To provide a freeze vacuum dryer with which fine source liquid particles do not self-freeze around a nozzle in the case that source liquid is injected into a vacuum freeze drying tower from the nozzle to conduct freeze-dry and a freeze vacuum drying method.
The nozzle 12 for injecting 5% aqueous solution of mannitol as the source liquid L into the vacuum freeze drying tower 11 is formed as a flat plate 13 with a micro pore 14 of, for example, 150 μm in inner diameter. With pressure in the vacuum freeze drying tower 11 at, for example, 50 Pa and pressure applied to the source liquid L at, for example, 0.3 MPa, a liquid column K of the source liquid L is formed below the micro pore 14 and the fine source liquid particles R formed by dispersion of the liquid column K from an lower end of the liquid column K in a fixed length which is determined by injection condition are self-freezed and collected as fine frozen particles Q. Ice contained in the fine frozen particles Q is sublimated by heating the fine frozen particles Q at a low temperature and dry them to obtain fine powder P of mannitol.
NAKAMURA KYUZO
HANAMOTO TAKASHI
ITO NOBUKI
