(6)High Capacity Piston Diaphragm Pumps for Tailings Slurry Transfer

摘要

To transfer abrasive slurries through pipelines, generally two types of pumps are used: pistondiaphragm pumps for low volumes of slurry against high pressures, and multistage centrifugalpumps for high volumes against low pressures.The discharge pressure of centrifugal slurry pumps is usually limited to 4 to 7 bars per pump. Toachieve higher pressures, multiple centrifugal pumps are placed in series, either in a single pumpstation or in several pump stations, which are placed along the pipeline depending on the overallpressure required. For example, a total system pressure of 60 bars would require approximatelyeight pumps in series. The maximum flow capacity of these pumps can be close to 10,000 m?/hr .The capacity of piston diaphragm pumps has historically been limited to approximately 750 m?/hper unit and therefore multiple pumps placed in parallel are needed to match the capacity of largecentrifugal pumps. Typically a high flow rate piston diaphragm pump station would therefore beequipped with five or six units operating in parallel.Using piston diaphragm pumps for slurry transfer has a number of potential advantages whencompared to centrifugal pumps, resulting particularly from piston diaphragm pumps deliveringconstant flow independent of discharge pressure, and generally the need for only a single pumpstation. There are also potential benefits to be achieved in efficiency and availability, as well asspare parts consumption. A new size of piston diaphragm pump has become available which mayprove to be a feasible alternative for multistage centrifugal pump systems. This new design offers aunit capacity of 1,400 m?/h at a discharge pressure of up to 60 bar.This paper describes the result of a feasibility comparison, including CAPEX and OPEX costingbetween this new large piston diaphragm pump system and a multistage centrifugal pump system.In addition to the commercial feasibility, piston diaphragm pumps also offer technical advantageswhich are described briefly.