In the process of float glass production, the bubble problem is always an important factor restricting the production and quality of stable float glass. There are many reasons for the formation of bubbles, and there are many aspects that need attention in the process.
1. Raw material bubble
The air brought into the compound forms bubbles -- raw material group (sheet) or ultrafine powder group (sheet), large grain glaucoma, broken glass enjoined into the air; Carbon dioxide -- the decomposition product of carbonate when the complex melts; Water vapor -- water nitrogen added to the complex -- air is enjoined into the complex and added to the furnace. The solubility of oxygen in the glass liquid is large, and most of the gas left is nitrogen.
2. Clarify the bubbles
Microbubbles are generally defined as bubbles less than 0.2mm in diameter. Microbubbles are mainly produced in the clarifying part.
Clarification temperature is too low, the end of the small furnace flame is too strong or weak. Clarifying zone flame atmosphere reduction, fuel atomization is poor, oil contains more granular carbon, bubble boundary instability, flame instability. A sudden change in convection.
In addition to the influence of clarifying temperature, it is also affected by the instability of bubble boundary, the change of feeding machine speed, the change of liquid level height and the change of atmosphere in the melting kiln. The fuel oil contains granular carbon, which is scattered on the surface of the glass liquid and caused by poor oil atomization. A sudden change in the amount of melting can also cause clarification bubbles.
3. Neck blisters
Bubble generated by the cooling equipment and the hanging wall of the neck. There are two kinds of cooling equipment here: big water pipe and stirrer. Water leakage of cooling equipment will cause bubbles. The cold glass liquid at the agitator is stuck with fallen mirbulite, and the mirbulite condensed in the exposed space of the large water pipe falls into the glass liquid due to the change of the cooling pressure, causing bubbles. This kind of bubble is generally in the upper middle or lower part of the float glass plate, there is no obvious rule. Under the microscope, generally left or heavy or light traces of glauber. The redissolution of crystallized glass produces bubbles.
This is only part of the reason why float glass produces bubbles. In order to avoid bubbles, production rules should be strictly observed in the production process to reduce the bubbles caused by work mistakes.