Lime kiln device with application of hot-air

Abstract

The invention relates to a lime kiln device with hot-air calcination and a method for producing lime by the utilization of the lime kiln device. When preparing lime, hot air generated from a combustion apparatus outside a kiln is used for calcination of limestone; waste hot air used after the calcination is used for preheating of the limestone mineral aggregate; the waste hot air used after preheating is discharged out of the kiln body, and then undergoes dedusting and finally used for preheating of coal gas and oxidizing air. Through the use of hot air for calcination of limestone, lime quality can be remarkably improved, lime yield is raised, and productivity is enhanced. The lime kiln proposed by the invention is not provided with a burner system, and the hot air for high temperature calcination is from a combustion furnace device outside the kiln. Blast-furnace gas can be used as a fuel for the combustion furnace device, and hot flue gas generated by the combustion device can be used as the hot air. Thereby, the kiln structure is simplified, and operating cost of the lime kiln is reduced.

Description

technical field [0001] The invention relates to a lime kiln which uses gas as fuel and uses hot air input outside the kiln for calcining and a process method for producing lime by using the lime kiln. Background technique [0002] Lime is calcium oxide (CaO), which is widely used in iron and steel industry, calcium carbide industry, alumina industry, refractory materials and other industries. It is also one of the necessary raw materials for these large-scale industrial fields. For example, in the metallurgical industry, every ton steel would require about 70 kg of lime. The main raw material for lime production is limestone, the main component of limestone is calcium carbonate (CaCO 3 ), the basic principle of burning lime is to use high temperature to decompose calcium carbonate in limestone into calcium oxide and carbon dioxide. [0003] Basic reaction formula: CaCO 3 +42.5Kcal=CaO+CO 2 [0004] Lime production process is mainly divided into preheating, calcination, ...

AI Technical Summary

Problems solved by technology

[0015] As mentioned above, for the different forms of gas-fired lime kilns that are widely used, although their structural forms and calcination forms are different, the process flow and main equipment are basically similar, and the common features are all adopted. The burner on the kiln body heats and calcines the mineral material. The calcination time is long, the equipment investment is large, the operating cost is high, the maintenance cost is high, and the productivity is low. It is difficult to eliminate the phenomenon of "under-burning" or "over-burning".

Although engineers and technicians have made many major improvements, the above-mentioned common problems have not been completely resolved

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