In view of the problem of low efficiency caused by the large amount of sand contained in the natural gas hydrate of the seabed in process of hydrates mining in the solid-state flow method, a novel separation process was presented based on the solid fluidization, and a hydrocyclone used for submarine gas-hydrate slurry was designed based on the properties of seabed gas-hydrate and the multiphase flow theory. The effects of particle (sands and gas-hydrate) size, inlet flux of slurry, and sands concentration in gas-hydrate slurry on separation efficiency and pressure drop were simulated by CFD. The results showed that the separation efficiencies of sand and gas-hydrate were more than 60%, and the maximum was 98.72%, the pressure drop was within 0.5 MPa, and the lowest was 0.03 MPa with the hydrocyclone at the conventional condition. The separation efficiency of sand increased first and then unchanged when particle size was increased. When inlet slurry flux was increased, the sand separation efficiency first increased and then decreased. When sand concentration in slurry was increased, the separation efficiency was always decreased. The separation efficiency of gas-hydrate increased first and then unchanged with increasing particle size and inlet slurry flux. When increasing sands concentration in slurry, the separation efficiency of gas-hydrate was decreased. The pressure drops in the overflow and underflow outlet were almost unchanged when particle size was increased, and increased with the sands concentration in slurry and inlet slurry flux increased. It was revealed and verified that the particle size, inlet slurry flux, and the sand concentration had great influence on the performance of the hydrocyclone. The separation performance was very good when the sand size was greater than 20 ?m, the hydrate size was greater than 40 ?m, the inlet slurry flux was about 5 m3/h, and the sand concentration was no more than 25vol%.
Shunzuo QIU Guorong WANG Guangshen WANG Shouwei ZHOU Qingyou LIU Lin ZHONG Leizhen WANG
. Effects of hydrocyclone separation on purification of natural gas-hydrate slurry and sand remove[J]. The Chinese Journal of Process Engineering, 2019
, 19(1)
: 64
-72
.
DOI: 10.12034/j.issn.1009-606X.218154
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