Utente:Ub/Sandbox: differenze tra le versioni

Versione delle 21:01, 24 giu 2006

Versione delle 21:02, 24 giu 2006

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=====Evaporative crystallizers=====

Most of industrial crystallizers are of the evaporative type, such as the very large [[sodium chloride]] and [[sucrose]] units, whose production accounts for more than 50 % of the total world production of crystals. The most common type is the ''forced circulation'' (FC) model (see [[evaporator]]). A pumping device (a [[pump]] or an axial flow [[mixer]] keeps the crystal [[slurry]] in homogeneous [[suspension]] throughout the tank, including the exchange surfaces; by controlling pump [[flow]] , control of the contact time of the crystal mass with the supersaturated solution is achieved, together with reasonable velocities at the exchange surfaces. The Oslo, mentioned above, is a refining of the evaporative forced circulation crystallizer, now equipped with a large crystals settling zone to increase the retention time (usually low in the FC) and to roughly separate heavy slurry zones from clear liquid.

====The DTB Crystallizer====