Patent US4608818A successfully refreshed from Google Patents.
US4608818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Medium-load power-generating plant with integrated coal gasification plant
Assignee: Kraftwerk Union AG
•
Filing: 1984-05-25
•
Granted: 1986-09-02
•
Expires: 2004-05-25
Abstract
Abstract Medium-load power generating plant with an integrated coal gasification plant, with a gas-turbine power generating plant part connected to the coal gasification plant, with a steam generating plant part connected to the raw-gas heat exchanger installation of the coal gasification plant, and with a methanol synthesis plant. The methanol synthesis plant has parallel-connected modules and is connected to the gas-turbine power generating plant part via a central purified gas distribution system which includes a purified gas continuous-flow interim storage plant connected parallel to the pure gas supply line and is connected on the gas side to the raw-gas heat exchanger installation.
Inventors
- 👤 Konrad Goebel
- 👤 Rainer Muller
- 👤 Ulrich Schiffers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:14
CPC Classifications
F; F01; F01K; F01K23/00; F01K23/02; F01K23/06; F01K23/067; F01K23/068; C; C07; C07C; C07C29/00; C07C29/15; C07C29/151; C07C29/1516; C07C29/1518; F02; F02C; F02C3/00; F02C3/20; F02C3/26; F02C3/28; Y; Y02; Y02E; Y02E20/00; Y02E20/16; Y02E20/18; Y02P; Y02P20/00; Y02P20/10; Y02P20/129
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
310 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, wherein the purified gas continuous-flow interim storage plant contains a low-pressure accumulator connected via a charging valve to the purified gas supply line and a high-pressure accumulator connected via a discharge valve to the purified gas supply line, which accumulators are connected to each other via a pressure-increasing compressor for keeping the pressure in the pure-gas supply line constant, as a control and interim storage plant (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system.
Claim 2
Independent Claim
310 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, wherein the purified gas continuous-flow interim storage plant contains a low-pressure accumulator connected via a charging valve to the purified gas supply line and a high-pressure accumulator connected via a discharge valve to the purified gas supply line, which accumulators are connected to each other via a pressure-increasing compressor for keeping the pressure in the pure-gas supply line constant, as a control and interim storage plant (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system.
Claim 3
Independent Claim
291 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, wherein the raw gas heat exchanger installation comprises three heat exchangers, of which the first and the third serve for generating steam and the second serves for preheating the purified gas flowing into the combustion chamber of the gas turbine of the gas turbine power generation plant, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system.
Claim 4
Independent Claim
291 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, wherein the raw gas heat exchanger installation comprises three heat exchangers, of which the first and the third serve for generating steam and the second serves for preheating the purified gas flowing into the combustion chamber of the gas turbine of the gas turbine power generation plant, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system.
Claim 5
Dependent Claim
116 words
Medium-load power generating plant according to claim 2, wherein the steam power generating plant with the steam turbine coupled to an electric generator are connected to the first and third heat exchangers for supplying at least part of the steam for driving the steam turbine, and wherein the heat exchange surfaces of the first and third heat exchangers are sufficient, with the gas turbine of the gas turbine power plant shut down and the coal gasification plant running, to extract adequate heat from the raw gas passing through said heat exchangers to generate steam to drive the steam turbine and maintain the internal electric supply of the coal gasification plant and of the methanol synthesis plant.
Claim 6
Dependent Claim
38 words
Medium-load power-generating plant according to claim 2, wherein the third heat exchanger is provided with adequate heating surface to take up the raw gas heat which is additionally produced under partial load or shutdown of the gas turbine.
Claim 7
Dependent Claim
38 words
Medium-load power-generating plant according to claim 3, wherein the third heat exchanger is provided with adequate heating surface to take up the raw gas heat which is additionally produced under partial load or shutdown of the gas turbine.
Claim 8
Independent Claim
283 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system, wherein the not completely reacted synthesis exhaust gas of at least one of the modules of the methanol synthesis plant can be returned by means of a loop compressor via a hydrogen enrichment stage into a methanol synthesis reactor.
Claim 9
Independent Claim
283 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system, wherein the not completely reacted synthesis exhaust gas of at least one of the modules of the methanol synthesis plant can be returned by means of a loop compressor via a hydrogen enrichment stage into a methanol synthesis reactor.
Claim 10
Independent Claim
290 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system, and (j) a mixing section into which the synthesis gas which is not fully reacted in a synthesis reactor of at least one module of the methanol synthesis plant can be fed to the purified gas supply line leading to the gas turbine power-generating plant part.
Claim 11
Independent Claim
290 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system, and (j) a mixing section into which the synthesis gas which is not fully reacted in a synthesis reactor of at least one module of the methanol synthesis plant can be fed to the purified gas supply line leading to the gas turbine power-generating plant part.
Claim 12
Dependent Claim
48 words
Medium-load power-generating plant according to claim 6, including connecting means for feeding the not completely reacted synthesis exhaust gas of at least one module of the methanol synthesis plant into a recirculation line leading back to a synthesis reactor of the other modules to accelerate the starting thereof.
Claim 13
Dependent Claim
48 words
Medium-load power-generating plant according to claim 7, including connecting means for feeding the not completely reacted synthesis exhaust gas of at least one module of the methanol synthesis plant into a recirculation line leading back to a synthesis reactor of the other modules to accelerate the starting thereof.
Claim 14
Independent Claim
286 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system, and (j) a bleed line from a recirculation line of a module of the methanol synthesis plant for the passage of synthesis exhaust gas to a steam generator wherein the exhaust gas is burned and steam generated by the heat of combustion.
Claim 15
Independent Claim
286 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system, and (j) a bleed line from a recirculation line of a module of the methanol synthesis plant for the passage of synthesis exhaust gas to a steam generator wherein the exhaust gas is burned and steam generated by the heat of combustion.
Claim 16
Dependent Claim
48 words
Medium-load power-generating plant according to claim 6, including a bleed line from a recirculation line of a module of the methanol synthesis plant for the passage of synthesis exhaust gas to a steam generator wherein the exhaust gas is burned and steam generated by the heat of combustion.
Claim 17
Independent Claim
292 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, including a second gas turbine coupled with a generator in addition to the gas turbine and generator of the gas turbine generating power plant for supplying the internal electric energy requirements by burning residual gas, largely reacted by recirculation, from the individual modules of the methanol synthesis plant, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system.
Claim 18
Independent Claim
292 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, including a second gas turbine coupled with a generator in addition to the gas turbine and generator of the gas turbine generating power plant for supplying the internal electric energy requirements by burning residual gas, largely reacted by recirculation, from the individual modules of the methanol synthesis plant, (h) a steam power generating plant having a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (i) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system.
Claim 19
Dependent Claim
55 words
Medium-load power-generating plant according to claim 6, including a second gas turbine coupled with a generator in addition to the gas turbine and generator of the gas turbine generating power plant, for supplying the internal electric energy requirements by burning residual gas, largely reacted by recirculation, from the individual modules of the methanol synthesis plant.
Claim 20
Dependent Claim
25 words
Medium-load power-generating plant according to claim 2, including a water-cooled regulating cooler for keeping the raw-gas output temperature of the raw-gas heat exchanger installation constant.
Claim 21
Independent Claim
302 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a first air compressor connected to supply air to the gas-turbine power generating plant and an air-separation plant associated with the coal gasifier, at least one additional air compressor which is connected parallel to the first air compressor and by which the supply of the air to the air-separation plant preceding the coal gasifier can be supplemented, (i) a steam power generating plant havng a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (j) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system.
Claim 22
Independent Claim
302 words
A medium-load power generating plant with an integrated coal gasification plant comprising (a) a coal gasification plant for producing raw hot fuel gas-containing carbon monoxide and hydrogen, (b) a raw gas heat exchanger installation having a first raw gas heat exchanger for indirect heat exchange between the hot raw gas from the coal gasification plant with feedwater to generate steam, (c) a gas purifier for purifying the raw gas, (d) a central purified gas distribution system, (e) a purified gas supply line connected to the raw gas heat exchanger installation and passing into the central purified gas distribution system, (f) a purified gas continuous-flow interim storage plant connected parallel to the purified gas supply line, (g) a gas turbine power generating plant connected to the coal gasification plant to receive fuel via the purified gas supply line, (h) a first air compressor connected to supply air to the gas-turbine power generating plant and an air-separation plant associated with the coal gasifier, at least one additional air compressor which is connected parallel to the first air compressor and by which the supply of the air to the air-separation plant preceding the coal gasifier can be supplemented, (i) a steam power generating plant havng a waste heat boiler for generating steam connected to an exhaust line from the gas turbine of the gas turbine power generating plant, a steam turbine connected to the waste heat boiler to receive steam to drive the steam turbine, a generator coupled with the steam turbine to generate electricity, and a condenser, pump and tank for recirculating steam condensate from the steam turbine to the waste heat boiler, (j) a methanol synthesis plant having parallel-connected modules for converting CO and H 2 into methanol connected to the gas turbine power generating plant via the central purified gas distribution system.
Claim 23
Dependent Claim
39 words
Medium-load power generating plant according to claim 15, including means for activating the additional air compressor to supply air to the coal gasifier plant for operating the methanol synthesis plant when the gas turbine power generating plant shuts down.
References Cited (Backward Citations)
US2401845A
Cited
US3183666A
Cited
US3244106A
Cited
GB1167493A
Cited
US3849662A
Cited
US3904386A
Cited
US3868817A
Cited
US4019314A
Cited
US4005996A
Cited
DE2807326A1
Cited
DE3100751A1
Cited
EP0038138A1
Cited
GB2075124A
Cited
EP0047596A1
Cited
US4404414A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-01 | 1990-03-03 | 1990-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-01 | 1994-03-03 | 1994-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-01 | 1998-03-03 | 1998-09-02 | $7700.00 | Window Closed / Lapsed |