Genomföringar i brandavskiljande konstruktioner i lantbruksbyggnader
Fire in farm buildings often starts in rooms with a high fire load density, for example barns, haylofts or food preparation rooms. It takes about l0 minutes between ignition and flash over. That is all the time the farmer has got to save the animals. To protect the animals against fire, the stable is made like a fire compartment. The separating elements ought to be sealed against fire and smoke, for at least 60 minutes. Movements of people, feed, animals, air etc. require openings and various penetrations. They have to fulfil the same demands of tightness, about 60 minutes. The Agricultural Fire Protection Committee (Lantbrukets Brandskyddskommitté) and The Swedish Insurance company Länsförsäkringar initiated a project to find practical solutions of penetrations through separating elements in agricultural environments. The project concentrates on the three penetrations: feed pipes, hay openings and rail passages. A literature study deals with the understanding of fire and its development together with laws, rules and regulations. No previous studies have been made to verify the assumption that rail passages contributes to a huge spread of combustion gas. The airflow around an I-beam was studied through experiments. Discussions with fire experts and field studies show the lack of awareness about the contribution of the combustion gas to the spread of fire. The economical climate and motivation today for improving fire protection are poor. • Flow measurements showed that the air flow through a longitudinal opening in a partly open door is lower than that past an I-beam in a recess when the opening widths are the same. However the beam guides the air flow through the recess resulting in an airflow twice as high as that through a longitudinal opening of the same length as the circumference of the I-beam. • Openings such as doors, main entrances, shutters should be closed when they are not used. If required magnet contacts and fire alarms are available to facilitate the closing of passages. The tightness of fire doors has to be carefully examined. • Well-constructed feed pipes, without any fractures, reduce the contribution to spread of combustion gas. The installation of casing around the feed pipes is good security if the pipe should break. • Folding rails are preferable in new and existing buildings. There are different ways to increase air tightness for existing recesses e.g., fire traps, the construction of door shutters or simply by sealing the insides of door frames. • The continued decimation of information is required to change attitudes and increase the understanding of adequate fire protection and it’s implementation. There should be greater co-operation between fire experts, authorities, fire consulting companies and building advisers. Continued research about the spread of combustion gas is needed.
Fire; farm buildings; prevention; openings; tightness
Rapport - Sveriges lantbruksuniversitet, Institutionen för lantbruksteknik
Publisher: Institutionen för lantbruksteknik, Sveriges lantbruksuniversitet
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