A shaft kiln with internal circulation of fine-grained lime and its calcining method

Abstract

The invention discloses a shaft kiln for fine-grained lime with internal circulation and a calcining method thereof. The shaft kiln comprises a silo (1), an adjustable lifting and lowering pipe (7), a shaft kiln body (2), and an annular preheating kiln. Chamber (3), multi-burner combustion chamber (6), injector (16), hollow cross beam (15), built-in heat exchanger (12), base air seat (11), cooling blower (17), driving blower (18), ash machine (19), metering bin (20), storage bin (21). According to the moisture content and impurity content of limestone raw materials, it is determined to select an internal circulation fine-grained lime shaft kiln without push rod or with push rod. The present invention aims at the disadvantage that the existing ordinary lime shaft kiln cannot calcinate or does not calcinate fine limestones well, and is applicable to both small particles of 5-15 mm and medium-grained limestones of 15-30 mm, which expands the utilization range of solid waste and saves 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...

AI Technical Summary

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.

Images