Usages: Vessel workshops; get rid of smoking and heat during electric soldering, Steel mill and casting factory; cooling purpose on extension pressure, The big workshop, tunnel and basement ventilation, Vessel workshops, get rid of smoking and heat during electric soldering, dry paint, fresh air and clear smell less, Steel mill and casting factory; cooling purpose on entension pressure and casting, Anti-heat an ventilation for work fields in high temperatures, Tunnel and basement ventilation.