Coal is blown up by the strong wind from the air-blower and the “fluidized state”; coal and air are sufficiently touch and burnt. A large amount of coal particles carried by the smoke enter into the separator. Heavier particles collected by the separator are sent into the main combustion chamber via the recycle device to “recycle” and burn again. Light smoke enters into end heating surface of boiler and continues to provide heat for the drum. Advanced combustion technology enables the thermal efficiency of this kind of boiler can reach over 86%. http://www.balturboiler.com/