The present invention relates to a float-glass manufacturing apparatus including a float bath and a heat treatment furnace, in which the heat treatment furnace includes: a dross box including a plurality of lift-out rolls; an annealing furnace including a plurality of lehr rolls; a first partitioning part; a second partitioning part; a gas ejection nozzle; and a guide member.

According to the present invention, provided is a heater including a heat generating member being conductive and configured to radiate heat rays by being fed with electric power, a tubular member constituted by a metal and accommodating the heat generating member, and an intermediate member arranged between the heat generating member and the tubular member and constituted by an electrically insulating material, wherein the intermediate member is arranged and/or configured to allow, among the heat rays radiated from the heat generating member, at least light having a wavelength of from 1 m to 2 m to pass through the intermediate member to reach the tubular member.

According to the present invention, provided is a heater including a heat generating member being conductive and configured to radiate heat rays by being fed with electric power, a tubular member constituted by a metal and accommodating the heat generating member, and an intermediate member arranged between the heat generating member and the tubular member and constituted by an electrically insulating material, wherein the intermediate member is arranged and/or configured to allow, among the heat rays radiated from the heat generating member, at least light having a wavelength of from 1 m to 2 m to pass through the intermediate member to reach the tubular member.

A hot-formed, chemically prestressable glass article having a low percentage of crystals or crystallites, in particular a plate-shaped, chemically prestressable glass article, as well as to a method and a device for its production are provided. The glass article has a composition including the components SiO.sub.2, Al.sub.2O.sub.3, and Li.sub.2O and a content of seed formers (ZrO.sub.2, SnO.sub.2, and TiO.sub.2) of at least 0.8 wt %, as well as at most ten crystals, including crystallites, per kilogram of glass, which have a maximum diameter greater than 1 m and up to at most 5 m.

Processes and methods for preparing glass panels for use with automobiles include mixing and melting glass particles. Molten glass is passed along into a lehr, where the molten glass is annealed. Annealed glass is cut into glass panels. A nozzle systems delivers compressed air to the glass panels to form a curvature for providing a top seal contact area. A nozzle system delivers a second blast of compressed air, which marks the glass panel to identify characteristics of the glass panel.

Processes and methods for preparing glass panels for use with automobiles include mixing and melting glass particles. Molten glass is passed along into a lehr, where the molten glass is annealed. Annealed glass is cut into glass panels. A nozzle systems delivers compressed air to the glass panels to form a curvature for providing a top seal contact area. A nozzle system delivers a second blast of compressed air, which marks the glass panel to identify characteristics of the glass panel.

A device for annealing glass panes includes rollers for transporting the glass panes and two sets of slit-shaped nozzles, which run parallel to the axes of the rollers and from which cooling air can be directed onto both sides of the glass panes. In the device, cooling air acts as effectively as possible on the two surfaces of the glass pane, and anisotropies and stresses within the glass are reduced. This can be achieved by each nozzle being formed as a continuous flow channel, which extends over the width of the glass panes and on both parallel running sides of which partitions are arranged, for the forming of a flow pocket assigned to this flow channel. The cooling air that comes back from the glass panes is returned between this flow channel and the associated partitions.

A device for annealing glass panes includes rollers for transporting the glass panes and two sets of slit-shaped nozzles, which run parallel to the axes of the rollers and from which cooling air can be directed onto both sides of the glass panes. In the device, cooling air acts as effectively as possible on the two surfaces of the glass pane, and anisotropies and stresses within the glass are reduced. This can be achieved by each nozzle being formed as a continuous flow channel, which extends over the width of the glass panes and on both parallel running sides of which partitions are arranged, for the forming of a flow pocket assigned to this flow channel. The cooling air that comes back from the glass panes is returned between this flow channel and the associated partitions.

A device for annealing glass panes includes rollers for transporting the glass panes and two sets of slit-shaped nozzles, which run parallel to the axes of the rollers and from which cooling air can be directed onto both sides of the glass panes. In the device, cooling air acts as effectively as possible on the two surfaces of the glass pane, and anisotropies and stresses within the glass are reduced. This can be achieved by each nozzle being formed as a continuous flow channel, which extends over the width of the glass panes and on both parallel running sides of which partitions are arranged, for the forming of a flow pocket assigned to this flow channel. The cooling air that comes back from the glass panes is returned between this flow channel and the associated partitions.

A device for annealing glass panes includes rollers for transporting the glass panes and two sets of slit-shaped nozzles, which run parallel to the axes of the rollers and from which cooling air can be directed onto both sides of the glass panes. In the device, cooling air acts as effectively as possible on the two surfaces of the glass pane, and anisotropies and stresses within the glass are reduced. This can be achieved by each nozzle being formed as a continuous flow channel, which extends over the width of the glass panes and on both parallel running sides of which partitions are arranged, for the forming of a flow pocket assigned to this flow channel. The cooling air that comes back from the glass panes is returned between this flow channel and the associated partitions.