Izrada uređaja za mjerenje raspodjele veličina čestica cementa

undergraduate thesis

• Title (english): Design of a device for measuring the size distribution of cement particles
• 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: 2020-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Napravljena je aparatura za određivanje raspodjele veličine čestica na temelju mjerenja mase sedimentiranih čestica u stupcu suspenzije. Tijekom eksperimenta ispitivane su tri vrste uzoraka: kalcit CaCO3, gibsit Al(OH)3 i talk Mg3Si4O10(OH)2, pripravljenih kao vodene suspenzije masene koncentracije čestica do 12 g/dm^3. Analitičkom vagom povezanom s računalom mjeri se povećanje mase na tanjuriću istaloženih čestica u ovisnosti o vremenu. Stokesov zakon primjenjiv je samo za niske vrijednosti Reynoldsove značajke (Re<0.25) i određuje brzinu nesmetane sedimentacije čestica. Za obradu rezultata (krivulja ovisnosti mase istaloženih čestica o vremenu) koriste se dvije matematičke metode: numerička aproksimacija prve derivacije diskretnih podataka i analitička derivacija pretpostavljenog matematičkog modela. Obradom rezultata eksperimenta (kumulativna taložna krivulja) određuje se veličina čestica veća od ekvivalentnog Stokesovog promjera.

Abstract (english)

Laboratory apparatus for determination of the particle size distribution was made based on the measurement of the mass of sedimented particles in the suspension column. During the experiment, three types of samples were tested: calcite CaCO3, gibbsite Al(OH)3 and talc Mg3Si4O10(OH)2, prepared as aqueous suspensions with a mass concentration of particles up to 12 gdm^-3. A computer-connected analytical balance measures the increase in mass on a balancing pan of precipitated particles as a function of time. Stokes' law is applicable only to low values of the Reynolds number (Re <0.25) and determines the rate of undisturbed sedimentation of particles. Two mathematical methods are used to process the results (mass of precipitated particles in time): numerical approximation of the first derivation of discrete data and analytical derivation of the assumed mathematical model. By processing the results of the experiment (cumulative sediment curve), the particle size larger than the equivalent Stokes diameter are determined.

• Keywords: raspodjela veličine čestica; matematički model; numerička aproksimacija derivacija; Stokesov zakon; Stokesov promjer; sedimentacija; kumulativna krivulja; gravitacijska sedimentacijska metoda; cement
• Keywords (english): particle size distribution; mathematical model; numerical approximation of derivatives; Stokes law; Stokes diameter; sedimentation; cumulative curve; gravitational sedimentation method; cement
• Language: croatian
• URN:NBN: urn:nbn:hr:149:741034
• Study programme: Title: Materials Science and Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-05-04 11:21:57