Float glass production device and float glass production method

A float-glass manufacturing apparatus comprising a float bath to form a glass ribbon on a molten metal and a heat treatment furnace to anneal the glass ribbon, wherein the heat treatment furnace comprises:

• a dross box comprising a plurality of lift-out rolls to lift the glass ribbon;
• an annealing furnace comprising a plurality of lehr rolls to convey the glass ribbon;
• a first partitioning part disposed in a bottom portion of the heat treatment furnace so as to lie between the lift-out roll located most downstream in a conveyance direction of the glass ribbon and the lehr roll located most upstream in the conveyance direction;
• a second partitioning part disposed over the first partitioning part, the second partitioning part and the first partitioning part being respectively on both sides of a conveyance route to convey the glass ribbon therethrough;
• a gas ejection nozzle which ejects a sulfur oxide gas from under the conveyance route toward the conveyance route;
• a gas discharge part disposed upstream in the conveyance direction from the gas ejection nozzle, wherein the heat treatment furnace comprises a shielding plate to partition a space between a bottom portion of the annealing furnace and the gas discharge part;
• the shielding plate is connected to a bottom portion of the gas discharge part;
• and
• a gas collection nozzle is disposed at an upper end portion of the first partitioning part.

A float-glass manufacturing method comprising forming a glass ribbon on a molten metal in a float bath and annealing the glass ribbon in a heat treatment furnace,

• wherein in the heat treatment furnace, the glass ribbon is lifted in a dross box using a plurality of lift-out rolls and is conveyed in an annealing furnace using a plurality of lehr rolls,
• a first partitioning part and a second partitioning part are respectively on both sides of a conveyance route to convey the glass ribbon therethrough, in which the first partitioning part is disposed in a bottom portion of the heat treatment furnace so as to lie between the lift-out roll located most downstream in the conveyance direction of the glass ribbon and the lehr roll located most upstream in the conveyance direction, and the second partitioning part is disposed over the first partitioning part,
• a sulfur oxide gas is ejected by a gas ejection nozzle from under the conveyance route toward the conveyance route,
• a gas discharge part is disposed upstream in the conveyance direction from the gas ejection nozzle, and
• a distance from the conveyance route to the first partitioning part or a distance from the conveyance route to the second partitioning part is regulated on the basis of results of detection with a gas collection nozzle disposed at an upper portion of the first partitioning part.