Oxygen-free drying and upgrading system of lignite and lignite drying process

Abstract

The invention relates to an oxygen-free drying and upgrading system of lignite and a lignite drying process. The drying and upgrading system comprises a drying device and a heating system, wherein the drying device comprises a vertical drying cylinder as well as a lignite inlet, a lignite outlet, a gas inlet pipe and a gas outlet pipe which are arranged at the upper and the lower ends of the vertical drying cylinder. The outer sides of two side walls of the drying cylinder are respectively provided with hot gas cavities, and a certain amount of discharge pipes or discharge plates are communicated between the two hot gas cavities so that the lignite in the drying cylinder is completely isolated from hot gas in the hot gas cavities and the discharge pipe or the discharge plate. A thermometer T1 and a thermometer T2 are respectively installed at the nozzle of the gas inlet pipe and the nozzle of the gas outlet pipe, and a thermometer T0 is arranged at a discharge hole. The drying cylinder is also internally provided with a steam pipe which is led out of the drying device. Drying is carried out at normal pressure, and the flue gas input temperature T1, the flue gas output temperature T2 and the final heating temperature T0 of the lignite are controlled, thereby part of combined water in the lignite can be removed, the lignite is transformed from soft coal to hard coal and from hydrophily to hydrophobicity, the lignite can be transported, stored and used as soft coal, and the lignite drying process is very beneficial to popularization and implementation.

Description

1. Technical field:

[0001] The invention relates to a lignite drying and upgrading modification technology, in particular to a lignite anaerobic drying and upgrading system and a lignite drying process. 2. Background technology:

[0002] According to statistics, the world's lignite reserves are about 2622.9 billion tons, accounting for about 24.4% of the world's total coal reserves. China has discovered lignite resources of 129.132 billion tons, accounting for about 12.7% of China's coal reserves. Because lignite is formed very shallow from the surface, it is suitable for open-pit mining, so it is cheap. But lignite also has the following outstanding problems:

[0003] 1. High moisture and low calorific value. Lignite generally has a moisture content between 30% and 65%, and its general calorific value is about 3000kcal / kg.

[0004] 2. Low density, easy weathering, spontaneous combustion when exposed to water, and the sales radius does not exceed 500 kilometers.

[0005] ...

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