In the production process of the new dry cement kiln, the calcining condition of the rotary kiln system is generally controlled centrally by the staff in the central control room through the computer, and the process parameters are adjusted according to the specific kiln conditions. In order to meet the production requirements, it is necessary to control the process law of the kiln calcining system and adjust the main parameters properly.
The Amount Of Raw Materials
Since the number of raw materials into the rotary kiln system determines the output of the kiln, the equipment capacity index at the rotary kiln is required to be stable.
And you have to deal with special problems with immediate responses. For example, in unstable weather conditions, the water content in the raw materials of the cement rotary kiln is not easy to control, and it is easy for the raw materials to agglomerate at the top of the warehouse or the walls of the warehouse. In this case, it is necessary to observe frequently and adjust in time to solve the phenomenon of agglomeration of materials. When the negative pressure of the kiln tail of the cement rotary kiln is too large, the outlet temperature, the temperature of the cyclone tube, the temperature of the decomposition furnace and the preheater will fall sharply. At this time, the speed of the rotary kiln should be appropriately reduced, the feeding rate should be reduced, and the coal pipe should be injected to increase Kiln tail temperature to enhance the effect of pre-sintering. Appropriate coal can also be added while avoiding reducing the atmosphere in the rotary kiln. In addition, when the current speed of the main electric kiln of the cement rotary kiln decreases, the kiln speed should be reduced, the pulverized coal burner should be withdrawn, and the exhaust gas should be reduced. The short-term flame can be used to restore it to normal.
Rotary Kiln Speed Control
Because rotary kiln speed has a direct impact on the material stay in the kiln through time, but also related to the rotary kiln clinker output and firing quality.
It has been proved by the user’s practice that under the condition that the slope of the rotary kiln is fixed, the user needs to maintain a reasonable speed according to the specific production conditions. Reasonable matching of the filling rate, moving speed and calcination conditions of the materials in the rotary kiln. It can more effectively improve product quality and productivity. Because in the past, the kiln speed was slow, so it was only 0.5 ~ 075r / min, and then increased to 1.0 ~ 1.5r / min. The kiln speed can generally reach about 3r / min.
The Feeding Amount Of Coal
Because the coal feeding operation of the decomposition furnace is mainly to provide a heat source, ensure the temperature required for the decomposition reaction in the kiln, so as to completely decompose the calcium carbonate in the raw materials.
Cement enterprises are high energy-consuming enterprises. Coal consumption accounts for about 40% of production costs. The instability of coal feeding at the kiln head and kiln tail not only leads to a decline in product quality but also causes a large amount of pulverized coal to not be completely burned, resulting in increased coal consumption. Continuous and accurate feeding of coal to rotary kiln and decomposition furnace is the key factor to reduce coal consumption, improve clinker quality, and ensure equipment safety and continuous and stable operation. Therefore, the coal feeding measurement control device must have the characteristics of stability, accuracy, and rapid movement.
The change in the temperature of the decomposition furnace under the set value exceeds 5 degrees, and the corresponding amount of coal fed at the end of the kiln will have a deviation of 0.25 tons, which can fully reflect the sensitivity of automatic control of the rotary kiln. According to the temperature change in the rotary kiln during actual production, we can judge that the amount of coal fed to the kiln tail during automatic control is more in line with the production requirements of the calcination process.
The Parameters Of Coal Feeding At Kiln Head
Coal feeding at kiln head mainly provides heat for the internal reaction of rotary kiln.
Air Volume Control Of Kiln Tail
Main exhaust fan of rotary kiln, which mainly provides the air volume required by the system.Because enough air volume not only provides air for coal combustion but also helps the system to promote the reasonable distribution of temperature. During the operation of the exhaust fan, there are basic requirements for controlling the upper limit temperature of the inlet and low-speed operation at normal temperatures. The exhaust fan device is a high-power, high-speed, high-temperature, continuous-operation equipment in the configuration of the rotary kiln system. There are higher requirements for the use of fans.
Air Volume Of Rotary Kiln Cooler
The cooler can not only cool clinker quickly, but also can recover heat, to achieve the energy-saving effect.
In a word, running a rotary calciner properly should control several parameters: raw materials, speed, amount of coal and air volume.