China Certification Center for Fire Products Ministry of Public Security. Fans shall continually run for at least 60min at 250℃ reliably and have relevant certificate.
Aluminum nameplate shall be permanently fixed and clearly indicate legible fan number, model and product serial number (i.e. unique identification of each fan), ensuring that customers can conveniently query the history records of the accessories.