Smoke medium and high temperature waste heat positive energy recycling and dust removing system of AOD furnace

Abstract

The invention relates to a smoke medium and high temperature waste heat positive energy recycling and dust removing system of an AOD furnace. During normal melting, primary smoke of the AOD furnace is mainly gathered through a vaporization smoke flue suction port cover, and secondary smoke generated during oxygen blowing, charging and tapping is gathered through a variable-flow roof smoke cover. An electric multi-blade butterfly valve is used for controlling the air quantity, a primary smoke exhausting system and a secondary smoke exhausting system are arranged in a combined mode, and the high dust and high temperature of the primary smoke are diluted and lowered by utilizing the characteristics that the secondary smoke is low in dust concentration, low in temperature and high in air quantity. Hot smoke passes through a system formed by an evaporation smoke flue and a finned-tube waste heat boiler, heat energy is absorbed through radiation convection, a large amount of saturated steam is generated to drive a turbine, the turbine directly drives a main dust removing fan, and therefore energy losses are avoided. By means of the smoke medium and high temperature waste heat positive energy recycling and dust removing system of the AOD furnace, waste heat positive energy of smoke of the AOD furnace can be recycled to the maximum, meanwhile, environment-friendly emission of smelting smoke can be realized, and the requirements for energy conservation, emission reduction and recycling economy are met.

Description

technical field [0001] The invention relates to a positive energy recycling and dedusting system for high, medium and high temperature waste heat of smoke and dust of an AOD furnace, and belongs to the technical field of energy recycling and environmental protection. Background technique [0002] There are more than 400 80-200 ton converters in the country, and the market for AOD furnaces is larger, and they are widely used in electric power, metallurgy, building materials, cement, chemical and other industries. Converter and AOD furnace will produce high-temperature smoke and dust during the working process, direct emission not only wastes energy, but also pollutes the environment. However, the recycling rate of waste heat power generation of converters and AOD furnaces is less than 20%, and the application ratio is low. At present, about 90 sets of AOD furnace waste heat power generation units have been built in my country, with a total installed capacity of 1.204 million...

AI Technical Summary

Problems solved by technology

Converter and AOD furnace will produce high-temperature smoke and dust during the working process, direct emission not only wastes energy, but also pollutes the environment

However, at present, the recycling rate of waste heat power generation of converters and AOD furnaces is less than 20%, and the application ratio is low

[0005] 1. The traditional process of converter is to arrange the vaporization flue in an "inclined upward" manner. Generally, the length of the vaporization flue is between 50 and 60 meters. In this way, the steelmaking workshop is very high, and the steel structure platform is high and heavy. The investment cost is high, and the installation and maintenance of the vaporization flue is difficult, etc., so the process is very inflexible

[0006] 2. It is difficult to collect dust during feeding and tapping of conventional converters. It takes three times of dust removal, which will cost a lot of investment.

[0007] 3. In terms of energy recovery, the main reason is that the amount of steam recovered is small, and the general high-temperature area is directly cooled with water; in terms of electric energy, there are too many conversion links of thermal energy-electric energy-kinetic energy, energy is lost in energy conversion, and energy utilization is reduced. rate, increasing the investment cost of the enterprise

[0008] 4. The traditional waste heat adopts the vaporization flue method, and the AOD furnace does not use the process of vaporization flue + finned tube waste heat boiler, so the waste heat in the high temperature area of ​​the smoke and dust is not recovered, and the amount of saturated steam produced is small, which directly affects the power generation power

[0009] 5. The electric energy generated by the steam turbine needs to be approved by the power department to be connected to the grid, and it is very inconvenient to pay the grid usage fee

[0010] 6. When the motor drives the fan, the torque is small, the transmission is not stable, and the speed regulation range is small

[0011] 7. The manufacturing cost of the waste heat power generation system is high, the electric energy is not directly used, and the loss in the conversion is large

[0012] 8. The filter medium in wet dust removal is water, and the filtered sewage brings secondary pollution. It is necessary to carry out sewage treatment on the filtered return water and increase investment; and the resistance of wet dust removal is relatively large, and the fan station wind in wet dust removal Moisture-containing smoke and dust are often stuck on the leaves. Long-term operation will cause the imbalance of the fan's motor balance and large vibrations, and frequent repairs and replacements are required.

[0013] 9. The existing dry electrostatic precipitator has high investment, high energy consumption and high maintenance cost

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