GB999256A - Improvements relating to continuous flow systems and methods of controlling them - Google Patents

Abstract

<PICT:0999256/C6-C7/1> In a chemostatic process for the continuous fermentation of sedimentable micro-organism in a substrate of lower specific gravity, e.g. brewers' wort, involving continuous equilibrium volumetric flow of substrate through one or a series of vessels containing micro-organisms, the concentration of micro-organisms in the effluent is controlled to have a lower value than the concentration in the main body of substrate. Wort seeded with yeast enters a pre-fermenter vessel 11, provided with stirrer 17, through pipe 12 and aerater 13 and after the yeast has multiplied in temperature controlled aerobic conditions is drawn off through pipe 14 which communicates with fermentation vessel 18 which has a stirrer 21 and a vent and filter system 19, 20. Primary effluent pipe 22 connects with an inclined shielding pipe 24 which isolates a region of the liquid in the vessel from the effects of agitation. Secondary effluent pipe 23, and primary effluent pipe 22 have valves 26, 25 respectively which control the rate of flow from the effluent pipes. Effluent drawn from pipe 22 contains little or no yeast since the yeast tends to settle in the inclined shielding pipe 24. The effluent drawn from pipe 23 carries yeast at the concentration obtaining in the main body of the vessel. Thus by varying the amount of effluent drawn from each pipe the concentration of yeast in the aggregate effluent may be controlled.