PIXACT PARTICLE MONITORING
INTRODUCTION
The Pixact Particle Monitoring (PPM) system is designed for the online analysis of process suspensions containing particles with varying morphology. The technology combines in-situ process microscopy with advanced image analysis techniques. Examples of particles analyzed with PPM include microparticles, granules, fibers, agglomerates and flocs.
PPM provides a live camera view of the particle suspension and detailed real-time measurement data on particle characteristics, such as size distribution, morphology and concentration.
The measurement results produced by PPM help you to optimize, control and troubleshoot your process efficiently. With PCM you can increase the yield and capacity of your process and minimize quality variations in the final product.
Offered with versatile installation options, PPM can be fitted into a variety of appli-cations from laboratories to manufacturing-scale process lines. Multiple illumination options are available: front lighting enables the inspection of particle color, whereas transillumination guarantees optimal image quality for even the smallest of particles.
See Benefits for customer reviews and benefits provided by the Pixact systems.
See Products for details on the technology utilized in the Pixact systems.
RESULTS
The particle analysis is based on the direct optical imaging of particle suspensions with a high-magnification camera system. The analysis algorithm detects the outline of each particle. The system produces measurement data based on this information.
Standard analysis results include
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Particle diameter (based on the circular equivalent area)
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Minor & major axis length
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Particle projection area
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Number of particles in the measurement volume
Typically, hundreds of particles are detected in each image and this data is used to compute size and shape distributions and related statistics, such as percentiles of cumulative distribution (D10, D50, D90, etc.). The mean particle size can be calculated as arithmetic, area (Sauter) or volume weighted value.
Example of particle detection and size classification
DETAILED ANALYSIS OF THE PARTICLE SIZE AND MORPHOLOGY
Based on the detected particle outline several standard and additional shape parameters can be computed. Currently, the Pixact analysis software includes modules for
Additional characteristic dimensions
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Feret diameters
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PCA (primary component analysis) or ICA (independent component analysis) providing min. and max. dimensions, directions and aspect ratios
Shape analysis based on the outline
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Perimeter
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Spikiness
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Roundness (by Pixact)
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Fourier-descriptors and related statistic
In addition to these parameters, any formulation in the standard ISO 13322-2 Particle size analysis – Image analysis methods can be easily implemented in the analysis software.
PARTICLE CLASSIFICATION
The detected particles can be classified into classes adjustable to the customer's needs. For example, the classification can be based on particle size or color. After classification, selected statistics are provided for each class separately.
ADDITIONAL RESULTS
Particle velocity
Some hardware configurations also allow the analysis of particle flow velocity.
Particle color
If the measurement system is based on front illumination (Pixscope FL), the analysis software can be complemented with an analysis module that measures the color of each particle.
Flocculation analysis
If the particles tend to form flocs and the properties of the flocs are of interest, the software can be complemented with a flocculation analysis module that measures floc properties.
APPLICATION EXAMPLES
OTHER EXAMPLES OF APPLICATIONS
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Particle detection and counting in lubrication oil systems
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Detection of particle agglomeration in paper making processes
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Analysis of fiber length, thickness and curl for QC purposes
ANALYSIS OF MINERAL PARTICLE SAMPLES AFTER GRINDING
The particle size distribution of diluted mineral slurry is measured with Pixcell DN06 flow-through cuvette and PPM software in a laboratory setup. The results are used to optimize the grinding process.
ONLINE DETECTION OF DIRT IN FLOWING PULP SUSPENSION
The detection of dirt particles (bark, non-cooked components, etc.) in flowing pulp suspension is carried out with a Pixscope FL probe and PPM software. The system is used to monitor the dirt level in the production.
ONLINE ANALYSIS OF PARTICLE POPULATION IN PAPER MACHINE WHITE WATER CIRCULATION
The particle size distribution of white water is measured with a PPM system equipped with an automatic dilution unit. The diluted sample is measured in a Pixcell DN06 flow-through cuvette.
