We have used speckle visibility spectroscopy (SVS) and synchronized force measurements to compare the granular dynamics of two cohesive lactose powders, with Sauter mean diameters of ~29 μm and ~151 μm, in a rotating drum. A load cell (LC) was used to measure forces on the drum mounting frame and enable monitoring of bulk powder motion; SVS is a dynamic light scattering technique particularly s...

ammonium perchlorate particles have been dried in a laboratory spouted bed dryer (screen-bottomed type) which is categorized as a fluidized bed dryer. the solid particles obtained in this process of drying were semi-porous and known as the group d of geldart classification. the variations of moisture content with resident time, the effects of bed height on the pressure drop, and the influence o...

Using a fast X-ray tomography setup measurements have been done on a 25 cm diameter f luidized bed of Geldart B pow^der and a 24 cm bed of Geldart A powder. The average bubble sizes have been determined over a measurement period of 60 seconds. The resolution of this setup is about 4.5 m m per pixel at a rate of 250 reconstructions per second. I t is possible to detect bubbles as small as 2.5 cm...

A reliable description of dense gas–solid two-phase flows of Geldart A particles in gasfluidized beds at life-size scale is of great practical importance in process industries. The classical two-fluid model, based on the kinetic theory of granular flows (KTGF), provides a very promising theoretical framework for predicting large-scale gas–solid twophase flows. However, thus far the two fluid mo...

heat transfer phenomena in batch fluidized bed dryer have been studied and analyzed using three phase model including solid phase, interstitial gas phase and bubble phase based on rizzi model. new correlations of heat transfer coefficient to surrounding and convection heat transfer coefficient between solid and interstitial gas are being proposed. in addition, some modifications have been done ...

[1] Experiments were carried out to study the fluidization behaviour of ignimbrite at high temperature and while being mechanically agitated. Geldart group C behaviour occurs up to 565 C when the material is subjected to increasing gas flow (without agitation) from the loosely packed state. In contrast, even gentle mechanical agitation inhibits channelling and results in group-A type behaviour ...

Discrete particle simulations are by now well established as an effective tool to study the mechanics of complex gas-solid flows in gas-fluidized beds. In this study, a state-of-the-art discrete particle model is used to explore the role of particle-particle interactions in bubbling gas-fluidized beds of Geldart A particles. We find that the particle-particle interactions, including inelastic p...

Vibration of gas-solid fluidized beds is often used to enable fluidization cohesive particles; however, it has also been shown reduce the minimum velocity (Umf). Here, we show via experiments that vibration can both Umf and bubbling (Umb) in Geldart Group B D particles. We observe reduced more than Umb, thereby creating a densely packed, bubble-free state when superficial gas between Umb. Umb d...

Ammonium perchlorate particles have been dried in a laboratory spouted bed dryer (screen-bottomed type) which is categorized as a fluidized bed dryer. The solid particles obtained in this process of drying were semi-porous and known as the group D of Geldart classification. The variations of moisture content with resident time, the effects of bed height on the pressure dro...

Heat transfer phenomena in batch fluidized bed dryer have been studied and analyzed using three phase model including solid phase, interstitial gas phase and bubble phase based on Rizzi model. New correlations of heat transfer coefficient to surrounding and convection heat transfer coefficient between solid and interstitial gas are being proposed. In addition, some modifications have been d...