In-process particle size distribution measurements and control

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:257071

Harvill, T L; Bonin, M P; Holve, D J

In-process measurement of particle size and concentration distributions provides continuous analysis and quality control of a product stream and can be used to monitor particulate emissions. As process production rates continue to improve, the delay between laboratory analysis and process correction of the product stream becomes more significant and costly in many applications. Elimination of sample handling and operator manipulation is now possible for most pneumatic flows using optical methods which are properly interfaced with the process stream. Insitec has developed an instrument methodology based on ensemble laser-diffraction which has been successfully applied to a wide range of research and industrial process applications. As part of the adaptation of instrumentation to the specific needs of different process applications, the authors have developed several different interface arrangements, including direct in-line measurements and an eductor bypass approach. To address the wide range of operating concentrations that occur in practice, a variable path length interface has been developed along with a deconvolution algorithm that corrects multiple scattering effects for light transmissions approaching 2%. Distribution update rates are computed and displayed in < 5 seconds. This methodology is particularly applicable to monitoring of pulverized coal feedpipe applications, where knowledge of particle loading and size distribution is an important factor for combustor optimization and control. Application examples will be described along with measurements in non-steady powder processing. Results show uniform size measurement for ten-fold concentration variations. Real time measurements allowed diagnosis and correction of non-steady feed rates for both ball mill and jetmill applications.

• OSTI ID: 257071
• Report Number(s): CONF-950952--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
COAL
COAL PREPARATION
DESIGN
LASER RADIATION
LIGHT TRANSMISSION
MONITORING
ON-LINE MEASUREMENT SYSTEMS
OPERATION
PARTICLE SIZE
PROCESS CONTROL
PULVERIZERS