Internal circulation type fine lime shaft kiln and calcination method thereof

Abstract

The invention discloses an internal circulation type fine lime shaft kiln and a calcination method thereof. The lime shaft kiln comprises a feed bin (1), a height adjustable feed pipe (7), a shaft kiln body (2), an annular preheating chamber (3), a multi-burner combustion chamber (6), an ejector (16), a hollow cross beam (15), a built-in heat exchanger (12), a bottom wind seat (11), a cooling airblower (17), a driving air blower (18), an ash extractor (19), a metering bin (20) and a storage bin (21). The selection of the internal circulation type fine lime shaft kiln with a push rod or without the push rod is determined according to the contents of water and impurities in a limestone raw material. Aiming at the defects of the prior common lime shaft kiln that the finely grained limestonecannot be calcined or well calcined, the invention is applicable to the calcination of the limestone with small size of 5-15 mm and medium size of 15-30 mm, thereby enlarging the utilization range ofsolid wastes and saving mineral resources.

Description

technical field [0001] The invention belongs to the field of lime production equipment, and in particular relates to an internal circulation fine particle lime shaft kiln and a calcining method thereof. Background technique [0002] Limestone crushing and screening produces a large number of fine particles of 0-30mm, generally 0-5mm is called powder; 5-15mm is called small particle; 15-30mm is called medium particle. Some limestone materials are used in cement, sand making, roadbed filling, building materials and other industries, and most of them are piled up in the field as solid waste, causing environmental pollution, especially high-grade medium-sized and small pieces of limestone. Sand, filling roadbed, resulting in overuse, is also a waste of resources. [0003] Ordinary shaft kilns cannot calcinate materials with a particle size of 5-15mm, and it is difficult to burn materials with a particle size of 15-30mm. Due to the "side wall effect" of the vertical kiln, the s...

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Problems solved by technology

[0002] Limestone crushing and screening produces a large number of fine particles of 0-30mm, generally 0-5mm is called powder; 5-15mm is called small particle; 15-30mm is called medium particle. Some limestone materials are used in cement, sand making, roadbed filling, building materials and other industries, and most of them are piled up in the field as solid waste, causing environmental pollution, especially high-grade medium-sized and small pieces of limestone. Sand, filling roadbed, resulting in overuse, is also a waste of resources

[0003] Ordinary shaft kilns cannot calcinate materials with a particle size of 5-15mm, and it is difficult to burn materials with a particle size of 15-30mm. Due to the "side wall effect" of the vertical kiln, the side wind is excessive and the ventilation in the middle of the kiln is insufficient. The direct harm of insufficient ventilation is the insufficient oxygen supply for combustion in the kiln, resulting in raw burning of materials and incomplete combustion of fuel. When the material moves to the kiln The bottom of the kiln is close to the air supply port where the oxygen condition is better and the fuel is fully burned, causing the material to be on fire. At this time, the kiln cannot operate and can only be stopped.

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