O type lengthwise set double-drum boiler is symmetrically structured with reasonable water circulation, sufficient heating surface and high heating efficiency. It has some other features: a wide adaptability of coal, big furnace space, even gas mixture and complete burning. The available for the light chain grate: small, medium and large blocks bars, active shaft bar, louver stoker and Denmark ECO type. First pioneered in China, active shaft bar does not break easily in addition to even ventilation, powerful dust-removal capacity, reduced coal leak and convenient maintenance. The boilers are ventilated at both sides, and distribution is even and individual. Leak tightness of the pipe is satisfactory, and temperature and pressure rise quickly. Seal plates at both sides of the grate are made of dismountable die plate so that grate can be examined and repaired while working. The boiler casing is made of light heat-insulating materials. Built with layers of rabbet bricks, it is then filled with vermiculite concrete. Its outer wall is packed with dismountable small blocks of die plate so that both air and heat leakage can be effectively prevented. Besides, they are strong, durable, pleasing to the eye and convenient for examination and repair. It has a high level of automation equipped with patent economizer and multilevel security protection device.
