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master's thesis
Utjecaj promjera miješala na kinetiku nukleacije pri sonokristalizaciji boraksa
diplomski rad
2022. urn:nbn:hr:167:578145
Jozić, Ana
University of Split
Faculty of Chemistry and Technology
Division of Engineering and Chemistry

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Jozić, A. (2022). Utjecaj promjera miješala na kinetiku nukleacije pri sonokristalizaciji boraksa : diplomski rad (Master's thesis). Split: University of Split, Faculty of Chemistry and Technology. Retrieved from https://urn.nsk.hr/urn:nbn:hr:167:578145

Jozić, Ana. "Utjecaj promjera miješala na kinetiku nukleacije pri sonokristalizaciji boraksa : diplomski rad." Master's thesis, University of Split, Faculty of Chemistry and Technology, 2022. https://urn.nsk.hr/urn:nbn:hr:167:578145

Jozić, Ana. "Utjecaj promjera miješala na kinetiku nukleacije pri sonokristalizaciji boraksa : diplomski rad." Master's thesis, University of Split, Faculty of Chemistry and Technology, 2022. https://urn.nsk.hr/urn:nbn:hr:167:578145

Jozić, A. (2022). 'Utjecaj promjera miješala na kinetiku nukleacije pri sonokristalizaciji boraksa : diplomski rad', Master's thesis, University of Split, Faculty of Chemistry and Technology, accessed 07 April 2025, https://urn.nsk.hr/urn:nbn:hr:167:578145

Jozić A. Utjecaj promjera miješala na kinetiku nukleacije pri sonokristalizaciji boraksa : diplomski rad [Master's thesis]. Split: University of Split, Faculty of Chemistry and Technology; 2022 [cited 2025 April 07] Available at: https://urn.nsk.hr/urn:nbn:hr:167:578145

A. Jozić, "Utjecaj promjera miješala na kinetiku nukleacije pri sonokristalizaciji boraksa : diplomski rad", Master's thesis, University of Split, Faculty of Chemistry and Technology, Split, 2022. Available at: https://urn.nsk.hr/urn:nbn:hr:167:578145

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Metadata
TitleUtjecaj promjera miješala na kinetiku nukleacije pri sonokristalizaciji boraksa : diplomski rad
Title (english)Influence of impeller diameter on nucleation kinetics of sonocrystallization of borax : master thesis
AuthorAna Jozić
MentorAntonija Čelan (mentor)
Committee memberMarija Ćosić (predsjednik povjerenstva)
Committee memberMarin Ugrina (član povjerenstva)
Committee memberAntonija Čelan (član povjerenstva)
GranterUniversity of Split
Faculty of Chemistry and Technology
(Division of Engineering and Chemistry)
Split
Defense date and country2022-10-31, Croatia
Scientific / art field,
discipline and subdiscipline		TECHNICAL SCIENCES
Chemical Engineering
Abstract
Glavni zadatak ovog rada bio je ispitati utjecaj promjera miješala u sustavu bez ultrazvučnog djelovanja (A=0 %) i u sustavu s ultrazvučnim djelovanjem (A=20 %) na kinetiku nukleacije boraksa u šaržnom kristalizatoru s kontroliranim hlađenjem. Za provedbu miješanja korištena su SBT miješala (engl. straight blade turbine) triju različitih promjera (D 1 =6,5 cm, D 2 =8,0 cm i D 3 =9,5 cm). Istraživanje je provedeno u kristalizatoru laboratorijskog mjerila volumena 2,65 dm 3 , pri... More čemu je matična otopina zasićena pri 30 °C, hlađena brzinom od 6 °C h -1 do temperature od 15 °C. U prvom dijelu ispitivanja provodila se kristalizacija uz mehaničko miješanje (A=0 %), dok se u drugom dijelu ispitivanja na matičnu otopinu djelovalo mehaničkim miješanjem i ultrazvučnim djelovanjem (A=20 %). U okviru ovog rada bilo je potrebno odrediti promjenu koncentracije matične otopine refraktometrijskom metodom, kao i promjenu apsolutne prezasićenosti tijekom procesnog vremena pri sva tri promjera miješala za oba ispitivana sustava. Također, analiziran je utjecaj promjera miješala na širinu metastabilne zone (ŠMSZ) te je primjenom Mersmannova nukleacijskog kriterija određen dominantni nukleacijski mehanizam. Rezultati su pokazali kako povećanje promjera miješala u sustavu bez ultrazvučnog djelovanja rezultira smanjenjem maksimalne prezasićenosti, odnosno širine metastabilne zone te brzine nukleacije. U sustavu s ultrazvučnim djelovanjem primijećeno je upravo suprotno. Kristalizacija je u svim ispitivanim slučajevima započela primarnim heterogenim mehanizmom. Primjenom granulometrijske analize metodom laserske difrakcije, sagledane su karakteristike finalnog produkta šaržne kristalizacije. Utvrđeno je da su kristali dobiveni u sustavu bez ultrazvučnog djelovanja značajno većeg srednjeg volumnog promjera i šire raspodjele od onih kristala dobivenih u sustavu s ultrazvučnim djelovanjem. Less
Abstract (english)
The main task of this research was to examine the effect of impeller diameter on nucleation kinetics in systems with (A=20 %) and without (A=0 %) ultrasound irradiation on the kinetics of borax nucleation in a batch crystallizer. Three different diameters of SBT impeller were used (D 1 =6.5 cm, D 2 =8 cm and D 3 =9.5 cm). The research was carried out in a laboratory-scale crystallizer with a volume of 2.65 dm 3 , where the mother solution was saturated at 30 °C and then ... More cooled at a rate of 6 °C h -1 to a temperature of 15 °C. In the first part of the research, only mechanical mixing (A=0 %) was carried out, while in the second part, mechanical mixing and ultrasound irradiation were simultaneously applied (A=20 %). It was necessary to determine the change of concentration of the mother solution using the refractometric method, as well as the change in the absolute supersaturation during processing time at all three impeller diameters in both investigated systems. Also, the influence of impeller diameter metastable zone width (MSZW) was analyzed and the dominant nucleation mechanism was determined by applying the Mersmann’s nucleation criterion. The results showed that the increase of impeller diameter in the system without ultrasound irradiation decreases the maximum supersaturation, MSZW as well as the nucleation rate. On the other hand, in the sonicated system, the opposite effect was observed. A primary heterogeneous mechanism initiated crystallization in all examined cases. Granulometric analysis of the product was conducted by using the laser diffraction method. It was found that the crystals obtained in silent system have a significantly larger mean volume diameter and a wider distribution than those obtained in the sonicated one. Less
Keywords
Keywords (english)
Languagecroatian
URN:NBNurn:nbn:hr:167:578145
Study programmeTitle: Chemical Technology; specializations in: Materials, Environmental Protection, Mediteranean Cultures, Materials and Environmental protection
Course: Materials
Study programme type: university
Study level: graduate
Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
Type of resourceText
File originBorn digital
Access conditionsOpen access
Embargo expiration date: 2024-11-16
Terms of useLicence In copyright icon
Created on2022-11-16 09:20:15
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