US3840326A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Industrial pollution control systems and components thereof
Assignee: Hauck Manufacturing Inc
•
Filing: 1972-12-13
•
Granted: 1974-10-08
•
Expires: 1992-12-13
Abstract
Abstract There is disclosed a closed combustion system designed to reduce the level of noise generated by its operation. The system includes an enclosed combustion chamber with ducts for supplying combustion air to the chamber and for supplying atomizing air to the fuel burner. The system is designed to be connected to an industrial furnace or kiln or rotary drier in a substantially sealed manner. The only opening to the atmosphere from the system is at the air inlet of the duct and here a noise attenuator is connected. A second noise attenuator is formed within the combustion chamber. The combination of the two attenuators and the closed construction of the system provides a reduction of the operational noise down to a tolerable level over a wide frequency band. The combustion chamber which is disclosed combines the functions of recuperation and noise attenuation. A cylindrical grill is positioned within the chamber in alignment with the fuel burner and contains a large number of holes spaced over its cylindrical surface to accommodate the flow of combustion air into its interior. The grill is formed of a high temperature material withstand withsatand combustion temperatures. During operation, the grill transfers heat back into the incoming combustion air to preheat this air and thereby increase the efficiency of combustion. The size of the grill and the crosssectional area of its holes are designed to have the grill function additionally as a Helmholtz chamber to absorb noise energy within the combustion chamber. The other attenuator disclosed herein is constructed of hollow partitions spaced from one another to form a plurality of open passageways for admitting air into the combustion system. The escape of noise from the system in the opposite direction through these passageways is limited by the sound absorbing properties of the passageways. To this end, the partitions are provided with a plurality of small holes having a range of sizes to that each partition functions as a multihole Helmholtz chamber having a wider attenuation band than normal. The partitions may be filled with an acoustic absorbing material to increase the absorption of sound in the higher frequencies.
Inventors
- 👤 R Schreter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:51
CPC Classifications
F; F23; F23M; F23M20/00; F23M20/005
Claims Analysis
Total Claims: 102
Claim 1
Independent Claim
162 words
A combustion system for use with furnaces, driers, and like equipment, said system being designed to abate the escape of noise therefrom, and comprising: A. an enclosed combustion chamber having 1. an open output end designed to be coupled to the aforesaid equipment; 2. a generally cylindrical outer shell, 3. an opening through said outer shell for admitting combustion air thereto, and 4. a substantially tubular inner shell mounted within and spaced from said outer shell, said inner shell having a plurality of holes spaced about the periPhery thereof and along the length thereof, each of said holes having a selected diameter to form together with said outer shell a Helmholtz resonator for absorbing acoustical energy within a selected frequency range and to enable said combustion air to enter said inner shell, B. a fuel burner mounted adjacent to said combustion chamber and adapted to direct its flame into said inner shell in order that combustion principally occurs within said inner shell.
Claim 2
Dependent Claim
162 words
A combustion system for use with furnaces, driers, and like equipment, said system being designed to abate the escape of noise therefrom, and comprising: A. an enclosed combustion chamber having 1. an open output end designed to be coupled to the aforesaid equipment; 2. a generally cylindrical outer shell, 3. an opening through said outer shell for admitting combustion air thereto, and 4. a substantially tubular inner shell mounted within and spaced from said outer shell, said inner shell having a plurality of holes spaced about the periPhery thereof and along the length thereof, each of said holes having a selected diameter to form together with said outer shell a Helmholtz resonator for absorbing acoustical energy within a selected frequency range and to enable said combustion air to enter said inner shell, B. a fuel burner mounted adjacent to said combustion chamber and adapted to direct its flame into said inner shell in order that combustion principally occurs within said inner shell.
Claim 3
Dependent Claim
3 words
a downstream end,
Claim 4
Dependent Claim
3 words
a downstream end,
Claim 5
Dependent Claim
6 words
an opening for receiving combustion air,
Claim 6
Dependent Claim
6 words
an opening for receiving combustion air,
Claim 7
Dependent Claim
34 words
means for moving said louvers to permit modulation of the flow of combustion air through said first air ducting means into said combustion chamber thereby to control the air/fuel ratio in the combustion chamber.
Claim 8
Dependent Claim
34 words
means for moving said louvers to permit modulation of the flow of combustion air through said first air ducting means into said combustion chamber thereby to control the air/fuel ratio in the combustion chamber.
Claim 9
Dependent Claim
3 words
a downstream end,
Claim 10
Dependent Claim
3 words
a downstream end,
Claim 11
Dependent Claim
6 words
an opening for receiving combustion air,
Claim 12
Dependent Claim
6 words
an opening for receiving combustion air,
Claim 13
Dependent Claim
5 words
a generally cylindrical outer shell,
Claim 14
Dependent Claim
5 words
a generally cylindrical outer shell,
Claim 15
Dependent Claim
57 words
A combustion system as claimed in claim 1 wherein said inner shell is made of a high temperature material which resists the high temperatures of combustion and wherein said inner shell effects preheating of said combustion air prior to the entry of said combustion air into said inner shell and increases the combustion rate of the fuel.
Claim 16
Dependent Claim
10 words
a sound absorbing material substantially filling each of said partitions.
Claim 17
Dependent Claim
10 words
a sound absorbing material substantially filling each of said partitions.
Claim 18
Dependent Claim
6 words
An opening for receiviNg combustion air,
Claim 19
Dependent Claim
6 words
An opening for receiviNg combustion air,
Claim 20
Dependent Claim
26 words
means for absorbing sound positioned adjacent said passageway to attenuate the noise flowinG out of said combustion system through said air ducting means and attenuator passageway.
Claim 21
Dependent Claim
26 words
means for absorbing sound positioned adjacent said passageway to attenuate the noise flowinG out of said combustion system through said air ducting means and attenuator passageway.
Claim 22
Dependent Claim
3 words
a downstream end,
Claim 23
Dependent Claim
3 words
a downstream end,
Claim 24
Dependent Claim
3 words
an aft opening,
Claim 25
Dependent Claim
3 words
an aft opening,
Claim 26
Dependent Claim
17 words
said aft opening positioned adjacent said fuel burner and said forward opening terminating within said tubular grill.
Claim 27
Dependent Claim
17 words
said aft opening positioned adjacent said fuel burner and said forward opening terminating within said tubular grill.
Claim 28
Dependent Claim
62 words
said downstream end terminating at said opening in said combustion chamber, D. a damper positioned within said combustion chamber between said opening and said fuel burner to control the flow of combustion air within said combustion chamber, E. a reflector connected at the upstream end of said first air ducting means for reflecting noise back into the interior of the combustion system.
Claim 29
Dependent Claim
62 words
said downstream end terminating at said opening in said combustion chamber, D. a damper positioned within said combustion chamber between said opening and said fuel burner to control the flow of combustion air within said combustion chamber, E. a reflector connected at the upstream end of said first air ducting means for reflecting noise back into the interior of the combustion system.
Claim 30
Dependent Claim
31 words
said downstream end terminating at said opening in said combustion chamber, D. a second acoustic attenuator connected to said air ducting means to be in airflow communication therewith, said attenuator having
Claim 31
Dependent Claim
31 words
said downstream end terminating at said opening in said combustion chamber, D. a second acoustic attenuator connected to said air ducting means to be in airflow communication therewith, said attenuator having
Claim 32
Dependent Claim
40 words
A combustion system as claimed in claim 2, wherein said combustion chamber further comprises: A. a damper positioned within said combustion chamber between said opening and said fuel burner to control the flow of combustion air within said combustion chamber.
Claim 33
Dependent Claim
4 words
an outer shell, and
Claim 34
Dependent Claim
4 words
an outer shell, and
Claim 35
Dependent Claim
73 words
said downstream end terminating at said opening in said combustion chamber, D. a damper positioned within said combustion chamber between said opening and said fuel burner to control the flow of combustion air within said combustion chamber, E. second means for ducting air, the second air ducting means being enclosed and connected at one end to said first means for ducting air and being connected at its opposite end to said fuel burner.
Claim 36
Dependent Claim
73 words
said downstream end terminating at said opening in said combustion chamber, D. a damper positioned within said combustion chamber between said opening and said fuel burner to control the flow of combustion air within said combustion chamber, E. second means for ducting air, the second air ducting means being enclosed and connected at one end to said first means for ducting air and being connected at its opposite end to said fuel burner.
Claim 37
Dependent Claim
12 words
an opening through said outer shell for admitting combustion air thereto, and
Claim 38
Dependent Claim
12 words
an opening through said outer shell for admitting combustion air thereto, and
Claim 39
Dependent Claim
4 words
an outer shell, and
Claim 40
Dependent Claim
4 words
an outer shell, and
Claim 41
Dependent Claim
4 words
an outer shell, and
Claim 42
Dependent Claim
4 words
an outer shell, and
Claim 43
Dependent Claim
125 words
a first acoustic attenuator mounted within and spaced from said outer shell and constructed to exhibit sound absorbing properties for noise generated within said combustion system, and including a. a grill of high-tempearture material for resisting the high temperatures of combustion and having i. a substantially tubular shape, ii. a plurality of apertures spaced throughout and sized to absorb noise energy within a selected frequency range, iii. said grill acting to transfer heat to the combustion air supplied to said combustion chamber to preheat said air and increase the combustion rate of the fuel, B. a fuel burner mounted adjacent to said combustion chamber to direct its flame thereinto, C. first means for ducting air to said combustion chamber, said means being enclosed and having
Claim 44
Dependent Claim
125 words
a first acoustic attenuator mounted within and spaced from said outer shell and constructed to exhibit sound absorbing properties for noise generated within said combustion system, and including a. a grill of high-tempearture material for resisting the high temperatures of combustion and having i. a substantially tubular shape, ii. a plurality of apertures spaced throughout and sized to absorb noise energy within a selected frequency range, iii. said grill acting to transfer heat to the combustion air supplied to said combustion chamber to preheat said air and increase the combustion rate of the fuel, B. a fuel burner mounted adjacent to said combustion chamber to direct its flame thereinto, C. first means for ducting air to said combustion chamber, said means being enclosed and having
Claim 45
Dependent Claim
42 words
A combustion system as claimed in claim 3, wherein said damper is A. positioned adjacent to the aft end of the inner shell to control the amount of air which flows around the aft end of the grill to said fuel burner.
Claim 46
Dependent Claim
126 words
a first acoustic attenuator mounted within and spaced from said outer shell and constructed to exhibit sound absorbing properties for noise generated within said combustion system, and including a. a grill of high-temperature material for resisting the high temperatures of combustion and having i. a substantially tubular shape, ii. a plurality of apertures spaced throughout and sized to absorb noise energy within a selected frequency range, and iii. said grill acting to transfer heat to the combustion air supplied to said combustion chamber to preheat said air and increase the combustion rate of the fuel, B. a fuel burner mounted adjacent to said combustion chamber to direct its flame thereinto. C. first means for ducting air to said combustion chamber, and means being enclosed and having
Claim 47
Dependent Claim
126 words
a first acoustic attenuator mounted within and spaced from said outer shell and constructed to exhibit sound absorbing properties for noise generated within said combustion system, and including a. a grill of high-temperature material for resisting the high temperatures of combustion and having i. a substantially tubular shape, ii. a plurality of apertures spaced throughout and sized to absorb noise energy within a selected frequency range, and iii. said grill acting to transfer heat to the combustion air supplied to said combustion chamber to preheat said air and increase the combustion rate of the fuel, B. a fuel burner mounted adjacent to said combustion chamber to direct its flame thereinto. C. first means for ducting air to said combustion chamber, and means being enclosed and having
Claim 48
Dependent Claim
99 words
a substantially tubular inner shell mounted within and spaced from said outer shell, said inner shell having a plurality of holes spaced about the periPhery thereof and along the length thereof, each of said holes having a selected diameter to form together with said outer shell a Helmholtz resonator for absorbing acoustical energy within a selected frequency range and to enable said combustion air to enter said inner shell, B. a fuel burner mounted adjacent to said combustion chamber and adapted to direct its flame into said inner shell in order that combustion principally occurs within said inner shell.
Claim 49
Dependent Claim
99 words
a substantially tubular inner shell mounted within and spaced from said outer shell, said inner shell having a plurality of holes spaced about the periPhery thereof and along the length thereof, each of said holes having a selected diameter to form together with said outer shell a Helmholtz resonator for absorbing acoustical energy within a selected frequency range and to enable said combustion air to enter said inner shell, B. a fuel burner mounted adjacent to said combustion chamber and adapted to direct its flame into said inner shell in order that combustion principally occurs within said inner shell.
Claim 50
Dependent Claim
125 words
a first acoustic attenuator mounted within and spaced from said outer shell and constructed to exhibit sound absorbing properties for noise generated within said combustion system, and including a. a grill of high-temperature material for resisting the high temperatures of combustion and having i. a substantially tubular shape, ii. a plurality of apertures spaced throughout and sized to absorb noise energy within a selected frequency range iii. said grill acting to transfer heat to the combustion air supplied to said combustion chamber to preheat said air and increase the combustion rate of the fuel, B. a fuel burner mounted adjacent to said combustion chamber to direct its flame thereinto, C. first means for ducting air to said combustion chamber, said means being enclosed and having
Claim 51
Dependent Claim
125 words
a first acoustic attenuator mounted within and spaced from said outer shell and constructed to exhibit sound absorbing properties for noise generated within said combustion system, and including a. a grill of high-temperature material for resisting the high temperatures of combustion and having i. a substantially tubular shape, ii. a plurality of apertures spaced throughout and sized to absorb noise energy within a selected frequency range iii. said grill acting to transfer heat to the combustion air supplied to said combustion chamber to preheat said air and increase the combustion rate of the fuel, B. a fuel burner mounted adjacent to said combustion chamber to direct its flame thereinto, C. first means for ducting air to said combustion chamber, said means being enclosed and having
Claim 52
Dependent Claim
44 words
A combustion system as claimed in claim 4, wherein: A. said damper is adjustable, and said combustion chamber further comprises: B. at least one movable rod attached to said damper, said rod extending outside of said combustion chamber to permit adjustment of the damper.
Claim 53
Dependent Claim
44 words
A combustion system as claimed in claim 5, wherein said damper comprises: A. an annular metal band positioned to be adjusted over the aft end of the inner shell to control the size of the annular opening at the rear of said combustion chamber.
Claim 54
Dependent Claim
20 words
A combustion chamber as claimed in claim 1, wherein: A. said holes are of uniform size throughout the inner shell.
Claim 55
Dependent Claim
15 words
A combustion chamber as claimed in claim 1, wherein: A. said holes vary in size.
Claim 56
Dependent Claim
45 words
A combustion chamber as claimed in claim 8, wherein: A. said holes are grouped into a plurality of cylindrical bands on said inner shell. B. the size of the holes in each band being different from the size of the holes in the remaining bands.
Claim 57
Dependent Claim
30 words
A combustion system for use with furnaces, driers, and like equipment, said system being designed to abate the escape of noise therefrom, and comprising: A. an enclosed combustion chamber having
Claim 58
Dependent Claim
30 words
A combustion system for use with furnaces, driers, and like equipment, said system being designed to abate the escape of noise therefrom, and comprising: A. an enclosed combustion chamber having
Claim 59
Dependent Claim
44 words
A combustion system as claimed in claim 10, wherein said second acoustic attenuator further comprises: A. a plurality of partitions mounted therein to define a plurality of passageways for the flow of combustion air therethrough, each of said partitions being formed hollow and having
Claim 60
Dependent Claim
18 words
A combustion system as claimed in claim 11, wherein: A. said plurality of holes are varied in size.
Claim 61
Dependent Claim
51 words
A combustion system as claimed in claim 12, comprising: A. second means for ducting air, B. said second air ducting means being enclosed and connected at one end to said first air ducting means downstream of said second acoustic attenuator, and being connected at its opposite end to said fuel burner.
Claim 62
Dependent Claim
36 words
A combustion system as claimed in claim 13, further comprising: A. air compressing means positioned in said second air ducting means for supplying compressed air to said fuel burner to atomize the fuel prior to combustion.
Claim 63
Dependent Claim
32 words
A combustion system as claimed in claim 14, wherein: A. at least a part of said first and second air ducting means incorporates means for relieving the pressure generated by an explosion.
Claim 64
Dependent Claim
37 words
A combustion system as claimed in claim 10, further comprising: A. a reflector connected upstream of said second acoustic attenuator for reflecting noise which escapes said attenuator back through said attenuator where it can be further attenuated.
Claim 65
Dependent Claim
42 words
A combustion system as claimed in claim 16, further comprising: A. an intake hood positioned at the upstream end of said first air ducting means, B. said intake hood connected to the inlet of said second acoustic attenuator and containing said reflector.
Claim 66
Dependent Claim
21 words
A combustion system as claimed in claim 17, wherein: A. said reflector comprises the front plane surface of said intake hood.
Claim 67
Dependent Claim
37 words
A combustion system as claimed in claim 17, wherein said reflector comprises: A. a plurality of vanes mounted in said intake hood, B. each vane having a concave inner surface which faces the inlet of said attenuator.
Claim 68
Dependent Claim
35 words
A combined recuperative combustion chamber and noise attenuator comprising: A. a substantially enclosed outer tubular shell, B. a grill supported within the interior of said outer shell, said grill having a substantially tubular shape, and
Claim 69
Dependent Claim
35 words
A combined recuperative combustion chamber and noise attenuator comprising: A. a substantially enclosed outer tubular shell, B. a grill supported within the interior of said outer shell, said grill having a substantially tubular shape, and
Claim 70
Dependent Claim
67 words
Apparatus as claimed in claim 20, wherein: A. said grill is made of a high temperature material which resists the high temperatures of combustion which takes place within its interior, and B. said grill is positioned to transfer heat to combustion air admitted into said combustion chamber thereby to preheat said air and increase the combustion rate of the fuel which is burned within said combustion chamber.
Claim 71
Dependent Claim
47 words
Apparatus as claimed in claim 21, wherein said grill is formed of: A. a plurality of arcuate longitudinal sections, B. each section having a lengthwise edge which overlaps the lengthwise edge of an adjacent section to form an articulated grill construction permitting thermal expansion of said griLl.
Claim 72
Dependent Claim
42 words
Apparatus as claimed in claim 22, further comprising: A. means for mounting said grill within said outer shell such that said grill is spaced from said outer shell substantially throughout its length to provide an annular space between the grill and shell.
Claim 73
Dependent Claim
47 words
Apparatus as claimed in claim 23, further comprising: A. a first opening formed in said outer shell for admitting combustion air into said combustion chamber such that said combustion air flows through said annular space and into the interior of said grill through said plurality of holes.
Claim 74
Dependent Claim
43 words
Apparatus as claimed in claim 24, wherein said mounting means mounts said grill eccentrically within said outer tubular shell such that the space on the side of the grill adjacent said opening is greater than the space around the remainder of said grill.
Claim 75
Dependent Claim
50 words
Apparatus as claimed in claim 25, wherein: A. said tubular shell has a forward end and an aft end, and said apparatus further comprises: B. a damper mounted between said grill and said outer shell to control the flow of combustion air between said first opening and said fuel burner.
Claim 76
Dependent Claim
49 words
Apparatus as claimed in claim 26, wherein: A. the aft end of said grill is closed, and B. said damper is positioned adjacent to the aft end of said grill to control the amount of air which flows around the aft end of the grill to said fuel burner.
Claim 77
Dependent Claim
40 words
Apparatus as claimed in claim 27, wherein: A. said damper is adjustable, said apparatus further comprising: B. at least one movable rod attached to said damper, said rod extending outside of said tubular shell to permit adjustment of the damper.
Claim 78
Dependent Claim
34 words
Apparatus as claimed in claim 28, wherein said damper comprises: A. an annular metal band adjustable coaxially of said grill to control the size of the opening around the aft end of the grill.
Claim 79
Dependent Claim
17 words
Apparatus as claimed in claim 27, further comprising: A. a substantially cylindrical ignition tile, said tile including
Claim 80
Dependent Claim
22 words
Apparatus as claimed in claim 30, further comprising: A. a layer of insulation attached to the interior of said outer tubular shell.
Claim 81
Dependent Claim
20 words
Apparatus as claimed in claim 31, wherein said tubular shell and said tubular grill are both of substantially cylindrical shape.
Claim 82
Dependent Claim
56 words
Apparatus as claimed in claim 32, further comprising: A. a second opening formed at the forward end of said outer tubular shell for discharging hot combustion gases, and B. an external flange formed on the outer periphery of said outer shell adjacent said second opening for mounting said combustion chamber onto furnaces, driers, and like equipment.
Claim 83
Dependent Claim
49 words
Apparatus as claimed in claim 20, wherein: A. said tubular shell has a forward end and an aft end, said apparatus further comprises: B. a damper mounted between said grill and said outer shell to control the flow of combustion air between said first opening and said fuel burner.
Claim 84
Dependent Claim
49 words
Apparatus as claimed in claim 34, wherein: A. the aft end of said grill is closed, and B. said damper is positioned adjacent to the aft end of said grill to control the amount of air which flows around the aft end of the grill to said fuel burner.
Claim 85
Dependent Claim
40 words
Apparatus as claimed in claim 35, wherein: A. said damper is adjustable, said apparatus further comprising: B. at least one movable rod attached to said damper, said rod extending outside of said tubular shell to permit adjustment of the damper.
Claim 86
Dependent Claim
34 words
Apparatus as claimed in claim 36, wherein said damper comprises: A. an annular metal band adjustable coaxially of said grill to control the size of the opening around the aft end of the grill.
Claim 87
Dependent Claim
23 words
Apparatus as claimed in claim 20 wherein: A. said plurality of holes are of a uniform size and are spaced throughout said grill.
Claim 88
Dependent Claim
21 words
Apparatus as claimed in claim 20, wherein: A. said plurality of holes vary in size and are spaced throughout said grill.
Claim 89
Dependent Claim
44 words
Apparatus as claimed in claim 39, wherein: A. said plurality of holes are grouped into a plurality of cylindrical bands on said grill, B. the size of the holes in each band being different from the size of the holes in the remaining bands.
Claim 90
Dependent Claim
24 words
Apparatus as claimed in claim 23, wherein: A. said plurality of holes are of a uniform size and are spaced throughout each arcuate section.
Claim 91
Dependent Claim
22 words
Apparatus as claimed in claim 23, wherein: A. said plurality of holes vary in size and are spaced throughout each arcuate section.
Claim 92
Dependent Claim
44 words
Apparatus as claimed in claim 42, wherein: A. said plurality of holes are grouped into a plurality of cylindrical bands on each section, B. the size of the holes in each band being different from the size of the holes in the remaining bands.
Claim 93
Dependent Claim
30 words
A combustion system for use with furnaces, driers, and like equipment, said system being designed to abate the escape of noise therefrom, and comprising: A. an enclosed combustion chamber having
Claim 94
Dependent Claim
30 words
A combustion system for use with furnaces, driers, and like equipment, said system being designed to abate the escape of noise therefrom, and comprising: A. an enclosed combustion chamber having
Claim 95
Dependent Claim
36 words
A combustion system as claimed in claim 44, further comprising: A. air compressing means positioned in said second air ducting means for supplying compressed air to said fuel burner to atomize the fuel prior to combustion.
Claim 96
Dependent Claim
32 words
A combustion system as claimed in claim 45, wherein: A. at least a part of said first and second air ducting means incorporates means for relieving the pressure generated by an explosion.
Claim 97
Dependent Claim
46 words
A combustion system as claimed in claim 45, further comprising: A. a second damper positioned in said first air ducting means, said second damper defining a flowpath for the combustion air which is supplied through said first air ducting means into said combustion chamber, and including
Claim 98
Dependent Claim
30 words
A combustion system for use with furnaces, driers, and like equipment, said system being designed to abate the escape of noise therefrom, and comprising: A. an enclosed combustion chamber having
Claim 99
Dependent Claim
30 words
A combustion system for use with furnaces, driers, and like equipment, said system being designed to abate the escape of noise therefrom, and comprising: A. an enclosed combustion chamber having
Claim 100
Dependent Claim
32 words
A combustion system as claimed in claim 48, further comprising: A. an intake hood positioned at the upstream end of said first air ducting means, B. said intake hood including said reflector.
Claim 101
Dependent Claim
23 words
A combustion system as claimed in claim 49, wherein: A. said reflector is formed as a front plane surface of said intake hood.
Claim 102
Dependent Claim
41 words
A combustion system as claimed in claim 49, wherein said reflector comprises: A. a plurality of vanes mounted in said intake hood, B. each vane having a concave inner surface which faces the downstream end of said first air ducting means.
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) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |