Patent ID: 9683741
Date: 2017-06-20
CPC Classifications: F23C,F23J,F23L,Y02E

Claim:
1. A fired heater, comprising: a fired heater body with an air inlet and an flue gas outlet, and a flue gas waste heat recovery system communicated with said fired heater body, including a first and second heat exchange chambers, wherein a first port of each of said first and second heat exchange chambers is configured to communicate with said flue gas outlet or air inlet, and a second port of each of said first and second heat exchange chambers is configured to communicate with the outside air or with a fume extractor, wherein, when the first port of the first heat exchange chamber is communicated with said flue gas outlet and the second port of the first heat exchange chamber is communicated with said fume extractor, the first port of the second heat exchange chamber is communicated with said air inlet and the second port of the second heat exchange chamber is communicated with the outside air, wherein a gas mixing tank is provided between said flue gas waste heat recovery system and said air inlet, wherein an inlet of said gas mixing tank is configured to communicate with the first port of said first or second heat exchange chamber, and an outlet of said gas mixing tank is configured to communicate with said air inlet, wherein said fired heater further comprises a first four-way valve and a second four-way valve for switchover of said first and second heat exchange chambers, wherein said first four-way valve is configured to communicate with the first ports of said first and second heat exchange chambers, said flue gas outlet and air inlet, and said second four-way valve is configured to communicate with the second ports of said first and second heat exchange chambers, said fume extractor and the outside air, wherein an inlet of the gas mixing tank is communicated with the first four-way valve, and wherein the gas mixing tank is only in communication with the first or second heat exchange chamber in an exothermic stage.