Večfazni numerični model razpršilnega sušenja suspenzije zeolit - voda

doktorska disertacija

Gregor Sagadin (Author), Matjaž Hriberšek (Mentor), Leopold Škerget (Co-mentor)

Abstract

V nalogi je obravnavan proces sušenja poroznega delca, sestavljenega iz omočenih kristalov zeolita 4A v razmerah, ki prevladujejo v razpršilnem sušilniku. Obstoječi numerični modeli v inženirskih programskih paketih obravnavajo vso vlago v delcu kot površinsko sušenje pa kot enostopenjsko, kar lahko vodi do netočnih in nepopolnih rezultatov. V želji po nadgradnji obstoječih numeričnih modelov je bil razvit model za večstopenjsko sušenje poroznega delca. Le-ta upošteva tudi kristalno vezano vlago, ki v procesu sušenja mokrega jedra prehaja skozi osušeno skorjo. Za opis prehoda vlage skozi osušeno skorjo v drugi stopnji sušenja je bil uporabljen model enostranske Stefanove difuzije, med tem ko je bila tretja stopnja sušenja razvita na osnovi karakteristik materiala, določenih s termo gravimetrično analizo. S pridobljenimi rezultati iz numeričnih simulacij je bila pripravljena primerjava z eksperimentalno pridobljenimi rezultati, ki je pokazala uporabnost ter fizikalno pravilnost uporabljenega numeričnega modela večstopenjskega sušenja.

Keywords

zeolit;razpršilno sušenje;večfazni numerični model;računalniška dinamika tekočin;prenos toplote in snovi;Strojništvo;Disertacije;

Data

Language:	Slovenian
Year of publishing:	2014
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FS - Faculty of Mechanical Engineering
Publisher:	G. Sagadin]
UDC:	519.6:[532.72:536.24]:66.074(043.3)
COBISS:	18010390
Views:	1766
Downloads:	267
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	Multiphase numerical model of spray drying of zeolite-water suspension
Secondary abstract:	The contribution deals with drying of a porous particle, composed of wet zeolite 4A crystals, in the conditions prevailing inside a spray dryer. The existing numerical models within the engineering codes consider the moisture as a surface attached liquid and drying as one stage drying, which are leading to possible inaccuracies and incompleteness of computational results. Therefore, In view of upgrading the existing numerical models, a multi-phase drying model for drying of a porous particle was developed. It includes also the crystalline moisture, which in the drying process diffuses through the dried outer core of the particle. In the latter case, the Stefan type of mass transfer in form of one sided diffusion is used in second stage of drying while third stage of drying was developed on the basis of material characteristics, set by thermo gravimetric analyses. The results obtained from the numerical model were compared with experimental results, which show the applicability and physical correctness of the proposed model.
Secondary keywords:	zeolite;spray drying;multiphase numerical model;computer fluid dynamics;heat and mass transfer;
URN:	URN:SI:UM:
Type (COBISS):	Dissertation
Thesis comment:	Univ. v Mariboru, Fak. za strojništvo
Pages:	XI, 95 f.
ID:	8729741