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Abstract This paper describes the main objectives and early achieved results from the MARENOR project. MARENOR is financed by the Research Council of Norway as well as Norwegian industry partners from oil and gas (EM survey company EMGS), fisheries (shipping company and shrimp trawler Remoy), positioning and navigation suppliers (Kongsberg Seatex and Polar Science Guiding) and telecommunication service suppliers (Telenor Satellite Broadcasting). Academic partners are MARINTEK, SINTEF ICT, University of Svalbard from Norway and Wroclaw University of Technology from Poland. MARENOR was kicked off in February 2012 and will end in February 2015. Test equipment for measuring system performance of navigation and communication systems in the High North has been installed at two vessels (Atlantic Guardian and Remoy) and at Kjell Henriksen Observatory at Svalbard. The data to be measured include performance parameters from navigation and communication systems, ionospheric parameters, atmospheric parameters, ship movements and positions.
ABSTRACT The paper presents results of an experimental investigation of conveyed particles and carrier liquid velocities during flow of heterogeneous mixture in a vertical pipe. Measurements were carried out in hydraulic laboratory of Wroclaw University of Environmental and Life Sciences in transparent pipe of inner diameter D = 150 mm. Velocities of individual particles of different diameters were measured by radiometric method during vertical mixture flow. Goal of investigation was determining of slip velocities for the artificial nodules of mean diameter d ˜ 30 mm during the heterogeneous mixture flow in vertical pipe for mixture velocity range from 1.5 m/s to 3.5 m/s, mean volume concentration of solids was about 5%.
Sobota, Jerzy (The Wroclaw University of Environmental and Life Science) | Strozik, Grzegorz (Silesian University of Technology) | Plewa, Franciszek (Silesian University of Technology) | Vlasak, Pavel (The Czech Academy of Sciences)
ABSTRACT: Flow of solid-liquid mixtures with different density and size of particles was investigated in a horizontal pipe loop. Concentration distribution in the vertical profile was measured with use of a radiometric method. The paper analyses the influence of density and size of solid particles on the vertical profile of the mixture density and concentration in a horizontal pipe. FLOW OF A SOLID-LIQUID MIXTURE IN HORIZONTAL PIPE The density distribution in transversal cross-section of the pipe is an important parameter for understanding the physical mechanism and description of the flow of two-phase mixture of a liquid and solid particles. In a case of mixtures that contains particles of different diameters, the vertical profile of solids concentration, within the range of applicable flow velocities, is curvilinear (heterogeneous distribution). METHODS OF DENSITY PROFILE MEASUREMENT Several methods have been applied to determine density profile of twophase liquid-solids mixture flow. The first work in that field was done by Pechenkin (1969), who introduced a photographic method with use of a high-speed camera, where solids were represented by particles of special kind of glass. Few years later a similar method was adopted by Ayukawa (1970). In the Russian school represented by Silin at al. from Kiev, Pitot tube of special construction has been adopted (Silin et al. 1971). Among the first ones, a group of scientists from Mining and Metallurgy University of Kraków and Wrocław University of Environmental and Life Science have adopted radioisotopic technique for precise determination of density distribution in the transversal cross-section of a pipe (Przewłocki, 1979). Later this method was also used by Shook (1991) and Wiedenroth (1984), who have measured profiles of mixtures density distribution in the transversal cross-section of a pipe. Generally saying, methods of density (concentration) profile measurements may be divided into invasive and non-invasive ones.
Sobota, Jerzy (Institute of Enviromnental Engineering, Agricultural University) | Boczarski, Stanislaw (Institute of Enviromnental Engineering, Agricultural University) | Petryka, Leszek (Institute of Physics and Nuclear Techniques, University of Mining and Metallurgy) | Kotlinski, Ryszard (Interoceamnetal Joint Organization) | Stoyanova, Valcana (Interoceamnetal Joint Organization)
ABSTRACT: The paper presents the results of nodule and water velocity measurements at upward flow in a pipeline of D=150 mm. The investigations were conducted on an experimental stand specifically constructed for this purpose in the hydraulic laboratory in the Department of Water Engineering and Hydrotransport of the Agricultural University of Wroclaw. The mixture phase velocity measurements were carried out with the application of radioisotopes. The presented results refer to velocities of 10-, 30and 50-mm-diameter nodules and water at the volume concentration equal 10%. Introduction One of the main elements of the technology of nodule recovery from the ocean bed is a pipeline connecting the system of nodule collection from the bed (miner) with the superficial platform. The How of the mixture of water and nodule in this pipeline is quite complex. One of the reasons is the difference in velocity between the two mixture phases. Nodules flowing upwards are moved in a direction opposite to the gravity force, i.e. in the direction of transported nodules settling. Therefore, in the vertical flow of the two-phase mixture of water and nodules, its phases move at different velocities. In Govier and Aziz's (1972) opinion, the minimal velocity for the vertical How should be tvice as high as the free fall velocity of the largest grains contained in the mixture (vm > 2Wo). However, Sellgren (1982), on the basis of pilot study with the use of granite particles, states that the minimal velocity should exceed the free fall velocity of the largest particles in still water by 4 to 5 times (vm > 4–5Wo). From the practical point of view, the knowledge of the water and nodules velocities is of primary importance in determining the actual efficiency of vertical hydraulic transport of solid material, e.g. in deep ocean mining of nodules.