CRA100 – Batch Cooling Crystallization Teaching Unit

The CRA/100 Batch Crystallization unit from Pignat is a bench-scale teaching pilot for studying controlled cooling crystallization in a stirred batch process. It allows students and researchers to explore how the solubility of a solid in a liquid phase falls with temperature, and to apply this principle by regulating both the temperature and the rate of cooling of a supersaturated solution to grow and recover crystals. The concentrated solution is held in a 3 litre glass crystallization tank fitted with a polypropylene cover, draining valve and product temperature measurement. A variable-speed stirrer running from 50 to 1300 rpm, combined with a four-blade mobile and three counter-blades, maintains a homogeneous mixture and consistent heat transfer. An immersed stainless steel coil with a 0.05 square metre exchange surface carries cooling fluid from a hot/cold thermoregulatory group rated at 2 kW heating and 500 W cooling at 20 degrees Celsius. Inlet and outlet temperature measurements on the coil, Pt100 probes, two digital thermometers and a 60 to 600 litre per hour flowmeter let users complete a full thermal and mass balance. By adjusting the cooling rate, operators can demonstrate the difference between rapid cooling, which yields small crystals, and slow cooling, which produces larger crystals. An optional glass Buchner filtration system and membrane vacuum pump allow the crystal paste to be recovered under vacuum, extending the unit to cover downstream separation. Bestech Australia supplies the CRA/100 Batch Crystallization unit with on-site training and commissioning support available.