the effect of the particle size distribution on non-newtonian turbulent ...

Appendix B Conference Paper B.IO
A test set conducted using <strong>the</strong> facility is defined as a set <strong>of</strong> tests using <strong>the</strong> four different
pipe diameters but <strong>the</strong> same slurry.
3.1 Test Facility
Slurry to be used for a test run is collected in a steel hopper which has a capacity 2m 3 •
From <strong>the</strong>re it is pumped by a four bladed Ma<strong>the</strong>r and Plat! 8x6 solids handling pump,
which is driven by a variable speed hydraulic drive, through <strong>the</strong> pipe circuit. Directly
after <strong>the</strong> pump <strong>the</strong> l50mm line splits up into a 90mm and l50mm pipeline. These two
pipelines have a vertical inverted "U" section <strong>of</strong> l7m, <strong>the</strong> flowrate being measured in
both downcomer sections by means <strong>of</strong> magnetic flux flow meters. A horizontal section
<strong>of</strong> approximately 30m follows with <strong>the</strong> return pipelines passing through an in-line heat
exchanger and pneumatic diverter valve before being re-routed back into <strong>the</strong> hopper.
The l50mm horizontal return pipeline splits into a l50mm line and a 200mm pipeline
<strong>the</strong> two joining toge<strong>the</strong>r after l2m. The 80mm and 150mm pipelines are PVC with clear
viewing and test sections located in <strong>the</strong> horizontal return pipelines. The 200mm line is
steel.
Flowrate can be calibrated by diverting <strong>the</strong> slurry using <strong>of</strong> <strong>the</strong> pneumatic diverter valve
into <strong>the</strong> weigh tank which is located alongside <strong>the</strong> hopper. The weigh tank, which has
a capacity <strong>of</strong> 1,5m 3 and is placed on a 1750kg mass scale, is used to calibrate <strong>the</strong>
magnetic flux flow meters. After flowrate determinations <strong>the</strong> slurry is directed back into
<strong>the</strong> looped circuit.
In order to accurately determine <strong>the</strong> rheology <strong>of</strong> <strong>the</strong> slurry a 25mm tube was used. A
tapping is taken from <strong>the</strong> l50mm horizontal return pipeline and using <strong>the</strong> back pressure,
slurry was circulated through <strong>the</strong> 25mm pipeline into <strong>the</strong> weigh tank. The flowrate was
measured using a 25mm nominal bore Altometer magnetic flux flowmeter. The flowrate
<strong>of</strong> <strong>the</strong> slurry was checked by doing a calibration using <strong>the</strong> weigh tank during a 25mm
pipe test.
No external agitation was required to maintain solids suspension in <strong>the</strong> hopper for <strong>the</strong>
slurries which were tested.
3.2 Measured Variables
Readings <strong>of</strong> head loss were taken at varying velocities and <strong>the</strong> data obtained was used
to plot a pseudo-shear diagram.
3.3 Water Tests
The hydraulic pipe roughness for each <strong>of</strong> <strong>the</strong> four pipe <strong>size</strong>s was first determined