High Speed Imaging Particle Sizing

The Artium Technologies High-Speed Image (HSI) particle sizing system is used when measuring drop size for spray plumes from large nozzles. When a spray plume contains large, non-spherical droplets or blobs, this instrument is ideal.

Gas Cooling Spray for Cooling Tower
Spraying Systems Co. worked with a electrical power generation company to determine the optimal spray nozzle for their cooling tower spray process. This process required very large hollow cone nozzles outputting hundreds of gallons of water per minute, which generate sprays with a very large array of droplets and blobs. The high-speed image sizing system was ideal in measuring the droplet and blob diameters providing the drop size statistics required to validate the spray nozzle performance for this gas cooling process.

High-speed image particle sizing offers many unique benefits due to its full-frame image results; standard or proprietary image analysis may be used to determine nearly any spray characteristic. Because the diffused LED illuminates the droplets from behind, bubbles and / or solid content within the droplets is often distinguishable, if present. The high-speed image sizing system is only limited in that each droplet must be visually distinguishable and is therefore best suited for low droplet-concentration sprays.

This high-speed image particle sizing instrument uses a diffused LED light source and an in-line camera to image a large field of view of 25.6 x 19.1 mm. A diffusive lens produces a uniform backlight illuminating the droplets from multiple angles to overcome shadowing from out of focus droplets. The LED light is pulsed to illuminate the particles for only a fraction of a second, resulting in an instantaneous spray image. The backlit imaging method allows for clear identification of particles as they block some percentage of the LED light from reaching the camera. These images are then analyzed to recover particle size, which is determined by outlining the perimeter of the particle, determining the area within the perimeter, and calculating the mean diameter. Image analysis determines sphericity, as well as a number of other spray characteristics.