Miniaturized draft tube baffle crystallizer for continuous cooling crystallization

Continuous Miniaturized Draft Tube Baffle Crystallizer with Particle Screw for Supportive Suspension Discharge

“…Tracer crystals, used for the outwash curve (negative step-response) and abrasion tests (see Section ), were manually dry pestled and sieved (Test Sieve Retsch, RETSCH GmbH, Haan, Germany). The same procedures were also applied in ref .…”

“…The same thermogravimetric method as described in ref and used already in refs and was used to determine the solid weight fraction ( w i ) of the suspension and to calculate the relative yield ( Y rel ) (eq ), which indicates how well the solubility line was reached and supersaturation was reduced. The relative yield needs the mass loading ( X i ) for determination.…”

“…A detailed description of the image analysis can be found in ref . The microscopic crystal images were taken on a Petri dish as described in ref . Depending on the investigation, the suspension after the particle screw was directly dropped onto the Petri dish from the product suspension tube or for crystal pictures inside the DTB, disposable pipettes (Pasteur pipette, 23 cm long, VWR 612-2842) were used to sample the suspension.…”

“…The pump speed of the peristaltic pump is held constant for a mass flow rate of 15 g min –1 in accordance with the performed cooling crystallization experiments . The reason for this is that with the future operation of the DTB with the screw, the incoming mass flow rate must be kept constant.…”

“…A known 1100 L DTB from literature, ref , was scaled down. , It was characterized regarding suspension and residence time behavior, and cooling crystallization experiments focused on the start-up procedure were made . However, during the cooling crystallization experiments, the product discharge tends to clog . Hence, it would be beneficial to develop a concept to overcome the clogging hurdle and guarantee continuous product discharge.…”