Coal drying device and drying method

Abstract

The invention relates to the field of chemical engineering, in particular to a coal drying device and drying method. The coal drying device comprises a machine casing, at least three vibration beds and radiation tubes with adjustable heating temperature. The inside of the machine casing is isolated from external air, at least three vibration beds are arranged in the machine casing from top to bottom in a zigzag type, each vibration bed is provided with a discharging port, the radiation tubes are arranged above the vibration beds, the radiation tubes are arranged from top to bottom, heating temperatures of the radiation tubes increase gradually, and the heating temperature of the radiation tube at the lowest layer is 300 DEG C to 350 DEG C. Coal can roll and fall on a plurality of layers of vibration beds in the coal drying device from top to bottom to be heated by the radiation tubes arranged on the vibration beds, the coal can increase from normal temperature to 300 DEG C-350 DEG C in a rolling and falling process, the coal can be dried in a heating process, volatile matters can be simultaneously prevented from being dissolved in quantity in a coal drying process, and the risk of coal crack is reduced.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a coal drying device and a drying method. Background technique [0002] my country is a country with primary energy resources dominated by coal. Coal can provide more than 65% of primary energy. Coal production ranks first in the world and increases year by year. my country's recoverable reserves of coal resources rank third in the world, accounting for about 11.5% of the world's total reserves. Among them, lignite reserves account for about 16% of the world's total lignite reserves. With the increasing demand for energy and the over-exploitation of bituminous coal and anthracite resources, the development and utilization of lignite in my country will become more and more important. Compared with bituminous coal and anthracite, lignite has the advantages of low price and high reactivity, but its calorific value is relatively low, its water content is high, generally 25-60%, it ...

AI Technical Summary

Problems solved by technology

[0005] Existing methods of drying coal, such as lignite, are mostly used such as drum drying, fluidized bed drying, belt drying, vibration mixed flow drying, etc. The drying devices used in these drying methods have complex structures, low efficiency, and poor drying degrees.

For example, the particle size of coal in the fluidized bed dryer is limited, the degree of drying in the vibrating mixed flow bed is low, and the drum dryer or rotary drum dryer is used for drying raw coal, which is bulky and occupies a large area. , large dust, easy to explode, poor safety, low production capacity

[0006] In addition, the existing drying methods are all drying at a fixed temperature. During the heating process of lignite, the water vaporization inside the coal block causes the internal pressure of the coal block to rise. When the heating rate reaches a certain level, the water vaporization rate inside the coal block exceeds The diffusion speed of water vapor in the capillary from the inside to the outside, the internal pressure value is too high, resulting in the bursting of the coal block, and the bursting of the coal block brings four difficulties to the coal processing process:

[0007] ① Coal seam ventilation is difficult

The fine powder produced by lignite bursting and fragmentation deteriorates the ventilation of the coal pillar, and the airflow deviation is serious, resulting in low gas-solid heat transfer efficiency and uneven coal seam temperature.

[0008] ② The safety of the dry coal system is reduced

Lignite bursting and fragmentation produces a large amount of coal dust. During the drying process, the high concentration of coal dust is easily detonated by static sparks and open flames, resulting in disastrous consequences.

[0009] ③The difficulty of transportation increases

Therefore, the safety of lignite drying and upgrading system is reduced due to the large amount of fine powder produced by lignite explosion.

[0011] In addition, due to the limitations of existing mechanical equipment and heating capacity, large-scale production cannot

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