The invention relates to freeze-drying, and more specifically to the production of freeze-dried particles as bulkware. One embodiment of a process line (300) for the production of freeze-dried particles under closed conditions comprises at least the following separate devices: A spray chamber (302) for droplet generation and freeze congealing of the liquid droplets to form particles; and a bulk freeze-dryer (304) for freeze drying the particles; wherein a transfer section (308) is provided for a product transfer from the spray chamber (302) to the freeze-dryer (304), and for the production of the particles under end-to-end closed conditions each of the devices (302, 304) and of the transfer section (308) is separately adapted for closed operation.