02207nas a2200205   4500008004100000022001400041245011300055210006900168260006800237300001400305490000700319520140200326653000801728653003101736653002801767100003001795700002301825700002201848856013101870       2010                        eng d  a0001-154100aHysteresis in cloud heights during solid suspension in stirred tank reactor: experiments and CFD simulations0 aHysteresis in cloud heights during solid suspension in stirred t  a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcNOV  a2795-28040 v563 a<p>Solid suspension in stirred tank reactor is widely used in process industries for catalytic reactions, dissolution of solids, crystallization, and so on. Suspension quality is a key issue in design and operation of stirred reactor and its determination is not straight forward. Cloud height measurements of solid suspension provide a relatively simple way to quantify quality of suspension. In this work, experiments were carried out to quantify variation of cloud heights with impeller speed and particle characteristics. These measurements were carried out using visual observations, image analysis, and ultrasound velocity profiler techniques. The obtained data demonstrated the existence of hysteresis in cloud heights with respect to impeller speed. Apart from possible applications in reducing power required for achieving desired solid suspension quality, the existence of hysteresis also provides a new way to evaluate computational fluid dynamics (CFD) simulations of solid liquid flows in stirred vessels. An attempt was made to capture observed hysteresis in cloud heights in CFD simulations. The simulated results were compared with the experimental data. The presented models and results (experimental and computational) will he useful for simulating complex solid liquid flows in stirred reactors. (C) 2010 American Institute of Chemical Engineers AIChE J, 56: 2795-2804, 2010</p>10aCFD10ahysteresis in cloud height10asolid velocity profiles1 aSardeshpande, Madhavi, V.1 aJuvekar, Vinay, A.1 aRanade, Vivek, V.  uhttps://library.ncl.res.in/content/hysteresis-cloud-heights-during-solid-suspension-stirred-tank-reactor-experiments-and-cfd-0