When it is time for a new pump change, operators need to determine exactly which chopper pump model and specifications will best fit their needs. From operating conditions to lifetime cost analysis, they need to research before placing that order. Arne Swenson, chief engineer for Vaughan Company, highlights some of the key focus areas for operators to keep in mind.
Know your fluid
Modern pumping challenges include pumping fluids mixed with various solids or debris. Chopper pumps excel at pumping fluids which contain unpredictable solids that would cause pump blockage in traditional non-clog pumps.
Pumping coke slurry at a steel mill with random rags or the occasional glove, various food wastes, plastics, raw sewage in a lift station with the presence of wipes and various plastics, scum and sludge in a wastewater treatment plant are a few examples and may all require the use of a chopper pump.
Understanding the pumped media helps operators pick the desired chopper pump model and motor to assure that the solids can reliably enter the pump. Also, choosing a chopper pump supplier with a history of success in a particular type of pumped media gives operators a better chance of success.
Properly define operating conditions
Lead oxide slurry with chunks of plastic in a battery plant may have a specific gravity of 2.0-2.5 while raw sewage from a municipal lift station may have a specific gravity of essentially 1.0. Pump power needed is directly proportional to fluid specific gravity; specific gravity of 2.0 means operators will need a motor twice as large compared to a specific gravity of 1.0.
The full article is available in the latest edition of Water & Wastewater Asia Jul/Aug 2022 issue. To continue reading, click here.