Abstract: This invention presents a versatile and continuous drying technology that utilizes controlled heat combined with forced air supply for drying a feedstock. The dryer virtually divided top-down into different zones, each having definite heated air distribution rate to secure desired condition for drying of the feedstock. The heat source of the dryer is waste heat, either provided by the feedstock itself through exothermic heat generated by the feedstock or reclaimed waste heat or solar heat. The discharge system of the dryer is a fail-safe discharge system, which ensures equal residence time for the feedstock through all the zones.