US3787171A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Closed loop, inert atmosphere, paint line oven heat source
Assignee: Hunter Engineering Co
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Filing: 1972-06-15
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Granted: 1974-01-29
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Expires: 1992-06-15
Abstract
Abstract A paint line oven and heat source comprising a stack having fuel-fired burners in the lower portion thereof, and a closed loop conduit system with a circulating blower therein, which takes hot, inert stack gas from the stack above the burners, and circulates it through the oven, where paint solvent is evaporated from the painted product. Solvent-laden oven atmosphere is discharged into the stack below the burners and mixes with excess air supplied through the burners, where the solvent burns, adding its heat to the heat of the burners. Stack atmosphere at the conduit intake is substantially oxygen-free, and is hotter than the predetermined oven temperature. A water-cooled heat exchanger in the conduit cools the stack atmosphere down to the preselected oven temperature before discharging it into the oven. In one embodiment, temperature-controlled valves regulate the volume of stack atmosphere delivered to the oven, and the rate of flow of coolant in the heat exchanger, so that uniform temperature is maintained automatically.
Inventors
- 👤 T Cromp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:10
CPC Classifications
F; F26; F26B; F26B23/00; F26B23/02; F26B23/022; F26B21/00; F26B21/40
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
258 words
A closed loop, inert atmosphere, paint line oven for evaporating paint solvent from freshly painted metal strip, comprising: an enclosed oven through which said painted strip passes; a heat source comprising an enclosure having means therein for generating heat; an intake conduit connected into said enclosure above said heat generating means; a blower having an intake duct and an outlet duct, said outlet duct discharging into said oven and said intake duct including a first branch connected to said oven and a second branch connected to said intake conduit; a discharge duct connected at one end to said blower outlet and at the other end to said enclosure below said heat generating means; valve means for deflecting a portion of the blower output into said discharge duct, whereby a portion of the oven atmosphere laden with solvent vapor is exhausted through said discharge duct into said enclosure; means associated with said enclosure for introducing a quantity of fresh air into the interior thereof just sufficient to combine with the solvent vapor and cause combustion thereof, the oxygen in said introduced air being consumed by the combustion of said solvent vapor, so that the hot gas in said enclosure at the level of said intake conduit is substantially oxygen-free and inert; and heat exchange means in said intake conduit for removing excess heat from the hot gas drawn from said enclosure before discharging the same into said oven, said heat exchange means reducing the temperature of said hot gas to substantially the same temperature as that of the oven.
Claim 2
Dependent Claim
258 words
A closed loop, inert atmosphere, paint line oven for evaporating paint solvent from freshly painted metal strip, comprising: an enclosed oven through which said painted strip passes; a heat source comprising an enclosure having means therein for generating heat; an intake conduit connected into said enclosure above said heat generating means; a blower having an intake duct and an outlet duct, said outlet duct discharging into said oven and said intake duct including a first branch connected to said oven and a second branch connected to said intake conduit; a discharge duct connected at one end to said blower outlet and at the other end to said enclosure below said heat generating means; valve means for deflecting a portion of the blower output into said discharge duct, whereby a portion of the oven atmosphere laden with solvent vapor is exhausted through said discharge duct into said enclosure; means associated with said enclosure for introducing a quantity of fresh air into the interior thereof just sufficient to combine with the solvent vapor and cause combustion thereof, the oxygen in said introduced air being consumed by the combustion of said solvent vapor, so that the hot gas in said enclosure at the level of said intake conduit is substantially oxygen-free and inert; and heat exchange means in said intake conduit for removing excess heat from the hot gas drawn from said enclosure before discharging the same into said oven, said heat exchange means reducing the temperature of said hot gas to substantially the same temperature as that of the oven.
Claim 3
Dependent Claim
31 words
A paint line oven as in claim 1, wherein said heat exchange means comprises a coil of pipe arranged in said intake conduit and connected to a source of coolant fluid.
Claim 4
Dependent Claim
105 words
A paint line oven as in claim 2, further comprising valve means connected into said coil of pipe to control the rate of flow of said fluid coolant therein, and a temperature sensor located downstream of said heat exchange means for measuring the temperature of the hot gas leaving said heat exchange means, said sensor being operatively connected to said valve means to increase the rate of flow of said coolant when the temperature rises above a predetermined level, and to decrease the rate of flow when the temperature falls below said level, whereby hot gas of substantially constant temperature is delivered to said oven.
Claim 5
Dependent Claim
77 words
A paint line oven as in claim 1, wherein said means for generating heat comprises at least one burner located in said enclosure between said discharge duct and said intake conduit, said burner being supplied with fuel and air, and the quantity of air being in excess of the amount required for combustion of the fuel, whereby there is an excess of oxygen supplied to the interior of said enclosure just sufficient to burn the solvent vapor.
Claim 6
Dependent Claim
92 words
A paint line oven as in claim 1, wherein said heat source enclosure has a solvent-burner section adjacent said heat generating means, said discharge duct emptying into said solvent burner section, and means supplying a limited quantity of oxygen to the solvent vapor laden gas discharged into said solvent burner section, so that said solvent vapor is caused to burn, thereby consuming both the solvent vapor and the oxygen, and leaving an inert atmosphere, the heat of combustion of said solvent being added to the heat output of said heat generating means.
Claim 7
Dependent Claim
84 words
A paint line oven as in claim 5, wherein said means for generating heat comprises at least one burner located in said enclosure between said solvent burner section and said intake conduit, said burner being supplied with fuel and air; a temperature sensor located within said enclosure above said burner; and control means actuated by said temperature sensor to shut down said burner when the temperature within said enclosure exceeds a predetermined level owing to the additional heat supplied by combustion of the solvent.
Claim 8
Dependent Claim
84 words
A paint line oven as in claim 6, wherein a second temperature sensor is located in said solvent burner section; and means actuated by said second temperature sensor responsive to variations in the temperature within said solvent burner section for increasing or decreasing the proportion of blower output diverted to said solvent burner section; and said means being operable to increase the amount of oven atmosphere discharged into said solvent burner section when the temperature therein rises, indicating a higher concentration of solvent vapor.
References Cited (Backward Citations)
US2795054A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |