کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
154633 | 456846 | 2015 | 9 صفحه PDF | دانلود رایگان |
• A particle adhesion by a dynamic liquid bridge was simulated.
• Validity of the simulation model was confirmed by three verifications.
• The adhesion of particles through a droplet on a particle surface was analyzed.
In powder handling processes treating wet powders (e.g. wet granulation, coating, and drying), a liquid bridge formed between particles is not static but dynamic due to continuous motion of the particles. Therefore, understanding of a particle–particle adhesion by such a dynamic liquid bridge is an important issue. We here conducted a numerical simulation of the particle–particle adhesion by the dynamic pendular liquid bridge. A computational fluid dynamics (CFD) approach with a constrained interpolation profile (CIP) method was applied to simulate a gas–liquid two phase flow, while a particle motion was calculated by taking into account the dynamic liquid bridge. To verify the simulation results, the following verifications were conducted; (i) wetting behavior of a droplet on a curved surface, (ii) static liquid bridge force between two particles, and (iii) rupture behavior of a liquid bridge with free falling of a particle. As a result, validity of the simulation results was confirmed. The particle–particle adhesion through a droplet on a particle surface was then simulated. In particular, effect of a collision velocity on a wet restitution coefficient was investigated. A velocity criterion for the particle adhesion was determined from the simulation results and compared with that estimated from an analytical model proposed by Ennis et al (1991).
Figure optionsDownload high-quality image (287 K)Download as PowerPoint slide
Journal: Chemical Engineering Science - Volume 138, 22 December 2015, Pages 607–615