Metal curing ovens with quick heat-up and cool-down, and processes of using same

A system comprising:

• (a) an insulated oven having an entry end, an exit end, and a longitudinal axis and comprising:
• (i) an oven entry enclosure at the entry end having one or more cool-down fans and one or more dampers attached thereto;
• (ii) a first direct-fired, forced draft combustion chamber mechanically and fluidly connected to the oven entry enclosure and comprising a first set of one or more direct-fired, forced draft combustion chamber burners;
• (iii) a first transition chamber mechanically and fluidly connected to an exit of the first direct-fired, forced draft combustion chamber;
• (iv) a second direct-fired, forced draft combustion chamber mechanically and fluidly connected to the first transition chamber and comprising a second set of one or more direct-fired, forced draft combustion chamber burners;
• (v) a second transition chamber mechanically and fluidly connected to an exit of the second direct-fired, forced draft combustion chamber;
• (vi) a converging enclosure mechanically and fluidly connected to a distal end of the second transition chamber, the converging enclosure having a cross-sectional area that decreases along the longitudinal axis from an exit of the second transition section, the converging enclosure comprising one or more upper direct-fired flame impingement burners and one or more lower direct-fired flame impingement burners;
• (vii) an oven exit enclosure mechanically and fluidly connected to an exit of the converging enclosure and having one or more exhaust fans fluidly connected to the oven exit enclosure;
• (viii) one or more cool-down doors on the second transition chamber;
• and
• (ix) one or more pilot burners;
• (b) one or more first actuators configured to stop movement through the insulated oven of a wet coated continuous metal sheet, a dried, uncured coated first cycle heated continuous metal sheet, and a dried, cured first cycle coated continuous metal sheet upon receipt of a first signal;
• (c) one or more second actuators configured to stop combustion in the first and second sets of one or more direct-fired, forced draft combustion chamber burners, the one or more direct-fired flame impingement upper burners, and the one or more direct-fired flame impingement lower burners, but maintain combustion of the one or more pilot burners;
• and
• (d) one or more third actuators configured to open the one or more cool-down doors, and one or more fourth actuators configured to operate the one or more cool-down fans and the one or more dampers to allow ambient air to flow into the first and second direct-fired, forced draft combustion chambers in a cool-down cycle upon receipt of a control signal to begin the cool-down cycle and reduce temperature of the dried, uncured coated first cycle heated continuous metal sheet and the dried, cured first cycle coated continuous metal sheet.