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There are three types of floating glass in the world today: flat drawn, float, and rolled. Float glass accounts for more than 90% of the current total glass production and is the basic building material in the world's architectural glass. The float glass production process was founded in 1952, setting a world standard for high-quality glass production. The floating glass process includes five main steps:

Float glass processing

Float glass processing

● Floating Glass Ingredients  

● Floating Glass Melting   

● Floating Glass Forming and Coating  

● Floating Glass Annealing   

● Floating Glass Cutting and Packaging

Floating Glass Ingredients  

The batching is the first stage, which prepares raw materials for melting. The raw materials include sand, dolomite, limestone, soda ash and Glauber's salt, which are delivered continuously by truck or train. These raw materials are stored in the batching room. There are silos, hoppers, conveyor belts, chutes, dust collectors, and necessary control systems in the material room to control the transportation of raw materials and the mixing of batch materials. From the moment the raw materials are delivered to the material room, they are constantly moving.   

Figure 1 Typical glass composition

Figure 1 Typical glass composition

Inside the batching room, a long flat conveyor belt continuously transports the raw materials from various raw material silos to the bucket elevator one by one in order, and then to the weighing device to check the compound weight. Recycled glass fragments or production line waste will be added to these components. Each batch contains approximately 10-30% glass cullet. The dry materials are added to the mixer and mixed into batch materials. The stirred batch materials are sent from the batching room to the kiln head silo through a conveyor belt for storage, and then fed into the furnace at a controlled rate by a feeder.

Figure 2 Broken glass yard

Figure 2 Broken glass yard

Floating Glass Melting

A typical furnace is a horizontal flame furnace with six regenerators, approximately 25 meters wide and 62 meters wide, and has a daily production capacity of 500 tons. The main part of the melting furnace is the melting tank/clarification tank, working tank, regenerator and small furnace, as shown in Figure 4, built of special refractory materials, and the outer frame has a steel structure. The batch material is sent to the melting pool of the melting furnace by the feeder, and the melting pool is heated to 1650 degrees by the natural gas spray gun.

Figure 3 Use a hopper to feed the mixed raw materials into the inlet end of the furnace up to 1650 degrees

Figure 3 Use a hopper to feed the mixed raw materials into the inlet end of the furnace up to 1650 degrees


Figure 4 Float glass furnaces realogram

Figure 4 Float glass furnaces realogram

The molten glass flows from the melting tank to the neck area through the clarification tank, and stirs evenly. Then flow into the working part, slowly cooling down to about 1100 degrees, so that it reaches the correct viscosity before reaching the tin bath.

Figure 5  A cross-sectional view of a typical melting furnace

Figure 5  A cross-sectional view of a typical melting furnace