JPS6290525A - Method and apparatus for analyzing converter exhaust gas - Google Patents

Abstract

PURPOSE:To always estimate the refining process of a converter with high accuracy, by controlling converter exhaust gas to predetermined pressure to bring the same to a high temp. plasma state and measuring the luminous intensity of the emission spectrum component of said exhaust gas at every wavelength. CONSTITUTION:The converter exhaust gas from a flue 1 is adjusted to constant quantity and constant pressure by a quantitative emission pump 4 to be introduced into a high frequency induction plasma generation apparatus 5 and brought to a high temp. plasma state by the high frequency current generated by a high frequency generator 51 to emit light and the luminous intensity of the spectrum component of each of exhaust gas and dust with respect to each wavelength is measured by a spectrometer 6. A component concn. calculator 7 calculates the component concns. of exhaust gas and dust on the basis of the relation between a stored component element and a specific wavelength and the relation between the luminous intensity of the spectrum component and the concn. of the element. Therefore, the exhaust gas and the dust are simultaneously and continuously analyzed regardless of the change of the condition in the flue and the refining process of a converter can be always estimated with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for analyzing converter exhaust gas. Specifically, the present invention relates to a method and apparatus for simultaneously and continuously analyzing component concentrations of converter exhaust gas and dust to accurately estimate the converter refining process.

(Conventional technology) Pig iron obtained from the blast furnace is refined in a converter.

In this refining process, it is necessary to control the height of the main lance, the oxygen supply rate, the amount of auxiliary material input, the flow rate of bottom blowing gas, the pressure, etc. according to the amount or speed of decarburization, desiliconization, dephosphorization, etc. It won't happen. Therefore, it is necessary to accurately estimate the amount or rate of decarburization, desiliconization, dephosphorization, etc.

In order to estimate the amount or rate of decarburization, desiliconization, dephosphorization, etc., conventionally, a mass spectrometer or the like was installed at the highest part of the exhaust gas flue to measure the component concentration of the exhaust gas. That is, the refining process has been estimated based on measured values of the component concentrations of exhaust gas, and operational parameters such as the height of the main lance, oxygen supply rate, amount of auxiliary raw materials input, bottom blowing gas flow rate, and pressure have been controlled.

(Problems to be Solved by the Invention) Since analysis of the concentration of exhaust gas components using a mass spectrometer or the like is limited to gas bodies, a filter is required in the sampling device. The analyzer is installed in an environment exceeding 1000 degrees Celsius, where the temperature changes significantly and there is a lot of dust.Therefore, the main lance of such an analyzer is not easy to install and often causes destruction or clogging of the device.

In addition, in the past, an estimation model of converter blowing was made based on information obtained only from the gas body and the refining process was estimated, but component analysis of exhaust gas alone is insufficient for accurate estimation.

That is, in order to accurately understand the refining process, C02C0
2. It is necessary to know not only the gas components such as C2, N2, H2, etc., but also the degree of oxidation of silicon, phosphorus, sulfur, etc. contained in pig iron, and the slag forming ability. Nevertheless, conventional methods only use information obtained from the gas body among conditions such as gas body, dust, and temperature. In order to accurately understand the refining process, it is necessary to check the slag components, such as Fe01Si0.
2. It is necessary to know the degree of generation of P2O5, MnO, CaO, etc., and for this purpose, component analysis of dust is essential. Conventional methods that rely only on the analysis of gas bodies cannot measure the state of slag formation, so the only way to estimate the slag composition is to create an estimation model, and estimation errors are unavoidable.For example, from high phosphorus steel to extremely low It has been impossible to maintain high estimation accuracy for all the various refining requirements involving phosphorous copper.

Therefore, an object of the present invention is to provide a method and apparatus for analyzing converter exhaust gas that solves the problems of these conventional techniques.

In particular, a converter exhaust gas analysis method that simultaneously and continuously analyzes gas bodies and dust in the exhaust gas and makes it possible to constantly and highly accurately estimate decarburization during the refining process and oxidation of silicon, manganese, phosphorus, etc. The purpose is to provide equipment.

(Means and effects for solving the problems) As a result of repeated research to achieve these objectives, the present inventor found that by using spectroscopic analysis that takes advantage of the fact that each element has its own unique emission spectrum, We have come up with the idea that the components of exhaust gas and dust can be analyzed simultaneously and continuously, and the refining process in the converter can be accurately estimated. That is, each element emits ultraviolet light, visible light, and infrared light of specific wavelengths in an excited state. By measuring the intensity of each component light constituting the emission spectrum of exhaust gas and dust, the concentration of each component element can be calculated.

However, conditions such as the pressure and temperature of the exhaust gas in the flue change. Therefore, if the luminescence in the flue is directly measured, it will be necessary to correct for these conditions. However, if the exhaust gas and dust in the flue are led out of the flue and emitted under certain luminous conditions and the spectral component light intensity is measured, the component concentration of the exhaust gas and dust can be calculated regardless of changes in the conditions inside the flue. can.

Therefore, the method for analyzing converter flue gas according to the present invention involves extracting the flue gas and dust in the flue of converter flue gas from the flue, adjusting it to a predetermined pressure, and raising the flue gas and dust at the predetermined pressure to a high temperature to emit light. , which decomposes the luminescence into spectra, measures the spectral component light intensity for each wavelength, and continuously calculates the component concentration of exhaust gas and dust in the flue based on the measured spectral component light intensity for each wavelength. It is.

Furthermore, the analyzer for converter flue gas according to the present invention includes a lead-out pipe that leads the flue gas and dust in the converter flue gas flue to the outside of the flue; A light-emitting device that heats exhaust gas and dust at a constant pressure sent from the metered-discharge pump to emit light; A light-emitting device that decomposes the emission of exhaust gas and dust in the light-emitting device into spectra, and analyzes each wavelength for each wavelength. It includes a spectrometer that measures the spectral component light intensity, and a component concentration calculator that calculates the component concentration of exhaust gas and dust in the flue based on the spectral component light intensity for each wavelength measured by the spectrometer.

Note that the component concentrations of exhaust gas and dust can be calculated by experimentally determining the relationship between the component concentration of exhaust gas and dust in the flue and the spectral component light intensity for each wavelength, and storing the relationship in a storage means. Preferably, this is done based on the relationship stored in the storage means.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.

(Example) FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

Exhaust gases and dust generated from a converter (not shown) during smelting are channeled into flue l. An exhaust gas and dust outlet pipe 3 is attached to the flue wall 2 via a water-cooled pipe 31, and the exhaust gas and dust in the flue 1 are led out to a metering discharge pump 4 in the direction of the arrow.

The lead-out pipe 3 includes a gas sampling probe 32 and a T-shaped pipe 33 connected to the gas sampling probe 32 at one end. The gas sampling probe 32 is inserted into a water-cooled pipe 31 surrounding it and attached to the flue wall 2. The inner surface of the gas sampling probe 32 is preferably plated with a hard metal such as chrome plating. This is to prevent wear and dust adhesion caused by high-temperature dust in the exhaust gas led from the flue 1.

On the other hand, the water cooling pipe 31 is composed of annular two-layer inner and outer waterways 31A and 31B that communicate with each other, and the cooling water introduced from the water inlet 31C of the inner and outer waterways 31A,
The water is drained from the water outlet 31D via 31B. As a result,
Gas sampling probe 32 protruding into the hot flue 1
is constantly cooled by cooling water. Since the temperature of the exhaust gas in the flue 1 reaches from 500°C to 1700°C during blowing, the water-cooled pipe 31 is necessary to protect the gas sampling probe 32 from thermal damage. It is preferable that the outer surface of the water-cooled pipe 31 protruding into the flue l be plated with a hard metal such as chrome plating. This is to prevent wear due to high-temperature dust in the exhaust gas flowing through the flue l and damage due to dust adhesion.

A cleaning bushing rod 34 is inserted into the T-tube 33, and the gas sampling probe 32 and the T-tube 3
Remove dust adhering to the inner surface of No. 3 as necessary.

The metered discharge pump 4 is constituted by, for example, a turbine pump having ceramic blades or blades whose surfaces are coated with chrome. Since the pressure within the flue 1 can vary within a range of approximately ±500 H20, a metering discharge pump 4 is provided to supply a constant amount of exhaust gas at a constant pressure to the high frequency induced plasma light emitting device 5. A pressure gauge 41 is further provided in the exhaust gas supply pipe from the quantitative discharge pump 4 to the high frequency induced plasma light emitting device 5, and based on the pressure measured by the pressure gauge 41, a pressure gauge 41 is provided in the discharge pipe branching from the supply pipe. The pressure regulating valve 42 is adjusted to adjust the pressure of the exhaust gas sent to the high frequency induced plasma light emitting device 5 to a predetermined value.

The exhaust gas and dust sent to the high-frequency induced plasma light emitting device 5 are brought into a high-temperature plasma state by the high-frequency current generated by the high-frequency current generator 51, and emit light. In other words, each element emits light with its own unique line spectrum. For example, in the ultraviolet range, carbon emits light with a line spectrum of 193.0
90m, 229.69r+n+, silicon 13180.7
3nm, 288.16nm, iron is 271.44nm,
229.82nm, 396.93nm, 288.37n
It has a line spectrum with wavelengths such as m, 288.08, etc. The same applies to phosphorus, manganese, etc., which are necessary for component analysis of exhaust gas and dust, and the relationship between each element and its specific wavelength is widely known. Therefore, the exhaust gas and dust that have become plasma in the high frequency induced plasma light emitting device 5 emit light with a spectral component light intensity specific to the component concentration.

The Ar gas pump 52 supplies Ar gas to the high frequency induced plasma light emitting device 5 via the pressure regulating valve 53 to purge the high frequency induced plasma light emitting device.

The emission of exhaust gas and dust within the high-frequency induced plasma luminescence bag w5 is decomposed into spectra in the spectrometer 6, and the spectral component light intensity is measured for each wavelength.

FIG. 2 shows an example of the output of the spectrometer 6.

In the figure, the values corresponding to the light intensity of the emission spectrum components are:
It is given as a function of the wavelength of each component light expressed in nm units on the horizontal axis. That is, the spectrometer 6 outputs the intensity of the spectral components of the light emitted within the high frequency induced plasma light emitting device 5 as a function of the wavelength of each component light.

The memory 71 of the component concentration calculator 7 stores wavelengths specific to the emission spectrum of each element, and also stores the relationship between the spectral component light intensity of those wavelengths and the concentration of each element. That is, each element has its own unique line spectrum, and the memory 71 records the relationship between the wavelengths making up these line spectra and each element.
It's on.

For example, in the ultraviolet range, carbon is 193.09 na+
, 229.69nn+, silicon is 180.73nI11
．． 288.16nm, iron is 271°44nm, 2
29.82na+, 396.93nm, 288.
It has a line spectrum of wavelengths such as 37nw and 288.08. Phosphorus, necessary for component analysis of exhaust gas and dust,
The same applies to manganese and the like, but the relationship between each element and its specific wavelength is widely known. In addition, the relationship between the concentration of the constituent elements of exhaust gas and dust and the light intensity of the emission spectrum components in the high-frequency induced plasma light emitting device 5 where the light emission conditions such as temperature are constant is determined experimentally in advance, and these relationships are determined experimentally in advance. It is also stored in the memory 71. Figures 3 and 4 are examples of graphs showing the relationship between the concentration of iron and silicon in exhaust gas and dust (vertical axis) and the intensity of spectral components of wavelengths specific to iron and silicon (horizontal axis), respectively. and these relationships are the memory 71
is stored in

The calculator 72 of the component concentration calculator 7 calculates the component concentrations of exhaust gas and dust based on the relationship between the component elements and specific wavelengths and the relationship between the spectral component light intensity and the element concentration, etc., stored in the memory 71.

(Effects) According to the present invention, as described above, the exhaust gas and dust in the flue 1 can be simultaneously and continuously analyzed, and the refining process of the converter can be estimated with extremely high accuracy. . In particular, the exhaust gas and dust in the flue 1 are removed from the outlet pipe 3.
is led out of the flue 1, adjusted to a predetermined pressure by a metering pump 4, and sent to a high-frequency induced plasma light emitting device 5 to emit light under certain light emitting conditions, and the intensity of the spectral component light is measured. Since we decided to calculate the exhaust gas and dust components at 4 degrees, it is possible to accurately measure the exhaust gas and dust components at 74 degrees regardless of changes in the conditions within the flue 1.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional block diagram of an embodiment of the present invention, and FIG. 2 shows an example of the output of the spectrometer 6 of the apparatus shown in FIG.
Graphs 3 and 4 are graphs of an example of the relationship between the component element concentration and the spectral component light intensity stored in the memory 71 of the component concentration calculator 7. 1: Flue 2: Flue wall 2 3: Outlet pipe 31: Water-cooled pipe 4: Meter discharge pump

Claims (8)

[Claims] (1) Exhaust gas and dust in the converter flue gas flue are led out from the flue and adjusted to a predetermined pressure, the flue gas and dust at the predetermined pressure are heated to a high temperature and emit light, and the emitted light is decomposed into a spectrum to produce a spectrum. A method for analyzing converter exhaust gas, comprising: measuring component light intensity for each wavelength; and continuously calculating component concentrations of exhaust gas and dust in the flue based on the measured spectral component light intensity for each wavelength. (2) Experimentally determine the relationship between the component concentration of exhaust gas and dust in the flue and the spectral component light intensity for each wavelength in advance, store this relationship in a storage means, and based on the relationship stored in the storage means 2. The converter exhaust gas analysis method according to claim 1, which calculates component concentrations of exhaust gas and dust in a flue. (3) The method for analyzing converter exhaust gas according to claim 1, wherein the exhaust gas and dust discharged from the flue are heated to a high temperature by a high-frequency induction plasma light emitting device to emit light. (4) Claim 1, in which the exhaust gas and dust led out from the flue are adjusted to a constant pressure by a metered discharge pump.
Converter exhaust gas analysis method described in section. (5) a discharge pipe that guides the exhaust gas and dust in the converter flue gas flue out of the flue; a fixed-quantity discharge pump that adjusts the exhaust gas and dust discharged from the flue by the discharge pipe to a constant pressure; and the fixed quantity. A light emitting device that heats exhaust gas and dust at a constant pressure sent from a discharge pump to emit light, and a spectrometer that separates the emission of exhaust gas and dust in the light emitting device into spectra and measures the spectral component light intensity for each wavelength. , a component concentration calculator that calculates the component concentration of exhaust gas and dust in the flue based on the spectral component light intensity of each wavelength measured by the spectrometer. (6) The component concentration calculator is equipped with a memory that stores the relationship by experimentally determining the relationship between the component concentration of exhaust gas and dust in the flue and the spectral component light intensity for each wavelength in advance, and stores the relationship in the memory. 6. The analyzer for converter exhaust gas according to claim 5, which calculates the component concentrations of exhaust gas and dust in the flue based on the relationship determined. (7) The analyzer for converter exhaust gas according to claim 5, wherein the light emitting device is a high frequency induced plasma light emitting device. (8) The analyzer for converter exhaust gas according to claim 5, wherein the exhaust gas and dust introduction portion from the flue of the outlet pipe is inserted into a water-cooled pipe and attached to the flue.