Measurement of the Surface Heat Transfer Coefficients for Freezing Time Prediction of Foodstuffs

식품의 동결시간 예측을 위한 표면열전달계수 측정

  • Jeong, Jin-Woong (Korea Food Research Institute) ;
  • Kong, Jai-Yul (Department of Biological Science and Technology, National Fisheries University of Pusan) ;
  • Kim, Min-Yong (Department of Refrigeration Engineering, Yosu National Fisheries College)
  • 정진웅 (한국식품개발연구원) ;
  • 공재열 (부산수산대학 생물공학과) ;
  • 김민용 (여수수산대학 냉동공학과)
  • Published : 1989.12.01

Abstract

For the accurate prediction of freezing time, probably the most difficult factor to measure and major error source is the surface heat transfer coefficient. In this work, surface heat transfer coefficient were determined for still air freezing and immersion freezing methods by theory of the transient temperature method and confirmed by using a modification of plank's equation to predict the freezing time of ground lean beef. The results showed the cooling rate of immersion freezing was about 11 times faster than that of still air freezing method. A comparison of surface heat transfer coefficient of copper plate and ground lean beef resulted an difference of 25-30% because the food sample surface is not smooth as copper plate. Also, when h-values measured by ground lean beef were applicated to modified model, the accuracy of its results is very high as difference of about 8%.

Keywords

surface heat transfer coefficient;still air freezing;immersion freezing;freezing time