Numerical Simulation Study on the Flow Field and Separation Efficiency by Built-In Twisted Tape in the Hydrocyclone

Aiming at the separation of mud and sand in natural gashydrate,for the designed built-in twisted tape hydrocyclone, the numericalsimulation method was used to study the effects of different typesof built-in twisted tape and operating conditions on the internalflow field of the hydrocyclone, separation efficiency, and influenceof hydrate particle size distribution. The research results show thatthe built-in twisted tape has the same swirling direction as the hydrocyclone,which is beneficial to improving the swirling intensity, and the abilityto carry and separate solid particles is obviously enhanced. The built-intwisted tape hydrocyclone with a length of 300 mm has better separationefficiency and internal flow field stability. By changing the conditionsof the inlet velocity and the initial concentration of hydrate particles,the comparison shows that when the inlet velocity is 8 m/s, the volumeof mud and sand is 25%, the initial concentration of hydrate particlesis 15%, and the built-in tape is 300 mm long. The tape hydrocyclonehas the best separation efficiency. Compared with the basic hydrocyclone,the built-in twisted tape hydrocyclone with a length of 300 mm increasesthe separation efficiency of mud and sand by 7.49%, while the pressuredrop only increases by 2.67%, showing the superiority of the built-intwisted tape structure.