NOTATION diffusion coefficient of Fe(CN&" in the solution; m2/sec diameter of the sphere; m mass-transfer coefficient; m/set translational velocity; m/set angular velocity: rad./sec kinematic viscosity of the fluid; m\*/sec Reynolds number for translation, Vd/v Reynolds number for rotation, od\*/v R
Spontaneous oscillation of a gas-fluidised bed
โ Scribed by M.H.I. Baird; A.J. Klein
- Publisher
- Elsevier Science
- Year
- 1973
- Tongue
- English
- Weight
- 834 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0009-2509
No coin nor oath required. For personal study only.
โฆ Synopsis
Well dellned spontaneous oscillations can occur in a gas-fluidised bed with a low resistance support and a large gas space beneath the support. Measurements of the instantaneous pressure drop as a function of time have been carried out in a 10 cm dia. bed with gas space volumes between 11 and 191. At superficial gas velocities in excess of the minimum fluidisation value, the pressure drop fluctuates regularly but not sinusoidally. The effects of variables such as bed mass, gas velocity and gas space volume upon the oscillation frequency have been measured and it is concluded that the oscillations are a relaxation phenomenon connected with the periodic formation of gas bubbles.
๐ SIMILAR VOLUMES
WE HAVE the following comments to make in reply to the communication by Mr. Godard and Professor Richardson: I. Equation (I) in our paper [ I] refers to a bubbling fluidised bed with constant voidage fraction between bubbles. Most liquid-solid systems are non-bubbling and of course fall outside the
A differential equation model is derived to describe particle segregation in a binary mixture of solids fluidised by gas. The model, which is formulated to conform with qualitative descriptions of the mechanism of segregation, yields solutions displaying the unusual features of the steady-state soli
Based on the observed pattern of coalescence of bubble pairs in vertical alignment in a two-dimensional bed, a theory is developed which describes how bubble size and frequency changes with height in a gas fluidised bed. It is confirmed by comparison with the reported data from 10 separate investiga