Matrix Pump Performance Evaluation While Cavitating
A main aim of this study was to monitor and record the performance of a typical matrix pump under vacuum-limiting suction conditions.
It was found that when the pump was not cavitating the effect of solids on the pump head and efficiency was about 3%. The NPSH required when pumping slurry was about 40% higher than for water.
In the field with the current pump located at its usual level above the pit running at its current operating speed of 500 rpm with a typical flow cavitation was shown to commence at a concentration of about 35% by weight and that for every two feet the NPSH is improved and concentration can be increased by about 10%.
The field data showed that large pump suction values enabled higher concentrations of slurry to be drawn into the pipeline, and that a relationship of pump efficiency could be established for large values of suction vacuum.
Total energy cost of four-pump system was calculated to be $1,142,872 for operation at 30% by weight. At higher suction values corresponding to pipeline concentrations of 40 and 50% by weight reductions on a cost per pound of solids transported were shown to be 10% and 20%.