Abstract A paint line oven and heat source comprising a stack having fuel-fired burners in the lower portion thereof, and a solventburner section at the bottom of the stack. A blower intake duct is connected to the stack above the burners and draws off part of the hot exhaust from the stack. This is mixed with fresh air and circulated through the oven, where it evaporates paint solvent. A portion of the solvent-laden air is bled off to the solventburner section, where the solvent vapor is ignited and burns, adding its heat to the heat of the burners. A first temperature sensor in solvent-burner section actuates a valve to increase the amount of oven atmosphere bled off to the solvent-burner section as the temperature rises. A second sensor responds to the temperature in the upper part of the stack to reduce the heat output of the burners as the heat of solvent combustion raises the stack temperature. A third sensor in the blower outlet duct actuates valves to vary the relative proportions of hot flue gas and fresh air, according to the temperature in the oven.
An emission-controlled 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; a mixing chamber having a hot air duct connected to said heat source enclosure and a fresh air duct for taking in atmospheric air; 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 mixing chamber; proportioning valve means for regulating the relative proportions of hot air and cool fresh air admitted to said mixing chamber, said valve means including an actuator; a first temperature sensor located in a position to respond to the temperature of the air being circulated to said oven by said blower, said sensor being operatively connected to said proportioning valve means actuator to increase or decrease the respective proportions of hot air and cold air admitted to said mixing chamber responsive to temperature changes in the air being circulated by the blower; said heat source enclosure having a solvent-burner section adjacent said heat generating means; a by-pass duct connected at one end to said blower outlet duct and at the other end to said solvent-burner section; igniter means within said solvent-burner section for igniting the solvent vapors delivered thereto by said by-pass duct; by-pass valve means and an actuator therefor to regulate the amount of blower air sent to said solvent-burner section; a second temperature sensor located in said solvent-burner section and operatively connected to said by-pass valve means actuator to open said by-pass valve means wider as the temperature in the solvent-burner section increases, and to close it as the tEmperature decreases; and a third temperature sensor located in said heat source enclosure in a position to measure the total heat-output due to said heat-generating means and to the combustion of solvent, said third temperature sensor being operatively connected to said heat-generating means to reduce their heat output as the heat of combustion of said solvent vapor causes the temperature in said enclosure to rise above a predetermined level.
Claim 2
Dependent Claim
367 words
An emission-controlled 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; a mixing chamber having a hot air duct connected to said heat source enclosure and a fresh air duct for taking in atmospheric air; 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 mixing chamber; proportioning valve means for regulating the relative proportions of hot air and cool fresh air admitted to said mixing chamber, said valve means including an actuator; a first temperature sensor located in a position to respond to the temperature of the air being circulated to said oven by said blower, said sensor being operatively connected to said proportioning valve means actuator to increase or decrease the respective proportions of hot air and cold air admitted to said mixing chamber responsive to temperature changes in the air being circulated by the blower; said heat source enclosure having a solvent-burner section adjacent said heat generating means; a by-pass duct connected at one end to said blower outlet duct and at the other end to said solvent-burner section; igniter means within said solvent-burner section for igniting the solvent vapors delivered thereto by said by-pass duct; by-pass valve means and an actuator therefor to regulate the amount of blower air sent to said solvent-burner section; a second temperature sensor located in said solvent-burner section and operatively connected to said by-pass valve means actuator to open said by-pass valve means wider as the temperature in the solvent-burner section increases, and to close it as the tEmperature decreases; and a third temperature sensor located in said heat source enclosure in a position to measure the total heat-output due to said heat-generating means and to the combustion of solvent, said third temperature sensor being operatively connected to said heat-generating means to reduce their heat output as the heat of combustion of said solvent vapor causes the temperature in said enclosure to rise above a predetermined level.
Claim 3
Dependent Claim
23 words
An emission-controlled paint line oven as in claim 1, wherein said first temperature sensor is located in the outlet duct of said blower.
Claim 4
Dependent Claim
92 words
An emission-controlled paint line oven as in claim 1, wherein said heat source enclosure comprises an elongated stack having fuel-fired burners discharging flame into the same near one end thereof, and combustion gases exhausting from the other end thereof, said solvent-burner section being located in said stack adjacent said one end whereby burning solvent vapors ignited in said solvent-burner section pass through the flame of said fuel-fired burners and continue to burn as they travel lengthwise in said stack, said third temperature sensor being located in said stack downstream of said burners.
Claim 5
Dependent Claim
54 words
An emission-controlled paint line oven as in claim 3, wherein said mixing chamber hot air duct is connected to said stack on the side of said burners toward said other end, said third temperature sensor being located in the area adjacent the point where said mixing chamber hot air duct connects to the stack.