US3931718A — Refrigerant screw compression with liquid refrige…

Claim 1

Independent Claim 137 words

A closed cycle refrigeration system, comprising an evaporator receiving liquid refrigerant and gasifying it, a rotary compressor receiving at its inlet side the refrigerant gas from the evaporator and compressing it, a condenser receiving the compressed gas discharged by the compressor and condensing it, means delivering at least a portion of the liquid refrigerant from the condensor outlet back to the discharge side of the compressor, and a second liquid line conducting liquid refrigerant from the inlet side of the compressor back to the evaporator, the liquid refrigerant returned to the compressor in said first liquid line traveling through the compressor to said second liquid line by way of the rotor clearance gaps in the compressor; and means including an expansion valve for delivering the remaining portion of liquid refrigerant from the condensor outlet to the evaporator.

Claim 2

Dependent Claim 137 words

A closed cycle refrigeration system, comprising an evaporator receiving liquid refrigerant and gasifying it, a rotary compressor receiving at its inlet side the refrigerant gas from the evaporator and compressing it, a condenser receiving the compressed gas discharged by the compressor and condensing it, means delivering at least a portion of the liquid refrigerant from the condensor outlet back to the discharge side of the compressor, and a second liquid line conducting liquid refrigerant from the inlet side of the compressor back to the evaporator, the liquid refrigerant returned to the compressor in said first liquid line traveling through the compressor to said second liquid line by way of the rotor clearance gaps in the compressor; and means including an expansion valve for delivering the remaining portion of liquid refrigerant from the condensor outlet to the evaporator.

Claim 3

Dependent Claim 14 words

A refrigeration system according to claim 1, wherein the compressor is a screw compressor.

Claim 4

Dependent Claim 27 words

A refrigeration system according to claim 1, wherein the liquid is injected into the compressor near the compressed gas delivery port and leaves near the gas inlet.

Claim 5

Dependent Claim 29 words

A refrigeration system according to claim 1, wherein the clearances within the compressor are larger at the low pressure end of the machine than at the high pressure end.

Claim 6

Dependent Claim 27 words

A refrigeration system according to claim 1, wherein counter flow of liquid and gas takes place in the same pipe line at the inlet to the compressor.

Claim 7

Dependent Claim 41 words

A refrigeration system according to claim 1, wherein a bypass passage, including said expansion valve, is provided through which a proportion of the liquid from the condenser can flow back to the evaporator without passing through the compressor rotor clearance gaps.

Claim 8

Dependent Claim 21 words

A refrigeration system according to claim 1, wherein the liquid is fed into the compressor at a plurality of entry points.

Claim 9

Dependent Claim 22 words

A refrigeration system according to claim 1, wherein the liquid inlet port comprises a plug of porous material such as sintered metal.

Claim 10

Dependent Claim 20 words

A refrigeration system according to claim 1, wherein the liquid refrigerant is employed to lubricate the bearings of the compressor.

Claim 11

Dependent Claim 25 words

A refrigeration system according to claim 1, wherein the compressor rotors are geared to one another and the gears are bathed in the liquid refrigerant.

Claim 12

Dependent Claim 20 words

A refrigeration system according to claim 1, wherein the inside of the compressor casing is roughened to retain liquid refrigerant.

Claim 13

Dependent Claim 117 words

A process of gas compression in an oil-free refrigeration system wherein a screw compressor draws gas into an inlet on its low-pressure side from an evaporator and delivers compressed gas from a delivery port at its high-pressure side into a condenser, including the steps of withdrawing part of the liquid phase of the gas being compressed from the liquid condensed in the condenser, injecting said withdrawn liquid into the compressor at a pressure point near its delivery port on the high-pressure side of the compressor whereby injected liquid is driven toward the low-pressure side of the compressor by the differential pressure across the compressor and liquid arriving at its inlet port is delivered directly to the evaporator.

Claim 14

Dependent Claim 117 words

A process of gas compression in an oil-free refrigeration system wherein a screw compressor draws gas into an inlet on its low-pressure side from an evaporator and delivers compressed gas from a delivery port at its high-pressure side into a condenser, including the steps of withdrawing part of the liquid phase of the gas being compressed from the liquid condensed in the condenser, injecting said withdrawn liquid into the compressor at a pressure point near its delivery port on the high-pressure side of the compressor whereby injected liquid is driven toward the low-pressure side of the compressor by the differential pressure across the compressor and liquid arriving at its inlet port is delivered directly to the evaporator.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-01-12	1979-07-14	1980-01-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-01-12	1983-07-14	1984-01-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-01-12	1987-07-14	1988-01-13	$7700.00	Window Closed / Lapsed

Refrigerant screw compression with liquid refrigerant injection

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