Evaporation — General principles

Food processing often requires an intermediate concentration step by evaporation. Solutions are usually aqueous.

Most units operate continuously, even if they are shut down for a few hours at a time for chemical cleaning. The length of time between cleaning operations varies considerably from one product to another, from twelve hours for whey to three months for beet sugar juice.

The aim of this article on evaporation in the food industry is to present the principles of concentration by evaporation, illustrate the different modes of implementation, discuss applications in the food industry and, finally, mention the questions to be asked when installing a new unit.

The first part [F 3 003] covers general principles, in particular how to determine the data needed to write balances. The second part [F 3 004] describes how evaporators are used, how they can be arranged to save energy and, finally, the questions to ask when considering the installation of a new evaporator.