Modeling size dispersion in the prediction of crystal-size distribution

✍ Scribed by A.D. Randolph; E.T. White

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 878 KB
• Volume: 32
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(77)80144-9

✦ Synopsis

Ah&act

-The phenomenon of size spreadmg of a narrow crystal-size dlstnbution (CSD) due to fluctuations 111 growth velocity was modeled usmg an eff ectlve number flux d&~s~vlty Use of tks tiusivity m the dunenslonless population balance descnbmg contmuous crystalhzer operation results m a second denvahve term with a dnuens~onless growth rate Peclet number coefficient The previously observed lmear mcrease III squared varmnce of CSD with tune m batch crystalhzers was correctly predlcted with thus dtiuslon model Growth dtiuslvlties of the order of lOOpm*/mm were calculated for sugar crystals grown from pure syrups and result m typIcal growth Peclet numbers of the order of 5-10 The magmtude of growth Wuslvlty IS a tied function of the magmtude of growth rate, values of growth dfiusivlty of 0 0015~m*/nun were observed m the slow-growing alumma system Solution of the conhnuous crystalhzatlon equations with the Wusivity term added mdlcate that the size dlspersron phenomenon IS unobservable with the wide CSD of the MSMPR crystalhzer but could be an unportant factor m configurations producmg a narrow CSD This predichon IS an agreement vvlth observations of the relative unportance of Size dispersion from batch UIS-(I-UIS contmuous discharge crystalkers