Dynamic pressure rise in the drying chamber as a remote sensing method for monitoring the temperature of the product during the primary drying stage of freeze drying


LIAPIS A., Sadikoglu H.

DRYING TECHNOLOGY, vol.16, no.6, pp.1153-1171, 1998 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 16 Issue: 6
  • Publication Date: 1998
  • Doi Number: 10.1080/07373939808917458
  • Journal Name: DRYING TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.1153-1171
  • Keywords: dynamic pressure rise in drying chamber, remote sensing of product temperature during freeze drying, PHARMACEUTICAL CRYSTALLINE, AMORPHOUS SOLUTES

Abstract

A novel dynamic pressure rise method is developed as a remote sensing procedure for determining at different times during the primary drying stage of the freeze drying process (i) the temperature of the moving interface between the dried and frozen layers of the product, (ii) the temperature close to the upper surface of the dried layer of the product, (iii) the temperature of the bottom surface of the frozen layer of the product, and (iv) the temperature profile of the frozen layer of the product. Furthermore, by knowing the temperature of the heating plate and determining the value of the temperature of the moving interface from the dynamic pressure rise method, the value of the position of the moving interface could be determined by an expression presented in this work.