Gas hazards
In the smelting process, the blast furnace produces a large amount of high-temperature waste gas containing CO and dust. Its calorific value is generally about 2000 to 3100 kcal/m3, which is a low calorific value gas. Like the converter gas, it has become an important secondary energy source for steel companies, such as Do not govern and recycle, that is, pollute the environment, harm physical and mental health, and waste energy.
The necessity of gas recovery
Iron-making plants with surplus blast furnace gas can also be used to generate electricity, which accounts for 25% to 30% of the fuel balance of the iron and steel metallurgy conglomerates. Its status is extremely important. The value of blast furnace gas as fuel: 4000 m3 of gas can be produced for every ton of coke burned, and 100034000 = 4000000 m3/t of gas can be produced per 1,000 hours of blast furnaces that consume coke. The dry gas has a calorific value of 3762 KJ. If the gas is fully used, 400000033762 = 15048000000 KJ of heat can be obtained, equivalent to 15048000000 ÷ 30514 = 493150 kg of coal having a calorific value of 30514 KJ, that is, 493t.
Dust removal equipment for blast furnace gas treatment
The purification of early blast furnace gas was mainly performed by scrubbing towers, venturis, and other wet scrubbing. Although the purpose of gas purification has been achieved, there are many unsolvable problems in the wet process, such as large water consumption, waste water containing CN-S2-, phenols, lead, zinc, and other heavy metals that are difficult to handle later; purification system equipment is complicated; washing equipment Severe corrosion fouling; gas sensible heat can not be recovered; gas moisture content caused by more moisture and other shortcomings, blocking the application of wet purification process. Therefore, the dry cleaning of blast furnace gas has received more and more attention.
Due to the low dust removal efficiency of the gravity dust collector, the country’s increasingly stringent environmental protection requirements limit its application. However, many of the advantages of the precipitator or stand alone precipitator as an advanced precipitator are obvious.
Blast furnace gas dust removal equipment generally uses the following processes:
1. Blast furnace gas → Gravity dust collector → Venturi scrubber → Electrostatic precipitator
2. Blast Furnace Gas → Gravity Dust Collector → One Venturi scrubber → Secondary Venturi scrubber
3, blast furnace gas → gravity dust collector → bag filter