- Author
-
Francis, M. K.
- Title
- High Magnification Video Probe for In-Situ Measurement of Particle Size Distributions. BFRL Fire Research Seminar. VHS Video.
- Coporate
- Maryland Univ., College Park
- Report
-
Video,
December 22, 1998,
- Keywords
-
particle size distribution
- Abstract
- The development of a new instrument for the in situ measurement of particle size distributions in the size range of 4 to 200 microns will be discussed. The system uses high magnification optics housed in a steel probe that can be inserted into a process vessel or stream. Pulsed lighting is used to freeze the motion of the particles in the flow field and present an image to the CCD video camera. The images are digitized and saved for subsequent processing. Automated image analysis routines are used to remove poorly focused particles and size the remaining particles. An extensive validation has been performed using latex microspheres and soda glass particles to determine the maximum particle concentration, minimum measurable particle diameter (as a function of the index of refraction) and particle sampling volume. The effects of size biasing on the sampling volume will be discussed. The utility of the instrument will be demonstrated by several experiments. These include drop size distribution measurements from high shear mixers and the ability to determine crystal shape in crystallizations and the presence of agglomeration.