US4429535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Geothermal plant silica control system
Assignee: Magma Power Co
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Filing: 1980-08-13
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Granted: 1984-02-07
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Expires: 2000-08-13
Abstract
Abstract A system for reducing silica scaling in a geothermal power plant energized by high temperature, high silica content geothermal brine from a source such as the Salton Sea geothermal field or the Brawley geothermal field. Particulate material capable of seeding silica precipitation thereon is injected into one or more zones in heat extraction equipment such as steam separators where substantial temperature drops occur, so as to seed the precipitation of dissolved silica from the brine in suspended, particulate form rather than as scaling in the heat extraction equipment. The silica precipitation seeding may be accomplished in flash crystallizer type steam separators, and the particulate seed material may be silica particles recovered from a reactor clarifier downstream of the heat extraction equipment.
Inventors
- 👤 John L. Featherstone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:37
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/58; C02F1/60; F; F03; F03G; F03G4/00; F03G4/074
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
227 words
The method of reducing silica scaling in a geothermal energy system which has a geothermal brine flow path comprising a production well providing a flow stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, which comprises: establishing a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, continuously introducing into said zone the geothermal brine flow stream from said production well, continuously flashing a portion of said geothermal brine stream into steam and removing such steam for power generating purposes, providing particulate material capable of seeding silica precipitation thereon, introducing said particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling. said zone being of sufficiently large cross-section to slow down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow sufficient time for the silica precipitation reaction to occur, circulating an unflashed portion of said geothermal brine stream through said zone a plurality of times under thermal power provided by the effects of said flashing, and combining the geothermal brine stream so circulated with the continuous geothermal brine flow stream being introduced into said zone.
Claim 2
Independent Claim
227 words
The method of reducing silica scaling in a geothermal energy system which has a geothermal brine flow path comprising a production well providing a flow stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, which comprises: establishing a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, continuously introducing into said zone the geothermal brine flow stream from said production well, continuously flashing a portion of said geothermal brine stream into steam and removing such steam for power generating purposes, providing particulate material capable of seeding silica precipitation thereon, introducing said particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling. said zone being of sufficiently large cross-section to slow down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow sufficient time for the silica precipitation reaction to occur, circulating an unflashed portion of said geothermal brine stream through said zone a plurality of times under thermal power provided by the effects of said flashing, and combining the geothermal brine stream so circulated with the continuous geothermal brine flow stream being introduced into said zone.
Claim 3
Dependent Claim
20 words
The method of claim 1, which comprises circulating said geothermal brine stream through said zone at least about 8 times.
Claim 4
Dependent Claim
23 words
The method of claim 1, wherein said geothermal brine stream has a residency time in said zone of at least about 8 minutes.
Claim 5
Independent Claim
191 words
The method of reducing silica scaling in a geothermal energy system which has a geothermal brine flow path comprising a production well providing a stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, which comprises: establishing a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, providing particulate material capable of seeding silica precipitation thereon, said introducing said particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling, said zone being of sufficiently large cross-section to slow down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow sufficient time for the silica precipitation reaction to occur, said zone being defined within flash crystallizer means, said flash crystallizer means having a central draft tube therein with its axis generally vertically arranged, and said particulate material being introduced into said flash crystallizer means proximate the lower end of said draft tube.
Claim 6
Independent Claim
191 words
The method of reducing silica scaling in a geothermal energy system which has a geothermal brine flow path comprising a production well providing a stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, which comprises: establishing a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, providing particulate material capable of seeding silica precipitation thereon, said introducing said particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling, said zone being of sufficiently large cross-section to slow down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow sufficient time for the silica precipitation reaction to occur, said zone being defined within flash crystallizer means, said flash crystallizer means having a central draft tube therein with its axis generally vertically arranged, and said particulate material being introduced into said flash crystallizer means proximate the lower end of said draft tube.
Claim 7
Independent Claim
210 words
The method of reducing silica scaling in a geothermal energy system which has a geothermal brine flow path comprising a production well providing a stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, which comprises: establishing a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, providing particulate material capable of seeding silica precipitation thereon, and introducing said particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling, said zone being of sufficiently large cross-section to slow down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow sufficient time for the silica precipitation reaction to occur, a plurality of said zones being provided in series in said flow path, said plurality of zones comprising a first relatively high temperature and relatively high pressure zone, and a second relatively low temperature and relatively low pressure zone downstream of said first zone, said particulate material being introduced into said second zone at a greater rate than into said first zone.
Claim 8
Independent Claim
210 words
The method of reducing silica scaling in a geothermal energy system which has a geothermal brine flow path comprising a production well providing a stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, which comprises: establishing a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, providing particulate material capable of seeding silica precipitation thereon, and introducing said particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling, said zone being of sufficiently large cross-section to slow down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow sufficient time for the silica precipitation reaction to occur, a plurality of said zones being provided in series in said flow path, said plurality of zones comprising a first relatively high temperature and relatively high pressure zone, and a second relatively low temperature and relatively low pressure zone downstream of said first zone, said particulate material being introduced into said second zone at a greater rate than into said first zone.
Claim 9
Dependent Claim
27 words
The method of claim 5, wherein said first and second zones are defined within respective first and second flash crystallizer means in series in said flow path.
Claim 10
Dependent Claim
228 words
In a geothermal energy system which has a geothermal brine flow path comprising a production well providing a flow stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, a system for reducing silica scaling which comprises: structure defining a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, means for continuously introducing into said zone the geothermal brine flow stream from said production well, means for continuously flashing a portion of said geothermal brine stream into steam and for removing such steam for power generating purposes, means for introducing particulate material into said zone, so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling on said structure, said zone comprising an enlarged cross-section that slows down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow time for the silica precipitation reaction to occur, and means for circulating an unflashed portion of said geothermal brine stream through said zone a plurality of times under thermal power provided by the effects of said flashing, said geothermal brine stream so circulated being combined with said geothermal brine flow stream being introduced into said zone.
Claim 11
Dependent Claim
228 words
In a geothermal energy system which has a geothermal brine flow path comprising a production well providing a flow stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, a system for reducing silica scaling which comprises: structure defining a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, means for continuously introducing into said zone the geothermal brine flow stream from said production well, means for continuously flashing a portion of said geothermal brine stream into steam and for removing such steam for power generating purposes, means for introducing particulate material into said zone, so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling on said structure, said zone comprising an enlarged cross-section that slows down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow time for the silica precipitation reaction to occur, and means for circulating an unflashed portion of said geothermal brine stream through said zone a plurality of times under thermal power provided by the effects of said flashing, said geothermal brine stream so circulated being combined with said geothermal brine flow stream being introduced into said zone.
Claim 12
Dependent Claim
19 words
The system of claim 7, wherein said geothermal brine stream circulates through said zone at least about 8 times.
Claim 13
Dependent Claim
23 words
The system of claim 7, wherein said geothermal brine stream has a residency time in said zone of at least about 8 minutes.
Claim 14
Dependent Claim
207 words
In a geothermal energy system which has a geothermal brine flow path comprising a production well providing a stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, a system for reducing silica scaling which comprises: structure defining a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, and means for introducing particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling on said structure, said zone comprising an enlarged cross-section that slows down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow time for the silica precipitation reaction to occur, a plurality of said structures defining a respective plurality of said zones in said flow path, said plurality of zones comprising a first relatively high temperature and relatively high pressure zone, and a second relatively low temperature and relatively low pressure zone downstream of said first zone, said particulate material being introduced into said second zone at a greater rate than into said first zone.
Claim 15
Dependent Claim
207 words
In a geothermal energy system which has a geothermal brine flow path comprising a production well providing a stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, a system for reducing silica scaling which comprises: structure defining a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, and means for introducing particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling on said structure, said zone comprising an enlarged cross-section that slows down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow time for the silica precipitation reaction to occur, a plurality of said structures defining a respective plurality of said zones in said flow path, said plurality of zones comprising a first relatively high temperature and relatively high pressure zone, and a second relatively low temperature and relatively low pressure zone downstream of said first zone, said particulate material being introduced into said second zone at a greater rate than into said first zone.
Claim 16
Dependent Claim
20 words
The system of claim 10, wherein each of said structures defining said first and second zones comprises flash crystallizer means.
Claim 17
Dependent Claim
181 words
In a geothermal energy system which has a geothermal brine flow path comprising a production well providing a stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, a system for reducing silica scaling which comprises: structure defining a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, and means for introducing particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling on said structure, said zone comprising an enlarged cross-section that slows down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow time for the silica precipitation reaction to occur, said structure comprising flash crystallizer means having a central shaft tube therein with its axis generally vertically arranged, and said introducing means introducing said particulate material into said flash crystallize means proximate the lower end of said draft tube.
Claim 18
Dependent Claim
181 words
In a geothermal energy system which has a geothermal brine flow path comprising a production well providing a stream of high temperature, high dissolved silica content geothermal brine and heat extraction means, a system for reducing silica scaling which comprises: structure defining a zone in said heat extraction means in which said geothermal brine stream undergoes a substantial decrease in temperature, and means for introducing particulate material into said zone so as to seed the precipitation of dissolved silica from said brine, whereby silica which precipitates in said zone will be primarily in suspended, particulate form rather than in the form of scaling on said structure, said zone comprising an enlarged cross-section that slows down the flow rate of said geothermal brine stream as said stream passes through said zone so as to allow time for the silica precipitation reaction to occur, said structure comprising flash crystallizer means having a central shaft tube therein with its axis generally vertically arranged, and said introducing means introducing said particulate material into said flash crystallize means proximate the lower end of said draft tube.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |