Experimental Investigation of Large Particle Slurry Transport in Vertically Oscillating Pipe for Subsea Mining

2021 ◽  
Author(s):  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Masao Ono
Keyword(s):  
Mixture Model ◽  
Pressure Loss ◽  
Prediction Method ◽  
Axial Direction ◽  
Hydraulic Gradient ◽  
Solid Particles ◽  
Homogeneous Mixture ◽  
Pipe Model ◽  
Slurry Transport ◽  
Homogeneous Mixture Model

Abstract For subsea mining, it is important to predict the pressure loss in oscillating pipes for the safe and reliable operation of ore lifting as well as the design of lifting system. In the present paper, the authors focused on the internal flow in vertical lifting pipe oscillating in the axial direction and carried out slurry transport experiment to investigate the effects of pipe oscillation on the pressure loss. The spherical alumina beads and glass beads were used as the solid particles in the experiment, and the oscillating periods and amplitudes of pipe model as well as the solid concentrations and the mean slurry velocities were varied. The time-averaged components of hydraulic gradient calculated by the prediction method for the steady flow proposed in the past by the authors agreed well with the experimental ones. As for the fluctuating components of hydraulic gradient, the calculation results using a homogeneous mixture model were compared with the experimental data. The comparison result indicated that the homogeneous mixture model would be applicable to the prediction of pressure loss in the vertical pipe oscillating in the axial direction.

Experimental Investigation of Large Particle Slurry Transport in Vertical Pipes With Pulsating Flow

2020 ◽  
Author(s):  
Sotaro Masanobu ◽  
Satoru Takano ◽  
Shigeo Kanada ◽  
Masao Ono ◽  
Hiroki Sasagawa
Keyword(s):  
Pressure Loss ◽  
Prediction Method ◽  
Internal Flow ◽  
Glass Beads ◽  
Solid Particles ◽  
Pulsating Flow ◽  
Massive Sulfides ◽  
Pressure Losses ◽  
Transport Experiment ◽  
Slurry Transport

Abstract For subsea mining, it is important to predict the pressure loss in oscillating pipes with pulsating flow for the safe and reliable operation of ore lifting. In the present paper, the authors focused on the pulsating internal flow in static vertical pipe and carried out slurry transport experiment to investigate the effects of flow fluctuation on the pressure loss. The alumina beads and glass beads were used as the solid particles in the experiment, and the fluctuating periods and amplitudes of pulsating water flow were varied. The time-averaged pressure losses calculated by the prediction method for the steady flow proposed in the past by the authors agreed well with the experimental ones. As for the fluctuating component of pressure loss, the calculation results using the quasi-steady expression of a mixture model were compared with the experimental data. The calculated results were different from experimental ones for alumina beads of which densities are almost same as those of the ores of Seafloor Massive Sulfides. It suggests that the expression is insufficient to predict the pressure loss for heavy solid particles. The calculated ones, however, provided those in the safety side. On the other hand, the calculated results for light solid particles such as glass beads agreed well with the experimental ones. It means that the expression would be applicable to the prediction of pressure loss for the mining of manganese nodules which are lighter than the ores of Seafloor Massive Sulfides.

Numerical Modeling of Aerated Cavitation Using a Penalization Approach for Air Bubble Modeling Coupled to Homogeneous Equilibrium Model

2014 ◽  
Author(s):  
Petar Tomov ◽  
Sofiane Khelladi ◽  
Christophe Sarraf ◽  
Farid Bakir
Keyword(s):  
Fluid Flow ◽  
Mixture Model ◽  
Stokes Equations ◽  
Saturation Pressure ◽  
Homogeneous Mixture ◽  
Navier Stokes ◽  
Strain Rate Tensor ◽  
Computational Domain ◽  
Time Step ◽  
Homogeneous Mixture Model

Cavitation is a well-known physical phenomena occurring in various technical applications. It appears when the pressure of the liquid drops below the saturation pressure. Coupling aeration in a cavitating flow is a recent technique to control the overall effect of the cavitation. It is achieved by introducing air bubbles into the flow. In order to reveal and explore the behaviour of air gas in the vicinity of the cavitation region, the paper is oriented towards the physics of the colliding vapor phase bubbles and cavitating regions. The re-entrant jet may influence the dynamics of the bubbles as well as the frequency of cavitation separation. Therefore, a two-way coupling between the fluid flow and the introduced vapor is of capital importance. By penalizing the strain rate tensor in the Homogeneous Mixture Model, the two-way coupling has been achieved. The contact-handling algorithm is based on the projections of the velocity fields of the injected particles over the velocity field of the fluid flow. At each time step the gradient of the distance between the bubbles, is kept non-negative as a guarantee of the physical non overlapping. The bubbles’ collisions are considered as inelastic. The differential equations system is composed of the Navier-Stokes equations, implemented with the Homogeneous Mixture Model. A high-order Finite Volume (FV) solver based on Moving Least Squares (MLS) approximations is used. The code uses a SLAU-type Riemann solver for the accurate calculation of the low Mach numbers. The computational domain is a symmetrical 2D venturi duct with an 18°–8° convergent/divergent angles respectively.

Experimental Studies of Pressure Loss for Large Particle Slurry Transport in Oscillated Pipe for Subsea Mining

2017 ◽  
Author(s):  
Satoru Takano ◽  
Sotaro Masanobu ◽  
Shigeo Kanada ◽  
Masao Ono ◽  
Motoki Araki ◽  
...  
Keyword(s):  
Flow Rate ◽  
Pressure Loss ◽  
Large Particle ◽  
Experimental Studies ◽  
Vertical Direction ◽  
Solid Particles ◽  
Experimental Conditions ◽  
Scaled Model ◽  
Riser Pipe ◽  
Slurry Transport

Subsea minerals exist in the deep water within Japanese exclusive economic zone. Development of slurry pump passing large particles is required for lifting ore. In design of slurry pump, it is significant to estimate the pressure loss in a riser pipe for large particle slurry transport. Therefore the authors have been studied the slurry flow model for large particle slurry transport. In addition, the authors developed the model for the static pipe including the inclined configurations. Since the lifting pipe will be oscillated due to the connected ship motion and VIV (Vortex Induced Vibration), the authors conducted the scaled model experiment to investigate the effects of pipe oscillation on the pressure loss. The model scale was 1/8. Alumina beads and glass beads were used as solid particles in the experiment. The pipe was vertical, and oscillated in horizontal or vertical direction. The experimental results showed that the horizontal and vertical oscillation had little influence on the static pressure loss in most of the experimental conditions. However the influence was observed for the horizontally oscillating pipe in the low slurry velocity and short oscillation period condition. On the other hand, the significant fluctuation components of pressure loss and flow rate were observed in vertically oscillating pipe. The results also indicated that the density of slurry and amplitude of oscillation had influence on the fluctuation components of pressure loss and flow rate but the particle diameters had little influence on them.

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