US3733777A
Expired / Lapsed
US
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Flue gas recovery method and apparatus
Assignee: Individual
•
Filing: 1971-06-10
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Granted: 1973-05-22
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Expires: 1991-06-10
Abstract
Abstract The invention is an improved process for the recovery of, for example, sulfur dioxide and heat from hot flue gas employing direct contact packed-bed heat exchangers, a packed bed absorber and desorber and packed bed liquid-liquid heat exchangers of improved design. The process utilizes the thermal energy of the hot flue gas to: desorb sulfur dioxide, preheat combustion air and to reheat absorber tail gas. The formation of a vapor plume and loss in stack gas draft is minimized by operating the absorber at low temperatures and by reheating the absorber tail gases. Heat is extracted from the hot flue gas and cooled by direct contact with an immiscible heat transfer fluid in a packed bed. Moisture is condensed from the flue gas by direct contact with cold heat transfer fluid, and separated from the heat transfer fluid by decantation. Sulfur dioxide is absorbed from the cooled flue gas in a packed bed by direct contact with a cold aqueous sulfite solution to form a bisulfite salt solution. The aqueous bisulfite salt solution is thermally decomposed and the sulfur dioxide desorbed by heating through direct contact with hot heat transfer fluid from the initial flue gas cooling step. Heat is recovered from the stripped sulfite absorption solution by direct contact with heat transfer fluid and used to preheat combustion air. The decomposition of the bisulfite solution during the sulfur dioxide desorption process is aided by the heat transfer fluid which contains an organic acid which is partially miscible with water at elevated temperatures. Improved absorber design is based upon the use of slant packed beds, slant inlet-outlet packed bed access parts and slant packed bed tower internals for reduced bed cloggage, reduced absorber height and ease of packing replacement while the absorbers are in use.
Inventors
- 👤 R Huntington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:49
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; Y; Y10; Y10S; Y10S261/00; Y10S261/09
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
22 words
Apparatus according to claim 1, including a dual packed bed flue gas heat exchanger unit for cooling and precleaning said flue gas.
Claim 2
Dependent Claim
31 words
Apparatus according to claim 2, wherein said dual packed bed flue gas heat exchanger unit includes a packed bed make-up air heating chamber and a packed bed flue gas cooling chamber.
Claim 3
Dependent Claim
137 words
An absorption-desorption process for recovering sulfur dioxide from hot flue gas comprising the steps of extracting thermal energy from the hot flue gas by directly contacting the flue gas with a cold heat transfer fluid forming a cold flue gas stream and a hot heat transfer fluid stream, extracting sensible thermal energy by cooling the flue gas with the cold heat transfer fluid and extracting latent thermal energy by condensing water from the flue gas with the cold heat transfer fluid and wherein the sulfur dioxide is continuously absorbed from the cold flue gas stream by contact with a cold aqueous absorption solution in an absorption chamber to form a cold saturated absorption solution and a cold sulfur dioxide free absorption chamber tail flue gas stream and continuously separating the water from the heat transfer fluid stream.
Claim 4
Dependent Claim
223 words
An absorption-desorption process for recovering sulfur dioxide from hot flue gas as set forth in claim 4, wherein said sulfur dioxide is continuously desorbed from the absorption solution by heating the cold saturated absorption solution stream by passing the cold absorption solution downwardly through a packed bed sulfur dioxide cooling chamber in direct contact with an upwardly flowing warm saturated sulfur dioxide gas stream to produce a cold sulfur dioxide gas stream and warm saturated absorption solution stream with the warm saturated absorption solution stream heated by direct contact at elevated pressure with the hot heat transfer fluid stream in a packed bed counter flow liquid-liquid heat exchanger, with said hot heat transfer fluid flowing upward through the liquid-liquid heat exchanger to produce a warm heat transfer fluid stream and said saturated absorption solution flowing downward through the liquid-liquid heat exchanger to produce a hot saturated absorption solution with the hot saturated absorption solution flowing upward to a packed bed desorption chamber and flashing to produce the up flowing warm saturated sulfur dioxide gas stream and a down flowing hot stripped absorption solution stream, with the hot stripped absorption solution passing downward and the warm heat transfer fluid stream flowing upward through a packed bed liquid-liquid counter flow heat exchanger to produce a hot heat transfer fluid stream and warm absorption solution stream.
Claim 5
Dependent Claim
32 words
An absorption-desorption process for recovering sulfur dioxide from hot flue gas as set forth in claim 5, wherein the hot heat transfer fluid is used to heat cold furnace make-up combustion air.
Claim 6
Dependent Claim
91 words
An absorption-desorption process for recovering sulfur dioxide from hot flue gas as set forth in claim 4, wherein the cold absorption chamber tail flue gas is heated by direct contact with the warm heat transfer fluid stream in a packed bed absorber tail gas reheat chamber to form a warm sulfur dioxide free flue gas stream and a cooled heat transfer fluid stream with said warm sulfur dioxide free flue gas vented to the atmosphere and said cooled heat transfer fluid stream returned to the packed bed fLue gas cooling chamber.
Claim 7
Dependent Claim
37 words
An absorption-desorption process for recovering sulfur dioxide from hot flue gas as set forth in claim 6, wherein said heat transfer fluid comprises in part a partially water miscible organic acid, and a high molecular weight paraffin.
Claim 8
Dependent Claim
35 words
An absorption-desorption process for recovering sulfur dioxide from hot flue gas as set forth in claim 6, wherein said sulfur dioxide absorption solution comprises in part an alkaline sulfite bisulfite solution and hydroquinone oxidation inhibitor.
Claim 9
Dependent Claim
65 words
A multiple compartment packed bed absorber unit comprising, in combination, a slant packed bed counter flow flue gas cooling chamber, a slant packed bed counter flow absorption chamber, a slant packed bed counter flow absorber tail gas reheat chamber effective to reheat tail gas, a slanting packed bed mist eliminator chamber, and means for distributing a heat transfer fluid, absorption fluid and a gas stream.
Claim 10
Dependent Claim
16 words
Apparatus according to claim 10, wherein said packed beds include slant fill and clean out ports.
Claim 11
Dependent Claim
118 words
A multiple compartment packed bed absorber unit as set forth in claim 10, wherein said slant packed bed counter flow flue gas cooling chamber includes a hollow shell, said shell defining a slant gas inlet plenum chamber and inlet port, a slant packed bed chamber, a slant distributor chamber, said slant gas inlet plenum chamber being partitioned from said packed bed chamber by a slant packed bed support grill, said packed bed chamber containing tower fill and partitioned from said slant distributor chamber by a slant packed bed hold down grill, said slant distributor chamber containing a slant heat transfer fluid distributor and heat transfer fluid and outlet ports, and means for circulating a common heat transfer fluid.
Claim 12
Dependent Claim
113 words
A multiple compartment packed bed absorber unit as set forth in claim 10, wherein said slant packed bed counter flow absorption chamber includes a hollow shell, said shell defining a slant gas inlet chamber, a slant packed bed chamber, a slant distributor chamber, said slant gas inlet chamber partitioned from said slant packed bed by a slant louvered packed bed support plate and a liquid sump communicating with a liquid outlet port, said slant packed bed chamber containing tower fill and partitioned from said slant distributor chamber by a slant packed bed hold down grill, said slant distributor chamber containing an absorption solution liquid distributor, and means for recirculating a common absorption solution.
Claim 13
Dependent Claim
119 words
A multiple compartment packed bed absorber unit as set forth in claim 10, wherein said slant packed bed counter flow absorber tail gas reheat chamber includes a hollow shell, said shell defining a slant gas inlet chamber, a slant packed bed chamber, a slant distributor chamber, said slant inlet chamber partitioned from said slant packed bed by a slant louvered packed bed support plate and a liquid sump communicating with a liquid outlet port, said slant packed bed chamber containing tower fill and partitioned from said slant distributor chamber by a slant packed bed hold down grill, said distributor chamber containing a heat transfer fluid distributor and liquid inlet port, and means for circulating a common heat transfer fluid.
Claim 14
Dependent Claim
51 words
A multiple compartment packed bed absorber unit as set forth in claim 10, wherein said slanting packed bed mist eliminator includes a hollow shell, said shell defining a distributor chamber, a slant packed bed eliminator chamber, a slant outlet chamber and gas outlet port, said packed bed chamber containing tower fill.
Claim 15
Dependent Claim
153 words
A unitized slant packed bed absorber unit comprising, in combination, a hollow shell, said shell partitioned into a base gas inlet plenum liquid sump chamber, a gas inlet port communicating with said sump chamber, said plenum liquid sump chamber partitioned from a slanting packed bed chamber by a slanting packed bed gas liquid inlet outlet grill, said support grill supported by said absorber shell, said packed bed containing suitable tower filL and partitioned from a slanting distributor gas plenum chamber by a slanting packed hold down gas outlet liquid inlet grill, said hold down grill supported by said absorber shell, said distributor gas plenum chamber containing a slanting liquid distributor communicating with a liquid inlet port, said liquid distributor plenum chamber partitioned from a gas outlet plenum chamber and outlet port by a slanting mist eliminator filter supported by said absorber shell, said packed bed shell having slanting clean out and fill ports.
Claim 16
Dependent Claim
77 words
a slanting packed column liquid distributor comprising, in combination, a slanting multiple compartment liquid inlet splitter trough, said compartments having side wall perforations and perforated compartment partitions arranged in cascade, said liquid splitter trough wall perforations positioned above a series of step spaced apart horizontal liquid distributor pans in transverse underlying relation to said splitter trough and positioned so as to receive liquid from respective trough wall perforations, said pans being notched with evenly longitudinally spaced v-cuts.
Claim 17
Dependent Claim
49 words
A multiple chambered packed desorber unit comprising, in combination, a hollow shell, said shell defining a slant packed bed gas cooling chamber, a slant packed bed desorption chamber, a packed bed liquid-liquid stripped absorption solution heat exchanger chamber and a packed bed liquid-liquid saturated absorption solution heat exchanger chamber.
Claim 18
Dependent Claim
49 words
A multiple chambered packed bed desorber unit as set forth in claim 18, wherein said slant packed bed gas cooling chamber contains suitable tower fill, a slant louvered packed bed support plate and liquid sump, a slant packed bed hold down grill, and means for distributing liquid downwardly therethrough.
Claim 19
Dependent Claim
47 words
A multiple chambered packed bed desorber unit as set forth in claim 18, wherein said desorption chamber contains suitable tower fill and includes a slant packed bed support grill, a slant packed bed hold down grill, means for distributing liquid downwardly therethrough, and a liquid sump chamber.
Claim 20
Dependent Claim
36 words
A multiple chambered packed bed desorber unit as set forth in claim 18, wherein said packed bed liquid-liquid absorption solution heat exchanger chambers include a lower liquid distributor, an upper liquid distributor and liquid inlet-outlet means.
Claim 21
Dependent Claim
51 words
A multiple chambered packed bed desorber unit as set forth in claim 21, wherein said upper and lower liquid distributors include a perforated sieve plate distributor pan having a plurality of liquid downcomer and riser bypass ports, with said downcomer and riser ports comprising hollow cylinders defining passageways through said pans.
Claim 22
Dependent Claim
135 words
An absorption-desorption process for removing waste gases from hot exhaust gas comprising the steps of extracting thermal energy from the hot exhaust gas by directly contacting the hot exhaust gas with a cold heat transfer fluid to form a hot heat transfer fluid stream and a cold exhaust gas stream, absorbing the waste gases from the cold exhaust gas stream by direct contact with a cold aqueous absorption solution to produce a cold stripped exhaust gas stream and a cold saturated absorption solution, contacting the cold absorption solution with the hot heat transfer fluid stream to produce a concentrated waste gas stream and a cold heat transfer fluid stream, with the cold stripped exhaust gas stream being reheated by direct contact with the hot heat transfer fluid stream, and disposing of excess heat by refrigeration.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |