Fermentation and Biochemical Engineering Handbook Figure 20. Photograph of radial flow impeller in a baffled tank in the laminar region, made by passing a thin plane of light through the center of the tank

Cross-flow filtration (CFF) also known as tangential flow filtration is not of recent origin. It began with the development of reverse osmosis (RO) more than three decades ago. Industrial RO processes include desalting of sea water and brackish water, and recovery and purification of some fermentation products. The cross-flow membrane filtration technique was next applied to the concentration and fractionation ofmacromolecules commonly recognized

Liquid-liquid extraction is a unit operation frequently employed in the pharmaceutical industry, as in many others, for recovery and purification of a desired ingredient from the solution in which it was prepared. Extraction may also be used to remove impurities from a feed stream

The engineer designing an ion exchange column operation usually will prefer to work with the simplest kinetic model and linear driving force approximations. The weakness ofthis approach is that any driving force law only regards the momentary exchange rate as a hnction of the solute concentration in the bulk solution and the average concentration in the particle, neglecting the effect of concentration profiles in the particle

Often in multiple-effect evaporators the concentration of the liquid being evaporated changes drastically from effect to effect, especially in the latter effects. In such cases, this phenomenon can be used to advantage by staging one or more of the latter effects. Staging is the operation of an effect by maintaining

The solids-liquid separation process can be accomplished by filtration or centrifugation. Centrifuges magnify the force of gravity to separate phases, solids from liquids or one liquid from another. There are two general types of centrifuges: Sedimentation Centrifuges-where a heavy phase settles out from a lighter phase

Historically, sterile bulk pharmaceutical manufacturing processes, prior to filling operations, have followed general bulk pharmaceutical guidelines. As technology and equipment have improved

The widespread use of advanced control and process automation for biochemical applications has been lagging as compared with industries such as refining and petrochemicals whose feedstocks are relatively easy to characterize and whose chemistry is well understood and whose measure￾ments are relatively

The purpose ofthis chapter is to review various forms of solids dryers and auxiliary components. It is intended to be a practical guide to dryer selection (as opposed to the theory of drying, which is addressed in various technical manuals referenced in the bibliography). From a microscopic

Copyright 8 1997 by Noyes Publications No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without permission in writing from the Publisher. Library of Congress Catalog Card Number: 96-29055 Printed in the United States