Spray Characteristics Analysis of Fire Sprinkler Spray with Image Processing

Abstract

Sprinkler systems are effective in suppressing fires during their initial stages. The ability of a sprinkler to suppress a fire is contingent on the density, size, and velocity of the droplets it emits. In this study, a high-speed camera was employed to measure the size and velocity of droplets generated by a sprinkler head with a K-factor of 80. To capture images of the sprinkler spray, two acrylic partitions were placed 3 cm apart, with the sprinkler head positioned in the center. A light source was positioned behind the spray, and images were recorded at a resolution of 1024 × 1024 pixels and a speed of 4000 fps. During the image processing phase, bounding circles were drawn using the mean of the major and minor axes of the droplets, and these circles were used to calculate the diameter, velocity, and momentum of the droplets. It was observed that smaller droplets were predominantly present closer to the sprinkler head, while larger droplets were more prevalent in regions farther away. The larger droplets exhibited higher velocities and momentum. As the vertical distance increased, droplet velocity and momentum also increased, primarily due to the influence of gravity.