Method for recovering water from hot carrier gas for lignite drying

Abstract

The invention discloses a method for recovering water from hot carrier gas for lignite drying, which comprises the following steps: feeding drying hot carrier gas from a drying unit into a washing tower under the action of a blower, and performing two-stage heat-insulated washing; feeding the tail gas after washing into an air cooler, and indirectly cooling with environmental air; performing gas-liquid separation, feeding the liquid phase into a water recovery tank, and performing simple treatment to ensure that the liquid phase meets the water standard for industrial circulating water; and returning the gas phase to the drying unit for recycling through a circulating tail gas blower. The system disclosed by the invention has the characteristics of low operating cost, favorable quality of recovered water, high water recovery rate and the like.

Description

technical field [0001] The invention relates to the technical field of drying hot carrier gas to recover water, in particular to a method for drying hot carrier gas from lignite and recovering water. Background technique [0002] Due to the characteristics of "three highs and two lows" (high moisture, high volatile matter, high ash content, low calorific value, and low ash melting point) of lignite, a series of problems have been brought to the operation of lignite boiler units: high moisture leads to water vapor in flue gas As the content increases, the loss of smoke exhaust increases; high volatile content and low ash melting point mean that lignite has strong slagging characteristics; low calorific value increases coal consumption, and the investment in fuel mining, transportation, storage, and processing increases. After the lignite is dried and upgraded, the calorific value of the lignite is greatly increased, and the emission of greenhouse gases after combustion is red...

AI Technical Summary

Problems solved by technology

[0002] Due to the characteristics of "three highs and two lows" (high moisture, high volatile matter, high ash content, low calorific value, and low ash melting point) of lignite, a series of problems have been brought to the operation of lignite boiler units: high moisture leads to water vapor in flue gas As the content increases, the loss of smoke exhaust increases; high volatile matter and low ash melting point mean that lignite has strong slagging characteristics; low calorific value increases coal consumption, and the investment in fuel mining, transportation, storage, and processing increases

Although this invention can recover the water in the flue gas, the recovery rate is not high, the recovered water is not high in purity, and subsequent water treatment is required. In addition, the flue gas is directly discharged into the atmosphere, which pollutes the environment on the one hand and is also a waste

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