We know that tin tanks are the key thermal equipment for glass molding in float glass production, because the glass liquid is diluted or stacked on the surface of the molten tin liquid into products of various thicknesses. Therefore, the working condition of the tin tank plays a crucial role in the quality and output of the glass. The nitrogen base atmosphere is not only the inert gas of the tin tank, but also the reducing gas, which plays a decisive role in the normal operation of the tin tank. When transporting nitrogen in the tin tank, it must be required to be continuous and stable, and to contain as little oxygen as possible. Once the gas supply fluctuates (or the gas supply is interrupted), a large amount of external oxygen will penetrate into the tin tank, causing tin oxidation, resulting in a large amount of volatilization of tin oxide and tin oxide, resulting in a turbidity in the tin tank, and production cannot be carried out.

There are about 70 float glass production lines in China, and the nitrogen demand of each production line is about 1500m3/h. Most of the configured air separation equipment is a single tower process of low pressure reflux expansion, and the gas supply of each equipment is 800~1600m3/h N2 during normal operation.

It is an effective way to save energy and reduce environmental pollution by using excess oxygen or oxygen-enriched air in float production line to promote the new oxygen-enriched combustion technology in glass melting kiln.

So far, there are more than 40 float glass production lines in operation in China (there are still some float production lines under construction). If the oxygen or oxygen-rich air in the float production line that has been put into operation is recovered, at least 115.63 million cubic meters of pure oxygen can be recovered every year. If all of this oxygen is added to the furnace to aid combustion, it can save 17,103.2 tons of fuel per year (equivalent to standard coal) only from the aspect of energy saving, which does not include the energy consumption saved by reducing the amount of smoke.

In addition, the use of oxygen-rich combustion can increase the flame temperature, improve the combustion condition, reduce the flue pollution, so it has good business and social benefits. It can be seen that the oxygen-rich combustion process has the characteristics of low investment, high benefit, safety and reliability, stable performance, etc., and it is worth popularizing and applying in the float glass production line.