Simulation of Oil-Water Two-Phase Steam Separation During Coal Pyrolysis Process by the Cyclone

According to the characteristics that the pyrolysis products of lignite exist in the form of vapor before cooling and the density difference between oil vapor and water vapor is large, thus oil-water separation can be realized by using cyclone separation process. In this paper, the Euler multiphase flow model is established by means of numerical simulation to study the influence of parameters on separation performance in the designed cyclone separator (overflow split ratio 0.25), and explored the effects of inlet velocity and water content on the volume distribution characteristics, radial pressure drop, tangential velocity, axial velocity and separation efficiency of oil vapor and water vapor in the cylindrical section of the cyclone separator. The results show that the oil vapor with higher density mainly flows out from the bottom outlet of the cyclone separator, while the water vapor and purge gas with lower density flow out from the overflow outlet. The inlet velocity increase will promote the stratification of oil vapor and water vapor in the cylindrical section of the designed cyclone separator, and the oil content in the cylindrical section will increase from 27.05% to 64.37%. In addition, when the inlet velocity increases from 2.0m/s to 12.0 m/s, the sweep range of the forced vortex zone increases from 10.2 mm to 22.25 mm, and the separation efficiency gradually increases from 27.66% to 91.88%.