Engineering Simulation Study Of Float Glass Annealing Process In Annealing Lehr A-B-C Region

Float glass production includes three thermal processes: melting, forming, the qualityof annealing influences the cutting of glass, deep processing of glass and subsequent using.It’s direct impact on the interests of the company. With the intense competition of floatglass market, the production of “multi-species, multi-specification, high-quality” floatglass has become an important means for enterprises to enhance their competitiveness.Due to the lack of understanding on the mechanism of the glass annealing process, it’sdifficult for enterprises to control properly, and then can not produce perfect glass thatmeets market demand. Therefore, the study of the float glass annealing process isparticularly important.This paper is based on the basic material properties of float glass and combined floatglass annealing process characteristic. The annealing process of float glass in the regionA-B-C of annealing lehr was researched by the ANSYS software.2D5mm glass finiteelement model that across thickness was build. The change of glass temperature field inannealing lehr region A and B was researched. The viscoelastic model was used to studythe variation law of stress across the thickness of glass in region A and B. The10mm,15mm,20mm,25mm glass were also studied under the same production scale, it includesthe variation of temperature difference between the surface and the center of glass ribbonin the region A and B, the variation of stress across thickness and the temperaturesdistribution across thickness at the outlet of region C. At the same time, permanent stresswhich produces in this process was calculated. Elastic model was used to calculate thetemporary stress of different thickness glass at the outlet of region C.By the above research, some conclusion could be done: the temperature acrossthickness of glass ribbon was parabolic distribution in annealing process; With theincrease of thickness, the maximum temperature difference between center and surfacegenerated in the region A increases, time to generate the maximum temperature differencealso increases; the temperature difference between center and surface is increaseddramatically at the junction of region A and B, and then becomes gradually smaller duringthe cooling process in B zone; when producing25mm glass, the core temperature of glassis385℃, the task of region C is unfinished. When the space temperature above glassribbon is adjusted to340℃, the core temperature can be lowered to380℃.The surface stress of glass ribbon experienced tensile stress-compressive stress- tensile stress-compressive stress changes process in the annealing lehr region A and B, onthe contrary, the center stress experienced compressive stress-tensile stress-compressivestress–tensile stress changes process. The stress direction experienced two transformationprocesses. As the thickness increases, the transition time increases. At the outlet of regionB, the residual stress in glass ribbon reaches maximum, and increases as the thicknessincreases. The surface permanent compressive stress produced in annealing process for5mm,10mm,15mm,20mm,25mm glass are respectively:1.35MPa,2.55MPa,3.78Mpa,5.14MPa,6.15MPa; the core permanent tensile stress are respectively:0.68MPa,1.28MPa,1.89MPa,2.56MPa,3.04MPa.At the outlet of region C, the temporary stress in glass ribbon glass increases as thethickness increases. The maximum temporary tensile stress at the outlet of region C for5mm,10mm,15mm,20mm,25mm glass are respectively:4.06MPa,6.28MPa,8.84MPa,9.49MPa,12.1MPa.