Analysis of Heat Transfer Mechanism for Shelf Vacuum Freeze-Drying Equipment

Autor: Hong-Ping Cheng, Shian-Min Tsai, Chin-Chi Cheng
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Advances in Materials Science and Engineering, Vol 2014 (2014)
Druh dokumentu: article
ISSN: 1687-8434
1687-8442
DOI: 10.1155/2014/515180
Popis: Vacuum freeze-drying technology is applicable to the process of high heat-sensitive products. Due to the long drying period and extremely low processing temperature and pressure, the uniform and efficiency of heat transfer fluid temperature in shelf are critical for product quality. Therefore, in this study, the commercial computer fluid dynamics (CFD) software, FLUENT, was utilized for three-dimension numerical simulation of the shelf vacuum freeze-drying process. The influences of different inlet and outlet positions for shelves on the uniformity of the flow rate and temperature were discussed. Moreover, it explored the impacts on the temperature gradient of shelves after heat exchange of different flow rates and low temperature materials. In order to reduce the developing time and optimize the design, the various secondary refrigerants in different plies of shelves were investigated. According to the effect of heat exchange between different flow rates and low temperature layer material shelves on the temperature gradient of shelves surface, the minimum temperature gradient was 20 L/min, and the maximum was 2.5 L/min.
Databáze: Directory of Open Access Journals