Cement, Energy and Environment

Introduc on by double valve airlock The double valve air lock unit consists of two electrical valves and a pneuma c safety shut off gate. This equipment is safe and reliable to resist the high working temperature of 1000 to 11000C at calciner in preheater tower. The bo om valve, safety shut of gate and bo om chute connec on piece is provided with refractory concrete lining. The opening and closing of the valves is realized by the pendulum of the single flap. An electric motor ensures a very short cycle me, efficient closing and opening. A VFD regulates the accelera on and decelera on of the valve, so that the flaps open and close smoothly and rapidly. Induc ve sensors are used to indicate the open, intermediate and closed posi on of each flap. The technical advantages of such electrical drives are mainly a cycle me reduc on of more than 50% compared to the pneuma c valves. Such double valve air locks can feed into calciner any kind of solid fuels with various grain sizes (1mm to 500mm) and with a very short cycle me minimizing the introduc on of false air. The mechanical performance of the double valve air lock is also due to the right choice of metallurgy which can handle up to 1100°C Counterweight is provided for automa c closing of the flap in case of power failure. Temperature sensor is provided to detect excessively high temperature and, in this case, both the valves with safety shut off gate is closed for security reason. Jamming sensor is provided to detect the jamming between flap and casing to ensure the complete closing of the flap. Several cement plants, mainly in Asia, have already been equipped with this new genera on of electrical double valve airlock. Since their commissioning, the installa ons have been running to the full sa sfac on of the customer. 29 Double valve airlock with safety shut off gate