Closed ferroalloy furnace coal gas dry method purification and recovery system

Abstract

The invention relates to a closed ferroalloy furnace coal gas dry method purification and recovery system. A closed ferroalloy electric furnace 1 is sequentially connected with a water-cooling flue 3, a spark catcher 4, a surface evaporation cooler 5, a bag filter 6, a condensation drainer 7, a coal gas fan 8, a torch burner 9, a coal gas water seal 10 and a coal gas cabinet 11 through metal pipelines, the connecting pipeline of the ferroalloy electric furnace 1 and the water-cooling flue 3, the connecting pipeline of the coal gas fan 8 and the torch burner 9 and the connecting pipeline of the torch burner 9 and the coal gas water seal 10 are respectively provided with a switching valve 2, an upper ash discharging valve 13, a middle ash tank 14 and a lower ash discharging valve 15 are sequentially installed below the spark catcher 4 and the bag filter 6 respectively, a furnace pressure measuring device 16 is installed on a furnace cover of the closed ferroalloy electric furnace 1, and an automatic control system 12 is connected with the mentioned equipment and a valve through signal lines. According to the closed ferroalloy furnace coal gas dry method purification and recovery system, coal gas purification efficiency and quality are improved, water pollution and sludge problems caused by a wet method purifying process are avoided, sewage treatment investment and operating expense are saved, corrosion, blocking, freezing and the other problems existing in the wet method process are avoided, and maintenance workloads are reduced.

Description

technical field [0001] The invention relates to a gas dry purification and recovery system of a closed ferroalloy furnace, which is suitable for dry purification and recovery of gas in a closed electric furnace in the ferroalloy industry. Background technique [0002] Ferroalloys are indispensable materials for steelmaking as deoxidizers and additives for steelmaking. The gas temperature of the closed ferroalloy furnace fluctuates greatly, the normal working condition temperature is 150-400°C, and the special working condition is as high as 800°C, with sparks, the gas dust concentration is 40-150g / m 3 , The dust belongs to fine particles, 90% of which have a particle size of less than 2 μm. The gas components in the gas are mainly CO, O 2 、H 2 、H 2 O.CO 2 Wait, the gas contains water vapor and tar, and when the gas temperature is too low, water and tar will come out. Ferroalloy gas purification is a negative pressure operation. When the seal is not tight, air will seep...

AI Technical Summary

Problems solved by technology

Wet purification mainly has the following problems: 1. Low purification efficiency, high dust content in gas, which cannot reach the limit of environmental protection emission standards; 2. Large water consumption, high investment in sewage treatment, high energy consumption for operation, and tons of steel products High cost and no competitive advantage in the market; 3. The gas has high water content, low calorific value, and low quality; 4. The washing water pipeline and equipment are often blocked, corroded or frozen, and the furnace is frequently shut down for maintenance, which affects normal production

The disadvantages of this process are: 1. When the gas suddenly becomes high temperature (such as 800°C), the carbon steel pipe material cannot withstand such a high temperature (the temperature resistance of carbon steel pipes is generally less than 400°C), and the system lacks a pipe cooling device; 2. The high-temperature gas in the system is cooled by air-cooled pipes. This cooling method in the project is not effective, and the volume and steel consumption are large; 3. Although the settling chamber in the system can remove large particles of dust, due to its low dust removal efficiency, it cannot Effective removal of Martian particles will cause burns or burning of the filter material of the bag filter, and serious air leakage in the settling chamber in the project; Large consumption of steel and steel, frequent maintenance

What needs to be pointed out in particular is that it uses purified gas as the gas source for backflushing and dust removal. Once the bag of the dust collector is broken, the dusty backflushing gas will pollute all filter bags, resulting in the failure of the dust collector.

5. According to the requirements of the specification, unqualified gas cannot be put into the gas cabinet, and the process has no disposal means and facilities for unqualified gas

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