| 摘要 |
<p>Freeze-drying of classified particulate material which is disintegrated in its frozen state but before it is supplied to the refrigeration vacuum drying chamber is carried out such that ranges of particulate fine material are removed successively by banks of superposed nozzles which direct the size batches of fine particles along ducts associated with discharge hoppers through which the gases carrying the particle size batches are exhausted to atm., and the bath of coarser particles is then passed through successive screens superposed over one another in the drying chamber and collected in a separate discharge hopper.</p> |
