Experiments on the suspension of spheres in inclined tubes—I suspension by water in turbulent flow

✍ Scribed by G.F. Round; Jan Kruyer

• Publisher: Elsevier Science
• Year: 1967
• Tongue: English
• Weight: 971 KB
• Volume: 22
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(67)80178-7

✦ Synopsis

Experiments have been made on the suspension of single spheres by water in tubes of diameters 0.970, 1.280, 2.489 and 5.133 cm. The angle of inclination of the tubes to the horizontal could be varied from 0 to 90". Measurements were made on the liquid velocities required to support the spheres and the pressure drops associated with these velocities. In general, four regimes of suspension prevailed; at low angles of inclination the spheres became stil1 and remained in this condition until they reached a "bounce-point".

This was the point at which friction between the sphere and the tube was reduced to zero. At larger angles the spheres bounced radially, until at angles very close to the vertical the spheres were freely suspended and rotated slowly at several rev/min free of the boundary. A fifth regime was noted for a certain diameter ratio range, approximately 0.8-1.0 and angles of inclination greater than about 20-30". In this regime the spheres tended to spiral and rotste very rapidly.

The drag coefficients were calculated and analysed in terms of diameter ratio and pipe Reynolds number. In the stil1 region it was found that the drag coefficient was independent of Reynolds number.

The velocity and pressure drop data correlated wel1 with other physical parameters of the system.