Sealed rotary system and method

In a system of the type wherein a working fluid is passed through a rotary machine, wherein said machine comprises a rotor housing, a rotor within said rotor housing integrally connected to and, in operation, rotating with a shaft on a common axis of rotation, wherein said shaft extends from said rotor housing and is supported by a first bearing assembly externally of the rotor housing, and wherein a lubricant is injected under pressure into said first bearing assembly and caused to flow through the first bearing assembly around said shaft and therefrom axially toward said rotor:

• the improvement which comprises seal means in said rotor housing surrounding a portion of said shaft adjacent said rotor for sealing said rotor housing around said shaft, means for separating seal fluid from said working fluid, means for injecting said separated seal fluid into said seal means around said shaft intermediate the axial extremities of the seal means, said seal fluid being non-reactive with said working fluid and said lubricant, the interior of said rotor housing defining a process zone on one side of said seal means containing said working fluid under a working pressure lower than said seal fluid as injected, a shaft housing enclosing said shaft adjacent said seal means and defining a lubricant zone on the other side of said seal means, said lubricant zone including a contact area between said seal means and said first bearing assembly and maintained under pressure lower than the pressure of said seal fluid as injected, whereby said seal fluid will leak into both said process zone and said contact area and will prevent intermingling of said working fluid and said lubricant.