Izrada i baždarenje uređaja za mjerenje raspodjele veličina čestica

master's thesis

• Title (english): Manufacture and calibration of device for measuring particle size distribution
• Author: Sara Kocijan
• Mentor: Juraj Šipušić (mentor)
• Committee member: Juraj Šipušić (predsjednik povjerenstva)
• Committee member: Krunoslav Žižek (član povjerenstva)
• Committee member: Vanja Kosar (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Napravljena je aparatura za određivanje raspodjele veličine čestica na temelju metode fotosedimentacije. Intenzitet svjetlosti propuštene kroz mjernu ćeliju s vremenom raste što je posljedica smanjenja koncentracije suspendirane tvari zbog sedimentacije čestica. Dodavanjem inkremnetalnih odvaga točno određene mase izrađen je baždarni dijagram za uzorak aluminijeva hidroksida. Tijekom eksperimenta ispitivane su četiri vrste uzoraka komercijalnih imena: BEDEK-185, SW-1, P-1-184 i Cr2O3, te aluminijev hidroksid. Uzorci su karakterizirani metodama optičke mikrosokopije, SEM-EDS, DRS i rendgenske difrakcijske analize na prahu. Uzorci su pripravljeni kao vodene suspenzije određene masene koncentracije, a fotodetektor je preko uređaja za akviziciju podataka povezan s računalom i mjeri povećanje intenziteta svjetlosti tijekom sedimentacije. Stokesov zakon primjenjiv je samo za niske vrijednosti Reynoldsove značajke (Re < 0.25) i određuje brzinu nesmetane sedimentacije čestica. Za obradu rezultata uveden je empirijski model čime se kao rezultat dobiva kumulativna krivulja raspodjele veličine čestica većih od ekvivalentnog Stokesovog promjera.

Abstract (english)

Laboratory apparatus for calibration and determination of the particle size distribution was made based on the measurement of the mass of sedimented particles in the suspension column the photosedimentation method. The intensity increases with time, which is a consequence of the reduction of the suspended concentration, since the sedimentation of particles occurs. By adding incremental scales of precisely determined mass, a calibration diagram was created for a sample of aluminum hydrate. During the experiment, four types of samples with commercial names: BEDEK-185, SW-1, P-1-184 and Cr2O3, and aluminum hydrate were tested. The samples were subjected to characterization methods based on which the composition of the samples was identified: Optical microscope, SEM, DRS, EDS and X-ray analysis. The samples are prepared as aqueous suspensions of a certain mass concentration, and the photosensor is connected to a computer and measures the increase in intensity as a function of time. Stokes' law is applicable only for low values of the Reynolds characteristic (Re<0.25) and determines the speed of undisturbed particle sedimentation. The assumed empirical model is used to process the results, a cumulative curve - determines the size of the particles larger than the equivalent Stokes diameter.

• Keywords: raspodjela veličine čestica; matematički model; fotosedimentacija; Stokesov zakon; Stokesov promjer; sedimentacija; kumulativna krivulja; Mie teorija
• Keywords (english): particle size distribution; mathematical model; photosedimentation; Stokes law; Stokes diameter; sedimentation; cumulative curve; Mie theory
• Language: croatian
• URN:NBN: urn:nbn:hr:149:342442
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-03-29 09:22:10