Gustafsson, Gösta
- Department of Rural Buildings and Animal Husbandry [LBT], Swedish University of Agricultural Sciences
Abstract
The airtightness of three different types of coverings for slurry storage tanks was studied: wooden roof, plastic tent and concrete roof. The air exchange rates were determined by measuring the decay in concentrations of injected tracer gas sulphur hexafluoride (SF6) from five different locations in the air space inside the tanks with an infrared spectrophotometer. The tracer gas SF6 has a much higher density than normal air. It was not possible to observe any form of layering/accumulation of the gas in any specific areas of the tanks. Different measuring locations showed small differences in the decay process, both with and without mixing the air volume above the slurry. Therefore, the high density of the gas is not a limiting factor for its use in this type of study. Measured ranges in ventilation rates in relation to the bottom areas of the tanks were 0.60 to 1.12 m3 /m2 for the wooden roof, 0.30 to 0.36 m3 /m2 for the plastic tent and 0.53 to 1.61 m3 /m2 for the concrete roof. Measurements indicated that wind may have a considerable effect on air leakages. Therefore, it is proposed that measurements of airtightness are made under wind-free conditions. Measurements also indicated that the areas of openings influence air exchange in the air volume inside the tanks. Since sulphur hexafluoride is a potent greenhouse gas, other tracer gases must be used in the future. It is suggested that the use of nitrous oxide (N2O) should be investigated.
Keywords
manure; slurry; storage; airtightness
Published in
Title: Emissions of Gas and Dust from Livestock
Publisher: INRA
Conference
International symposium on EMIssion of gas and dust from Livestock (EMILI 2012)
SLU Authors
UKÄ Subject classification
Animal and Dairy Science
Veterinary Science
Publication identifier
- ISBN: 978-2-85969-221-6
Permanent link to this page (URI)
https://res.slu.se/id/publ/38334