FLOW CHARACTERISTICS AND PARTICLES MOTION BEHAVIOR IN SPIRAL
SHULING GAO*, DEZHOU WEI, PING FANG, ZICHUAN GUAN, BAOYU CUI &YANBAI SHEN
College of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China
ABSTRACT
Nowadays, the environmental consciousness of energy conservation and emissions reduction is growing.
As a kind of typical gravity equipment which uses the compound force field of centrifugal force and gravity to
separate, the spiral receives much concern. It is also of particular importance to carry out elaborate research on
the flow field and particles motion behavior in spiral to reveal its separating mechanism.
In this study, the flow field and particles motion behavior in spiral with diameter of 300mm are studied
systematically by numerical simulation and test methods. The water flow mainly collects on the outer rim, and
the water thickness increases gradually firstly from inner to outer, and after a sharp increasing, it decreases
closing to side walls. The flow velocity increases gradually from the bottom of the spiral to the water surface,
and reaches its maximum on the surface. Besides the flow velocity levels off at some depth which varies
depending on the radial position, and this result is consistent with experimental data trend. The turbulent kinetic
energy basically decreases gradually from the bottom to the water surface, and the difference between them are
relatively small at each radial distance except for closing to the water surface. The separation tests show that
the pulp flow is mainly discharged from tailing belt, and the volume yield is more than 90%, which are
consistent with the test results. And it is conducive to the flow layer spreading along the groove increasing the
feed concentration. The simulation results show particles with different sizes and densities zone downward
gradually from the inlet where they are dispergated, and their radial distribution rule at the outlet is consistent
with the actual separation results of hematite and quartz particles.
1.0
0.9
0.8
Relative depth
0.7
0.6
0.5
132mm
135mm
138mm
140mm
142mm
144mm
146mm
0.4
0.3
0.2
0.1
0.0
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
Flow velocity/m/s
Figure 1 – Flow velocity distribution chart at different radial distance of the end of the third turn
KEYWORDS
Spiral, CFD, Flow velocity, Particle motion behavior, Radial distance