Particle & Particle Systems Characterization

Cover image for Particle & Particle Systems Characterization

November, 2005

Volume 22, Issue 3

Pages 157–223

    1. Experimental Study on Particle Size Distribution and Concentration Using Transmission Fluctuation Spectrometry with the Autocorrelation Technique (pages 161–171)

      Xiaoai Guo and Ulrich Riebel

      Version of Record online: 6 DEC 2005 | DOI: 10.1002/ppsc.200500956

      The fluctuating signal of light transmission through a particle suspension is used for measuring particle size distributions. A theory for suspensions of completely absorbing spheres is presented and evaluated by experiments which cover a particle size range from 1 μm to 1000 μm and particle concentrations of up to 12%. Finally, an iterative inversion algorithm is used, to retrieve the information on the particle size distribution and particle concentration from the measured transmission fluctuation signal.

    2. Laser-induced Breakdown Detection (LIBD) for the Highly Sensitive Quantification of Aquatic Colloids. Part I: Principle of LIBD and Mathematical Model (pages 172–180)

      Tobias Bundschuh, Tobias U. Wagner and Rainer Köster

      Version of Record online: 6 DEC 2005 | DOI: 10.1002/ppsc.200500908

      A new type of Laser-induced Breakdown Detection is being developed for direct quantification of aquatic colloids. The method is capable to measure very small particles in the range of 10 to 1000 nm and from about 1 ng/L (ppt) up to some mg/L (ppm), which are not detectable at reasonable accuracy and resolution by the commercial methods currently available. Practically, this method is non-invasive, sample preparation is not required, and measurement can take place online. In this first part of the publication the principle of LIBD is explained and mathematical models for the evaluation of the measurements are discussed.

    3. Laser-induced Breakdown Detection (LIBD) for the Highly Sensitive Quantification of Aquatic Colloids. Part II: Experimental Setup of LIBD and Applications (pages 181–191)

      Tobias Bundschuh, Tobias U. Wagner and Rainer Köster

      Version of Record online: 6 DEC 2005 | DOI: 10.1002/ppsc.200500918

      This second part of the publication on Laser-induced Breakdown Detection describes both, the basic experimental set-up as well as the latest developments and improvements of the method. Especially calibration of the method is discussed extensively. Furthermore, a number of practical application examples is given as well as a comparison of the technology with standard laboratory methods like dynamic light scattering as well as laser light obscuration.

    4. PDA and Neural Network Investigation of Swirl Spray Interaction Phenomena (pages 192–206)

      M. Reza Soltani, Kaveh Ghorbanian, Mehdi Ashjaee and Mohammad R. Morad

      Version of Record online: 6 DEC 2005 | DOI: 10.1002/ppsc.200500913

      Experiments are performed to investigate the atomization characteristics of the mixing-interaction region of two swirling sprays installed side by side. Both droplet size and velocity distributions are measured using a PDA system. A neural network algorithm is used to reconstruct the entire spray field in extrapolation regimes for injector spacing as well as three dimensional spatial coordinates. Excellent agreement between the predicted values and the measurements is obtained. The results indicate the capability of performing design- and optimization studies by applying only a modest amount of experimental data.

    5. Effect of Mechanochemical Processing on Illite Particles (pages 207–211)

      Huaming Yang, Wuguo Yang, Yuehua Hu, Chunfang Du and Aidong Tang

      Version of Record online: 6 DEC 2005 | DOI: 10.1002/ppsc.200500953

      Dry grinding of illite particles has been investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption techniques. Structural changes from crystallinity towards amorphous state and changes in porosity towards macrostructural pores are determined. Furthermore, mechanochemical effects are shown to markedly effect structural changes. The mechanisms and required conditions are discussed in detail.

    6. Numerical Simulation of Flow Patterns in Cyclones of Different Cone Dimensions (pages 212–218)

      Rong B. Xiang and Ken W. Lee

      Version of Record online: 6 DEC 2005 | DOI: 10.1002/ppsc.200500946

      This numerical study investigates the influence of the cone dimension on the flow pattern within different cyclones and its influence on the particle separation behaviour. The numerical results are compared to experimental data and show good agreement for the flow patterns as well as particle separation. The results suggest that a CFD simulation is capable of predicting the flow patterns in cyclones and the respective consequences for the separation efficiency.

    7. Study on the Relationship between Particle Size and Near Infrared Diffuse Reflectance Spectroscopic Data (pages 219–222)

      Annamária Szalay, István Antal, Zsolt Zsigmond, Sylvia Marton, István Erős, Géza Regdon jr. and Klára Pintye-Hódi

      Version of Record online: 6 DEC 2005 | DOI: 10.1002/ppsc.200500870

      Near-infrared diffuse reflectance spectroscopy (NIRDRS) was used to retrieve the mean particle size of compacted powders. Sieved sorbitol was used as a model substance for pharmaceutical products. The effects of the particle characteristics on the spectral changes were described on the basis of the Kubelka-Munk theory, taking the scattering into consideration. It is shown that this technique offers a fast, non-destructive test method that can be applied after elaborate calibration.