Hydraulic Lifting of Manganese Nodules Through a Riser

2004 ◽  
Vol 126 (1) ◽  
pp. 72-77 ◽  
Author(s):  
J. X. Xia ◽  
J. R. Ni ◽  
C. Mendoza
Keyword(s):  
Deep Sea ◽  
Solid Phase ◽  
Laboratory Data ◽  
Manganese Nodule ◽  
Hydraulic Gradient ◽  
Design Tool ◽  
Water Mixture ◽  
Upward Flow ◽  
Manganese Nodules ◽  
Experimental Apparatus

The calculation of the hydraulic gradient due to the upward flow of a large size particles—water mixture in a vertical pipe is a central problem in the design of systems for deep-sea mining of manganese nodules. Here, the problem is investigated experimentally and with a new calculation method. An experimental apparatus that mimics the deep-sea mining system was built to measure the hydraulic gradient due to the mixture upward flow, the settling velocity of a single manganese nodule, and to explore the relationship between the concentration of fluidized manganese nodules and the solid slip velocity. Experimental relations are found. Also, a formula to compute the total hydraulic gradient of the mixture flow under different flow and solid-loading conditions is developed; the formula accounts for the hydraulic gradients produced by the liquid phase, the solid phase, and the inter-particle collisions. The predictions obtained with the derived equation are compared with experimental data readily available and with the newly acquired laboratory data; these predictions agree very well with the empirical data and demonstrate the value of the model as a design tool.

Thermal Hydraulics Behavior Around a Single Heated Rod With Sodium-Water Reaction (1)

2010 ◽  
Author(s):  
Hideyuki Kudoh ◽  
Masanori Nishizaki ◽  
Ken-ichiro Sugiyama ◽  
Hiroyuki Ohshima
Keyword(s):  
Heat Transfer ◽  
Solid Phase ◽  
Gas Jet ◽  
Gas Mixture ◽  
Water Mixture ◽  
Thermal Hydraulics ◽  
Heat Transfer Tube ◽  
Transfer Tube ◽  
Experimental Apparatus ◽  
Secondary Failure

The LMFBRs (Liquid Metal Cooled Fast Breading Reactors) is a key technology for the future electricity demand. Therefore, the establishment of safety of LMFBRs is deeply desired. To evaluate the safety of LMFBR steam generators, empirical studies have been performed for the ruptures of heat transfer tube caused by the overheat due to sodium-water reaction in case of a practical scale conditions. But few systematical experiments have been performed for the clarification of phenomena from the viewpoint of thermal hydraulics and physical chemistry. The absence of such studies is derived from the fact that sodium is chemically active and is not feasible for visualized experiments. To evaluate the safety against the secondary failure of heat transfer tubes by an analytical code, which has been tried in JAEA, it is required to understand the heat transfer phenomena around the tube. In this study, we investigated experimentally the thermal hydraulics behavior around a single heated rod with sodium-water reaction as an essential study for the clarification of raptures phenomena of heat transfer tube. The experimental apparatus was consisted of a sodium pool tank, an electrically heated test rod, a gas jet nozzle of argon-water mixture. We set horizontally in the sodium pool the test rod that is heated with the constant heat flux, and to which a gas jet of argon-water mixture was supplied for the sodium-water reaction from its lower side. The temperature of sodium pool was kept to be 420K so that a product of sodium-water reaction, NaOH (melting point is 591K), may exist as a solid phase. Gas jet velocity was set to be 17.3m/s, and the amount of water vapor in the gas mixture was 3% in mass. Just after the introduction of gas mixture, the temperature of sodium pool increased by the heat of chemical reaction. At the same time, the heat transfer to the rod surface decreased rapidly. By the observation after the experiment, it was confirmed that coarse reaction products deposited thickly at the upper side of the rod and finely granular products adhered to the lower ones. Thus, at low-sodium temperature conditions, the products of sodium-water reaction on the rod surface cause the decrease of heat transfer rate between the rod and sodium pool, which depends on the local distribution of deposits. The present authors therefore obtained experimentally the phenomena important for the development of an analytical code of JAEA.

Influence of Pumps on Salinity of a Coastal Aquifer with Legal Protection (A Zone in the North of Isla Cristina, Huelva, Spain)

1991 ◽  
Vol 24 (11) ◽  
pp. 251-260 ◽  
Author(s):  
A. González ◽  
E. Romero
Keyword(s):  
Coastal Aquifer ◽  
Salt Water ◽  
Legal Protection ◽  
Hydraulic Gradient ◽  
Water Mixture ◽  
Residual Flow ◽  
Legal Requirements ◽  
The North ◽  
North Side ◽  
Rational Distribution

In this article we show that the legal measures for protection of aquifers are not enough to lessen the pumping if the users are not associated and determined to have a rational distribution of water. The expansive agriculture on the North side of Isla Cristina (Huelva, Spain), based on citrus and strawberry growing, uses high volumes of groundwater that comes from a tertiary age detritic coastal aquifer with a significant lack of resources. This causes a decrease of the residual flow to the sea, deep pumpcones, and an inversion of the hydraulic gradient, which initiates the progressive salinization of the aquifer northwards, in the sense that the fresh-salt water mixture zone is moving. The problem is worsening because the number of uncontrolled pump-works in the areais increasing. This problem could be alleviated if a Users Community for the whole aquifer were created, itself to watch over the fulfilment of the legal requirements and to regulate the water extractions.

V.—Manganese in the Sea

1876 ◽  
Vol 1 (2) ◽  
pp. 50-53 ◽  
Author(s):  
A. H. Church
Keyword(s):  
Chemical Analysis ◽  
Deep Sea ◽  
The Other ◽  
Manganese Nodules ◽  
Red Clay ◽  
Chemical Examination ◽  
Sea Bottom ◽  
Ample Supply

To the geologist, the mineralogist and the chemist, two of the observations made during the voyage of the Challenger are of especial interest. One of these observations is the occurrence over vast areas of the deep sea bottom of a peculiar red clay, containing silica, peroxide of iron, and alumina. The other discovery to which I refer has been described by Sir Wyville Thomson as the occurrence throughout this red clay of nodules of “nearly pure peroxide of manganese.” To these nodules, as well us to the red clay, an organic origin has been assigned. But the immediate source of so much manganese is hard to find, for this element is by no means an abundant constituent of animal or vegetable organisms. The difficulty is, however, somewhat lessened when the manganese nodules are submitted to a more minute chemical examination. From two correspondents I have received an ample supply of these curious concretions, accompanied by a suggestion that they should be submitted to chemical analysis.

scholarly journals Sponge and coral communities of potential mineral resources in the deep-sea: An overview

2018 ◽  
Author(s):  
Tina Molodtsova ◽  
Christopher Kelley ◽  
Lénaick Menot ◽  
Les Watling
Keyword(s):  
Deep Sea ◽  
Slow Growth ◽  
Mineral Resources ◽  
Ore Deposits ◽  
Manganese Nodules ◽  
Cumulative Impact ◽  
Mining Sites ◽  
Intensive Exploitation ◽  
Coral Communities ◽  
Hard Substrata

Depletion of commercially valuable minerals on land and increased need of such resources for modern electronics and manufacturing is attracting more and more attention to deep-sea mineral deposits such as cobalt crusts, manganese nodules, phosphorites, polymetallic sulfides and even deep-sea ooze. In a few years we expect intensive exploitation in the deep-sea. Being suspension feeders, corals and sponges associated with hard substrata in potential mining sites would be adversely impacted by deep-sea mining. Deep-sea corals and sponges are characterized by extremely slow growth rates and, as can be seen from fishery impacts, they may take decades to centuries to restore. At the same time, they serve as a substrate, shelter and food for a number of associated deep-sea organisms, thus increasing the cumulative impact of their loss. We summarize here the available data on coral and sponge communities of solid deep-sea ore deposits and possible mechanisms driving their diversity.

The detection of magnetotactic bacteria in deep sea sediments from the east Pacific Manganese Nodule Province

2016 ◽  
Vol 8 (2) ◽  
pp. 239-249 ◽  
Author(s):  
Yi Dong ◽  
Jinhua Li ◽  
Wuchang Zhang ◽  
Wenyan Zhang ◽  
Yuan Zhao ◽  
...  
Keyword(s):  
Deep Sea ◽  
Manganese Nodule ◽  
Magnetotactic Bacteria ◽  
East Pacific ◽  
Deep Sea Sediments
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