Effect of Structural Parameters on the Performance of Axial-Flow Inlet Hydrocyclones for In Situ Desanding from Natural Gas Hydrate Mixed Slurry

Structural parametersplay a decisive role in the performance ofhydrocyclones for in situ natural gas hydrate (NGH) recovery and desanding.In this paper, the effects of key structural parameters on its performancewere investigated by numerical simulations and experimental methods.The results show that the most influential factors are the spiralpitch of the spiral inlet, the vortex finder diameter, and the spigotdiameter. The second most influential factors are the spiral turnnumber and the cone angle. Other parameters have the least influence.Specifically, the NGH recovery efficiency and pressure drop increase,but desanding efficiency decreases as d (0)/D and the cone angle increase. The NGH recoveryefficiency and pressure drop decrease and desanding efficiency increasesas d (s)/D increases. Therefore,it is necessary to choose a suitable value to balance the efficiencyand pressure drop to improve the performance, for example, selectingthe appropriate diameter ratio of the vortex finder and spigot. Theabove results can be used for the engineering design of in situ separatorsin marine hydrate mining and further realize in situ desanding, NGHrecovery, and sand backfilling.