AOD furnace smoke and dust high and medium temperature waste heat positive energy recovery and dust removal system

Abstract

The invention relates to the positive energy recycling and dust removal system of AOD furnace flue dust, high temperature and waste heat. The primary flue gas of the AOD furnace during normal smelting is mainly captured by the vaporization flue suction hood, and the secondary flue gas during oxygen blowing, feeding, and tapping is captured by the variable-flow roof fume hood. The electric multi-leaf butterfly valve is used to control the air volume, and the primary flue gas and secondary flue gas exhaust systems are combined to set up, and the characteristics of the low dust concentration, very low flue gas temperature and large air volume of the secondary flue gas are used to dilute And reduce the high dust and temperature conditions in the primary flue gas. The hot smoke and dust pass through the system composed of vaporization flue and finned tube waste heat boiler, absorb heat energy through radiation convection, generate a large amount of saturated steam to drive the steam turbine, and the steam turbine directly drives the dust removal main fan to avoid energy loss. The invention can not only recycle and utilize the waste heat positive energy of AOD furnace dust to the greatest extent, but also realize environmental protection discharge of smelting dust, and meet the requirements of energy saving, emission reduction and circular economy.

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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