VACUUM FREEZE DRYING APPARATUS AND FROZEN PARTICLE MANUFACTURING METHOD

摘要

A technology for protecting a valve seat inside a collection tank from the adherence of frozen particles in a vacuum freeze-drying apparatus and a frozen particle manufacturing method. The inside of a vacuum tank 11 and a collection tank 12 are vacuum evacuated, a raw material liquid is injected into the vacuum tank 11 to produce frozen particles, and the frozen particles are piled up on a surface of a heating/cooling shelf 17. After a first opening 22 of a main pipe 21 which is exposed inside the collection tank 12 is opened, an auxiliary pipe 31 inserted into the main pipe 21 is moved to a position where the bottom end of the auxiliary pipe 31 protrudes to the outside of the main pipe 21 through the first opening 22. When the frozen particles on the heating/cooling shelf 17 are transferred into the collection tank 12 through the inside of the auxiliary pipe 31, the frozen particles do not adhere to a valve seat 23 which surrounds the first opening 22. Next, the auxiliary pipe 31 is moved to a position where the bottom end enters the inside of the main pipe 21 through the first opening 22; the first opening 22 is blocked, and the frozen particles are carried out from the inside of the collection tank 12.