Computer Tomograph Measurements in Shear and Gravity Particle Flows
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Tartalom: http://real.mtak.hu/5920/
Archívum: MTA Könyvtár
Gyűjtemény: Status = Published

Type = Conference or Workshop Item
Cím:
Computer Tomograph Measurements in Shear and Gravity Particle Flows
Létrehozó:
Dencs, B.
Szépvölgyi, J.
Bogner, P.
Földes, T.
Gyenis, János
Dátum:
2002
Téma:
TP Chemical technology / vegyipar, vegyészeti technológia
Tartalmi leírás:
The paper reports the recent results obtained on the applicability of cross-sectional digital
imaging method to study particle flow characteristics in 3D particle beds forced to move by
gravity or shear. X-ray CT imaging technique is widely used in medical diagnostics and, during
the last decades, its spatial and temporal resolution has been improved significantly. In this study,
an attempt was made to use this technique for engineering purposes. Two experimental set-ups
with different types of particle flows were investigated using Siemens Somatom Plus type CT
equipment. A series of trials were carried out in a small model hopper with flat bottom and
almost cylindrical side wall slightly deviating from verticality. Non steady-state flow was studied
during the outflow of particulate material from this vessel, through a central hole at the bottom.
Further investigation was fulfilled in a modified Cuette-type shearing device to study steady-state
shear flow. This equipment consisted of an almost cylindrical vessel identical to that used for
gravity flow measurements, and a smaller inner cylinder rotating within this vessel concentrically,
around its vertical axis. The surface of the inner cylinder was notched vertically, i.e.
perpendicularly to the direction of rotation to increase wall friction between the particles and the
cylinder. Almost spherical sucrose granules, also used for gravity flow measurements, were filled
into the gap between the rotating cylinder and the outer wall of the equipment. Movement of
particles took place due to shear, generated within the particle bed. By using X-ray CT technique,
cross-sectional digital images were obtained in every two seconds for both types of particle flows.
For this, the cross-sectional variation of the local Hounsfield density values were measured in a
matrix of 0.1x0.1x2.0 mm space elements. It was proved that the applied non-invasive crosssectional
imaging technique was suitable to distinguish the stationary and moving particle
regions, and by this, to estimate the location of the boundary zone between them.
Típus:
Conference or Workshop Item
NonPeerReviewed
Formátum:
text
Azonosító:
Dencs, B. and Szépvölgyi, J. and Bogner, P. and Földes, T. and Gyenis, János (2002) Computer Tomograph Measurements in Shear and Gravity Particle Flows. In: 4th World Congress on Particle Technology, 2002. július 22-25., Sydney, Australia.
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