Vpliv sušilnih pogojev na konvekcijsko sušenje bukovine

diplomsko delo - univerzitetni študij

Janko Mazi (Author), Milan Šernek (Reviewer), Željko Gorišek (Mentor)

Abstract

Na vzorcih bukovine (Fagus sylvatica L.) smo proučevali vpliv procesnih parametrov sušenja na hitrost masnega kapilarnega toka in na vzpostavljeni vlažnostni profil po prerezu lesa. Poskuse smo izvedli na radialno orientiranih preizkušancih debeline 6 mm, 12 mm, 18 mm in 24 mm. Konvekcijsko sušenje lesa smo simulirali v laboratorijskem sušilnem kanalu pri konstantni temperaturi (T = 30 °C) in konstantni relativni zračni vlažnosti (85 %), z variiranjem hitrosti zraka (h) od 0,6 m/s do 2,1 m/s. Med sušenjem smo v zaporednih časovnih intervalih gravimetrično določali povprečno lesno vlažnost (u), vlažnostni gradient in masni tok vode iz lesa vzorcev v okolico. Sušilna hitrost se je povečevala s hitrostjo gibanja zraka v sušilni komori ter zmanjševala z večanjem debeline preizkušancev. Povečanje začetne sušilne hitrosti je povzročilo krajšanje faze konstantne sušilne hitrosti. Prevelika začetna stopnja sušenja je povzročila takojšnjo nepovratno zaustavitev začetnega masnega toka vode in znatno podaljšala postopek sušenja.

Keywords

les;sušenje;transport vode;snovna upornost;vlažnost lesa;bukev (Fagus sylvatica L.);

Data

Language:	Slovenian
Year of publishing:	2010
Source:	Ljubljana
Typology:	2.11 - Undergraduate Thesis
Organization:	UL BF - Biotechnical Faculty
Publisher:	[J. Mazi]
UDC:	630*847.2
COBISS:	1795209
Views:	1000
Downloads:	252
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Impact of drying condition on convective drying of european beechwood
Secondary abstract:	The impact of climate conditions on capillary mass flow and induced moisture content gradient was monitored during convective drying of beechwood (Fagus sylvatica L.). 6 mm, 12 mm, 18 mm, 24 mm radially oriented beechwood specimens were used. Series of conventional drying processes were carried out in a laboratory tunnel drier at constant drying temperature of 30 °C and constant relative humidity (RH) of 85 % with varying air velocity (h) from 0.6m/s to 2.1 m/s. During the drying, moisture content, moisture content gradient and water mass flow were gravimetrically determined at successive time intervals. Increasing the air velocity, the drying rate generally increased; increasing the thickness of wood the drying rate decreased. Increase of the air velocity shortened the period of initial constant drying rate, and eliminated it at greater material thicknesses. A high initial drying rate caused immediate irreversible reduction of initial water mass flow, and significantly prolonged the drying procedure.
Secondary keywords:	wood;wood drying;water transport;mass transfer resistance;moisture content;beech (Fagus sylvatica L.);
Type (COBISS):	Undergraduate thesis
Thesis comment:	Univ. v Ljubljani, Biotehniška fakulteta, Odd. za lesarstvo
Pages:	X, 38 f., [6] f. pril.
Keywords (UDC):	applied sciences;medicine;technology;uporabne znanosti;medicina;tehnika;agriculture and related sciences and techniques;forestry;farming;wildlife exploitation;kmetijstvo ter sorodne vede in tehnologije;forestry;gozdarstvo;forest products and their utilization;gozdni proizvodi in njihova uporaba;
ID:	21827