Suitable for drying of materials which cannot resist high temperature, materials which are easily oxidized, volatile materials which should be retrieved, materials strong irritant and poisonous matters. The rotocone dryer with improved technology integrates during operation under vacuum. The Rotocone dryer facilitates enhanced drying efficiency, low temperature operation and economy of process by total solvent recovery. It helps GMP based working by achieving optimum dust control, while offering the advantages of efficient charging and discharging of materials. The drying unit equipped with lump breakers initially breaks large lumps and subsequently powders them (in single cone). The rotary action of the dryer together with mechanical action of the breakers, cuts down drying time and gives a lump free product.