Prosijavanje praškastih materijala potpomognuto ultrazvukom visokog intenziteta

master's thesis

• Title (english): Sieving of powder materials using high intensity ultrasound
• Author: Ivana Cugelj
• Mentor: Mladen Brnčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Unit Operations); Zagreb
• Defense date and country: 2010-11-29, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom diplomskom radu provedeno je sijanje uzoraka pšenične krupice i rižinog brašna potpomognuto ultrazvukom. Provedena je i granulometrijska analiza uzoraka u svrhu dobivanja optimalne raspodjele veličina čestica kako bi se utvrdilo je li upotreba ultrazvuka pospješila operaciju sijanja u svrhu razbijanja aglomerata nastalih za vrijeme prosijavanja uzoraka kroz sita različitih veličina očica. Korištena su sita promjera očica: 500, 450, 355, 315, 280, 200 i 100 μm za sijanje pšenične krupice, dok su dimenzije očica kod sita za sijanje rižinog brašna bile: 450, 355, 280, 200, 100, 80 i 45 μm.Uzorci su prosijani pri amplitudi trešnje od 2,00 mm u vremenskom intervalu od 5 sekundi te promjenjivom trajanju od 5, 10 i 15 minuta sa promjenjivom amplitudom ultrazvuka od 30, 60 i 90 %. Rezultati granulometrijske analize prikazani su kao ovisnost relativne učestalosti o veličini otvora očica sita pri svim amplitudama ultrazvuka. Pokazano je da ultrazvuk visokog intenziteta poboljšava učinak sijanja, a vrijeme prosijavanja i amplituda ultrazvuka ima značajan utjecaj na raspodjelu veličine čestica.

Abstract (english)

In this Graduate Thesis sieving of semolina wheat and rice flour was performed and aided by the ultrasound. There is also sieving analysis of samples performed in order to obtain optimal particle size distribution to confirm did the using of ultrasound facilitate the sieving process for the purpose of breaking up agglomerates which have been formed during the sample sieving through sieves of various sieve opening sizes. Sieve opening sizes were: 500, 450, 355, 315, 280, 200 and 100 μm in wheat semolina sieving, while the dimensions of sieve opening sizes, for rice flour sieving, were: 450, 355, 280, 200, 100, 80 and 45 μm. The samples were sieved in the shaking amplitude from 2.00 mm in a time interval of 5 seconds and a variable duration of 5, 10 and 15 minutes with a variable amplitude of ultrasound 30, 60 and 90 %. Results of sieving analysis are presented as a step – like frequency distribution curve at all amplitudes of ultrasound. It is shown that the high intensity ultrasound enhances the effect of sieving, while the sieving time and the ultrasound amplitude have a significant effect on the distribution of particle sizes.

• Keywords: ultrazvuk visokog intenziteta; sijanje; granulometrijska analiza
• Keywords (english): high intensity ultrasound; sieving; sieving analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:159:014745
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-08-25 12:51:41