MODELING OF REFRACTANCE WINDOW FILM DRYER FOR LIQUIDS | ||||
| Misr Journal of Agricultural Engineering | ||||
| Article 16, Volume 27, Issue 2, April 2010, Page 676-687 PDF (594.07 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/mjae.2010.105936 | ||||
 View on SCiNiTO | ||||
| Author | ||||
| T.H. Ghanem | ||||
| Assoc. Prof., Agric. Eng.. Fac. of Agric., Al-Azhar Univ., Egypt. | ||||
| Abstract | ||||
| The aim of the present study is to develop mathematical analysis of a film dryer or refractance type dryer that helps in design, operation, modification, evaluating drying time and rates, improving quality and increasing energy efficiency. Strawberries juice was used as an example of liquid foods. For justifying this purpose a pilot plant refractance window dryer was designed. A film of juice with an initial thickness of approximately 3 mm, was applied on a hot glass plate heated by water underneath, that continuously contacts it. Nine experiments were conducted, namely: three variable flow rates per unit surface area of the dryer, 0.25, 0.21 and 0.18 m3/m2.s , and also three different levels of heating rates for each flow rate were also applied, i.e. 15.2 , 24.3 and 36.6kW/m2 respectively. Liquid strawberries drying time ranged between 0.77-0.90 h compared to 5 h for traditional hot-air dryer at 60 oC .The model is reasonably accepted for predicting the drying coefficient-elapsed time product and moisture ratio with coefficients of determination of 97%. | ||||
| References | ||||
|
AOAC., 1990.Official methods of analysis of Association of Official analytical chemists. 5th Ed. by Kennen Helrich.
Brendan,I.A.Juming,T.andCharlesG.E.1999.Evaluation of the energy efficiency and quality retention for refractance window drying system.Dept.of Biological Systems Eng.Washington stat Univ. Project Report:1-36.
Dennis,R.H and Singh R,P.1981.Food process engineering. Second Ed.AVI Pub.CompanyInc. Wesport Conn.U.S.A:269.
Feng,H.,Tang, J.and Cavalierie,R.P.1999.Combined microwave and sprouted bed drying of diced apples:Effect of drying conditions on kinetics and product temperature,Drying technology.17(10)1981-1998.
Gehrmann,D.1979.Theoretische experimentelle untersuchungen, Disssertian.Universitat Darmstadt.(C.f.Sjoholm,1982).
Lin, S.H.andAgalloco,J.1979.Degradation kinetics of ascorbic acid. Process Biochemistry J.:22-27.
Jean,A., and Penington, T.1994.Food values portions commonly used.J.B.Lippinott Co. Lib. of Congress Cataloging- 55087-1:55,267.
Murphy,G.1950.Similitude in engineering . N. Y. The Roland Press Co. :36-37.
Rai G.D.1980. Solar energy utilization.1 st. Ed., Pub. By Romesh Chander Khanna.2-8 North market, New Delhi.110006.:58-67,192-196.
Sjoholm,I.1982.Heat and mass transfer in sugar solutions during drying. Eng. and Science in the Food Industry. Edited by Brian M. Mckena. (1): 177-184.
Toledo,R.T.1991.Fudamentals of food process engineering. An AVI book Pub. By Van Nostrand Reinhold.N.Y.10003.ISBN. o-442-23988-6:133-136. | ||||
|
Statistics Article View: 222 PDF Download: 239 |
||||
