A Comprehensive Introduction To Float Glass Furnace: Flue
The flue is the passage for gases. Exhaust gases go down to the regenerator from the port and then are emitted into the atmosphere through the flue and chimney. Besides, it can also adjust the gas flow and pressure with shutters. It can produce pumping power by it height to overcome the resistance of the furnace including the chimney. Air is sprayed into the furnace and then the exhaust gases are discharged outside the furnace.
The flue system includes the air flue, coal gas flue, air branch flue, coal gas branch flue, the middle flue, the general flue and the flue leading to the waste heat boiler.
Above the flues are arch structures. The central angle is generally 90 °. The thickness of the arch is 230 mm. Its height is equal or bigger than its width. The exhaust gases through the flues is hot(500-600℃). The inner wall is built with
fireclay bricks, the external wall is built with red bricks and the bottom is built with concrete. To prevent concrete from being too hot, diatomite insulation bricks are paved. The top arch of ground flues or outdoor flues and the sidewalls are generally insulated with a insulation layer to avoid big drop og temperature.
In float glass furnaces fueled with heavy oil or natural gas, the flue arrangement is simple. Flues are set in the inside of regenerators below the furnace. A flue is composed of the general flue, and branch flues. Dampers and combustion air inlets are set on the branch flues. Air(smoke)-gas reversing dampers are set on branch flues. Rotary dampers are set on the general flues to adjust the pressure of furnaces. A damper is set in the chimney to adjust the pumping power.
In float glass furnaces fueled with coal gas, the flue arrangement is complex since there are two flues, air flue and coal gas flue.
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