Dry-process slag discharge device and method for entrained flow bed

Abstract

The invention relates to a dry-process slag discharge device and method for an entrained flow bed. The device is sequentially divided into a reaction section, a cooling section and a slag discharge section from top to bottom, wherein the reaction section comprises an inner barrel; the inner barrel is fixed on the top wall of the reaction section, and is opened downwards; the top wall of the reaction section is provided with a feed nozzle in a penetrating mode, which is opened to the internal space of the inner barrel; and the side wall of the reaction section is provided with a product gas outlet. According to the invention, gas flow deflection is utilized to implement primary separation of the gas product and solid product, and the solid coke slag and gas product are respectively cooled to satisfy the requirements of cooling the solid product and gas product to different temperatures; and the entrained flow bed operation and moving bed operation are combined to substitute the slag tank on the lower part of the entrained flow bed to further cool the coke slag, thereby effectively reducing the black water discharge amount and implementing clean conversion of coal resources.

Description

technical field [0001] The invention relates to the technical field of coal gasification, in particular to a dry slag discharge device and method for an entrained bed. The invention is especially suitable for coal hydrogasification and other production processes that have different requirements on the condensation temperature of gaseous products and solid products. Background technique [0002] Coal gasification technology has become an important technology to realize the clean transformation of coal, and it is developing in the direction of large-scale, strong adaptability of pulverized coal, low pollution, and easy purification. In recent years, entrained bed gasification technology has attracted more and more attention due to its advantages of strong feedstock adaptability, high carbon conversion rate, and high cold gas efficiency, and has become the mainstream of gasification technology development. Several existing mainstream entrained bed gasification technology proce...

AI Technical Summary

Problems solved by technology

In this cooling process, a large amount of black water will be produced, which contains a large amount of pollutants and needs to be further treated, which will increase the production cost and increase the water consumption of the gasification process, which is not conducive to the development of gasification technology

Especially for entrained bed hydrogenation gasification technology, the solid product semi-coke and gaseous product produced after the reaction, the gaseous product also contains oil product in addition to the syngas product, if the cooling temperature of the gaseous product is too low, the oil product It will condense and precipitate and adhere to the pipeline, which not only greatly reduces the oil yield, but also easily blocks the pipeline, causing hidden dangers of accidents. In order to improve the oil yield, reduce the risk of pipeline blockage and ensure that the temperature Above 300°C, the solid product and the gaseous product need to be cooled separately. In addition, the semi-coke product in the hydrogasification process is porous and low-density, and the powdery semi-coke will float on the water surface. Unable to realize the normal discharge of hydrogasification coke residue products

[0003] CN 1405277A discloses a solid-state slag discharge dry powder entrained gasification process and device, which is characterized in that the high temperature operating entrained bed gasification reactor is combined with the medium temperature operating fluidized bed gasification reactor, and the medium temperature operating fluidized bed gasification reactor is used. The slag discharge is carried out due to the low coking temperature of the fluidized bed, but the gaseous products and solid products are still cooled at the same time in this method, which cannot be applied to the situation where the gaseous products and solid products are condensed to different temperatures respectively, and cannot meet the requirements of the entrained bed hydrogenation gasification process. In addition, this technology ignores the different requirements for the particle size of the raw material particles during the normal operation of the fluidized bed and the entrained bed, and it is difficult to select an appropriate fluidization gas velocity to achieve normal and stable operation.

[0004] In principle, this technology can realize coke-cooled slag, slag discharge under dry conditions, and avoid the generation of black water. The addition of large particles makes the fluidized state of the fluidized bed constantly disturbed, making it difficult to achieve stable operation. At the same time, because the ash particles formed in the entrained bed are small, they are easily carried by the product gas at the operating gas velocity of the large particle fluidized bed. out of the fluidized bed, which increases the difficulty of the product gas purification section. In addition, the combination of the entrained flow bed and the fluidized bed has a limited processing capacity, and it is difficult to achieve engineering scale-up to meet the large-scale requirements of modern coal gasification technology.

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