Crosscutting Technology Development at the Center for Advanced Separation Technologies

The U.S. is the largest producer of mining products in the world. In 2003, U.S. mining operations produced $57 billion worth of raw materials that contributed a total of$564 billion to the nation's wealth. Despite these contributions, the mining industry has not been well supported with research and development funds as compared to mining industries in other countries. To overcome this problem, the Center for Advanced Separation Technologies (CAST) was established to develop technologies that can be used by the U.S. mining industry to create new products, reduce production costs, and meet environmental regulations. Originally set up by Virginia Tech and West Virginia University, this endeavor has been expanded into a seven-university consortium -- Virginia Tech, West Virginia University, University of Kentucky, University of Utah, Montana Tech, New Mexico Tech and University of Nevada, Reno - that is supported through U.S. DOE Cooperative Agreement No. DE-FC26-02NT41607: Crosscutting Technology Development at the Center for Advanced Separation Technologies. Much of the research to be conducted with Cooperative Agreement funds will be longer-term, high-risk, basic research and will be carried out in five broad areas: (1) Solid-solid separation; (2) Solid-liquid separation; (3) Chemical/biological extraction; (4) Modeling and control; and (5) Environmental control. Distribution of funds is handled via competitive solicitation of research proposals through Site Coordinators at the seven member universities. These were first reviewed and ranked by a group of technical reviewers (selected primarily from industry). Based on these reviews, and an assessment of overall program requirements, the CAST Technical Committee made an initial selection/ranking of proposals and forwarded these to the DOE/NETL Project Officer for final review and approval. The successful projects are listed by category, along with brief abstracts of their aims and objectives

Studies of fluidic systems for environmental applications

A Hydrodynamic Vortex Separator (HDVS) is a form of Combined Sewer Overflow (CSO) used for solid-liquid separation. HDVSs are also used at sewage treatment works for the separation of grits that are transported through the sewer network. The residence time of the fluid that passes through these devices is increased by the rotational nature of the flow and hence, the time that gravity has to act on particulates is also increased. This feature of the fluid dynamics means that a HDVS may also be used as a contact vessel for disinfection of wastewater during a CSO event. To date the physics of these systems is not completely understood in terms of particulate separation. To achieve a greater understanding of the HDVS an initial sensitivity study using Computational Fluid Dynamics (CFD) was carried out looking at factors that may influence the efficiency and to gain an insight into variables that should be accounted for during experimentation and test rig design. Following this sensitivity study a 0.75m diameter HDVS was studied under laboratory conditions where it was found that a parameter described as the particle surface load controls the efficiency of the HDVS and not the particle settling velocity as previously thought. A model was developed to describe the retention efficiency and was also applied to scaling. However, more work is required to achieve a greater understanding of the application of the retention efficiency model to larger separators. Experimental trials on a 3.4m diameter HDVS were undertaken and from this it was found that the most suitable residence time distribution model for a HDVS is the axial dispersion model. Attempts to use CFD to model the separation efficiency of such systems have to date failed. However, validations of the residence time characteristics are reasonable. This has allowed CFD to be used to study the application of residence time to disinfection where it has been shown that an existing disinfection model may be developed to describe the disinfection performance of a HDVS. Scaling laws have also been developed using CFD for the residence time and CFD has consequently given an insight into the fluid dynamics within the HDVS.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Studies of fluidic systems for environmental applications

A Hydrodynamic Vortex Separator (HDVS) is a form of Combined Sewer Overflow (CSO) used for solid-liquid separation. HDVSs are also used at sewage treatment works for the separation of grits that are transported through the sewer network. The residence time of the fluid that passes through these devices is increased by the rotational nature of the flow and hence, the time that gravity has to act on particulates is also increased. This feature of the fluid dynamics means that a HDVS may also be used as a contact vessel for disinfection of wastewater during a CSO event. To date the physics of these systems is not completely understood in terms of particulate separation. To achieve a greater understanding of the HDVS an initial sensitivity study using Computational Fluid Dynamics (CFD) was carried out looking at factors that may influence the efficiency and to gain an insight into variables that should be accounted for during experimentation and test rig design. Following this sensitivity study a 0.75m diameter HDVS was studied under laboratory conditions where it was found that a parameter described as the particle surface load controls the efficiency of the HDVS and not the particle settling velocity as previously thought. A model was developed to describe the retention efficiency and was also applied to scaling. However, more work is required to achieve a greater understanding of the application of the retention efficiency model to larger separators. Experimental trials on a 3.4m diameter HDVS were undertaken and from this it was found that the most suitable residence time distribution model for a HDVS is the axial dispersion model. Attempts to use CFD to model the separation efficiency of such systems have to date failed. However, validations of the residence time characteristics are reasonable. This has allowed CFD to be used to study the application of residence time to disinfection where it has been shown that an existing disinfection model may be developed to describe the disinfection performance of a HDVS. Scaling laws have also been developed using CFD for the residence time and CFD has consequently given an insight into the fluid dynamics within the HDVS