The DAC (dynamic axial compression) column adopts latest design by ATL. The piston of column always produce a stable pressure on packing bed which can effectively prevent the collapse and loose of the column bed. Short length, Large inner diameter, Pancake shaped. It is far shorter than the open column which length is always more than 1m. Besides, its inner diameter is 10mm to 1000mm.The separation cycle of the pure material will be shorter and the yield will be higher.