Modeling brewers' yeast flocculation

摘要: Flocculation of yeast cells occurs during the fermentation beer. Partway through become flocculent and start to form flocs. If environmental conditions, such as medium composition fluid velocities in tank, are optimal, flocs will grow size large enough settle. After settling main part green beer is left, containing only a small amount necessary for rest conversions next process step, lagering. The physical flocculation dynamic equilibrium floc formation breakup resulting bimodal distribution single cell were measured under different conditions that occur full scale fermentation. Influences on strength, specific power input, total number suspension studied. A model was developed, data used validation. Yeast can be described with collision theory assuming constant efficiency. appears mainly via two mechanisms, splitting erosion from surface. rate determines average cells. Regarding respect turbulence, viscous subrange needs considered. With model, predicted at certain point For this, bond strength between cells, fractal dimension yeast, input tank have known. Copyright 1998 John Wiley & Sons, Inc.