Pulverized coal gasification pulverization and water recovery integrated system and method for high-moisture coal

Abstract

The invention relates to a powder coal gasification powder processing and water recovery integrated system for high-moisture coal. The system comprises a steam indirect heat transfer drying machine, an absorption tower, a flash tower, a vacuum pump / Venturi injection pump and a raw coal bunker. The steam indirect heat transfer drying machine is connected with the raw coal bunker, a bag-type dust collector I and a surge bunker; the surge bunker is connected with a coal mill; the coal mill is connected with a hot blast heater, and a bag-type dust collector II and a delivery pipe II are arranged at the top of the coal mill respectively; the top of the absorption tower is connected with a carrier gas initial heater, a circulating pump is arranged at the bottom, and the side of the absorption tower is connected with the flash tower; the circulating pump is connected with an air heater and connected with the carrier gas initial heater; the air heater is connected with the flash tower and the hot blast heater respectively; the flash tower is connected with a condenser which is connected with the vacuum pump / Venturi injection pump; and the flash tower is connected with the carrier gas initial heater. The invention further discloses an application method of the system. According to the system and the method, the investment is small, and energy consumption can be reduced effectively.

Description

technical field [0001] The invention relates to technical fields such as coal pre-drying for gasification and heat recovery of tail gas in a pulverizing system, water recovery in dusty tail gas, etc., especially relates to pulverized coal gasification pulverization and water recovery integrated system of high-moisture coal and its method. Background technique [0002] The pulverized coal gasification device has strict requirements on the moisture and particle size of the coal, and the raw coal needs to be pulverized before entering the pulverized coal gasification device. At present, the pulverization system usually adopts a coal mill that feeds hot flue gas into pulverization. The hot flue gas is produced by combustion of gas, and the fine powder after pulverization is collected by the bag filter and sent to the subsequent gasification system. Gas consumption of moisture coal pulverization plant, high moisture coal pulverization plant is generally equipped with steam pre-d...

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Problems solved by technology

[0003] (1) The temperature of the dried coal powder reaches 60~80°C, and a large amount of dust and steam are generated during the transportation process. Due to the large amount of fine powder and low moisture content, it is easy to generate a large amount of dust when conveyed by belt or buried scraper, not only It pollutes the environment, the operating environment is poor, and the fine coal powder is easy to catch fire naturally, and even serious accidents such as flash explosions may occur, which will affect the stable use of conveying equipment

[0005] (3) The dry tail gas produced by the steam pre-drying process is directly discharged into the atmosphere after dust removal (commonly used methods include bag dust removal, electric dust removal and wet dust removal), and a large amount of water vapor and heat contained in the dry tail gas have not been recycled.

[0006] ⑷The dry tail gas contains a large amount of non-condensable gas. If it is used to directly heat the combustion air, it is a gas-gas heat exchange. Since the heating side of the heat exchange equipment is in the gas phase, the heat transfer coefficient is very small, and a large heat transfer is required. Therefore, the equipment investment is huge, which is not only economically unfeasible, but also has the risk of coal dust in the dry tail gas clogging the heat exchange equipment and condensation

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