The use of the Aluminum melting furnace has a large single furnace capacity, which has the effect of reducing consumption, reducing burning loss, improving product quality, reducing labor intensity, improving working conditions and improving production efficiency, and is suitable for intermittent operation, with alloy and recycled materials. Smelting. Then, the Aluminum melting furnace has a low temperature in practical applications. What is the reason for this?
The non-ferrous metal Aluminum melting furnace passed the check of the furnace calculation of the original manufacturer, and found that the calculated value of the flue temperature of the furnace exit of the Aluminum melting furnace was too high (the original design was 1149 ° C, and the check calculation was about 1079 ° C).
The excess air ratio at the furnace outlet has the following effects on the main and re-steam temperatures: First, it can increase the amount of flue gas, change the distribution of radiation and convection heat, and increase the share of heat absorbed by the convective characteristics of the superheater, reheater, etc. The heat absorption share of the evaporation surface is reduced, which is beneficial to increase the steam temperature. Secondly, the theoretical combustion temperature can be increased by increasing the excess air coefficient of the furnace outlet within a certain range, and the smoke temperature of the furnace outlet can be increased, which is also advantageous for increasing the steam temperature.
The test shows that the air leakage rate of the air preheater is as high as 35% (the original design air leakage rate is 12%), which leads to insufficient output of the induced draft fan. The excess air coefficient of the furnace outlet at full load can only reach about 1.1. After calculation, under the condition of “running coal type 2” design parameters, the excess air coefficient of the furnace outlet is increased from 1.1 to 1.25, and the temperature of the smoke can be increased by 14 °C.