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How many of these glass kiln melting systems do you know?
Dec 10, 2018

The kiln is characterized by intermittent operation. The whole process of glass melting is carried out in sequence at the same time and in different times. Therefore, the temperature should be changed according to the different requirements of each stage of the fusion casting process.



The melting temperature is determined mainly based on the glass composition and the nature of the batch. The temperature required for clarification, homogenization and cooling should be determined according to the viscosity required at these stages. The enthalpy temperature is generally equivalent to a temperature of 0.7 to 10 Pa·s of 10, and the cooling temperature should be controlled at the phase. The viscosity of the gas at a viscosity of 10 to the power of 2 to 10 to the third power Pa•S, the viscosity can be adapted to the need for the glass to begin to form. The temperature regime of the kiln should be determined by the temperature of the glass melting, enthalpy, homogenization and cooling and the time required to conform to the melting process in the crucible. However, there are exceptions. If some of the heat exchangers in the multi-heating kiln do not work at the same time, often when several 坩埚 just describe the melting, the other 坩埚 are undergoing cooling and forming processes, and the kiln should not be heated. Only the forming temperature can be maintained. The temperature of each crucible should be restricted by the temperature system, but within a certain range, it can be adjusted by means of the opening and closing degree of the rake and the ram of the wicking port.


When kiln is used to melt ordinary household glass (such as utensils and bottles), the process is basically the same, usually in the following five processes.


(1) Temperature rise. After the formation of the last material, the temperature in the open space is generally 1150~1250 °C. In order to ensure the rapid baking of the batch, the hollowing should be simmered for 1~2h, so that the temperature rises to about 1400 °C, and then the feeding is started. .


When replacing the new crucible, the furnace should be gradually heated to the temperature of the molten glass, and it is not added for a day or night. The anti-corrosion ability of the crucible is enhanced when sintering for a long time.


(2) Melting. When the predetermined temperature is reached in the kiln, the feeding can be started, generally in 3 to 5 times. The last few feeds should start after the previous meltdown. Sometimes the time of the first feeding is relatively late, and the feeding time interval can only be shortened. At this time, the feeding can be carried out when there is still a small pile in the center of the sputum. Generally, the daily glass needs 10 hours from the start of feeding to the completion of melting.


When switching to a new one, the first feeding should not be too much. If some cullet with the same composition as the molten glass is added first, after the baking, the glass solution is applied around the crucible to hang the protective glaze layer, reduce the erosion of the powder, and shorten the melting time. This method is commonly known as "washing the tank." Usually the "washing" operation can be carried out several hours after the replacement of the new one.


(3) Clarification and homogenization. After the batch is completely melted, it can be measured by temperature and observed with the material brazing material. At this time, fine sand grains and bubbles can be seen on the wire. With the accumulation of heat, the maximum temperature in the kiln is reached, and the viscosity of the glass liquid drops. By around 10 Pa•s, clarification and homogenization will proceed quickly. This process generally takes 2~4h.


(4) Cooling. Clarify that the perfect glass liquid contains almost no bubbles or few small bubbles, which can be gradually dissolved in the glass during the cooling process. In order to ensure the quality of the molten glass, the cooling process should be carried out cautiously and slowly, about 2 hours. If conditions permit, the time can be extended as appropriate.


Cooling should avoid the phenomenon that the temperature of the molten glass is lower than the temperature required for forming and then reheated to avoid the generation of secondary bubbles.


(5) Forming. At the time of forming, it is necessary to adapt the temperature in the furnace to the viscosity requirement of the glass forming operation, and the shape of the glass is different depending on the size of the glass component, the molding method, and the product.


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