Apparatus and method for continuous lyophilization

• US 8,528,225 B2
• Filed: 11/19/2010
• Issued: 09/10/2013
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: Komline-Sanderson Corp.
• Original Assignee: Wyssmont Company, Inc.
• Inventors: Weisselberg, Edward
• Primary Examiner(s): Gravini, Steve M
• Application Number:
  US12/950,336
• Publication Number:
  US 20110138646A1
• Time in Patent Office: 1,026 Days
• Field of Search: 342/220.1, 348/06, 414/27, 414/38, 414/90, 201/27, 201/38, 201/90, 208/390, 208/400, 208/407, 208/408, 202/109, 202/117, 202/118
• US Class Current: 34/284
• CPC Class Codes: A23L 3/44 Freeze-drying
• CPC Class Codes: F26B 17/003 with fixed floors provided with scrapers F26B17/006 and F26B17/007 take precedence
• CPC Class Codes: F26B 17/005 with rotating floors, e.g. around a vertical axis, which may have scrapers F26B17/002, F26B17/006, F26B17/007 take precedence
• CPC Class Codes: F26B 17/006 the movement being imparted by oscillation or vibration
• CPC Class Codes: F26B 21/024 by using movable fan units
• CPC Class Codes: F26B 21/04 partly outside the drying enclosure F26B21/006 takes precedence
• CPC Class Codes: F26B 21/083 by using sorbent or hygroscopic materials, e.g. chemical substances, molecular sieves
• CPC Class Codes: F26B 5/00 Drying solid materials or objects by processes not involving the application of heat separating liquids from solids by straining B01D; replacing liquids in wet solids by other liquids, e.g. water by spirit, B01D12/00; drying by electrophoresis B01J
• CPC Class Codes: F26B 5/06 the process involving freezing
• CPC Class Codes: F26B 5/14 by applying pressure, e.g. wringing; by brushing; by wiping

Abstract

A method and apparatus for the continuous sublimation of a substance includes cascading a material containing a substance capable of sublimation, such as water, between a plurality of trays vertically stacked within a processing zone provided within a processing chamber. A substantially atmospheric environment is maintained within the processing zone at a temperature whereby the substance sublimes forming a sublimate within the environment. The environment containing the sublimate is contacted with a drying agent such as a desiccant to maintain the environment whereby the substance sublimes at substantially atmospheric pressure and at the controlled temperature.

Claims

1. A method for the continuous sublimation of a substance, the method comprising:

cascading a material containing a substance capable of sublimation between a plurality of trays vertically stacked within a processing zone provided within a processing chamber;

maintaining a substantially atmospheric environment within the processing zone and at a temperature whereby the substance sublimes forming a sublimate within the environment;

recovering the sublimate from the environment; and

contacting the environment after recovering the sublimate therefrom with a drying agent to maintain the environment whereby the substance sublimes at substantially atmospheric pressure at the temperature.

2. The method of claim 1, further including maintaining the environment whereby the partial pressure of the substance in the processing zone is less than the vapor pressure of the substance in the material.

3. The method of claim 2, further including maintaining the temperature in the range of about 20-30°

F.

4. The method of claim 1, wherein the drying agent comprises a desiccant.

5. The method of claim 4, wherein the desiccant is selected from the group consisting of lithium chloride, calcium chloride, calcium sulfate, phosphorous pentoxide, triethylene glycol, diethylene glycol, ethylene glycol, tetrathylene glycol, silica gel, and molecular sieves.

6. The method of claim 1, wherein the drying agent comprises a gas having a dew point whereby the substance sublimes at substantially atmospheric pressure at the temperature.

7. The method of claim 1, further including supplying the material to the processing chamber in particulate form.

8. The method of claim 7, further including supplying the material at a temperature of less than 32°

F. whereby the substance is frozen.

9. The method of claim 1, further including recovering the sublimate from the drying agent.