Process and apparatus for utilizing medium-temperature smoke pre-heating combustion-supporting coal gas and air in hot-air stove

Abstract

A process and apparatus by medium-temperature smoke preheated and combustion-supporting air and gas in hot-air furnace are disclosed. The process is carried out by mixing medium-temperature smoke with low-temperature smoke or heat exchanging to obtain high-heat value smoke, preheating to obtain high-heat value combustion-supporting air and gas, setting smoke outlet in medium-temperature area of regenerative chamber, gas-flow exchanging and leading out preheated combustion-supporting air and gas partially. It's cheap, simple, has more heat efficiency and occupies less space.

Description

technical field [0001] The invention relates to a technology and special equipment for preheating combustion-supporting air and coal gas by using medium-temperature flue gas of a hot blast stove, which can be used in ironmaking technology. Background technique [0002] How to increase the blast furnace inlet air temperature is an urgent issue faced by ironworkers. On the one hand, due to the shortage of coking coal resources, it is required to increase the amount of coal injection in blast furnace smelting, thereby reducing the coke ratio into the furnace. However, after blast furnace smelting increases the amount of coal injection, the combustion temperature of the tuyere will decrease, and the combustion rate of pulverized coal will decrease. In order to ensure the smelting effect after increasing the amount of coal injection, an oxygen-enriched process can be used. However, domestic iron and steel plants are usually constrained by the limitation of surplus oxygen sources...

AI Technical Summary

Problems solved by technology

But there are also the following problems: ①The process is relatively complicated and occupies a large area

It is extremely difficult to arrange the flue gas furnace and its pipelines for general transformational blast furnaces due to the limitation of the site; ②The thermal efficiency of the front flue gas furnace is poor. From the perspective of energy utilization, whether it is economically cost-effective requires further demonstration

Because the energy conversion of this technology requires a flue gas furnace, and the temperature of the flue gas furnace is generally controlled below 1000°C, the use of blast furnace gas still requires a high excess air coefficient, and the enthalpy of gas with low calorific value is not enough. fully use

③After the temperature of the hot blast stove vault rises, it brings about the problem of rising exhaust gas temperature

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