KR102213975B1 - Apparatus for recoverying linz donawitz gas and method of recoverying linz donawitz gas using the same - Google Patents

Abstract

According to one aspect, a Linz-Donawitz converter gas recovery device comprises: an upper analyzer disposed upstream of a dust collection device on a path of Linz-Donawitz converter gas generated from a converter and measuring and analyzing concentration of component containing carbon monoxide in the Linz-Donawitz converter gas by using a laser; a lower analyzer disposed downstream of the dust collection device and measuring and analyzing the concentration of the component containing the carbon monoxide in the Linz-Donawitz converter gas by using a laser; and a gas holder recovering the Linz-Donawitz converter gas when the concentration of the carbon monoxide contained in the Linz-Donawitz converter gas passing the upper and lower analyzers is at least a predetermined value.

Description

Converter gas recovery device and converter gas recovery method using the same {APPARATUS FOR RECOVERYING LINZ DONAWITZ GAS AND METHOD OF RECOVERYING LINZ DONAWITZ GAS USING THE SAME}

The present invention relates to a converter gas recovery apparatus and method, and more particularly, to a converter gas recovery apparatus using the laser analyzer to improve recovery efficiency and operational safety, and a converter gas recovery method using the same.

In the steel making process, by-product gases such as blast furnace gas (BFG), coke oven gas (COG), and linz donawitz gas (LDG) are generated. Among these by-product gases, the content of carbon monoxide (CO) varies according to the progress of the furnace gas (LDG). If the content of carbon monoxide (CO) is higher than a certain value, the converter gas (LDG) is recovered and stored in a gas holder and used for power generation in power plants.If the content of carbon monoxide (CO) is less than the standard value, it is dissipated into the atmosphere in the form of combustion gas. Can be. On the other hand, when determining the recovery or release of the converter gas (LDG), in addition to the concentration of carbon monoxide (CO), the concentration of oxygen (O ₂ ) and hydrogen (H ₂ ) must be considered to prevent explosion.

Methods of determining the timing of recovery of the converter gas (LDG) include a method of calculating through an equation and a method of using an infrared or magnetic field meter. In the case of the calculation method, since the value is not actually measured, there is a problem of inferior accuracy, and the method using an infrared or magnetic field meter has a disadvantage of delaying the process due to a long analysis time. Since neither method is able to specify the exact recovery point, there may be cases in which low-calorie LDG with a low carbon monoxide (CO) component is recovered or a high-calorie LDG with a high carbon monoxide (CO) component is released.

As a related technology, there is Korean Patent Application Publication No. 10-2012-0057981 (published on June 7, 2012, a method for predicting the level of an LDG holder).

The problem to be solved by the present invention is to provide a converter gas recovery device with high recovery efficiency and improved operational safety, and a converter gas recovery method using the same, since components in the converter gas are measured using a laser.

The converter gas recovery device according to an aspect of the present invention is disposed upstream of the dust collector on the path of the converter gas generated in the converter, and measures and analyzes the concentration of a component including carbon monoxide in the converter gas using a laser. Analyzer; A lower analyzer disposed downstream of the dust collecting device and measuring and analyzing a concentration of a component including carbon monoxide in the converter gas using a laser; And a gas holder for recovering the converter gas when the concentration of carbon monoxide contained in the converter gas passing through the upper and lower analyzers is higher than a predetermined value.

It is preferable that the upper analyzer measures the concentration of hydrogen, oxygen, carbon monoxide, and carbon dioxide, and the lower analyzer measures the concentration of hydrogen and carbon monoxide.

At least one of the upper analyzer and the lower analyzer may include a laser irradiation unit irradiating laser light to be perpendicular to the flow of the converter gas; And a laser light receiving unit receiving the laser light.

The lower analyzer includes: a first insertion tube protruding from the laser irradiation unit to surround the laser optical path; And at least one of a second insertion tube protruding from the laser light receiving unit to surround the optical path of the laser light.

The upper analyzer includes a separate pipe installed in the pipe of the converter gas generated in the converter; A laser meter installed inside the pipe to measure a component concentration of the converter gas inside the pipe according to the amount of light received by irradiating a laser; And a filter disposed at a front end of the laser measuring instrument to remove dust in the converter gas.

The pipe is branched into two, and a pressure gauge for measuring the pressure of the converter gas in the pipe may be further included at both ends of the pipe.

In the converter gas recovery method according to another aspect of the present invention, (a) it is disposed upstream of the dust collector on the path of the converter gas generated in the converter, and measures the concentration of a component including carbon monoxide in the converter gas using a laser, and Measuring the content of carbon monoxide and hydrogen in the converter gas using an upper analyzer for analysis; (b) When the content of hydrogen is less than the threshold value of the risk of explosion, a lower analyzer is disposed downstream of the dust collecting device and measures and analyzes the concentration of a component including carbon monoxide in the converter gas using a laser. Measuring the concentration of carbon monoxide and oxygen by using; And (c) recovering the converter gas when the concentration of carbon monoxide in the converter gas measured by using the lower analyzer exceeds 15% and the concentration of oxygen is less than a threshold value at risk of explosion. It is characterized.

Before performing the (a) and (b) steps, (a-1) measuring the transmittance of the upper analyzer, and (b-1) measuring the transmittance of the lower analyzer, respectively. I can.

In step (c), if the concentration of carbon monoxide is less than the threshold value, the concentration of oxygen exceeds the threshold value that may cause explosion, or the blow rate exceeds the threshold value, it is preferable to terminate the recovery and terminate the work. Do.

In the step (a-1), when the transmittance of the upper analyzer is less than 1%, a warning alarm sounds and the operation is terminated, and in the step (a-1), the transmittance of the upper analyzer exceeds 1%, and the ( In step b-1), if the transmittance of the lower analyzer is less than 1%, the concentration of carbon monoxide measured in step (a) exceeds the threshold value, and the concentration of oxygen is less than the threshold value at risk of explosion. It is desirable to start the recovery of the gas.

According to the present invention, since the converter gas component is analyzed using a laser analyzer, the accuracy is excellent, and since the analysis can be performed immediately within 1 to 2 seconds in the pipe, the recovery delay is reduced compared to the method using the conventional infrared and magnetic field. Increased and operational stability improved. Therefore, it is possible to improve power generation efficiency through the recovery of high-calorie operating gas.

1 is a view for explaining a converter gas recovery apparatus according to the present invention.
2 is a view showing an upper analyzer of a converter gas (LDG) recovery apparatus according to an embodiment of the present invention.
3A and 3B are diagrams showing a cross section of an analyzer including a laser gas analyzer.
FIG. 4 is a flowchart illustrating a converter gas recovery method according to the present invention shown in FIG. 1.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. The present invention may be implemented in a number of different forms, and is not limited to the embodiments described herein. The same reference numerals are assigned to the same or similar components throughout the present specification. In addition, detailed descriptions of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

The present invention aims to increase the amount of LDG recovered by shortening the measurement time and improving the recovery time through measurement of a laser analyzer (TDLS: Tunable Diode Laser Spectrometer) when recovering LDG.

1 is a view showing an OG type converter gas recovery apparatus 100 as an embodiment for explaining a converter gas processing apparatus according to the present invention.

Referring to FIG. 1, while high-purity oxygen is injected into a furnace containing molten iron at high pressure and high speed for the composition of steel in the steel making converter 1, a converter gas (LDG) is generated as a by-product gas. The converter gas generated in the converter 1 is collected by the hood 2 disposed on the top of the converter 1, and the collected converter gas is cooled in the radiating unit 3, and then the converter gas is My dust and so on are removed. The converter gas after dust collection passes through the IDF 5 and a damper 6 and is recovered to the gas holder 7 or discharged to the combustion and dissipation tower 8 according to the carbon monoxide (CO) content in the converter gas. In this way, the converter gas LDG flows from the converter 1 on the upstream side through the pipe 10 toward the defense tower 8 or the gas holder 7 on the downstream side.

In order to determine the recovery or dissipation of the converter gas by measuring the gas concentration in the converter gas after the dust collection, a laser is used to measure and analyze the gas concentration in the converter gas in the radiating section, which is a path upstream of the dust collector 4 An upper analyzer 20 is installed, and a lower analyzer 30 is installed to analyze the gas concentration in the converter gas by using a laser on the downstream side before the defense tower 8 or the gas holder 7 after dust collection.

The determination of whether to recover the converter gas to the gas holder 7 or to dissipate it into the atmosphere via the defense tower 8 depends on the gas analysis results of the upper analyzer 20 and the lower analyzer 30. At this time, in order to prevent explosion, the concentration of oxygen (O2) as well as carbon monoxide (CO) is considered together and determined. In addition, in the case of intermittently measured hydrogen gas, it is generated by thermal decomposition of moisture in an auxiliary material, and since hydrogen also has a risk of explosion like oxygen, it is necessary to accurately measure and respond quickly. For example, the concentration of carbon monoxide (CO) in the converter gas analyzed by the upper analyzer 20 is 15% or more, and the oxygen concentration in the exhaust gas analyzed by the upper analyzer 20 and the lower analyzer 30 is both 2%. The following are the recovery conditions, and when the recovery conditions are satisfied, the converter gas is recovered to the gas holder 7. If any of the conditions are out of the way, the recovery conditions are not established, and the converter gas is dissipated from the dissipation tower 8. The recovery condition is an example and can be appropriately changed for each facility.

When the blow job is started in the converter 1, the oxygen concentration in the converter gas is high and the concentration of carbon monoxide (CO) is low, so that the converter gas is dissipated from the diffusion tower 8. As the blowing operation progresses, the concentration of carbon monoxide (CO) increases from the beginning to the middle of the blowing and then decreases again toward the end of the blowing. That is, the content of carbon monoxide in the converter gas fluctuates according to the blowing time, starts to increase from the beginning of blowing, reaches the maximum value in the middle period, and decreases again toward the end of blowing. In this way, since the concentration of carbon monoxide (CO) in the converter gas varies according to its flow, the amount of the converter gas is reduced by separating and recovering the converter gas according to the content of carbon monoxide (CO) using a preset value. It can be used widely. The gas concentration analyzers 20 and 30 using lasers have shorter analysis times than those using infrared and magnetic fields, and thus determine the exact recovery time of the converter gas to improve the converter gas recovery rate.

The upper analyzer 20 installed in the radiating unit of the OG facility may include a device for measuring the content of oxygen (O2) in order to prevent the risk of explosion as well as the content of carbon monoxide (CO) in the converter gas. In the case of the intermittently measured hydrogen gas, it is generated by thermal decomposition of moisture in the auxiliary material, and hydrogen, like oxygen, may be included in the upper analyzer 20 because it is necessary to accurately measure and respond quickly because there is a risk of explosion. In the case of the lower analyzer 30 installed on the downstream side before the defense tower 8 or the gas holder 7 after dust collection, a carbon monoxide (CO) meter and an oxygen (O2) meter may be included.

2 is a view showing an upper analyzer 20 of a converter gas (LDG) recovery device according to an embodiment of the present invention, and FIGS. 3A and 3B are cross-sectional views of upper and lower analyzers including laser gas analyzers. It is a drawing.

Referring to FIG. 2, a separate tube 21 is installed in the radiating part of the OG facility, and a Tunable Diode Laser Spectrometer (TDLS) (22-25) is installed inside the tube 21. A laser measuring instrument (TDLS) is a laser-type gas analyzer that irradiates a laser light and measures a gas concentration from a change in the amount of light due to light absorption of the laser light. A hydrogen meter 22 for measuring the concentration of hydrogen (H2), and oxygen ( An oxygen meter 23 for measuring the concentration of O2), a carbon monoxide meter 24 for measuring the concentration of carbon monoxide (CO), and a carbon dioxide meter 25 for measuring the concentration of carbon dioxide (CO2) are installed, respectively. . In the case of hydrogen and oxygen, there is a risk of explosion, so the risk of explosion is prevented by measuring it in the upper analyzer. Since the dust concentration of the converter gas (LDG) in the radiant part of the OG facility is 200 g/Nm ³ or more, after removing the dust using the dust filter 28 disposed in the front end of the laser measuring instrument (22-25), each TDLS (22- 25) is used to measure the concentration. Pressure gauges (P1, P2) are installed at both ends of the pipe where TDLS is installed to measure the pressure at two points. When the pressure difference between the two points rises above a certain value, it is assumed that the life of the dust filter 28 is over and the dust filter 28 is replaced. In addition, by branching the pipe 21 into two places and installing valves 26 and 27 in each branch pipe, when the dust filter 28 in one place is replaced, the gas can move to the other branch pipe. I can.

The upper analyzer 20 is a laser type gas analyzer that irradiates a gas with a laser light and measures a gas concentration from a change in an amount of light due to light absorption of the laser light. As shown in FIG. 3A, the laser-type analyzer detects a laser irradiation unit 31 that irradiates a measurement laser light 300 toward a space to be measured, and a measurement laser light 300 transmitted through the measurement space. It includes a laser light receiving unit 32. The output signal of the laser light receiving unit 32 is processed by an arithmetic processing device (not shown). By continuously changing the wavelength of the laser light 300 emitted from the laser irradiation unit 31 and irradiating the measurement space, analyzing and calculating the output signal of the laser light receiving unit 32 obtained as a result, the average concentration of the target molecule or atom and Average temperature data can be obtained.

As shown in FIG. 3A, the laser irradiation unit 31 is disposed outside the tube 21, and the laser light 300 is directed toward the converter gas so as to form a right angle with respect to the center line of the flow of the converter gas in the tube 21. Investigate. The laser light receiving unit 32 is disposed on the outer side opposite to the laser irradiation unit 31. Although one laser meter is shown in FIG. 3A, as shown in FIG. 2, the upper analyzer 20 is equipped with four measuring devices to measure hydrogen, oxygen, carbon monoxide, and carbon dioxide, respectively. With the laser-type gas analyzer 20 arranged in this way, the concentration of the converter gas flowing through the pipe of the OG facility can be analyzed.

On the other hand, the lower analyzer 30 measures only the content of carbon monoxide and oxygen because it is just the front end to determine the recovery or dissipation of the converter gas. The lower analyzer 30 is also a laser type measuring instrument that irradiates a gas with laser light and measures the gas concentration from the change in the amount of light due to the absorption of the laser light. As shown in FIG. 3B, it is for measurement toward the space to be measured. A laser irradiation unit 31 that irradiates the laser light 300 and a laser light receiving unit 32 that detects the measurement laser light 300 that has passed through the measurement space. The output signal of the laser light receiving unit 32 is processed by an arithmetic processing device (not shown). By continuously changing the wavelength of the laser light 300 emitted from the laser irradiation unit 31 and irradiating the measurement space, analyzing and calculating the output signal of the laser light receiving unit 32 obtained as a result, the average concentration of the target molecule or atom and Average temperature data can be obtained. A laser irradiation unit 31 is disposed outside the tube 10, and the laser light 300 is irradiated toward the converter gas so as to form a right angle with respect to the center line of the flow of the converter gas in the tube 10. The laser light receiving unit 32 is disposed on the outer side opposite to the laser irradiation unit 31.

The lower analyzer 30 may be installed between the IDF 5 and the damper 6, and when installed close to the IDF 5, accurate component measurement may be difficult due to vibration. Therefore, in order not to be affected by the vibration of the IDF, the lower analyzer 30 is preferably installed between the dampers 6 to be spaced a predetermined distance from the IDF (5). In addition, if a plurality of TLDS are installed, the measurement may be disturbed due to the nitrogen gas purge line. Therefore, it is preferable to install the two TDLSs not on the same line but out of alignment.

On the other hand, in the transfer line 10 in which the lower analyzer 30 is installed, the temperature of the converter gas is usually lowered to 100° C. or less, so condensation is likely to occur. When a lot of dust or water droplets exist in the converter gas, when the optical path of the laser light 300 is too long, the laser light 30 may be scattered by the dust or water droplets, making measurement difficult. In this case, as shown in Fig. 3B, from the laser irradiation unit 31 side and the laser light receiving unit 32 side, the insertion tube protrudes to surround the optical path of the laser light 300, and the tip is opened. It is preferable to arrange an insertion tube 35). In addition, it is preferable that nitrogen gas flows into the insertion tube 35 as a purge gas so that it flows toward the tip of the insertion tube inside the furnace.

Accordingly, the optical path through which the measurement gas flows in the optical path of the laser light 300 becomes the distance between the tip of the insertion tube 35 extending from both sides, that is, the gap between the tip of the insertion tube 35 . Therefore, by installing the insertion tube 35, the optical path length of the laser light 300 passing through the measurement gas can be shortened. As a result, even if dust or water droplets are contained in the converter gas, scattering of the laser light 300 can be reduced, and the concentration of carbon monoxide and oxygen in the gas can be analyzed with high precision.

In the case of the LDG pipe 10, the diameter is 2.5 m, and optimal performance can be obtained by installing a tube having a length of about 50 cm on both sides. In addition, dust may accumulate on the inside of the inserted tube, which also causes a decrease in the transmittance of the laser, so it is preferable to use a tube coated to prevent dust from being trapped.

FIG. 4 is a flowchart illustrating a converter gas recovery method according to the present invention shown in FIG. 1. In FIG. 4, reference numerals S110 to S180 denote steps using an upper analyzer (20 in Fig. 1), and reference numerals S210 to S260 denote steps using a lower analyzer (30 in Fig. 1).

Referring to FIG. 4 together with FIG. 1, first, the transmittance of the upper analyzer (20 of FIG. 1) is checked in order to confirm the normal operation of the upper analyzer (20 of FIG. 1) (S110, S120). If the transmittance of the upper analyzer is less than 1%, an analysis error occurs and it is determined that a problem has occurred in the upper analyzer, and a warning alarm is given (S310), and the process is terminated.

When the transmittance of the upper analyzer exceeds 1%, it is determined that normal operation is possible, and the concentrations of hydrogen, oxygen, carbon monoxide, and carbon dioxide in the converter gas are measured using the upper analyzer (20 in FIG. 1) (S130). In the case of hydrogen, moisture in the subsidiary material is generated by thermal decomposition at high temperatures, but there is a risk of explosion, so it is necessary to measure accurately and respond quickly. When the concentration of hydrogen exceeds 4% as a result of measuring the respective concentrations in the converter gas, the operation is urgently stopped because there is a risk of explosion (S320) and the recovery operation is terminated.

As a result of the measurement using the upper analyzer, if the concentration of hydrogen is less than 4%, there is no risk of explosion, so it is checked whether the transmittance of the lower analyzer (30 in FIG. 1) exceeds 1% (S210, S220). When the transmittance of the lower analyzer exceeds 1%, it operates normally, and the concentration of oxygen and carbon monoxide is measured using the lower analyzer (30 in FIG. 1) (S230).

When the concentration of carbon monoxide in the converter gas exceeds the recoverable lower limit, for example 15%, and the oxygen concentration is less than the upper limit at which no explosion, for example, 2% (S240), such a converter gas is a gas holder (FIG. 1 Since it can be separated and recovered in 7), recovery starts (S350). As mentioned, when the blowing operation in the converter (1 in Fig. 1) is started, the oxygen concentration in the converter gas is high and the concentration of carbon monoxide (CO) is low, so that the converter gas is dissipated to the defense tower, and as the blowing operation proceeds, The concentration of carbon monoxide (CO) tends to increase from the beginning of the blowing to the middle period and then decrease again toward the end of the blowing. Therefore, when the recovery of the converter gas starts in step S350, the concentration of carbon monoxide and oxygen is continuously measured (S250), but the concentration of carbon monoxide is less than 5%, or the oxygen concentration exceeds 2%, thereby increasing the risk of explosion, or When the blowing rate exceeds 93% (S260), the recovery is terminated (S360) and the operation is terminated.

On the other hand, when the concentration of hydrogen measured by the upper analyzer is less than 4%, it is determined that there is no risk of explosion by hydrogen (S140), and the transmittance of the lower analyzer does not exceed 1% (S220), When it is determined that there is no risk of explosion because the concentration of carbon monoxide exceeds 15% and the concentration of oxygen is less than 2% (S150), recovery is started (S330). When the recovery proceeds, the concentration of carbon monoxide and oxygen is continuously measured (S170), but if the concentration of carbon monoxide is less than 5% or the oxygen concentration exceeds 2%, the risk of explosion increases, or the blow rate exceeds 93%. (S180), the collection is ended (S340) and the operation is ended. In step S150, if the concentration of carbon monoxide does not exceed 15% or the concentration of oxygen is 2% or more and it is determined that there is a risk of explosion, the concentrations of carbon monoxide and oxygen are continuously measured until a recoverable state is reached (S150). .

According to the present invention described above, since the converter gas component is analyzed using a laser analyzer, the accuracy is excellent, and since the analysis can be performed immediately within 1 to 2 seconds in the pipe, the recovery delay is reduced compared to the method using the conventional infrared and magnetic field. The quantity is increased, and the operation stability is improved by accurately measuring the concentration of oxygen and hydrogen that are at risk of explosion. Therefore, it is possible to improve the power generation efficiency through the recovery of the converter gas of high calorific value.

In the above, the embodiments of the present invention have been described mainly, but various changes or modifications may be made at the level of those skilled in the art. These changes and modifications can be said to belong to the present invention as long as they do not depart from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the claims set forth below.

Claims (10)

delete delete delete delete delete delete (a) Carbon monoxide and hydrogen in the converter gas by using an upper analyzer that is arranged upstream from the dust collector on the path of the converter gas generated in the converter and measures and analyzes the concentration of components including carbon monoxide in the converter gas using a laser. Measuring the content of;
(b) When the content of hydrogen is less than the threshold value of the risk of explosion, a lower analyzer is disposed downstream of the dust collecting device and measures and analyzes the concentration of a component including carbon monoxide in the converter gas using a laser. Measuring the concentration of carbon monoxide and oxygen by using; And
(c) when the concentration of carbon monoxide in the converter gas measured by using the lower analyzer exceeds 15% and the concentration of oxygen is less than a threshold value at which there is a risk of explosion, recovering the converter gas,
Converter gas recovery method.
The method of claim 7,
Before performing the steps (a) and (b),
(a-1) measuring the transmittance of the upper analyzer, and
(b-1) each further comprising the step of measuring the transmittance of the lower analyzer,
Converter gas recovery method.
The method of claim 7,
In the step (c), the concentration of carbon monoxide is less than the threshold value,
The concentration of oxygen exceeds the threshold for the risk of explosion, or
When the blow rate exceeds the threshold, the recovery is terminated and the work is terminated.
Converter gas recovery method.
The method of claim 8,
In the step (a-1), when the transmittance of the upper analyzer is less than 1%, a warning alarm sounds and the operation is terminated,
When the transmittance of the upper analyzer in step (a-1) exceeds 1%, and the transmittance of the lower analyzer in step (b-1) is less than 1%, the carbon monoxide measured in step (a) When the concentration exceeds the threshold and the concentration of oxygen is below the threshold at risk of explosion, the recovery of the converter gas begins,
Converter gas recovery method.

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