Research On Combined Single Pump And Ore Tank Deep-Sea Mining Flexible Pipe Transporting System

Because of the resource scarcity on land, many developed countries are carrying research on deep-sea mining technology for the "ocean economy age". China also attaches great importance to this subject. The manganese nodules and cobalt crust are poly-metallic minerals that lying widely on the seabed about 1500-6000 meters deep. They have to be transported to the ship on the sea level through the deep-sea mining system of which the mineral transporting technology is most important. It is widely recognized that the hydraulic transporting system has great potential for industrial appliance and the system that adopts flexible pipe to transport mineral is the best scheme. This paper is a research on flexible pipe mineral transporting system, and the follow is the main content.Based on the requirements of flexible pipe mineral transporting system, a sort of mineral transporting equipment is invented by combining vessel with high-pressure pump for deep-sea mining. According to Bernoulli's equation, two phases hydrodynamics and principle of pipeline transporting as well as the features of vessel transporting, the designing theory of transporting equipment is established. Parameters of flexible pipe mineral transporting system for carrying minerals from 5000m sea floor to sea level as well as parameters for 1000m crust middle test mining system have been calculated and analysed. Conclusion has been reached accordingly that the combined transporting equipment is a kind of ideal designing for deep-sea mining.In real condition, the transporting pipe is moved under the draft of mining vehicle and ship, meanwhile it is under the action of the complex coupling loads that include gravity and buoyancy of the transporting pipe, the resistance caused by ocean current and pipe moving, and the force of the inner fluid exerted on the pipe. Based on gravity wave theory, the experience calculating formula of ocean current, hydrodynamics and Morsion resistance equation, the theory to analysis the moving and complex coupling loads of the transporting pipe is established. According to the established theory, the movement and the coupling loads of the system have been analysed.Based on D'Alembert principle and Newton-Raphson method, the geometric nonlinear finite element theory has been established to analysis the transporting pipe. According to the large deformation features of the transporting pipe, the tangent stiffness matrix of the pipe element and the stiffness matrix of the transporting pipe have been deduced. The geometric nonlinear static analysis for the transporting system of 1000m crust middle test mining system have been done under the hypothesis that the mining vehicle and ship moving in different modes and the transporting pipe under coupling action of different loads. The research covers the following parameters: the moving speed and mode of the mining vehicle and ship, the mining range of the mining vehicle, the forces on the two ends of the transporting pipe, the shape of the transporting pipe, how large the buoyancy of the buoy should be and how the buoyancy distributes along the transporting pipe etc.Starting with the configuration analysis of the transporting pipe, theoretic research has been done on the transporting pipe . The geometric nonlinear static analysis has been done for the 5000-meter-deep mineral transporting system under the hypothesis that the mining vehicle and ship moving in different modes and the transporting pipe under coupling action of different loads. The research covers the following parameters: the moving speed and mode of the mining vehicleand ship, the mining range of the mining vehicle, the forces on the two ends of the transporting pipe, the shape of the transporting pipe, how large the buoyancy of the buoy should be and how the buoyancy distributes along the transporting pipe etc.Based on D'Alembert principle, the dynamics analysis theory of mining transporting system has been established. Through modal analysis, the vibration features (natural frequencies) of the transporting system of 1000m middle test crust mining system and the 5000-meter-deep mineral transporting system have been determined. The harmonic response force of the transporting pipe ends has been analysed when the mineral transporting system of 1000m crust middle test mining system and the 5000-meter-deep mining system are under ocean wave force or the up end of the transporting pipe follows the ocean wave movingBased on model theory, the model equipment for the mineral transporting system has been made and through which the analysis on 5000-meter-deep mining transporting system has been done. The model experiment mechanics analysis theory of the transporting pipe has been established, and a model pipe has been selected for analysis. Experimental analysis has been made on the end forces and the shape of transporting pipe. The comparative analysis on experiments and calculating has proved that the application of finite element analysis in the mineral transporting systems is correct and believable.Through the application of advanced theories and calculating methods as well as experiments, this paper made research on the mineral transporting system for lifting minerals from 5000-meter-deep sea floor to sea level through flexible transporting pipe. The research provides an advanced technological prototype for deep-sea mining mineral transporting system and the 1000m crust middle test mining system.