HWAHAK KONGHAK, Vol.23, No.3, 189-197, June, 1985
연속흐름교반반응기에서의 액체 혼합특성
Liquid Mixing Characteristics in a Continuous Flow Stirred Tank Reactor
초록
입구와 출구를 각각 반응기의 하부와 상부에 위치시키고 6-bladed turbine impeller를 사용한 연속흐름교반반응기에서의 액체혼합특성을 연구하였다.
반응기내의 혼합지역을 입구지역, 임펠라지역과 재순환흐름지역으로 나누고 각 혼합지역의 혼합특성을 고려한 액체혼합 모델을 세워 비가역 2차 반응계의 실험값과 비교하였다.
실험결과, 입류속도가 낮고 교반속도가 낮은 경우에는 입구지역과 재순환흐름지역이 macrofluid의 혼합특성을 가지나 입류속도가 높거나 교반속도가 큰 경우에는 macrofluid인 재순환흐름의 영향으로 입구지역은 microfluid가 완전혼합되는 특성을 나타내었다. 또한 microfluid로 볼 수 있는 임펠라지역은 교반속도가 증가할수록 그 크기가 증가되었다.
반응기내의 혼합지역을 입구지역, 임펠라지역과 재순환흐름지역으로 나누고 각 혼합지역의 혼합특성을 고려한 액체혼합 모델을 세워 비가역 2차 반응계의 실험값과 비교하였다.
실험결과, 입류속도가 낮고 교반속도가 낮은 경우에는 입구지역과 재순환흐름지역이 macrofluid의 혼합특성을 가지나 입류속도가 높거나 교반속도가 큰 경우에는 macrofluid인 재순환흐름의 영향으로 입구지역은 microfluid가 완전혼합되는 특성을 나타내었다. 또한 microfluid로 볼 수 있는 임펠라지역은 교반속도가 증가할수록 그 크기가 증가되었다.
The mixing characteristics of liquid was investigated in a continuous flow stirred tank reactor （CFSTR） with a 6-bladed turbine impeller. The inlet and the outlet were located at the bottom center and the top edge of the reactor, respectively.
For the CFSTR, three zones （inlet zone, impeller zone and recirculation flow zone） with different mixing characteristics were assumed and the theoretical conversions based on the assumption were compared with the experimental results obtained from the irreversible second order reaction system.
For the case of the lower inlet flow rate and the lower agitation speed, the experimental results showed that the mixing characteristics of the inlet and the recirculation flow zones were considered to be that of macrofluid. For the higher inlet flow rate as well as the higher agitation speed, however, the inlet zone showed the perfect mixing nature of microfluid with a considerable dilution of the macrofluid of recirculation. Also, the higher agitation speed, the larger was the volume of the impeller zone, in which the microfluid characteristics could be excellently assumed.
For the CFSTR, three zones （inlet zone, impeller zone and recirculation flow zone） with different mixing characteristics were assumed and the theoretical conversions based on the assumption were compared with the experimental results obtained from the irreversible second order reaction system.
For the case of the lower inlet flow rate and the lower agitation speed, the experimental results showed that the mixing characteristics of the inlet and the recirculation flow zones were considered to be that of macrofluid. For the higher inlet flow rate as well as the higher agitation speed, however, the inlet zone showed the perfect mixing nature of microfluid with a considerable dilution of the macrofluid of recirculation. Also, the higher agitation speed, the larger was the volume of the impeller zone, in which the microfluid characteristics could be excellently assumed.