Vertical Flow Centrifugal Separator -- Effects of Geometry

Abstract

The vertical flow centrifugal separator (VFCS) is a device for separating gas liquid streams at high pressure. It has been investigated as a possible alternative to the above surface cyclone separator conventionally used for a geothermal installation, particularly where a geofluid has a high non condensable gas content. the VFCS would be installed down a well just above the flashing level and would separate the fluid into a liquid stream which would later flash into a water/steam mixture as it progressed up the well bore, and a gas rich gas/steam stream which would be transmitted to the surface via a gas tube. The two separate fluid streams would then be utilized as required. Early work on an above surface model using fluid from a Broadlands geothermal well had demonstrated that the device was capable of performing its designed function. The work reported in this paper demonstrates the effect of the VFCS geometry on the efficiencies of separation. It is concluded that a vortex blade exit angle close to zero is desired and that, for a geothermal installation downhole, a large gas tube diameter is preferred.