一. The purpose of refractory oven
Refractory materials are usually composed of powder or granular substances, and a certain amount of water or water-based slurry will be added during the construction process. Oven treatment can help remove moisture from the construction process, allowing the refractory to dry. In order to avoid the furnace body heating up too fast during use, the water will expand a lot, causing the furnace body to burst, bubbling, and even the furnace wall to collapse, which will affect the strength and service life of the furnace wall.
二. the method of refractory material oven
1. Generally, low-temperature baking is used first, and wood and diesel can be used as fuel. The temperature of the exhaust gas at the kiln tail is controlled at 250~350℃, and the baking time is 8~12h;
2. After 12 hours, spray a small amount of coal appropriately, gradually raise the temperature, and control the temperature at the kiln tail below 600°C. At this time, turn the kiln at a speed of 1/4 revolution every 30 minutes after the total time of 20 hours, and then turn it at a speed of 1/2 revolution every 30 minutes for 2 revolutions (4 hours), until the total time is 28 hours Then turn the kiln at a speed of 1 circle every 30 minutes;
3. Keep the temperature at 600°C for 8 hours, at this time, a small amount of kiln material can be added;
4. After a total time of 36 hours, heat up at a rate of 50°C per hour until it reaches the operating temperature. In short, it is necessary to achieve a slow temperature rise so that the kiln lining bricks can be fully baked.
三. Oven curve of refractory material
Since 300°C is the stage of tidal discharge, the structural water brought in during the construction process is gradually discharged, and 500-600°C is the stage of discharging crystal water. In this stage, some components that constitute minerals will be decomposed, and crystal water will be gradually discharged.
四. Principles followed by refractory ovens
The baking system of the cement rotary kiln should follow the principle of "slow heating and no turning back" during the drying process, that is, the principle of slow heating and no cooling. By controlling the temperature and heating rate, the temperature in the refractory material can be uniform. raised. In order to make the kiln lining evenly heated, the cylinder rotates from low speed to normal speed, which can not only maintain the uniformity of the surface temperature of the kiln lining, but also avoid deformation of the kiln body.
五. Rotational speed of cement kiln during refractory baking period
During the heating process of the rotary kiln, the upper and lower cylinders are heated to different degrees. In order to prevent the deformation of the cylinder due to uneven heating, the rotary kiln must switch its position. As the temperature rises, the rotation speed also increases.
When the kiln tail temperature is 300~400°C, turn the kiln once an hour, 120° each time
When the kiln tail temperature is 400~600°C, turn the kiln once every 30 minutes, each turn 120°
When the kiln tail temperature is 600~700°C, turn the kiln once every 15 minutes, each turn 120°
When the kiln tail temperature is 700~800°C, turn the kiln once every 5 minutes, each turn 120°
