Slurry Flow

Slurry Flow: Principles and Practice describes the basic concepts and methods for understanding and designing slurry flow systems, in-plan installations, and long-distance transportation systems. The goal of this book is to enable the design or plant engineer to derive the maximum benefit from a limited amount of test data and to generalize operating experience to new situations. Design procedures are described in detail and are accompanied by illustrative examples needed by engineers with little or no previous experience in slurry transport. The technical literature in this field is extensive: this book facilitates its use by surveying current research results and providing explanations of mechanistic flow models. This discussion of background scientific principles helps the practitioner to better interpret test data, select pumps, specify materials of construction, and choose measuring devises for slurry transport systems. The extensive range of topics covered in Slurry Flow: Principles and practice includes slurry rheology, homogeneous and heterogeneous slurry flow principles, wear mechanisms, pumping equipment, instrumentation, and operating aspects.

1,1 Applications of Slurry Transport Vast tonnages are pumped every year in the form of solid-liquid mixtures, known as slurries. The application which involves the largest quantities is the dredging industry, continually maintaining navigation in harbours and rivers, altering coastlines and winning material for landfill and construction purposes. As a single dredge may be required to maintain a throughput of 7000 tonnes of slurry per hour or more, very large centrifugal pumps are used. Figures 1-1 and 1-2 show, respectively, an exterior view of this type of pump, and a view of a large dredge-pump impeller (Addie & Helmley, 1989). The manufacture of fertiliser is another process involving massive slur- transport operations. Li Florida, phosphate matrix is recovered by huge draglines in open-pit mining operations. It is then slurried, and pumped to the wash plants through pipelines with a typical length of about 10 kilometres. Each year some 34 million tonnes of matrix are transported in this manner. This industry employs centrifugal pumps that are generally smaller than those used in large dredges, but impeller diameters up to 1. 4 m are common, and drive capacity is often in excess of 1000 kW. The transport distance is typically longer than for dredging applications, and Chapter 1 Figure LI. Testing a dredge pump at the GIW Hydraulic Laboratory Figure 1. 2. Impeller for large dredge pump 1. Introduction 3 hence a series of pumping stations is often used. Figure 1-3 shows a boost- pump installation in a phosphate pipeline.

This book benefits users, manufacturers and engineers by drawing together an overall view of the technology. It attempts to give the reader an appreciation of the extent to which slurry transport is presently employed, the theoretical basis for pipeline design, the practicalities of design and new developments.

Written by experts from around the world, this book presents a comprehensive overview of slurry technology. The editor is grounded in the science of dilute concentrations of coarse particles in horizontal ducts, including settling distributions, critical deposition, swirling flow, and the two-layer model. This volume includes ten chapters that address such topics as process modelling, measurement (including non-Newtonian rheology), high-concentration conveying, vertical transport of fine-particle slurries, rheometry of sludges, pipe wear, and wastewater applications. There is also a chapter on an application at the fringe of our subject: fluidisation.