Effect of Feeding Rate for Operation Properties of Centrifugal Thin Film Evaporator

급액속도가 원심식 박막증발기의 운전 특성에 미치는 영향

  • Published : 1991.08.01

Abstract

During the evaporation of garlic juice by centrifugal thin film evaporator (Centri-Therm, CT-1B), the effect of feeding rate was investigated for its operation properties. On the process condition of feeding rate of 25 to 125 kg/h, theoretical average thickness of the garlic juice film on the rotating cone and residence time of the juice in the evaporator varied in the range of 0.52 to 0.89 mm and 1.77 to 6.75 second, respectively. And the flow of garlic juice was considered as a streamline flow by Reynolds number. At constant temperatures of steam and juice evaporation, concentration ratio decreased with the increase of the feeding rate. But the evapoartion rate and overall heat transfer coefficient increased with the increase of the feeding rate until the feeding rate reached a certain value and then decreased. On the conditions of $25{\leq}$feeding rate ${\leq}125\;kg/h$, evaporation temperature of $40^{\circ}C$, $95{\leq}steam$ $temperature≤120^{\circ}C$ and initial feed concentration of $32^{\circ}Brix$, concentration ratio and overall heat transfer coefficient were $1.04{\sim}2.04\;and\;3,074.33{\sim}17,614.70kJ/m^{2}{\cdot}h{\cdot}^{\circ}C$.

Keywords

centrifugal thin film evaporator (Centri-Therm, CT-1B);garlic juice;evaporation