JPS6119720A - Operation of hermetically closed-type converter exhaust gas treatment apparatus - Google Patents

Abstract

PURPOSE:To enhance safety against explosion by sufficiently forming an inert gas layer, by adjusting the components of exhaust gas by blowing air in a converter after blowing-in was started and stopping the blowing-in of air when said gas reaches a definite amount. CONSTITUTION:When CO gas is generated from a converter after the beginning of blowing-in, the amount of air to be blown in is adjusted by the damper 13' of an air blow-in apparatus 12 on the basis of the signal of an exhaust gas analysis terminal 14 so as to obtain a predetermined exhaust gas composition such that O2-concn. is 5.5% or less and CO-concn. is 12.5% or less. The blowing- in amount of air is increased with the increase in the amount of the gas generated from the converter 1 and the O2 or CO- concn. in exhaust gas is controlled to a predetermined composition. The exhaust gas amount of an inert gas state, wherein O2 in the exhaust gas is 5.5% or less and CO therein is 12.5% or less, is measured and integrated by an exhaust gas flow meter 17 and, when the integrated amount reaches a predetermined one, a damper 13 is completely closed to stop the blowing-in of air and the treatment of the exhaust gas is brought to a hermetically closed state. By this method, the recovery of high purity CO gas can be performed.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to a closed converter exhaust gas system that is operated in a hermetically sealed or nearly hermetic state, which improves safety and makes it possible to recover CO gas with high purity. It relates to a method of operating a processing device.

(Prior art and its problems) A large amount of CO gas is generated during refining by blowing pure oxygen into a converter containing hot metal (hereinafter referred to as blowing). This CO gas poses a risk of explosion if it comes into contact with outside air. Also, if it leaks outside, it is dangerous as it can cause carbon monoxide poisoning.

5K is working to safely dispose of the dangerous gases generated from the converter using exhaust gas treatment equipment.

First, an overview of the converter exhaust gas treatment device and its operating method will be explained using FIG. In the figure, hot metal produced in a blast furnace (not shown) is injected into a converter 1 and sealed by a skirt 2. In this state, pure oxygen is blown into the converter 1 through the oxygen lance 11, and blowing is started. In this way, the carbon in the hot metal reacts with the injected oxygen and decarburizes, producing high-quality steel. This decarburization reaction generates a large amount of CO gas.

This CO gas is drawn into the 7-door 3 by the induced blower 7, cooled in the 7-door 3 and the cooler 4, and then removed with dust removal amounts 5 and 6, and recovered as valuable gas in the gas holder IOK. Ru.

In this converter exhaust gas treatment device, the converter operation is performed as follows. Start of blowing*a, 7-Air is accumulated between the door 3 and the switching damper 9. If this air comes into contact with the CO gas generated during blowing, there is a danger of an explosion.

Therefore, in order to avoid this explosion, the CO gas is combusted by sucking the outside air through the gap between the furnace mouth and the skirt 2 and burning the CO gas at a low Ca2 concentration in the early stage of blowing.
5- or less CO concentration is 12.5- or less, a gas layer mainly composed of N2 gas and CO2 gas is generated between the air stagnant in the equipment and the CO gas generated at the peak of blowing. Preventing contact between air and CO gas through the above gas layer,
Trying to prevent explosions. Also, at the end of blowing, outside air is similarly sucked in between the skirt 2 and the furnace mouth to generate the above-mentioned gas layer, thereby preventing contact with outside air that enters at the end of blowing.

In other words, CO gas with a high CO concentration at the peak of blowing has a CO concentration of 5.5% or less and a CO concentration of 12.5% or less produced by combustion at the beginning and end of blowing. Inert gas is a gas whose main components are N2 gas and CO2 gas, which are separated from the outside air in a state where the main components are 0□11 degrees and 5.5% or less, and CO2 gas is 125% or less. layer) is safely recovered. Note that this inert gas layer is dissipated into the atmosphere by the switching damper 9 and from the dispersion tower 8.

In the converter operation mentioned above, recently, in order to improve the quality of recovered gas and the basic unit of recovered gas, the space between the converter and the skirt is sealed or close to sealed to prevent outside air from entering, resulting in high purity. Recovery of CO gas has become desirable.

In this way, in the so-called closed type converter exhaust gas treatment equipment in which the gap between the converter mouth and the skirt is sealed or close to sealed, there is no or very little intrusion of outside air, so it is not enough. There is a problem that an inert gas layer is not generated.

The current method of operating closed-type converter exhaust gas treatment equipment is to raise the skirt at the beginning and end of blowing, and create a gap between the converter mouth and the skirt to draw outside air from here. It is designed to generate an inert layer by suction.

However, the skirt is raised at the beginning and end of the blowing process,
In the end, the suction of outside air is no different from the conventional exhaust gas treatment equipment, and there is a problem in that the effects of using a closed converter exhaust gas treatment equipment cannot be expected, and high purity cO gas cannot be recovered.

(Purpose of the Invention) The present invention is a book that aims to solve this problem and provide a method for operating a closed converter exhaust gas treatment device that makes it possible to recover CO gas. Structure) The present invention does not raise the skirt and draw in outside air from between the furnace mouth and the skirt as in the past, but instead installs an air blowing device. With the furnace closed or close to closed, adjust the pressure inside the furnace and adjust the amount of air blown in from the air blowing device to ensure that the CO in the exhaust gas is 12.51 or less and 0□ is 5.5 or less. Adjust the gas components to a predetermined exhaust gas composition,
At the same time, the gas flow rate of the above components is measured, and when this gas amount reaches a certain amount, the air blowing device stops blowing air.
It is characterized by stopping.

(Example) An embodiment of the present invention will be described in detail.

In Fig. 2, CO gas generated from the converter 1 is drawn into the 7-door 3 by the air blower 7, cooled by the 7-door 3 and cooler 4, and then removed by dust removers 5 and 6. and collected in the gas holder 10.

Note that 2 is a skirt, 8 is a diffusion tower, and 9 is a flow switching valve. 1
Reference numeral 2 denotes an air blowing device provided as close as possible to the furnace mouth of the converter 1, and is provided with two dampers 13, 13'. 17 is a gas flow meter.

In this closed type converter gas treatment apparatus, the dampers 13 and 13' of the air blowing apparatus 12 are opened at the beginning and end of blowing. The opening degree adjustment of the dampers 13 and 13' is performed as follows.

First, the damper 13 is adjusted by the signal 15 of the gas flow meter 17. That is, at the beginning and end of blowing, the damper 13 is fully opened until inert gas is generated.

Therefore, the amount of air blown from the air blowing device 12 is adjusted by the damper 13. The opening degree adjustment of the damper 13' is performed by a signal from the gas component (COh 02 ) detection end 14.

That is, the amount of CO concentration gas generated at the beginning and end of blowing varies depending on the amount of air supplied and the amount of gas generated in the converter. The gas component is detected by the gas component detection end 14, and the CO component that does not cause an explosion is 12.5% or less and the 02 component 5.
The opening degree of the damper 13' is adjusted so that the exhaust gas composition becomes a predetermined value of 5- or less, and so-called inert gas is generated in which the concentration of CO and 02 becomes less than a predetermined value.

Inert gas is generated in this way, and the flow rate of the inert gas is measured by the gas flow meter 17, and when a sufficient amount is reached, the damper 13 is fully closed, and the exhaust gas treatment device becomes completely sealed.

This operating method will be explained in more detail using FIG. FIG. 3 shows the initial stage of blowing.

In other words, it shows the state of transition from the state immediately before blowing to operation. In the figure, just before blowing, air is blown into the converter 1 through the skirt 2 through the air blowing device 12 while the furnace opening of the converter 1 is closed or close to closed. Therefore, the amount of exhaust gas is the amount of air blown into it.

Next, blowing is started, and when COO20 begins to be generated from the converter, a signal from the exhaust gas analysis terminal 14 indicates that the 02 concentration in the exhaust gas is 5.5 inches or less, and the CO concentration is 12.5 inches or less. The amount of air blown is adjusted by the damper 13' so that the composition of the exhaust gas is achieved. Immediately after the start of blowing, the amount of CO gas generated from the converter is small, so the amount of blown air temporarily decreases, but as the amount of gas generated from the converter increases, the amount of blown air increases, and the amount of CO gas in the exhaust gas increases. The CO concentration is controlled to a predetermined composition. The composition of this waste gas is 025.
The amount of exhaust gas in the so-called inert gas state, which is within the range of 5ts or less and CO12.5% or less, is measured and integrated by the exhaust gas flow meter 17, and when the integrated amount reaches a predetermined amount, the damper 13 is When it is closed, air blowing is stopped and the exhaust gas treatment device becomes completely sealed or nearly sealed.

Therefore, the composition of the exhaust gas at this time is CO with high purity, and the amount of exhaust gas is equal to the amount of gas generated in the converter.

(Effects of the Invention) As detailed above, the operating method of the closed type converter exhaust gas treatment device according to the present invention is such that the converter exhaust gas treatment device is provided with an air blowing device, and the concentration of CO and 02 is controlled at the initial and final stages of blowing. After adjusting the amount of air blown from the air blowing device to reliably generate inert gas (C02 gas) and confirming that a sufficient amount of this inert gas has been generated,
Since the air blowing is stopped, it is possible to reliably generate an inert gas layer with the exhaust gas treatment device completely connected between the pipes, ensuring safety, and also to ensure safety.
It has an industrially excellent effect in that it is possible to recover OO20 and greatly improve the value of COO20 as a valuable gas.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the converter exhaust gas treatment equipment, Figures 2 and 3
The figure shows one embodiment of the present invention. Figure 2 is a schematic configuration diagram showing a converter exhaust gas treatment equipment for carrying out the operating method of the present invention. Figure 3 shows the composition and amount of exhaust gas during operation. ,
FIG. 2 is a diagram showing the relationship between the amount of air blown and the amount of gas generated in the converter. 1... Converter 2... Skirt 7... Induced blower 12... Air blowing device 14... Gas analysis detection end 15... Flow rate detection end 17... Gas flow meter

Claims (1)

[Claims] In a converter exhaust gas treatment device equipped with an air blowing device near the furnace mouth of the converter flue gas treatment device, while adjusting the pressure inside the furnace with the furnace mouth in a sealed or nearly sealed state, from the air blowing device. By adjusting the amount of air blown in, the gas components are adjusted so that CO in the exhaust gas becomes a predetermined composition of 12.5% or less and O_2 is 5.5% or less, and at the same time the gas flow rate of the above components is adjusted. 1. A method for operating a closed converter exhaust gas treatment device, which comprises measuring the amount of gas and stopping blowing air from an air blowing device when this gas reaches a certain amount.