Modeling Maximum Stopping Times in Long Distance Slurry Pipelines

One of the most important aspects of the operation of long distance slurry pipelines is how to maximize safe stopping times without the need for filling the pipe with water -a lengthy and expensive operation-. This operational restriction occurs from the particle migration process occurring in inclined sections towards local low points on the route. Unsafe stopping times are often related with extended sections with slurry plugs that may induce exceedingly high startup pressures with subsequent potential of pipe rupture. Optimizing stopping times would allow for enhanced operational flexibility and, concurrently, significant savings in water consumption -with the corresponding economical implications-. The process of particle accumulation at the bottom of the pipe section is related the pipeline topography and the characteristics of the slurry. In the present paper, a model for maximum stopping times is proposed based on the concept of maximum acceptable concentration. The model is compared with existing pipeline data.