Pipelines have become an important transportation means for the mineral industry. Each year there are many long distance slurry pipelines being studied, designed and constructed. A pipeline hydraulic simulation is essential for design optimization and operator training. However, the presence of solids make the simulation more complex than a single-phase flow. Many theories have been developed for simulation. Durand (1953) published his pioneer work to predict hydraulic gradient for solid-liquid flow in the pipe. Wasp et al. (1963) improved the calculation method and applied it to commercial slurry pipeline design. Hanks (1978) developed his methodology to estimate the friction factor for non-Newtonian homogeneous flow. Wood and Kao (1966), Thorely and Hwang (1979), Bechteler and Vogel (1982) derived their acoustic wave speed equations for solid-liquid flow based on different assumptions. Ricks (1985) commented on these equations and called for more supporting tests. Shou and Martinson (1997) combined these researchers' theories with the method of characteristics and developed a solid-liquid flow simulation software package. Recent development of computer technology and SCADA system make the on-line data collection and analysis more convenient. A test program was proposed to check the simulation accuracy of the software.
The method of characteristics is used for the simulation. There are three modules in the software. The gradient module calculates f and the hydraulic gradient for each reach based on the local solids density, particle size distribution and other parameters. The batch module simulates the hydraulic response caused by slurry batch movement along the pipeline. The transient module models the flow and head change caused by transient conditions. Simulation results are reported in both numerical form and graphical form for comparison against the data collected in the field test. 3. Test Conditions The pipeline tested is buried and is 126 miles long with a pipe OD of 7". Three different wall thicknesses are used, i.e. 0.25", 0.28" and 0.312". The pipe grade is X60. There are fifteen pressure transmitters on the pipeline (Figure 2). Chokes are installed at VS2 and Term (terminal). The number of chokes can be adjusted from five to eighteen. Six-inch plug valves are used in the main pipeline for shutdown at each valve station (VS). The valve stroke time is 14 seconds. The test data were collected by the SCADA system. 4. Test Results and Discussion A series of tests were conducted to validate the above-mentioned procedures and to estimate friction factor, acoustic wave speed and finally the maximum transient pressure in the pipeline. 4.1 Pipe friction factor The pipeline is divided into seven sections by the pressure monitoring stations. The slurry batches were tracked. The particle size distribution, slurry concentration and rheology for each batch were measured before the batch was pumped into the pipeline. When the system reached a stable condition, a real time HGL plot was recorded (Figure 3).