US3964675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Appartus for limiting vacuum and pressure in a furnace
Assignee: Individual
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Filing: 1974-10-15
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Granted: 1976-06-22
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Expires: 1994-10-15
Abstract
Abstract A furnace system having a combustion chamber, and heat transfer surfaces, forced and induced draft fans for moving gas through the burner, chamber, and heattransfer surfaces, first controls for maintaining predetermined gas flows and furnace pressure or draft dependent upon the desired normal operating conditions, and second controls responsive to the flow of the gas exterior to the chamber, e.g., at the inlet or outlet of the induced draft fan and, if desired, at the outlet of the forced draft fan, for controlling a damper or dampers in the gas path or the speed of the fans so as to limit the vacuum which can be developed in the chamber by the induced draft fan to a value less than the chamber vacuum withstanding design value. Also, if desired, the second controls at the outlet of the forced draft fan can limit pressure which can be developed in the chamber by the forced draft fan to a value less than the chamber pressure withstanding design value.
Inventors
- 👤 Perry C. Euchner, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:34
CPC Classifications
F; F23; F23N; F23N1/00; F23N1/04; F23N1/047; F23N5/00; F23N5/18; F23N5/188; F23N2233/00; F23N2233/02; F23N2233/04; F23N2233/06; F23N2233/08; F23N2235/00; F23N2235/02; F23N2235/04; F23N2235/06
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
307 words
In a furnace system having a combustion chamber, fan means and duct means connected to said chamber for moving gas along a path extending from exteriorly of and into said chamber, through said chamber and then outwardly from and away from said chamber, said fan means including at least one fan having an inlet and an outlet and the gas pressure internally of said chamber being at least partially dependent upon the level of flow of the gas which is supplied to and removed from said chamber, said chamber being subject to damage when said gas pressure internally of said chamber reaches a predetermined value, gas flow modifying means in said path for modifying the flow of gas through said chamber and control means comprising measuring means in said path and connected to at least part of said gas flow modifying means for normally maintaining the flow of said gas at predetermined levels required for normal operation of said system, the combination therewith of gas flow measuring means in the path of said gas outside said chamber and adjacent said fan, said last-mentioned measuring means being responsive to changes in the flow of said gas at one of said inlet and said outlet, and gas flow limiting means interconnecting said last-mentioned measuring means and at least part of said gas flow modifying means for changing the flow of said gas from said predetermined levels to further predetermined levels which are dependent upon the rate of flow of said gas exteriorly of said chamber, said further predetermined levels being higher with an increasing rate of flow of said gas exteriorly of said chamber and lower with a decreasing rate of flow of said last-mentioned gas but being less than the gas flow level which will cause the gas pressure internally of said chamber to reach said predetermined value.
Claim 2
Dependent Claim
307 words
In a furnace system having a combustion chamber, fan means and duct means connected to said chamber for moving gas along a path extending from exteriorly of and into said chamber, through said chamber and then outwardly from and away from said chamber, said fan means including at least one fan having an inlet and an outlet and the gas pressure internally of said chamber being at least partially dependent upon the level of flow of the gas which is supplied to and removed from said chamber, said chamber being subject to damage when said gas pressure internally of said chamber reaches a predetermined value, gas flow modifying means in said path for modifying the flow of gas through said chamber and control means comprising measuring means in said path and connected to at least part of said gas flow modifying means for normally maintaining the flow of said gas at predetermined levels required for normal operation of said system, the combination therewith of gas flow measuring means in the path of said gas outside said chamber and adjacent said fan, said last-mentioned measuring means being responsive to changes in the flow of said gas at one of said inlet and said outlet, and gas flow limiting means interconnecting said last-mentioned measuring means and at least part of said gas flow modifying means for changing the flow of said gas from said predetermined levels to further predetermined levels which are dependent upon the rate of flow of said gas exteriorly of said chamber, said further predetermined levels being higher with an increasing rate of flow of said gas exteriorly of said chamber and lower with a decreasing rate of flow of said last-mentioned gas but being less than the gas flow level which will cause the gas pressure internally of said chamber to reach said predetermined value.
Claim 3
Dependent Claim
26 words
A furnace system as set forth in claim 1, wherein said fan is an induced draft fan connected to said chamber for removing said gas therefrom.
Claim 4
Dependent Claim
26 words
A furnace system as set forth in claim 2, wherein said gas flow modifying means comprises means for varying the speed of said induced draft fan.
Claim 5
Dependent Claim
43 words
A furnace system as set forth in claim 3, wherein said duct means comprises an inlet duct and an outlet duct connected to said induced draft fan and wherein said measuring means is in one of said inlet duct and said outlet duct.
Claim 6
Dependent Claim
25 words
A furnace system as set forth in claim 4, wherein said measuring means comprises means for measuring the velocity of the flow of said gas.
Claim 7
Dependent Claim
292 words
In a furnace system having a combustion chamber, fan means and duct means connected to said chamber for moving gas along a path extending from exteriorly of and into said chamber, through said chamber and then outwardly from and away from said chamber, said fan means comprising an induced draft fan and said duct means comprising an inlet duct interconnecting said fan with said chamber for removing said gas therefrom and an outlet duct connected to said fan, gas flow modifying means in said path for modifying the flow of gas through said chamber and control means comprising measuring means in said path and connected to at least part of said gas flow modifying means for normally maintaining the flow of said gas at predetermined levels, the combination therewith of gas flow measuring means in the path of said gas outside said chamber and responsive to changes in the flow of said gas, limiting means interconnecting said last-mentioned measuring means and at least part of said gas flow modifying means for changing the flow of said gas from said predetermined levels to further predetermined levels dependent upon the rate of flow of said gas exteriorly of said chamber, said further predetermined levels being higher with an increasing rate of flow of said gas exteriorly of said chamber, said gas flow modifying means comprising a variable damper in said inlet duct for varying the duct passageway size at said damper, said measuring means comprising a flapper pivotally mounted in said outlet duct adjacent to said fan and variable in position in accordance with the rate of flow of the gas in said outlet duct and said interconnecting means comprising mechanical means for varying said passageway size dependent upon the position of said flapper.
Claim 8
Dependent Claim
292 words
In a furnace system having a combustion chamber, fan means and duct means connected to said chamber for moving gas along a path extending from exteriorly of and into said chamber, through said chamber and then outwardly from and away from said chamber, said fan means comprising an induced draft fan and said duct means comprising an inlet duct interconnecting said fan with said chamber for removing said gas therefrom and an outlet duct connected to said fan, gas flow modifying means in said path for modifying the flow of gas through said chamber and control means comprising measuring means in said path and connected to at least part of said gas flow modifying means for normally maintaining the flow of said gas at predetermined levels, the combination therewith of gas flow measuring means in the path of said gas outside said chamber and responsive to changes in the flow of said gas, limiting means interconnecting said last-mentioned measuring means and at least part of said gas flow modifying means for changing the flow of said gas from said predetermined levels to further predetermined levels dependent upon the rate of flow of said gas exteriorly of said chamber, said further predetermined levels being higher with an increasing rate of flow of said gas exteriorly of said chamber, said gas flow modifying means comprising a variable damper in said inlet duct for varying the duct passageway size at said damper, said measuring means comprising a flapper pivotally mounted in said outlet duct adjacent to said fan and variable in position in accordance with the rate of flow of the gas in said outlet duct and said interconnecting means comprising mechanical means for varying said passageway size dependent upon the position of said flapper.
Claim 9
Dependent Claim
54 words
A furnace system as set forth in claim 6, wherein said mechanical means comprises a cam, first levers interconnecting said flapper and said cam for rotating said cam under control of said flapper and second levers interconnecting said cam and said damper for positioning said damper in accordance with the position of said cam.
Claim 10
Dependent Claim
59 words
A furnace system as set forth in claim 7, further comprising a second cam engageable with one of said second levers for positioning said damper in accordance with the position of said second cam and means interconnecting said control means and said second cam for positioning said second cam and hence, said damper, under control of said control means.
Claim 11
Dependent Claim
26 words
A furnace system as set forth in claim 6, wherein said mechanical means comprises a plurality of levers and linkages interconnecting said flapper and said damper.
Claim 12
Dependent Claim
130 words
A furnace system as set forth in claim 2, wherein said fan means also comprises a forced draft fan having an inlet and an outlet and said duct means comprises an outlet duct interconnecting said outlet of said forced draft fan and said chamber for supplying air to the latter and further comprising measuring means in said outlet duct and responsive to changes in the rate of flow of the air in said outlet duct, air flow modifying means at said inlet of said forced draft fan for varying the flow of air through said forced draft fan and means interconnecting said last-mentioned measuring means and said air flow modifying means for increasing the air flow through said forced draft fan when the air flow in said outlet duct increases.
Claim 13
Dependent Claim
111 words
A furnace system as set forth in claim 2, wherein said fan has an inlet and an outlet and rotatable gas impelling means between said inlet and said outlet for drawing gas into said inlet and expelling gas out of said outlet and thereby causing gas to flow through said fan, said inlet being connected to said chamber, and wherein said gas flow modifying means comprises control means connected to said gas impelling means for controlling the rate at which said impelling means causes gas to flow through said fan, said last-mentioned control means being connected to said last-mentioned measuring means for varying the flow rate of gas through said fan.
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) | 1979-06-22 | 1979-12-22 | 1980-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-22 | 1983-12-22 | 1984-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-22 | 1987-12-22 | 1988-06-22 | $7700.00 | Window Closed / Lapsed |