Evaluación y rediseño del sistema de calentamiento y enfriamiento del biorreactor liflus gx : rediseño del sistema de control automático de temperatura del biorreactor tipo tanque agitado liflus gx.

Abstract

The cooling system of LiFlus GX bioreactor comprises a U-tube with freshwater circulation and a pure proportional temperature controller that incorporates a solenoid valve. Heating is achieved by a metallic jacket, a solid-state relay (SSR) and an automatic ON/OFF control. An empty space between the jacket and the bioreactor tank is identified which becomes the main flaw. This hinders the heat transfer to the culture medium and compromises the integrity of the SSR. In this sense, this work targets the revamping of the automatic temperature control system without the jacket. Then, the mathematical model that describes the current behavior of the bioreactor was formulated and validated through fermentations with Saccharomyces cerevisiae in YPD at 5% glucose. Modifications in the revamping were incorporated into the mathematical model and the predictive results were compared with those obtained from the current behavior. Formulated model successfully describes current behavior with 0.67% and 2.78% deviations for culture medium and heating water temperature, respectively. The implementation of pure proportional controller and solenoid valve provides the decrease of temperature stabilization time (60 minutes), the SSR energy (162 J/min) and total water consumption (120.11 L). However, the original solenoid valve and SSR state oversized.