High-Quality Steel Cement Rotary Kiln For Cement Production Process

Rotary kiln is rotary forging kiln for short, which is one of building material equipment. It is divided into cement kiln, metallurgy and chemical kiln and lime kiln as per the different material treatment. Cement kiln is applied to carline cement clinker, which has two types,dry-type cement production kiln and wet-type cement production kiln. Metallurgy and chemical kiln is mainly used to magnetizing roast lean iron ore, oxidation roast the nickel chromium iron ore in the steel and iron plant. It is also used to roast bauxite chamotte in the refactory plant and chamotte, aluminium hydroxide in alumimium plant,crome ore in the Chemical plant. Lime kiln is use to roast active lime and soft-burned dolomite in steel plant and iron alloy plant.The cement kiln burns rawmix to produce clinker, which is then ground to make cement.

The cement kiln is the heart of the cement making process: this is today almost a cliché, but was not always quite so true. In the modern cement plant, the kiln is the most expensive and technically complex part of the plant, and because it must be run all the time (unlike other sections of the plant) it effectively defines the output capacity of the plant. It stands out also in that, unlike the other processes involved, the “pyroprocessing” stage of cement manufacture is absolutely unique to the industry, and has devoted to it a complex and specialized multi-disciplinary technology all its own.

Because of this, the cement kiln scarcely needs to be considered under the general category of “kilns”. In addition to its uniqueness, it also stands out among pyroprocessing equipment as by far the most economically significant world-wide. The blast furnace for iron production produces less than half the tonnage produced by cement kilns, although it runs ahead in terms of fuel usage. In terms of CO2 production, Portland cement kilns – when using limestone as a raw material – are by far the largest industrial manufacturing source. The taming of these emissions is likely to further increase the sophistication of the kiln design.

2.Cement rotary kiln technical characteristics:

• Kiln body is made of high quality composed of carbon steel or alloy steel plate and automatic welding;
• Tyre,Support Roller,Open gear adopts alloy cast steel；
• Sliding bearing with large gap not scraping tile bearing;
• Transmission device adopts hard tooth surface reducer, flexible diaphragm coupling, dc motor;
• Adopts hydraulic gear wheel;
• Preheater scales were used respectively to veiw of kiln head, and cylinder pressure tight seal;
• A slow drive device.

• Application Industry
  Cement Plant, Steel Mill, Chemical Plant & Incinerator
• Output
  180~10000 t/d                                                   

In a modern works, the blended raw material enters the kiln via the pre-heater tower. Here, hot gases from the kiln, and probably the cooled clinker at the far end of the kiln, are used to heat the raw meal. As a result, the raw meal is already hot before it enters the kiln.

The dry process is much more thermally efficient than the wet process.

Firstly, and most obviously, this is because the meal is a dry powder and there is little or no water that has to be evaporated.

Secondly, and less obviously, the process of transferring heat is much more efficient in a dry process kiln.

An integral part of the process is a heat exchanger called a 'suspension preheater'. This is a tower with a series of cyclones in which fast-moving hot gases keep the meal powder suspended in air. All the time, the meal gets hotter and the gas gets cooler until the meal is at almost the same temperature as the gas.

The basic dry process system consists of the kiln and a suspension preheater. The raw materials, limestone and shale for example, are ground finely and blended to produce the raw meal. The raw meal is fed in at the top of the preheater tower and passes through the series of cyclones in the tower. Hot gas from the kiln and, often, hot air from the clinker cooler are blown through the cyclones. Heat is transferred efficiently from the hot gases to the raw meal.

The heating process is efficient because the meal particles have a very high surface area in relation to their size and because of the large difference in temperature between the hot gas and the cooler meal. Typically, 30%-40% of the meal is decarbonated before entering the kiln.

A development of this process is the 'precalciner' kiln. Most new cement plant is of this type. The principle is similar to that of the dry process preheater system but with the major addition of another burner, or precalciner. With the additional heat, about 85%-95% of the meal is decarbonated before it enters the kiln.

In addition to these distinctions, a further category has emerged in the last 40 years: Precalciner Kilns, in which a proportion of the kiln fuel is burned in a static preheater before the feed enters the rotary kiln.