System and method for improving characteristics of coal as fired of slag tapping furnace by utilizing fly ash circulation

Abstract

The invention relates to a system and a method for improving the characteristics of coal as fired of a slag tapping furnace by utilizing fly ash circulation. The system comprises a fly ash return device, a quantitative adding device for fly ash and raw coal linkage and a fly ash collecting device. The fly ash return device is connected with the fly ash collecting device, a fly ash conveying device presses fly ash from the fly ash collecting device to a coal grinding system in a pneumatic conveying mode, and the quantitative adding device synchronously controls the adding amount of the fly ash through feeding linkage of the fly ash and raw coal. The system and the method are suitable for improving the coal with low coal ash content and poor viscosity-temperature characteristic for the liquid slagging gasifier in the field of coal chemical industry, and the fly ash (fine fly ash) discharged by a dry ash removal system is conveyed and blended into raw coal by utilizing the characteristics of fine particles and high silica-alumina ratio, so that the index requirements of the coal for the gasifier are met, the gasifier is prevented from collapsing or blocking slag, and long-period safe and stable operation is realized.

Description

technical field [0001] The invention relates to the related field of coal chemical industry, in particular to a system and method for improving the characteristics of coal fed into a liquid slagging furnace by using fly ash circulation. Background technique [0002] Shell gasifier is a pressurized entrained entrained gasification technology for raw coal, which adopts the structural mechanism of liquid slag removal and slag resistance, and its requirements on coal quality are relatively stringent. There are certain range requirements for coal moisture content, ash content, ash melting point, and ash slag viscosity-temperature characteristics. It is difficult to have a single coal in the market that meets these requirements. In actual production, the coal blending process is usually used to blend two or more coals, or to add special modifiers to reconcile various indicators. [0003] However, due to the limitation of coal formation conditions, the coal types in a region gene...

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Problems solved by technology

[0003] However, due to the limitation of coal generation conditions, the coal types in a region generally have the same coal quality characteristics, and the two types of coal with complementary indicators are usually far apart, which virtually increases the coal cost of the gasifier

In addition, due to the influence of production, transportation, market, and policies, the safe and stable supply of coal pairing cannot be fundamentally guaranteed, which poses a severe test to the safe and stable production of enterprises

[0004] In addition, special modifiers are generally composed of a single or composite of several metal-rich substances, which need to be processed separately, and the cost is relatively high, and the production and operation pressure of enterprises is high.

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