Cases of equal pressure recovery of blast furnace gas such as Shandong Longsheng

1. Production status and environmental protection requirements

In the blast furnace smelting production process, the pressure-equalizing gas in the furnace top tank is usually discharged directly into the atmosphere after passing through the cyclone dust collector and the muffler. This part of the gas is a toxic and combustible gas mixture containing a large amount of CO and dust. The atmospheric environment, especially the blast furnace production area, causes pollution and wastes energy.

With the increasingly strict environmental protection requirements, most regions and iron and steel enterprises now require the use of a full recovery method, and the blast furnace gas is not released throughout the process;

2. Rationale

Pressure equalization recovery part (full recovery):

Before charging the material tank, the pressure in the material tank is consistent with the pressure in the furnace and is in a high pressure state, while the pressure in the gas recovery device connected to the atmospheric gas pipe network is in a normal pressure state, and the gas recovery between the material tank and the recovery device is opened. The valve uses the natural pressure difference to recover the gas discharged from the tank. After the recovery process is completed, the remaining gas in the tank with pressure close to normal pressure is released according to the blast furnace charging procedure. This process is "partial recovery".

The so-called "full recycling" means that after the natural recycling process ends:

Through the injection and suction device, the high-pressure clean gas is used to drive the remaining pressure gas in the material tank into the recovery device through the injection and suction effect. When the injection and suction recovery is completed, cut off the valve of the gas recovery system and stop the injection and suction, and open the upper sealing valve to load the material.

During the whole process of the process, the venting valve is always in a closed state, no venting occurs, and all the gas that is vented in the intermediate material tank can be fully recovered.

3. Advantages of Shanghai Xuanding

For the blast furnace gas pressure equalization recovery and wind break release project, Nanjing Xuanding, a wholly-owned subsidiary of Xuanding, as the smelting division, is specialized and responsible for the specific implementation of this type of project;

The professional and technical personnel in Xuanding smelting are all from well-known design institutes such as Jiangsu Metallurgical Design Institute and major universities. They are very familiar with and understand the process flow and equipment of smelting, and can respond to the different actual conditions and needs of customers. to provide the most suitable solution;

Based on the professional team's familiarity and understanding of the blast furnace production process, the design of the pressure equalization recovery system will be specially designed and formulated for the production rhythm of the existing blast furnace, and the recovery process will not have any impact on the blast furnace charging rhythm;

Fully demonstrate and theoretically check the ejection system and the existing blast furnace ejection medium (high-pressure gas or nitrogen, etc.), and combine the successful operation of multiple pressure equalization recovery systems to ensure the ejection effect and achieve full recovery;

4. Project case and production effect

Shanghai Xuanding has successively built a number of blast furnace gas pressure equalization recovery projects (full recovery), all of which have achieved dry ash discharge, and the original pressure equalization relief valve is closed throughout the process, and no gas is discharged;

The following is the introduction of the blast furnace gas equalization recovery project of Shandong Longsheng and Shandong Zouping Special Steel;

4.1 The application of internal and external heat tracing technology of patented technology can realize dry ash

4.2 Ejector design and full recovery

The recovery time period and ejection time are reasonably determined according to the blast furnace charging cycle, without affecting the blast furnace charging and production capacity

According to the pressure of the ejected medium and the characteristics of the medium, the ejector is designed in a targeted manner to ensure that the ejection time meets the requirements

5. Production effect