The clinker calcination process is a vital link in cement manufacturing. As the main equipment in this process, the selection and application of cement kiln will directly affect the output and quality of cement products. Why cement kiln is so important? In terms of the equipment function, it is the device that finally completes the clinker sintering. After the raw materials are heated at high temperature in the cement kiln, a series of chemical reactions will take place, and then the cement clinker will be finally formed. However, during this process, the kiln diameter, thermostability, cooling speed, kiln speed, kiln model and many other factors will affect the cement quality, especially the kiln model.
AGICO is an experienced cement equipment manufacturer in China. In cement plant construction, the cement rotary kiln and vertical shaft kiln is the main cement kiln we adopt. They are very different in calcination methods and properties. Next, we will look at these two cement kilns in detail.
What Is Cement Rotary Kiln?
Cement rotary kiln can be divided into the dry method rotary kiln and wet method rotary kiln. Their main difference is that the former calcines dry powder raw meals, while the latter calcines slurry raw meals. Therefore, the wet method rotary kiln needs to evaporate additional material moisture, about 30% to 40%, which consumes more heat and energy. However, due to the homogeneous composition of the slurry raw meal, the clinker calcined in the wet method rotary kiln usually has high quality, high strength grade and less dust pollution.
Under normal circumstances, the body of cement rotary kiln is placed horizontally and inclined to a certain angle with the ground. Materials enter from the kiln tail and move to the other end with a slow rotation. During this process, cement raw meal will undergo decomposition, sintering and other technological processes under high-temperature heating to finally form cement clinker.
AGICO cement rotary kiln is suitable for a variety of materials with stable performance, low energy consumption, high yield and convenient operation. This system adopts advanced Hydro-Damper, high-precision plunger pump and speed regulating valve. Compared to kilns of the same specification, its operation rate is increased by 10%, the output is increased by 5% – 10%, and the heat consumption is reduced by 15%.
What Is Vertical Shaft Kiln?
Vertical shaft kiln is a kind of vertical cement kiln, the kiln body is upright on the ground and can not rotate. Materials in the kiln move from top to bottom, and the combustion-supporting air flows from bottom to top. The heat carried by the high-temperature materials will preheat the combustion-supporting air, which reduces the heat loss. Besides, the clinker discharge temperature of the shaft kiln is controlled within the ambient temperature + 60 ℃, so its thermal principle is reasonable.
Compared with vertical shaft kiln, the heat transfer mode of cement rotary kiln is radiation. Its filling rate of raw materials is only 5-17%, so most of the space is idle. Moreover, it has a large surface area and fast heat dissipation. Therefore, as thermal equipment, its thermal efficiency is not high, generally only 40%. In addition, the new dry-process cement system has strict requirements on raw materials, listing K2O, Na2O, Cl- and SO3 as harmful components, which leads to the unavailability of many mineral resources. While the shaft kiln cement manufacturing technology does not have these limitations. The cement plant that regards the shaft kiln as main equipment has low requirements for ore reserves, and it is more able to effectively utilize small reserves mines. These characteristics in the use of resources are undoubted of great significance.
The cement vertical shaft kiln produced by AGICO uses high-quality refractories. Under normal circumstances, it can be used for 6-10 years. Secondly, the shaft kiln we produced covers a small area. Due to its vertical layout and the compact layout of various functional areas, the floor area is reduced. Besides, the steel structure of the kiln has few machined parts, low installation difficulty, and low processing cost.