Design and Operation
A two-phase nozzle converts fluid pressure into a high-velocity, homogeneous jet. The jet impinges near-tangentially onto the inner surface of a drum rotor. Viscous coupling between the liquid and the moving drum surface transfers power to the rotor. Rotation of the drum and the vortex flow of the fluids create an effective high "g" separation field. The gas disengages from the liquid and can pass through impulse blading to recover additional energy, if required. The RST Bi-Phase separator is designed to handle full well stream conditions including sand and scale.

First Commercial Installation
In 2000 and 2001, Dresser-Rand, together with a leading international oil and gas exploration and production company, undertook a series of tests of a 20/30/600 model RST Bi-Phase separator concept package installed on a TLP located in the Gulf of Mexico. The unit demonstrated a separation efficiency of up to 99.9 percent during a wide range of mass flow, GOR, watercut, temperature, and rotation speeds. As a result of the successful testing, the first commercial RST Bi-Phase separator package was designed, assembled and installed on a TLP located in the Gulf of Mexico early in 2003. The new commercial package is a motor-driven unit suitable for both high-pressure and low-pressure operation, directly from the well head manifold with minimum differential. The package comprises the Bi-Phase separtator, electric drive motor, integrated lube and seal oil system, and a full control and monitoring system. Companies in the oil and gas industries are beginning to experience the benefits of RST technology.