Collision process details control the hydrodynamics and heat transfer in fluidized bed reactors

✍ Scribed by Masayuki Horio

• Publisher: Elsevier
• Year: 2005
• Tongue: English
• Weight: 27 KB
• Volume: 3
• Category: Article
• ISSN: 1672-2515
• DOI: 10.1016/s1672-2515(07)60155-9

✦ Synopsis

Adhesion force distributions have to be measured and interpreted when meaningful results are expected for rough surfaces. We propose three different types of adhesion force distributions: a monomodal Weibull distribution, a bimodal Weibull distribution, when the contact geometry is well defined by distinct asperities, and a broad lognormal distributions for very rough surfaces with a wide variety of contact geometries. Experimental results on model surfaces support these theoretical findings. These results are complemented by experimental studies on the influence of various parameters including humidity and contact time. These measurements show that the detachment of particles from a substrate is not a static but a dynamic process originating from material transfer between the adhesion partners. MD-simulations for the alumina system indicate that this mass transfer occurs due to nano-fiber formation either between adsorbed water layers or surprisingly between alumina partners in the absence of water.