Abstract
Ultrasonic Doppler velocimetry (UDV), a non-invasive fluid flow measurement technique suitable for use in opaque systems, was used to measure pulp suspension flow velocity in a rectangular 1 : 11-scale agitated pulp stock chest. The flow characteristics of a Maxflo impeller were measured as a function of fibre mass concentration, fibre type and impeller speed. Using the velocity profiles measured, the impeller pumping rate and flow number were calculated as a function of suspension yield stress (itself a function of fibre mass concentration and fibre type). The flow number was found to decrease as the suspension yield strength increased. For example, when the mass concentration of a hardwood pulp was increased from 0% (water) to 3.3%, the flow number decreased from 0.64 to 0.43. UDV was also used to identify regions of poor mixing by measuring flow profiles at critical locations within the vessel. This study also demonstrates the ability of UDV to measure the cavern size of the pulp suspension during agitation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.