Low-temperature furnace smoke sucking exhaust gas and hot air drying composite powder feeding bituminous coal and meagre coal universal type powder preparing system

Abstract

The invention relates to a low-temperature furnace smoke sucking exhaust gas and hot air drying composite powder feeding bituminous coal and meagre coal universal type powder preparing system. A middle bin storage type steel ball coal mill hot air power feeding and meagre coal power preparation system is adopted as a prototype, and part of low-temperature furnace smoke is sucked from an outlet of a suction fan by a furnace smoke fan as an inert medium and part of drying mediums to be mixed with hot air taken from an outlet of an air preheater to enter a coal mill for drying and delivering coal powder; the oxygen content of the powder preparation system is reduced, and the explosion preventing requirement on grinding bituminous coal can be met. In addition, part of exhaust gas at an outlet of a power exhauster is led to an inlet of a heat primary fan by an exhaust gas transfer pipeline to be mixed with hot air to enter a primary bellows for delivering the coal powder; the temperature of a primary air and powder mixture and the oxygen concentration of the system are effectively reduced, and the combustion and explosion preventing requirement of bituminous coal delivery is met. Isolating doors are both installed on a furnace smoke system and an exhaust gas transfer system; by the switch control of the isolating doors, the switching of a typical hot air power feeding meagre coal system and a low-temperature furnace smoke exhaust gas and hot air drying composite powder feeding bituminous coal system is realized, and the invention is not only suitable for the meagre coal, but also suitable for the bituminous coal.

Description

technical field [0001] The invention belongs to the field of pulverizing systems for power station pulverized coal boilers, and in particular relates to a universal pulverizing system for extracting low-temperature furnace fume, drying exhaust gas, hot air and compositely feeding pulverized bituminous coal and lean coal. Background technique [0002] The pulverizing system is an important part of the combustion system of the pulverized coal boiler in the power station. Its main function is to prepare and transport pulverized coal, and to provide the boiler with a mixture of pulverized coal of qualified fineness and air powder of suitable temperature (usually called primary air). According to the different properties of the fuel, pulverized coal boilers can be divided into lean coal boilers and bituminous coal boilers. The type of pulverizing system is selected according to the type of coal designed. Usually, a pulverizing system is only suitable for one type of coal. The con...

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Problems solved by technology

[0008] Whether it is the hot air powder feeding method or the exhaust gas powder feeding method, it can only be adapted to the grinding and transportation of lean coal or bituminous coal, and cannot take care of both

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