JPS602617A - Method for fractionating, recovering and reutilizing converter gas - Google Patents

Abstract

PURPOSE:To reduce cost by separating and recovering gaseous CO2 from the CO2-contg. gas generated in the initial and end periods of a converter operation and utilizing the same as bottom flowing gas for the converter. CONSTITUTION:The CO2-contg. gas resulting from combustion of the gas generated in the initial period by operating a converter 1' with composite top and bottom blowing is fed into a gas holder 13' provided on the downstream of an induced fan 4 of a converter gas treating device. A damper 11' is then opened and dampers 8', 18 are closed to feed the gaseous CO in the max. blowing period to a gas holder 13. The gas contg. the burned gaseous CO2 generated in the end period is fed into said gas holder 13'. Only the gaseous CO2 is separated and recovered from the gas in the holder 13'. The recovered gaseous CO2 is blown as bottom blowing gas for composite blowing into the converter from the bottom thereof. The need for forming freshly a large amt. of gaseous CO2 is thus eliminated and cost is reduced.

Description

[Detailed description of the invention] The present invention relates to a method for separately collecting and reusing converter gas.

During converter operation, gas generated from the converter 1) shown in FIG. 1 is subjected to F treatment in a converter gas treatment device 2. That is, the gas generated from the converter 1 is <CO2> as shown in FIG.
The initial layer of blowing, which is low in concentration, is completely formed and is useful for the safe collection of high concentration CO gas generated during that time.
These combustion gases are sucked in by the operation of the induced fan 4 of the converter gas treatment equipment 2, cooled by the gas cooler 5, and sequentially removed by the secondary dust collector 6 and secondary dust collector 7, and then Blower 4? Flow path 9 where the damper 8 is opened as shown by the dotted line via f-
It is dissipated into the atmosphere through 10 chimneys and chimneys. When blowing is at its peak, the CO concentration of the gas generated from the converter 1 is high as shown in FIG. The gas is collected as fuel in the gas holder 13.

By the way, in recent converter operations, there is a tendency to use both top blowing and bottom blowing in combination, and A as the bottom blowing gas.
Inert gases such as R and N2 have been used, but recently the use of C02 gas has become effective for decarburization.

However, newly producing a large amount of C02 gas as bottom blowing gas requires all equipment and fuel, which increases costs.

The present invention was made in view of the actual situation, and this invention
The CO2 generated at the beginning and end of the blowing process was dissipated into the atmosphere.
Gas containing v? Separate recovery and reuse of converter gas that is recovered, separated and recovered, and used as gas for bottom blowing of the converter, eliminating the need for equipment and fuel to produce CO2 gas and reducing costs. The purpose is to provide a method.

The method for separately recovering and reusing converter gas according to the present invention includes all the gas generated by top-blowing and bottom-blowing converter operations, the gas contained in CO2 combusted at the beginning and end of blowing, and the gas contained in the CO2 burned at the beginning and end of blowing. The CO2 gas was collected separately from the CO2 gas in the first stage, and collected in two gas holders installed downstream of the induced blower of the converter gas treatment equipment, and from the collected CO2 gas (), only the CO2 gas was completely separated and collected. After that, this CO. gas? It is characterized by being blown from the bottom of the converter as the bottom blown gas for complex blowing.

Embodiments of the method for separate recovery and reuse of converter gas according to the present invention will be explained below with reference to FIG. 4. During the operation of the converter 1' with both top blowing and bottom blowing, the Since the CO concentration of the gas is low at the beginning of blowing as shown in Figure 2, it is forced to burn and becomes CO2 gas as shown in Figure 3.
A containing inert gas zone (tampon layer) is formed. Then, this combustion gas is sucked in by the operation of the induced fan 4 of the converter gas treatment device t2, and is cooled by the gas cooler 5.
- After being sequentially removed by the secondary dust collector 6 and the secondary dust collector 7, it is collected via the induced fan 4 into one of the two gas holders 13 and 13' installed downstream. be done. That is, the entire flow path 9' with the damper 8' open (as shown by the dotted line) passes through four induced blowers, and the flow path 15 with the damper 14 open. The gas passes through and is collected in the gas holder 13'. At this time, the damper 11' of the flow path 12' is closed, the downstream damper 16 of the flow path 9' is closed, and the damper 18 of the bypass flow path 17 is closed.

When the blowing reaches its peak, the CO concentration of the gas generated from the converter 11 increases as shown in Figure 2, so this CO gas flows through the flow with the damper 11' opened, as shown by the solid line in Figure 4. Road 12'
The fuel passes through the gas holder 13 and is recovered as fuel. At this time, the damper 8' of the flow path 9' is closed as shown by the solid line, and the damper 18 of the bypass flow path 17 is also closed.

When blowing enters the final stage, the gas generated from converter 1' is transferred to the second
As shown in the figure, as the CO concentration becomes diluted, it is forced to burn again and an inert gas zone (tampon layer) containing all CO2 is formed as shown in Figure 3, and this combustion gas is absorbed by the dotted line in Figure 4. The gas passes through the channel 9' where the damper 8' is opened, and further passes through the channel 15 where the damper 14 is opened, and is collected in the gas holder 13'.

When the blowing is completed and the inert gas zone (tampon layer) has disappeared, the damper 14' of the flow path 15 is closed, and the damper 16 downstream of the flow path 9' is opened to release the gas (in the converter 1'). Flow path 9'? It is dissipated into the atmosphere through the dissipation chimney 10.

In addition, during the initial and final stages of blowing, when recovering the inert gas to the gas cylinder 13' (5), in the unlikely event that the damper 8' of the flow path 9' and the damper 14 of the flow path 15 break down and open. If not, the damper 18 of the bypass flow path 17 is opened to allow the combustion gas to pass through the entire bypass flow path 17' and diffuse into the atmosphere from the emission chimney 10. ′! The CO gas at the peak of blowing is transferred to gas holder 1.
3, even if the damper 11' of the flow path 12' fails and does not open, the damper 18 of the bypass flow path 17 will be opened and the CO gas will be passed through the bypass flow path 17 and released into the chimney 10.
It combusts at the top of the tower and dissipates into the air.

The co2'i collected in the gas holder 13'
The CO2 absorber 19 separates and absorbs only the CO2 gas from the combustion gas that it contains, and this CO2 gas is transferred to the CO2 holder 2.
Converter 1 as blowing gas during blowing after being recovered
Blow from nozzle 21〃λ at the bottom of '.

(The coke in the gas injected from the bottom of the converter 1'
2 is reduced as 2CO2 → 2CO+02, and the hot iron in the converter 1' receives a good decarburization effect (6) due to the cooperation of the top-blown oxygen from the lances 3 and the reduced oxygen, Blowing is performed well. As a result, the CO concentration of the converter gas generated from the converter 1' increases, the initial CO concentration during blowing increases more quickly, and the CO concentration at the end of blowing decreases more slowly. Therefore, the period for forming the tampon layer is shortened, and the amount of CO gas recovered is increased.

Of the CO2 gas recovered in the CO2 holder 20, the remaining CO2 gas that is not used as bottom blowing gas is utilized for other purposes.

As can be seen from the above explanation, the method for separately recovering and reusing converter gas of the present invention burns the gas generated during converter operation with combined top blowing and bottom blowing at the beginning and end of blowing. CO
The gas containing □ and the CO gas at the peak of blowing are collected separately in two gas holders, and the recovered CO2 gas is further separated and recovered from the CO2 gas.
Since O2 gas is injected from the bottom of the converter as the bottom blowing gas for combined blowing, inert gas such as Ar * N2 is used as the bottom blowing gas of the converter as in the conventional method. There is no need to use it, and there is no need to create a new CO2 gas as a bottom blowing gas, so the equipment and fuel required for this become unnecessary, and costs are reduced. 1) The CO2 gas injected from the bottom of the converter is reduced, which increases the CO concentration in the gas generated from the F converter, shortens the period for formation of the tampon layer, and increases the amount of CO gas recovered. There are other effects.

[Brief explanation of drawings]

Figure 1 is a schematic system diagram showing the converter gas processing bag R of a conventional top-blown converter, and Figure 2 is a diagram showing the converter gas treatment bag R of a conventional top-blown converter.
Figure 3 is a graph showing the change in the 002 concentration in the gas at 7c when the converter gas is burned at the beginning and end of blowing, and Figure 4 is the graph showing the change in the 002 concentration in the gas at 7c at the beginning and end of blowing. FIG. 1 is a schematic system diagram showing a converter gas processing apparatus in a converter of combined blowing of top blowing and bottom blowing in which all the separation recovery and reuse methods are carried out. 1'...Converter with top blowing and bottom blowing combined blowing 2...Converter gas treatment equipment 3...Lance 4...Induced blower 5...Gas cooler 6...-Next collection Dust container 7... Secondary dust collector 8', 11', 14, 16.18... Damper 9', 12', 15... Channel 10... Induced blower 13, 13'...・Gas holder 17...
・Bypass flow path 19...C02e, revenue 20...
CO2 holder 21... Nozzle applicant Kawasaki Heavy Industries, Ltd. (9)

Claims (1)

[Claims] The gases generated during converter operation of top-blown and bottom-blown double blowing are divided into the gas containing CO□ combusted at the beginning and end of blowing, and the CO gas at the peak of blowing. Installed downstream of the induced blower of the furnace gas treatment equipment, the CO2 gas is collected in two gas holders (fc), and after completely separating and recovering only the CO2 gas from the gas contained in the recovered 10,000 CO2's, this CO2 gas is transferred to a double blower. A method for separately collecting and reusing converter gas, which is characterized in that it is blown from the bottom of the converter as bottom-blown gas for refining.