CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Ultrasound velocity profile (UVP) measurements of pulp suspension flow near the wall.

Helena Fock (Institutionen för kemi- och bioteknik, Kemisk apparatteknik) ; J. Wiklund ; Anders Rasmuson (Institutionen för kemi- och bioteknik, Kemisk apparatteknik)
Journal of Pulp and Paper Science (0826-6220). Vol. 35 (2009), 1, p. 26-33.
[Artikel, refereegranskad vetenskaplig]

An Ultrasound Velocity profiling (UVP) technique is used in this study to investigate the pipe flow of pulp suspensions in the near wall region. Four flow rates and two consistencies were investigated: 1.9 and 4.8% (w/w) consistency. The mean velocity profiles showed a distinct plug at the centre of the pipe, surrounded by a sharp velocity gradient. The plug size increased with increasing consistency or decreasing bulk velocity. The demodulated echo amplitude (DMEA) profile slowly rises from low values near the wall to a distinct maximum at the plug front before slowly decaying towards the pipe centre. Since only the fibres and fines contribute to the attenuation of ultrasound, the demodulated echo amplitude profiles thus indicate and support the hypothesis of the existence of a consistency profile in the near wall area, with a decreasing amount of fines and fibres close to the pipe wall.

Denna post skapades 2009-12-17. Senast ändrad 2016-07-25.
CPL Pubid: 104009


Institutioner (Chalmers)

Institutionen för kemi- och bioteknik, Kemisk apparatteknik (2005-2014)



Chalmers infrastruktur