US3831381A — Lubricating and sealing system for a rotary power…

Claim 1

Independent Claim 285 words

In a system of the type wherein a working fluid comprising a plurality of constituents 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 a labyrinth seal in said rotor housing surrounding a portion of said shaft adjacent said rotor for sealing said rotor housing around said shaft, said rotor housing having a seal fluid passageway therethrough for injecting a seal fluid into said seal around said shaft intermediate the axial extremities of the seal, said seal fluid comprising one of the constituents of said working fluid and 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 containing said working fluid under a working pressure lower than said seal fluid as injected, a shaft housing enclosing said shaft adjacent said seal and defining a lubricant zone on the other side of said seal, said lubricant zone including a mixing area between said seal and said first bearing assembly and maintained under pressure lower than the pressure of said seal fluid passageway, whereby said seal fluid will leak into both said process zone and said mixing area and will prevent intermingling of said working fluid and said lubricant.

Claim 2

Dependent Claim 285 words

In a system of the type wherein a working fluid comprising a plurality of constituents 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 a labyrinth seal in said rotor housing surrounding a portion of said shaft adjacent said rotor for sealing said rotor housing around said shaft, said rotor housing having a seal fluid passageway therethrough for injecting a seal fluid into said seal around said shaft intermediate the axial extremities of the seal, said seal fluid comprising one of the constituents of said working fluid and 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 containing said working fluid under a working pressure lower than said seal fluid as injected, a shaft housing enclosing said shaft adjacent said seal and defining a lubricant zone on the other side of said seal, said lubricant zone including a mixing area between said seal and said first bearing assembly and maintained under pressure lower than the pressure of said seal fluid passageway, whereby said seal fluid will leak into both said process zone and said mixing area and will prevent intermingling of said working fluid and said lubricant.

Claim 3

Dependent Claim 47 words

A system according to claim 1 wherein said seal fluid is separable from said working fluid and said lubricant, said system further including means for recovering said seal fluid from said lubricant and from said working fluid and for recycling said seal fluid through said labyrinth seal.

Claim 4

Dependent Claim 79 words

A system according to claim 2 wherein the pressure in said first bearing assembly is higher than the adjacent pressures in said lubricant zone whereby said seal fluid is prevented from flowing axially past said first bearing assembly, said seal fluid is substantially more volatile than said lubricant, and the pressure of said mixing area is such that said seal fluid is in a gaseous state and said lubricant is in a liquid state at said mixing area pressure.

Claim 5

Dependent Claim 119 words

A system according to claim 3 including a separating chamber, mixture vent and drain means connecting said mixing area with said separating chamber such that said lubricant and said seal fluid can flow from said mixing area into said separating chamber, said separating chamber being maintained at substantially the same pressure as said mixing area, means for limiting the level of said lubricant in said separating chamber to a predetermined level less than the full volume of said separating chamber, whereby the major portion of said seal fluid separates from said lubricant in said separating chamber and occupies the space above said maximum depth level in said separating chamber, and means for removing said seal fluid from said space.

Claim 6

Dependent Claim 130 words

A system according to claim 4 further comprising a lubricant reservoir, a lubricant conduit connecting said lubricant reservoir to said separating chamber below said maximum depth level, and means for selectively opening said conduit when said lubricant tends to rise above said maximum depth level to allow flow of lubricant from said separating chamber to said lubricant reservoir, wherein the pressure in said lubricant reservoir is substantially lower than the pressure in said separating chamber whereby any of said seal fluid which is contained in liquid form in the lubricant flowing through said lubricant conduit flashes to a gaseous state in said lubricant reservoir and collects in an upper part of said reservoir, said system further comprising means for drawing said seal fluid from the upper part of said reservoir.

Claim 7

Dependent Claim 45 words

A system according to claim 4 wherein said seal fluid removing means comprises a seal fluid conduit connecting said space above said maximum depth level in said separating chamber with a seal fluid collecting duct of lower pressure than the pressure in said separating chamber.

Claim 8

Dependent Claim 106 words

A system according to claim 5 wherein said seal fluid removing means comprises a seal fluid conduit connecting said space above said maximum depth level in said separating chamber with a seal fluid collecting duct of lower pressure than the pressure in said separating chamber but greater than the pressure in said lubricant reservoir, and wherein said seal fluid drawing means comprises a compressor operative to draw said seal fluid from said upper part of said reservoir and direct said seal fluid into said seal fluid collecting duct while increasing the pressure of said seal fluid from that of said reservoir to that of said duct.

Claim 9

Dependent Claim 30 words

A system according to claim 1 wherein said seal gas is comprised of a lightest one of said constituents and is substantially free of the heavier ones of said constituents.

Claim 10

Dependent Claim 60 words

A system according to claim 6 wherein said rotary machine is a turboexpander operative to expand said working fluid and said seal is comprised of a lightest one of said constituents and is substantially free of the heavier ones of said constituents, and wherein said seal fluid collecting duct is in equal pressure communication with the outlet of said turboexpander.

Claim 11

Dependent Claim 103 words

A system according to claim 8 wherein said rotary machine is a turboexpander operative to expand said working fluid, said system further including a countercurrent hEat exchanger for vaporizing said working fluid, feed means for feeding said vaporized working fluid into the inlet of said turboexpander, said heat exchanger having tap means located at a point in said heat exchanger at which a major part of a vaporized portion of the working fluid is comprised of said lightest constituent, said tap means allowing escape of said vaporized portion and a seal fluid line communicatively connecting said tap means with said seal fluid passageway.

Claim 12

Dependent Claim 44 words

A system according to claim 10 wherein said seal fluid line includes a seal fluid condenser between said tap means and said seal fluid passageway for liquefying at least a fraction of the vaporized portion of said working fluid escaping through said tap means.

Claim 13

Dependent Claim 34 words

A system according to claim 11 further including a seal fluid storage tank connected to said seal fluid condenser for storing a quantity of said liquefied fraction to serve as a seal fluid reserve.

Claim 14

Dependent Claim 43 words

A system according to claim 12 further including a reserve line connecting said seal fluid storage tank to said seal fluid line downstream of said seal fluid condenser, and valve means in said reserve line operative to open and close said reserve line.

Claim 15

Dependent Claim 80 words

A system according to claim 11 further including a fractionating tower in said seal fluid line immediately adjacent said tap means and having its lower end connected to said tap means, a reflux line connecting a liquid containing portion of said seal fluid condenser to the upper end of said fractionating tower, and wherein a segment of said seal fluid line further connects the upper end of said fractionating tower to a vapor containing portion of said seal fluid condenser.

Claim 16

Dependent Claim 30 words

A system according to claim 5 wherein said shaft housing has lubricant vent and drain means adjacent said first bearing assembly opposite said mixing area and leading to said reservoir.

Claim 17

Dependent Claim 26 words

A system according to claim 15 including a second bearing assembly supporting said shaft, said lubricant vent and drain means being located between said bearing assemblies.

Claim 18

Dependent Claim 83 words

A system according to claim 16 wherein said shaft housing has a vent located adjacent said second bearing assembly opposite said lubricant vent and drain means, said system further including auxiliary lubricant collection means between said second bearing assembly and said vent and connected to said reservoir for collecting said lubricant and returning it to said reservoir and having a control valve mechanism operative to substantially prevent exchange of gases between said reservoir and said shaft housing through said auxiliary lubricant collection means.

Claim 19

Dependent Claim 91 words

A system according to claim 9 including a countercurrent heat exchanger for vaporizing said working fluid, a working fluid line connecting said duct and said outlet end of said turboexpander to a cool end of said heat exchanger, said working fluid line including a working fluid condenser for liquefying said seal fluid and the working fluid flowing from the outlet end of said turboexpander; and a working fluid pump for directing said working fluid, including said seal fluid, through said working fluid line to said cool end of said heat exchanger.

Claim 20

Dependent Claim 24 words

A system according to claim 1 wherein said rotary machine is a turboexpander operative to expand said working fluid and thereby drive said shaft.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-08-26	1978-02-25	1978-08-27	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-08-26	1982-02-25	1982-08-27	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-08-26	1986-02-25	1986-08-27	$7700.00	Window Closed / Lapsed

Lubricating and sealing system for a rotary power plant

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