Process for large-proportion blending combustion of coal slime in intermediate storage type coal pulverizing system

Abstract

The invention discloses a process for large-proportion blending combustion of coal slime in an intermediate storage type coal pulverizing system. The process comprises the following steps: high-temperature flue gas at the bottom of a boiler furnace is sucked by an injection smoke pipe; the high-temperature flue gas is guided into a pre-drying pipe; pre-drying of wet coal slime is performed; cold smoke at an outlet of a draft fan is induced by a cold smoke fan, serves as a temperature adjusting medium of the coal pulverizing system and is mixed with medium-temperature smoke at an outlet of thepre-drying pipe; and full-furnace smoke drying of the coal pulverizing system is achieved. According to the process, an ejection smoke pipe is adopted to extract high-temperature smoke in the furnace;meanwhile, a pre-drying pipe is arranged; and the coal slime is pre-dried through the high-temperature smoke from the ejection smoke pipe. A whole furnace smoke drying mode is adopted, and a primaryfan is canceled, so that the interior of a coal pulverizing system is in an inert atmospher; the adaptability of the coal pulverizing system to coal slime volatile components is improved; air at an outlet of an air feeder is divided into two parts after being heated by an air preheater; one part serves as powder feeding hot air; the other part serves as secondary air for organizing combustion; andpowder feeding hot air and pulverized coal fed by a powder bin powder feeder are evenly mixed in an air-powder mixer and then sprayed into a hearth through a combustor.

Description

technical field [0001] The invention belongs to the technical field of co-firing coal slime with a large proportion of power plant boilers, and in particular relates to a process for co-firing coal slime with a large proportion in a mid-storage pulverizing system. Background technique [0002] Coal slime is a by-product produced in the coal washing process. With the increase of coal washing rate in my country, the treatment of coal slime has gradually become a more prominent problem. Using power plant boilers for coal slime blending is an important way to realize coal slime comprehensive utilization and harmless treatment through coal-fired power plants. It can bring considerable economic benefits to power plants and promote the formation of circular economy industries in mining areas. However, due to the characteristics of high moisture content and high viscosity of coal slime at this stage, the normal operation of power plant boilers is affected to a certain extent during ...

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Problems solved by technology

[0008] The purpose of the present invention is to overcome the disadvantage that the existing wet coal slime direct feeding pulverizer technology cannot realize large-scale coal slime blending in the steel ball pulverizer mid-storage pulverizing system, and to provide a mid-storage The process of blending and burning coal slime in a large proportion of the traditional pulverizing system adopts the whole furnace smoke drying method, which greatly improves the drying capacity of the steel ball coal mill, and at the same time takes into account the explosion-proof requirements of the pulverizing system to achieve a large proportion of blending coal slime

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