Response Characteristics of Sprinkler Heads Mounted in a Paint Box: BRANDFORSKProject 726-911

摘要

The response of sprinklers mounted in a paint box is usually influenced by paintcovering the heat-sensitive element. To avoid the problem, sprinklers are often covered with bags to prevent the paint accumulating on the heat-sensitive element. The influence of various numbers of paint layers and different types of bags on the response time of two types of sprinkler heads has been investigated. Both wind-tunnel tests and full-scale fire tests were performed with glass bulb sprinklers. The thickness of the paint was limited to ensure a uniform distribution of the paint over the heat-sensitive element. Plunge tests were performed in the wind-tunnel. This is a standardize testing procedure for investigating response of sprinklers. The full-scale fire tests were performed in a test room measuring 9.6 m x 6 m and in height. The sprinkler was mounted at the centre of the ceiling of the test room and a heptane fire was used located 1.5 m or 2.8 m from the sprinkler. It was found that bags delayed the activation of the sprinklers considerably. The gas temperature inside the bags at sprinkler activation was found to be considerably lower than the gas temperature outside the bags. Covered with a bag, faster response was obtained with a quick responsesprinkler than with a standard response sprinkler.