LandGlass explains the advantages of forced convection glass tempering furnaces, compared with radiation furnaces:
- Forced convection glass tempering furnaces use a combination of a high-temperature convection blower and a convection chamber to heat the glass in the furnace through forced convection.
This approach does not require a thermal balance device used in the radiation tempering furnace. The intensity of convection heating is adjustable. The high-temperature convection blower uses different rotation rates in different heating phases to control the temperature rising speeds of the upper and lower surfaces so that both surfaces can reach heat uniformity quickly to meet the process requirements for high-quality tempered glass. Especially when processing off-line Low-E glass and tempered laminated glass, the surface deformation of the finished tempered glass is minimal, with the local bow of a 5mm thick Low-E glass ≤ 0.06mm.
It is simply not possible for a conventional radiation glass tempering furnace to accomplish these results.
- Forced convection glass tempering furnaces take less time than radiation furnaces to heat the glass, offering higher efficiency.
The time it takes for a convection glass tempering furnace to heat ordinary clear glass: 35 to 40 seconds per millimetre; the time for heating Low-E glass: 40 to 50 seconds per millimetre. A forced convection tempering furnace can increase the output by 20 to 30 percent compared with that of a radiation furnace while the actual oven temperature can be lowered by approximately 20℃, resulting in 20 to 30 percent of energy savings in comparison with the radiation tempering furnace.