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Please use this identifier to cite or link to this item:
http://hdl.handle.net/2282/1164
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| Title: | The Influence of the Physical Characteristics of Particulate Materials on their Conveyability in Pneumatic Transport Systems |
| Authors: | Martinussen, Svein Erlend |
| Issue Date: | Dec-1996 |
| Abstract: | The aim of the investigation has been to establish a link between the physical
characteristics of particulate materials, measurable on small samples in a laboratory, and
the conveyability of these materials in a pneumatic conveying line. The focus of the
investigation has been on conveying velocity limits, and the problem has been approached
by comparing own experimentally obtained values against existing models for the
prediction of such limits. A quantitative analysis shows that the accuracy of these models
range from 77% under prediction to 116% over prediction at certain operating conditions
within the area in which they are claimed to be valid.
The pressure data obtained in the experimental investigation have been subjected to
various methods of analysis to identify typical behaviour of the pressure fluctuations along
the pipeline when changes in the mode of flow, or blockage, is approached. The results of
this analysis show that the change from stratified flow (or partially settled suspension
flow) to unstable flow, often also referred to as the saltation limit, is associated with the
occurrence of coherent structures moving along the pipeline.
To investigate the possibility of applying a fluid dynamic model to understand these
phenomena, experiments with wave propagation and damping have been carried out in a
channel with fluidized powders. This investigation shows that the wave propagation
velocity at large wave length to bed depth ratios for a fluidized powder is identical to that
expected from theory on fluid dynamics. The fluid dynamic model is then applied to
establish a model for the prediction of maximum obtainable feed rate of solids in a given
pipeline. It is also used to establish a model to predict the limit of stable conveying, in
suspended or partially suspended flow, based on the Kelvin Helmholz instability for
stratified flow of liquids in closed pipelines. The models are purely mechanistic and
require no empirical fitting. |
| Keywords: | pneumatic transport |
| Publisher: | Telemark University College |
| Document type: | Doctoral thesis |
| Peer reviewed: | Peer reviewed |
| Bibliographic citation: | Martinussen, Svein Erlend. The Influence of the Physical Characteristics of Particulate Materials on their Conveyability in Pneumatic Transport Systems. Doctoral thesis, University of Greenwich, 1996 |
| Appears in Collections: | Institutt for prosess-, energi- og miljøteknologi
Doktoravhandlinger
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