Freeze-drying device and freeze-drying method

Patent metadata

Field	Value
Publication number	US-11480390-B2
Application number	US-202217683028-A
Country	US
Kind code	B2
Filing date	Feb 28, 2022
Priority date	Feb 16, 2021
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

A freeze-drying device includes a controller configured to control depressurization of containers filled with a liquid including a raw material and a medium to freeze the liquid from a liquid surface. The freeze-drying device also includes a gas capture pump configured to exhaust a freeze-drying chamber accommodating the containers, and a positive-displacement pump configured to discharge gas from a space accommodating the gas capture pump. The controller executes an exhaust mitigation process that performs the depressurization at an exhaust capability that is less than a rated exhaust capability of the freeze-drying device. The controller uses a partial pressure value of the medium to determine when the exhaust mitigation process ends. The controller maintains an exhaust speed of the gas capture pump and decreases an exhaust speed of the positive-displacement pump in the exhaust mitigation process.

First claim

The invention claimed is:

1. A freeze-drying device comprising:
a controller configured to control depressurization of containers filled with a liquid including a raw material and a medium to freeze the liquid from a liquid surface,
a gas capture pump configured to exhaust a freeze-drying chamber accommodating the containers; and
a positive-displacement pump configured to discharge gas from a space accommodating the gas capture pump,
wherein the controller executes an exhaust mitigation process that performs the depressurization at an exhaust capability that is less than a rated exhaust capability of the freeze-drying device, and the controller uses a partial pressure value of the medium to determine when the exhaust mitigation process ends; and
wherein the controller maintains an exhaust speed of the gas capture pump and decreases an exhaust speed of the positive-displacement pump in the exhaust mitigation process.

2. The freeze-drying device according to claim 1 , wherein the controller sets an exhaust speed of the freeze-drying device to be greater than a rated exhaust speed of the freeze-drying device after the exhaust mitigation process.

3. The freeze-drying device according to claim 1 , wherein the controller sets an exhaust speed of the freeze-drying device to a rated exhaust speed of the freeze-drying device or larger before the exhaust mitigation process.

4. The freeze-drying device according to claim 1 , wherein the controller executes an exhaust intensification process after the exhaust mitigation process and uses a partial pressure value of the medium to determine when the exhaust intensification process ends.

5. The freeze-drying device according to claim 4 , wherein the controller executes a boiling hindrance process after the exhaust intensification process and uses low-temperature gas or ice fog when recovering pressure during the boiling hindrance process.

6. The freeze-drying device according to claim 1 , wherein the controller changes a temperature of a holding surface on which the containers are held in the exhaust mitigation process.

7. The freeze-drying device according to claim 6 , wherein the controller sets the temperature of the holding surface in the exhaust mitigation process to be higher than that before the exhaust mitigation process.

8. A freeze-drying device comprising:
a controller configured to control depressurization of containers filled with a liquid including a raw material and a medium to freeze tare liquid from a liquid surface,
wherein the controller executes an exhaust mitigation process that performs the depressurization at an exhaust capability that is less than a rated exhaust capability of the freeze-drying device, and the controller uses a partial pressure value of the medium to determine when the exhaust mitigation process ends; and
wherein the controller sets an exhaust speed of the freeze-drying device to a rated exhaust speed of the freeze-drying device or larger before the exhaust mitigation process.

Assignees

• Ulvac Inc

Inventors

• Yoshimoto Tsuyoshi
• Ohinata Yoichi
• Ozeki Tomomitsu

Classifications

• F26B5/044

  for drying materials in a batch operation in an enclosure having a plurality of shelves which may be heated (F26B5/045 takes precedence) · CPC title

• F26B5/06 Primary

  the process involving freezing · CPC title