Seal system and method

Claim 2

In a system including a working chamber closed to the exterior except for a working fluid inlet and outlet and a shaft passing through an opening in a wall of the chamber, said chamber containing a captive working fluid subject to being evaporated and condensed under pressures and temperatures within predetermined ranges to be employed in the system during operation, and a seal means for preventing escape of said working fluid from said chamber along said shaft, said seal means comprising a lubricant type bearing seal spaced from said chamber with means for injecting lubricant into said bearing seal intermediate its extremities and under pressure greater than the working pressure within said chamber so that part of the lubricant injected will flow in said bearing seal toward said chamber, means for trapping lubricant flowing from said bearing seal toward said chamber before it reaches said chamber, a labyrinth type seal between said chamber and said trapping means, means for injecting a seal fluid into said labyrinth type seal with a portion of the labyrinth seal between the chamber and the point of such injection, and at a pressure great enough to cause the seal fluid to flow toward said chamber and thereby prevent escape of working fluid through said labyrinth type seal means to the point of injection of seal fluid, and cause part of the seal fluid to flow toward and into said trapping means and thereby prevent the flow of lubricant toward said chamber through said labyrinth seal, the improvement which comprises a separator in communication with said trapping means for receiving and separating from one another a mixture of said lubricant and seal fluid so received, condenser means connected to receive such seal fluid as flows through said labyrinth type seal toward said chamber, and for cooling said mixture to condense and separate working fluid from the seal fluid, said means for injecting seal fluid being connected to draw seal fluid from the seal fluid from said separator and condenser means.

Claim 3

A system as set forth in claim 1 in which the point of injection of the seal fluid is at the opposite end of the labyrinth type seal from said chamber.

Claim 4

A system as set forth in claim 1 in which the point of injection of the seal fluid is directly into said trapping means.

Claim 5

A system as set forth in claim 1 in which the point of injection of the seal fluid is at an intermediate point along the length of the labyrinth type seal.

Claim 6

The improvement set forth in claim 1 in which said seal fluid is nonreactive and not significantly soluble in either the working fluid or the lubricant.

Claim 7

The improvement set forth in claim 1 in which said seal fluid is nonreactive and not significantly soluble in either the working fluid or the lubricant and is of a nature that it is gaseous throughout said pressure and temperature ranges.

Claim 8

The improvement set forth in claim 1 in which said predetermined pressure range is superatmospheric throughout the range.

Claim 9

The improvement set forth in claim 7 in which the lubricant type seal separates said seal fluid under superatmospheric pressure less than its highest pressure, from ambient atmospheric pressure externally of said system.

Claim 10

The improvement set forth in claim 8 in which a portion of the lubricant leakage from said lubricant type bearing seal is directly to the ambient atmospheric pressure and temperature externally of the system, in combination with means for reinjecting said lubricant into the lubricant containing portion of said separator.

Claim 11

The improvement set forth in claim 9 in which the space into which said lubricant leakage occurs is enclosed except for an annular labyrinth type opening around said shaft through which it is exposed to the exterior of the system, an auxiliary mechanical seal means engageable within and throughout a speed range of said shaft from zero r.p.m. to a rotary speed less than the normal operative speed of said shaft, to provide a complete mechanical seal of said annular space during periods of nonoperation of the system, so as to prevent leakage of lubricant, seal gas, and working fluid through said annular space when the system is not in operation.

Claim 12

In a system including a working chamber closed to the exterior except for a working fluid inlet and outlet and a shaft passing through an opening in a wall of the chamber, said chamber containing a captive working fluid subject to being evaporated and condensed under pressures and temperatures within predetermined ranges to be employed in the system during operation, and a seal means for preventing escape of said working fluid from said chamber along said shaft, said seal means comprising a lubricant type bearing seal spaced from said chamber with means for injecting lubricant into said bearing seal intermediate its extremities and under pressure greater than the working pressure within said chamber so that part of the lubricant injected will flow in said bearing toward said chamber, means for trapping lubricant flowing from said bearing seal toward said chamber before it reaches said chamber, a labyrinth type seal between said chamber and said trapping means, means for injecting a seal fluid into said labyrinth type seal with a portion of the labyrinth seal between the chamber and the point of such injection, and at a pressure great enough to cause the seal fluid to flow toward said chamber and thereby prevent escape of working fluid through said labyrinth type seal means to the point of injection of seal fluid, and cause part of the seal fluid to flow toward and into said trapping means and thereby prevent the flow of lubricant toward said chamber through said labyrinth seal, the improvement which comprises a separator in open communication with said trapping means for receiving and separating from one another a mixture of said lubricant and seal fluid so received, condenser means in open communication with said labyrinth seal between the point of injection of said seal fluid and said chamber to receive such seal fluid as it flows through said labyrinth type seal toward and before it reaches said chamber, together with seal fluid from said separator, and for cooling said mixture to condense and separate any working fluid from the seal fluid, said means for injecting being connected to draw seal fluid from seal fluid from which working fluid has been so separated.

Claim 13

In a system including a working chamber closed to the exterior except for a working fluid inlet and outlet and a shaft passing through an opening in a wall of the chamber, said chamber containing a captive working fluid subject to being evaporated and condensed under pressures and temperatures within predetermined ranges to be employed in the system during operation, and a seal means for preventing escape of said working fluid from said chamber along said shaft, said seal means comprising a lubricant type bearing seal spaced from said chamber with means for injecting lubricant into said bearing seal intermediate its extremities and under pressure greater than the working pressure within said chamber so that part of the lubricant injected will flow in said bearing toward said chamber, means for trapping lubricant flowing from said bearing seal toward said chamber before it reaches said chamber, a labyrinth type seal between said chamber and said trapping means, means for injecting a seal fluid into said labyrinth type seal with a portion of the labyrinth seal between the chamber and the point of such injection, and at a pressure great enough to cause the seal fluid to flow toward said chamber and thereby prevent escape of working fluid through said labyrinth type seal means to the point of injection of seal fluid, and cause part of the seal fluid to flow toward and into said trapping means and thereby prevent the flow of lubricant toward said chamber through said labyrinth seal, the improvement which comprises a separator in open communication with said trapping means for receiving and separating from one another a mixture of said lubricant and seal fluid so received, condenser means in open communication with said labyrinth seal between the point of injection of said seal fluid and said chamber to receive such seal fluid as it flows through said labyrinth type seal toward and before it reaches said chamber, together with seal fluid from said separator, and for cooling said mixture to condense and separate any working fluid from the seal fluid, said means for injecting being connected to draw seal fluid from seal fluid from which working fluid has been so separated.

Claim 14

The improvement set forth in claim 11 in which said seal fluid is of a nature that is gaseous throughout said pressure and temperature ranges.

Claim 15

The improvement set forth in claim 11 in which said means for injecting is capable of maintaining a pressure in said condenser lower than that in said chamber.

Claim 16

The improvement set forth in claim 11 in which said means for injecting propels said seal fluid through a cycle including the labyrinth seal means, sump, separator and condenser, said cycle being closed against escape of seal fluid to the atmosphere.

Claim 19

The method of claim 15 in which the seal fluid flowing from its point of injection toward said chamber is drawn off before it reaches said chamber and chilled to separate any working fluid therefrom.

Claim 20

The method of claim 15 in which the lubricant and working fluid separated from the seal fluid are collected into reserve liquid bodies separated from one another pending reinjection and the seal fluid from which they are separated is collected over said lubricant and working fluid liquid bodies with an interface therewith pending reinjection.