Abstract: A cyclone separator for generating snow from liquid carbon dioxide comprising a flexible frustoconical member having an open upper end and an open lower end and defining a separation chamber. Injection nozzles having orifices for injecting liquid carbon dioxide located in the upper end of the separation chamber. Each injection nozzle is radially spaced inwardly from the frustoconical member and the orifice of each nozzle is directed outwardly toward the frustoconical member so that liquid carbon dioxide injected into the separation chamber forms a mixture of snow and vapor which is discharged from the open lower end of the frustoconical member. A mechanical impactor mounted at the lower end of the frustoconical member to contact the frustoconical member and loosen snow which builds up in the separation chamber.