Smoke semi-closed circulating lignite straight pipe type airflow drying method

Abstract

The invention relates to a smoke semi-closed circulating lignite straight pipe type airflow drying method, which ensures the safety and reliability of a device and makes the maximization of the device possible through direct combustion of lignite to generate smoke, once drying of a straight pipe type airflow dryer to meet the moisture requirement of a product, large-grain inertia setting, collection of a fine grain bag type dust collector, even blending of large grains and fine grains through a blending device, emptying and air quantity control through a mixed temperature fan and a booster fan.

Description

Technical field [0001] The invention relates to the technical field of lignite drying, and is a semi-closed circulation type direct drying method for lignite flue gas, which belongs to the convection heat transfer type drying. Background technique [0002] Lignite is the coal with the lowest degree of coalification. It is converted from peat under moderate pressure. The degree of coalification is between peat and bituminous coal. It has high water content and is easily weathered in the air; it contains a certain amount of primary humic acid; it contains carbon. The content is low, the oxygen content is high, and the hydrogen content varies greatly; the volatile content is generally between 45% and 55%, which is easy to spontaneously combust. [0003] The drying method of 80 tons / hour brown gas flow has not been reported in China. The equipment reported in China is the production equipment of Ningxia Shizuishan Coking Plant with a production capacity of 40,000 t / a built in 1994. Th...

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Problems solved by technology

The existing problems are as follows: ① Coal drying needs three stages of drying: preheating tube, heating tube and drying tube to meet the requirements. The required supporting equipment is complex, there are many equipment connection surfaces, the system is under negative pressure, easy to leak air, and the oxygen content is not easy to control , the equipment cannot be promoted on a large scale; ②The cyclone separator is used for dust removal, and the equipment wears seriously. If spraying technology is used, the equipment investment is large; ③The heat source uses gas, which is a secondary energy source, and it cannot be used in places without secondary energy sources such as mining plants; ④ The scale of the device is small, and it is difficult to scale up, which cannot meet the needs of industrialized mass production

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