Resolving Operational Problems in Pumping Non-Settling Slurries
Daniel W. Wood, DuPont and Trey Walters, Applied Flow Technology - Presented at the Twenty-Eighth International Pump Users Symposium, September 24-27, 2012
A case history is presented pertaining to five pumping systems that operated satisfactorily until a new production requirement was imposed on the pumping systems. A new slurry product initially developed at lab scale was introduced into the production plant for an initial trial run. Problems began to surface immediately on three out of five batch process pumping systems when the slurry could not be pumped through the plant at contract rate. Additionally, significant "heels" (unwanted fluid levels) were left in some of the suction vessels that were unable to be pumped out, resulting in considerable yield losses. This manufacturing problem had not been anticipated by the team, and without quick resolution, a loss of customer confidence and a significant delay in the new product would have resulted.
The authors present an improved method for analyzing fitting losses in pumping systems when dealing with nonsettling slurries operating in the laminar regime. In addition, design considerations are presented to minimize the impact that piping has on the pumping system when handling non-settling slurries operating in the laminar regime. A commercially available software package (AFT Fathom) was used to model the systems to better understand the hydraulics.