Oslo type crystallizer are used when large homogenous crystal sizes are required. Oslo Crystallizer are characterize by the production of super saturation in a circulating stream of solvent. They are also known as growth crystallizer.

Depending upon the nature of fluid Oslo crystallizer  can be designed to operate under vacuum or under pressure. Design ability to provide more residence time to the crystals for them to grow till a desired level. Normally the crystals are removed from the lower side of liquid bed and the supernated liquid along with crystals under growth remain on the upper side of liquid bed.

Oslo crystallizer can be of evaporative type or surfaced cooled type.

These type of crystallizers are cost efficient and require low maintenance.