Optimal control of a freeze dryer—I Theoretical development and quasi steady state analysis

✍ Scribed by Athanasios I. Liapis; Rod J. Litchfield

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 595 KB
• Volume: 34
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(79)85009-5

✦ Synopsis

A mathematical model which describes the nonsteady state heat and mass transfer operations durmg the freeze drymg process IS presented With the use of tins model the problem of operating a freeze dryer to obtam a fixed final mmsture content m mmlmum trme IS formulated as an optImaI control problem Radiator energy output and total pressure m the drymg chamber are consldered control varrables Constramts are placed on the system state variables by the scorch pomt of the dried product and the meltmg pomt of the frozen Interface A quasi steady state analysis IS performed which provides general guldehnes about the optimal controt pohcy at the beamnmp. of the drymrr process (when neither of the state constraints IS active), as well as durmg operationwhen the pro&s may be-hei< and/or mass transfer limited