What Are The Temperature Control Requirements for Glass Tempering Furnaces Equipment?

Most glass processing factories use horizontal tempering furnaces to produce tempered glass. What are the requirements for temperature control in a glass tempering furnace when using a horizontal tempering furnace? Simply put, there are two basic requirements.

1. The temperature of each part of the glass surface should not differ too much, which means uniform heating should be achieved;

2. Glass must be quickly heated to the required temperature.

The temperature control requirements of the glass tempering furnace during the tempering process revolve around these two core aspects.

1. Uniform heating

1.1. To avoid the influence of temperature difference between the upper and lower surfaces of glass on the glass tempering effect. If the temperature difference between the upper and lower surfaces is too large, it is easy to cause unevenness, deformation, and even breakage of the glass. In the production process, we need to achieve the following two points: first, the arrangement of glass placement in each furnace and the gap time between each furnace should be uniform; Then, in order to ensure the uniformity and consistency of the roller temperature and avoid excessive temperature between the glass plates, if there is a gap in the longitudinal direction during the placement of the glass, this gap should be filled when placing a furnace of glass.

1.2.When the glass first enters the furnace, convection heating should be increased, and the upper and lower heat balances should be activated. Through the high-temperature hot air circulation system in the furnace, the high-temperature air in the furnace can be circulated to effectively solve the problem of large temperature differences at various points of the glass.

In the second half of the glass tempering furnace, the temperature difference at each point of the glass is no longer significant. The main approach should be to increase the heating speed. The various heat balances can be turned off until the glass temperature is consistent with the set furnace temperature, and the heating process ends.

1.3.If we encounter the phenomenon of convexity and concavity at the edges of the glass, we can control it from two aspects. On the one hand, we can increase the thermal balance pressure inside the furnace, increase thermal convection, and adjust the thermal balance inside the furnace to reduce the temperature difference between the middle and edge of large glass areas. On the other hand, we can appropriately extend the heating time of the glass, which can also reduce the temperature difference between the middle and edge of the glass.

2. Heating temperature

2.1. The thinner the tempered glass in the glass tempering furnace, the higher the heating temperature. The thicker the glass, the lower the heating temperature. Therefore, in terms of tempered glass technology, it is not clear which temperature setting to set. The choice of temperature largely depends on the quality of the original glass and the process parameters adjusted by the operator. The process parameters can be found online, so I won't describe them much here. In actual production, the adjustment of heating temperature is mainly achieved by adjusting the heating time to control the heating temperature. Every operator should master the basic calculation method of heating time.

2.2.The bottom temperature measured by the heating system of the glass tempering furnace is not the roller temperature, but the average temperature after the heating element at the bottom of the tempering furnace compensates for the heat absorbed by the roller glass. For this reason. The measured temperature is generally higher than the measured upper temperature, so the temperature setting for upper heating is generally higher than that for lower heating.

2.3. Avoid overloading the glass tempering furnace. Under normal operating conditions, there is always glass absorbing heat in the heating area of the heating element in the middle of the glass tempering furnace, and there is always glass present in this area of the electric furnace. If the heat consumption in a certain area of the electric furnace exceeds the heating effect, the temperature in that area will start to decrease and continue to drop until the temperature is balanced. Therefore, once the glass tempering furnace experiences overload, it will cause the glass to break in the cooling section.