Two-Layer Model for Horizontal Pipe Flow of Newtonian and Non-Newtonian Settling Dense Slurries

Experimental Characterization Techniques for Solid-Liquid Slurry Flows in Pipelines: A Review

In industrial environments, having instrumentation able to attain fast, accurate, and autonomous measurements is pivotal to understanding the dynamics of liquid and particles during transport. Ideally, these instruments, consisting of either probes or sensors, should be robust, fast, and unintrusive, i.e., not cause interference on the very flows being monitored, and require minimal maintenance. Beyond monitoring, the process knowledge gained through real time inspection allows teams to make informed technical decisions based on particle behavior, i.e., settling of particles causing pipe wear and clustering or blockages that can damage the unit or cause shutdowns, both of which with economical drawbacks. The purpose of this review is to examine experimental measurement techniques used to characterize physical properties and operational parameters of solid-liquid slurry flows, focusing on non-ionizing radiation methods. With this text the intent is not to provide an exhaustive examination of each individual technique but rather an overview on the most pertinent types of instrumentation, which will be presented, in addition to application examples from the literature, while directing the reader for pertinent seminal and review papers for a more in-depth analysis.

Modelling of multiphase solid-liquid laminar flow with non-Newtonian carrier in pipelines using a layered model

This paper discusses two-phase laminar flows of mixtures of solids in non-Newtonian carrier consisting of spherical particles in a 50-mm pipe at the Czech Technical University in Prague. Special attention is paid to the frictional head loss and thickness of transport layers. For the prediction of various transport characteristics, a layered model is used. Suitability of the layered model to predict the transport characteristics is investigated. Prediction results are compared to own experimental data.

Simplified Layer Model for Solid Particle Clusters in Product Oil Pipelines

Pipe corrosion caused by the pressure tests using water before starting the normal operation occurs often in Chinese product oil pipelines because of remaining water. To explore the migration of the corrosion impurities in the product oil pipelines, this study started from the force balance principle and considered the entire particle cluster as the research object. This paper established a one-dimensional migration model, and proposed the Froude number equality criterion to calculate the particle cluster length in the equilibrium state. The proposed criterion was verified by experiments. A loop was built to conduct the tests and obtain the migration velocities of the particle cluster from the non-equilibrium state to the equilibrium state in the pipeline. The proposed model was verified using the experimental data. Verification results demonstrate that the model can describe the development process from the non-equilibrium state to the equilibrium state of particle clusters after sudden external disturbance and accurately predict some important parameters, including the velocity of the particle cluster in the equilibrium state and the critical velocity that leads to the transition from fixed bed flow to moving bed flow. The model provides the theoretical basis and calculation method to remove corrosion impurities from product oil pipelines.

Solid-phase zirconium and fluoride species in alkaline zircaloy cladding waste at Hanford

The United States Department of Energy Hanford Site, near Richland, Washington, USA, processed plutonium between 1944 and 1987. Fifty-six million gallons of waste of various origins remain, including waste from removing zircaloy fuel cladding using the so-called Zirflex process. The speciation of zirconium and fluoride in this waste is important because of the corrosivity and reactivity of fluoride as well as the (potentially) high density of Zr-phases. This study evaluates the solid-phase speciation of zirconium and fluoride using X-ray diffraction (XRD) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). Two waste samples were analyzed: one waste sample that is relatively pure zirconium cladding waste from tank 241-AW-105 and another that is a blend of zirconium cladding wastes and other high-level wastes from tank 241-C-104. Villiaumite (NaF) was found to be the dominant fluoride species in the cladding waste and natrophosphate (Na7F[PO4]2 · 19H2O) was the dominant species in the blended waste. Most zirconium was present as a sub-micron amorphous Na-Zr-O phase in the cladding waste and a Na-Al-Zr-O phase in the blended waste. Some zirconium was present in both tanks as either rounded or elongated crystalline needles of Na-bearing ZrO2 that are up to 200 μm in length. These results provide waste process planners the speciation data needed to develop disposal processes for this waste.