A lignite drying device and method coupled with entrained flow bed and fluidized bed

Abstract

The invention provides an entrained-flow bed and fluidized bed coupled lignite drying device. A fluidized bed reactor and an entrained-flow bed reactor are communicated with each other from top to bottom; the middle lower part of the fluidized bed reactor is provided with a first drying heat source inlet; and the middle lower part of the entrained-flow bed reactor is provided with a second drying heat source inlet. When a wet coal raw material is input from the upper part of the entrained-flow bed reactor, a drying heat source is sprayed into the first drying heat source inlet and the second drying heat source inlet, and the wet coal raw material is divided into upper small-grain coal and lower large-grain coal in a downward flowing process under the action of gravity, so that the small-grain coal is fully dried in the entrained-flow bed reactor, the large-grain coal is dried in the entrained-flow bed reactor and then subject to secondary deep drying in the fluidized bed reactor, the small-grain coal and the large-grain coal can be fully dried at the same time, the dehydration efficiency and the controllability are high.

Description

technical field [0001] The invention relates to a lignite drying device and method coupled with an airflow bed and a fluidized bed, and belongs to the technical field of lignite drying. Background technique [0002] my country is a country where coal is the main energy source. Coal accounts for about 70% of the energy structure, and this energy structure will not change much in the long term. With the continuous expansion of the world's energy use and the increasing shortage of energy resources, vigorously developing the application technology of low-grade energy resources has been placed in an important position. [0003] Lignite is a kind of coal with a low degree of coalification. With the consumption of high-quality coal resources such as bituminous coal and anthracite, the large-scale development and utilization of lignite is put on the agenda. Proven lignite reserves account for about 13% of my country's coal reserves. Due to the low degree of coalification, lignite h...

AI Technical Summary

Problems solved by technology

In the above-mentioned device, when the solid particle material enters the upper entrained bed, the small particle material contained therein has a very small density, and under the action of the hot air medium, the above-mentioned small particle material will be blown out of the system by the hot air medium in a short period of time, thereby The residence time is short, it is difficult to achieve sufficient drying of small particle materials, and the dehydration rate is low, and for large particle materials, due to their heavy weight, they fall to the bottom of the fluidized bed in a short time, and it is also difficult to achieve sufficient drying

In addition, the above-mentioned device uses hot air as the drying medium. When the lignite is dried, it is prone to explosion, and the safety performance of the system is poor.

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