Online Spray Droplet and Particle Size Measurement

When you need to measure the size and shape of your particles, droplets or bubbles, turn to image based analysis for size distribution measurement. Our online droplet sizing systems capture high-speed images of a particle cloud, spray (e.g. for water droplet size measurement) or bubble stream to give the drop size. In addition to measuring the particle diameter distribution, Oxford Lasers imaging systems also provide real-time shape and velocity analysis.

We Can

• Measure particle or droplet size in real time
• Measure particle or droplet velocity and direction
• Measure individual particles
• Capture images of the particle in flight
• Make non-intrusive measurements
• Make in-situ measurements
• Report on-line, real-time results

Size with Velocity and Direction

Visisize's unique sizing algorithms allow simultaneous measurement of particle size and velocity with direction. This means that you can correlate the sizes of particles of droplets with their velocity. Discover whether the velocity gradient in your spray is related to size and work out what parameters you need to change to get the result you desire.

Online Analysis

Our powerful online analysis systems measure particle diameter, shape and velocity distributions for solids, liquids and gases suspended in any transparent medium. No other droplet sizing system is as intuitive to use as direct imaging equipment.

Simple, yet powerful

If you can operate a camcorder or digital camera, you can master a VisiSizer. sizing system. VisiSizer not only provides accurate diameter distributions but also records images of your subject.

Non-Intrusive Measurement

VisiSizer has the unique ability to generate particle size, drop diameter, (e.g. for nozzle characterization), bubble diameter and velocity measurements, together with simultaneous images of the particles. The technique works by capturing images of the spray using a high-resolution camera together with short pulse laser illumination to freeze the motion. Software then measures the diameter and shape and calculates the diameter distribution. The non-contact online measurement means that you can add a VisiSizer particle sizing system to your current process (providing that there is suitable optical access) without causing disruption.

Image-based sizing measures shape

Air inclusion in a spray droplet

On the left is the first ever in-flight image of the output from an agricultural "air-inclusion" nozzle. From this image, taken from a VisiSize system, not only are the water drops non-spherical, but air bubbles are visible within them. Other measurement techniques such as PDA or laser diffraction would mis-size the water droplet without indicating they had done so - and you would never have known about the air inclusions

A powerful research tool

 

The VisiSizer range also double as very powerful laser imaging systems. As well as capturing images for sizing, the systems can image the nozzle and the break-up and drop formation processes. This can provide a very valuable insight into nozzle effects and problems. When combined with the quantitative diameter data this makes image based sizing an extremely powerful tool for R&D.

Applications

• Fuel injector characterization
• Agricultural spray characterization
• Paint sprays
• Pharmaceutical devices (MDIs, DPIs, nasal sprays)
• Nozzle characterization
• Fire suppression/extinguisher
• Bubble column characterization
• On-line particle sizing of solids in the production process

Attachment	Size
Related paper - Pneumatic Atomization of Laundry Detergent Slurries (ILASS 2007)	726.58 KB
Related paper - Droplet Size and Velocity Measurements (ASME 2003)	453.53 KB