Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B35/00—Transporting of glass products during their manufacture, e.g. hot glass lenses, prisms
  • C03B35/14—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands
  • C03B35/16—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors
  • C03B35/18—Construction of the conveyor rollers ; Materials, coatings or coverings thereof
  • C03B35/183—Construction of the conveyor rollers ; Materials, coatings or coverings thereof specially adapted for thermal adjustment of the rollers, e.g. insulating, heating, cooling thereof
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B27/00—Tempering or quenching glass products
  • C03B27/04—Tempering or quenching glass products using gas
  • C03B27/044—Tempering or quenching glass products using gas for flat or bent glass sheets being in a horizontal position
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B29/00—Reheating glass products for softening or fusing their surfaces; Fire-polishing; Fusing of margins
  • C03B29/04—Reheating glass products for softening or fusing their surfaces; Fire-polishing; Fusing of margins in a continuous way
  • C03B29/06—Reheating glass products for softening or fusing their surfaces; Fire-polishing; Fusing of margins in a continuous way with horizontal displacement of the products
  • C03B29/08—Glass sheets
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B35/00—Transporting of glass products during their manufacture, e.g. hot glass lenses, prisms
  • C03B35/14—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands
  • C03B35/16—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors
  • C03B35/162—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors combined with means for thermal adjustment of the rollers, e.g. cooling

Definitions

• the glass surface cools down before tempering, it will not be tempered or at least higher cooling power will be required. That is why it is advantageous to ensure, that the glass is in high enough temperature when it comes into the tempering. Overheating of the glass does not help achieving correct degree of tempering, but it would worsen optical quality and waste energy.
• Thin glasses cool down especially quickly after exiting from the furnace. Even in still air, the cooling rate is about 6 centigrade per second. If the glass is subjected to convection caused by moving air, the cooling rate is multiplied. Even if the air blown onto the glass is hot, (however cooler than the glass), it would still cool down the glass. Thin glasses require very high cooling power, so especially for them correct choices are important in order to get the best result.
• the most usual method for elimination of the mentioned disadvantages is that the glass is driven into the tempering section with high speed, normally about 0, 6 m /s. There are different known methods, trying to eliminate the air flow into the direction of the furnace.
• the glass driving speed could be reduced to 0, 3 m/s, it would be possible to shorten the tempering section down to 0, 6 m and glass would still remain under the quench the necessary 2 seconds.
• Thicker glasses are driven into the tempering section normally with lower speed, about 0, 3 m/s, but with thin glasses that has not been possible due to the reasons mentioned earlier.
• a very short and effective border between hot section, (furnace) and cold section, (tempering part) would be necessary so that the glass would not cool down during this travel.
• the border should also have similar characteristics on the top and bottom sides of the glass. Otherwise the result would be different cooling on the top side and on the bottom side and the glass would bend during tempering.
• Publication 0425998 A1 describes sucking channels arranged between the furnace and the tempering section above and below the glass. The problem caused by them is cooling of glass by air flow flowing along the surfaces of the glass before the glass arrives under the tempering nozzles. Another disadvantage is increased need for the space between the rollers.
• a very short and effective borderline between hot and cold are arranged so that glass cooling is prevented before it enters under the first row of tempering nozzles.
• the trailing end of the glass will be supported by roller or other means just before the first row of tempering nozzles so that the distance from the last support to the first row of tempering nozzles will be remarkably less that typical roller C-C distance, under 120 mm, preferably something like half of that.
• Figure 1 shows side view of a part of the tempering furnace according to the invention.
• Figure 2 shows an alternative solution to stop the flow of cooling air.
• Figure 1 shows advantageous arrangement to transfer the glass G from furnace F into tempering section.
• Picture 1 shows hot air jets Jha, furnace roller Rf, hot air return AEha and first or few first ones or even all tempering air exit channel(s) with under pressure Aeup.
• the tempering section rollers R are smaller ones and cooling blowing is arranged through nozzle blocks NB to the under- and topside of the glass. The air if fed from air supply channel AS.
• the tempering air blown through the first nozzle block(s) is removed from temperi g section by leading on the top and bottom sides of the glass suitable under pressure Aeup at least aside of the first row of tempering nozzles on the direction of the glass travel, on the side of the tempering section. It is also advantageous to aim the first air jets somewhat in the direction of the tempering section.
• the system shown on the picture also makes it possible to arrange the first row of tempering nozzles close to the last roller or other supporting means of the furnace. Thus it immediately cools down the glass and the trailing end of the glass does not need to stay as completely hot, longish “cantilever" supported by the first roller of tempering section, in which case it would bend more easily.
• the cooling jets are arranged in the similar way as in picture 1.
• the end of the furnace there are air beds AB with small clearance, into which hot air, with temperature of glass tempering temperature, is blown.
• air beds With air beds it is possible to create short and effective border with cold and hot and thus prevent cooling of glass before tempering.
• the air beds must be located very near to the tempering jets, J.
• the air bed AB is advantageous at least under the glass, where it also supports the glass, as the glass exits from the furnace. Under pressure Aeup on the other hand is suitable above the glass. These air flow arrangements, under pressure and air bed together or alone or combined in various ways, prevent the flow of tempering air into the direction of the furnace.
• the upper air bed has to be made adjustable up and down to facilitate tempering of different glass thicknesses and to close the furnace for the heating period.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8564029

Family Applications (1)

Country Status (4)

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Family Cites Families (6)

• 2002
  • 2002-05-30 FI FI20021014A patent/FI20021014A0/sv unknown
• 2003
  • 2003-05-30 AU AU2003238532A patent/AU2003238532A1/en not_active Abandoned
  • 2003-05-30 WO PCT/FI2003/000427 patent/WO2003101897A1/en not_active Application Discontinuation
  • 2003-05-30 EP EP03732601A patent/EP1511693A1/en not_active Withdrawn

Non-Patent Citations (1)

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