Preliminary Design Through Analysis of a Bottom Weighted Rigid Riser for Subsea Mining

2014 ◽  
Author(s):  
Savin Viswanathan ◽  
R. Panneer Selvam ◽  
Deepak C. Raphael
Keyword(s):  
Wall Thickness ◽  
Deep Ocean ◽  
Ocean Basin ◽  
Preliminary Design ◽  
Mining System ◽  
Coupled Dynamic Analysis ◽  
Central Indian Ocean ◽  
Increasing Demand ◽  
Response Amplitude Operators ◽  
Nodule Mining

Polymetallic nodules found in the deep ocean basins contain many economically valuable metals and are viewed as potential resources to supplement depleting onshore reserves and tackle increasing demand. The present work focuses on the preliminary design through analysis of a bottom weighted rigid riser which would form a part of the future full scale prototype nodule mining system under development by the National Institute of Ocean Technology (NIOT), India, operating in a water depth of around 6500m in the Central Indian Ocean Basin. A semisubmersible platform is chosen as a surface support vessel and the hydrodynamic analysis of a conceptual semisubmersible platform is carried out with WAMIT [3] to determine the heave Response Amplitude Operators (RAOs). The initial riser diameter, material grade and wall thickness configuration are arrived at using basic engineering principles and semi-coupled dynamic analysis of the platform riser system is carried out using ORCAFLEX [8] software to determine the loads imposed on the riser. The wall thickness is optimized to meet requirements of offshore standard DNV OS F 201 [6]. Vortex Induced Vibration (VIV) and Fatigue Analysis are then carried out using ORCAFLEX.

Conceptual Design of TMR-Less Manganese Nodule Mining System and the Economy Examination

2012 ◽  
Author(s):  
Tetsuo Yamazaki ◽  
Amon Yamada ◽  
Rei Arai ◽  
Naoki Nakatani
Keyword(s):  
Conceptual Design ◽  
Manganese Nodule ◽  
Deep Ocean ◽  
Mining Method ◽  
Manganese Nodules ◽  
Mining System ◽  
Mining Site ◽  
Nodule Mining ◽  
The One ◽  
Very High

Manganese nodules on deep ocean floors have been interested in as future metal resources these forty years. The Total Materials Requirement (TMR) of the conventional proposed mining method, however, is very high because of the much lifted water with the nodules from the seafloor to the sea surface and the longer transportation from the mining site to the smelting plant. An innovative conceptual design of the TMR-less mining system is presented. The economy is examined and compared with the one of the conventional method.

Manganese nodule mining

1978 ◽  
Vol 290 (1366) ◽  
pp. 125-133
Keyword(s):  
Large Scale ◽  
Manganese Nodule ◽  
Deep Ocean ◽  
Final Decision ◽  
Legal Regime ◽  
Mining System ◽  
Mining Site ◽  
Nodule Mining ◽  
Large Scale Tests ◽  
Large Investment

This paper considers the mining of manganese nodules from the deep ocean at up to 5000 m, drawing attention to the essential need for a satisfactory legal regime under which mining companies can operate with security. The necessary exploration that has to be carried out before large investment can be made is indicated and the type and size of mining site required are determined. The paper also considers the equipment required to collect, lift and transport the nodules. The most likely form of collection and lift is hydraulic but there are considered to be substantial development problems still to be solved. This indicates the need for large scale tests before the final decision on the mining system can be completed. The paper describes briefly a test collector operated in late 1974 and early 1975. A brief description of the possible environmental problems is also included.

Estimation of Reliability of Underwater Polymetallic Nodule Mining Machine

2015 ◽  
Vol 49 (1) ◽  
pp. 131-147 ◽  
Author(s):  
Nidhi Varshney ◽  
Siva Rajesh ◽  
Anantha Padmanabhan Aarthi ◽  
Narayanmurthy Renganayahi Ramesh ◽  
Narayanswamy Vedachalam ◽  
...  
Keyword(s):  
Water Depth ◽  
Ocean Basin ◽  
Mining Machine ◽  
Hydraulic Systems ◽  
Term Operation ◽  
Control Power ◽  
Polymetallic Nodule ◽  
Central Indian Ocean ◽  
Key Factor ◽  
Nodule Mining

AbstractThis paper presents the reliability analysis carried out on the subsystems of the underwater polymetallic nodule mining machine developed by National Institute of Ocean Technology, India, which is being enhanced for polymetallic nodule mining technology demonstration at 6,000-m water depth in the Central Indian Ocean Basin, where manganese nodules are available in abundance. The mining machine, which is a tracked vehicle, was successfully demonstrated at a water depth of 512 m, wherein the nodules are collected, crushed, and pumped to the mother vessel. Reliable long-term operation at 6,000 m is the key factor, as retrieval of the system to the top side for rectification is costly and time-consuming. It is identified that the reliability of the 6,000-m-rated mining machine subsystems could be improved by the use of localized control power, redundant electronics, and hydraulic systems. It is estimated that, with the suggested improvements, the probability of failure of the systems involved in vehicle maneuvering, mineral crushing, and pumping could be reduced from 91%, 88.8%, and 84.59% to 68%, 57%, and 39%, respectively, when the systems are operated for a period of 1,460 h in a year. The results serve as a guideline for 6,000-m-depth-rated mining machine system design with a trade-off on size, weight, and required level of reliability.

scholarly journals Research on Hydroelastic Response of an FMRC Hexagon Enclosed Platform

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1110
Author(s):  
Wei-Qin Liu ◽  
Luo-Nan Xiong ◽  
Guo-Wei Zhang ◽  
Meng Yang ◽  
Wei-Guo Wu ◽  
...  
Keyword(s):  
Time Domain ◽  
Numerical Models ◽  
Structural Response ◽  
Deep Ocean ◽  
Surface Model ◽  
Large Area ◽  
Floating Structure ◽  
Small Depth ◽  
Response Amplitude Operators ◽  
Hydroelastic Response

The numerical hydroelastic method is used to study the structural response of a hexagon enclosed platform (HEP) of flexible module rigid connector (FMRC) structure that can provide life accommodation, ship berthing and marine supply for ships sailing in the deep ocean. Six trapezoidal floating structures constitute the HEP structure so that it is a symmetrical very large floating structure (VLFS). The HEP has the characteristics of large area and small depth, so its hydroelastic response is significant. Therefore, this paper studies the structural responses of a hexagon enclosed platform of FMRC structure in waves by means of a 3D potential-flow hydroelastic method based on modal superposition. Numerical models, including the hydrodynamic model, wet surface model and finite element method (FEM) model, are established, a rigid connection is simulated by many-point-contraction (MPC) and the number of wave cases is determined. The load and structural response of HEP are obtained and analyzed in all wave cases, and frequency-domain hydroelastic calculation and time-domain hydroelastic calculation are carried out. After obtaining a number of response amplitude operators (RAOs) for stress and time-domain stress histories, the mechanism of the HEP structure is compared and analyzed. This study is used to guide engineering design for enclosed-type ocean platforms.

scholarly journals Biological productivity, terrigenous influence and noncrustal elements supply to the Central Indian Ocean Basin: Paleoceanography during the past ∼ 1 Ma

2005 ◽  
Vol 114 (1) ◽  
pp. 63-74 ◽  
Author(s):  
J. N. Pattan ◽  
Toshiyuki Masuzawa ◽  
D. V. Borole ◽  
G. Parthiban ◽  
Pratima Jauhari ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Ocean Basin ◽  
Biological Productivity ◽  
The Past ◽  
Central Indian Ocean ◽  
Central Indian Ocean Basin

Distribution and Origin of Seamounts in the Central Indian Ocean Basin

2005 ◽  
Vol 28 (3) ◽  
pp. 259-269 ◽  
Author(s):  
Pranab Das ◽  
Sridhar D. Iyer ◽  
V. N. Kodagali ◽  
K. S. Krishna
Keyword(s):  
Indian Ocean ◽  
Ocean Basin ◽  
Central Indian Ocean ◽  
Central Indian Ocean Basin

Heave Induced Internal Flow Fluctuations in Vertical Transport Systems for Deep Ocean Mining

2014 ◽  
Author(s):  
Stephan D. A. Hannot ◽  
Jort M. van Wijk
Keyword(s):  
Transport System ◽  
Internal Flow ◽  
Deep Ocean ◽  
Vertical Transport ◽  
Transport Systems ◽  
Ship Motions ◽  
Centrifugal Pumps ◽  
Mining System ◽  
Pump System ◽  
Ocean Mining

Deep ocean mining systems will have to operate often in harsh weather conditions with heavy sea states. A typical mining system consists of a Mining Support Vessel (MSV) with a Vertical Transport System (VTS) attached to it. The transport system is a pump pipeline system using centrifugal pumps. The heave motions of the ship are transferred to the pump system due to the riser-ship coupling. Ship motions thus will have a significant influence on the internal flow in the VTS. In this paper, the influence of heave motions on the internal flow in the VTS for a typical mining system for Seafloor Massive Sulfide (SMS) deposits in Papua New Guinea is analyzed. Data on the wave climate in the PNG region is used to compute the ship motions of a coupled MSV-VTS. The ship motions then are translated into forces acting on the internal flow in order to compute fluctuations in the internal flow. In this way, the workability of the mining system with respect to the system’s production can be assessed. Based on a detailed analysis of the internal flow in relation to ship motions, the relevance of a coupled analysis for the design of VTS is made clear. This paper provides a method for performing such analyses.

scholarly journals Detrital and authigenic(?) baddeleyite (ZrO2) in ferromanganese nodules of Central Indian Ocean Basin

2011 ◽  
Vol 2 (4) ◽  
pp. 571-576 ◽  
Author(s):  
Bibhuranjan Nayak ◽  
Swapan Kumar Das ◽  
Kalyan Kumar Bhattacharyya
Keyword(s):  
Indian Ocean ◽  
Ocean Basin ◽  
Ferromanganese Nodules ◽  
Central Indian Ocean ◽  
Central Indian Ocean Basin
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