KR102114819B1 - Metal smelting apparatus - Google Patents

Abstract

According to an embodiment of the present invention, the metal smelting apparatus includes: a main duct through which combustion gas generated in an electric furnace flows; It is formed on one side and has an inlet through which the combustion gas flows in and an outlet through which the combustion gas flows through the inlet and the inlet through which the combustion gas flows, and has an internal flow path through which the combustion gas flows. A dust collecting block having an acceleration section, the cross-sectional area gradually decreasing from the inlet to the acceleration section and gradually increasing in cross-sectional area from the acceleration section to the outlet; At least one filter disposed between the acceleration section and the outlet section of the internal flow path; At least one adsorption screen and at least one oxidation screen are spaced apart in the interior space, the adsorption screen is an illite material and the oxidation screen is a reaction block coated with an oxidation catalyst; And includes a chimney for discharging the combustion gas that has passed through the reaction block, the dust collecting block has a recovery passage and a supply passage connected to the acceleration section, a portion of the combustion gas moving to the chimney is the recovery passage Through it, it is possible to flow into the internal flow path and external air can flow into the internal flow path through the supply flow path.

Description

Metal smelting device {METAL SMELTING APPARATUS}

The present invention relates to a metal smelting apparatus, and more particularly, to a cooling apparatus capable of treating combustion gas generated during the process of obtaining molten iron by melting scrap metal in an electric furnace.

In general, electric furnaces are manufactured by melting metals such as iron by using electric arc heat of high pressure and high current.

When such an electric furnace has a high internal temperature, the material inside the furnace can be completely melted and smelted as desired. Accordingly, the temperature inside the electric furnace is usually 1000 ° C or higher.

When the metal is melted in the electric furnace as described above, combustion gas is generated, and the generated combustion gas includes dust and gas, so it is necessary to filter out gas and dust from the combustion gas discharged from the electric furnace. Also, if the combustion gas is discharged as it is, a large amount of harmful substances are discharged together, so dust must be filtered and only purified air should be discharged using a dust collector.

Most of the filters of the dust collector are made of fibers such as non-woven fabric or polyester, and when the high-temperature combustion gas having an electric furnace temperature of 1000 ° C or higher flows directly into the dust collector, the filter of the dust collector is damaged, so that the high-temperature combustion gas is cooled to flow into the dust collector. have.

Korean Patent Publication No. 2011-0121087 (2011.11.07.)

An object of the present invention is to provide a metal smelting device capable of purifying and cooling combustion gas.

Other objects of the present invention will become more apparent from the following detailed description and accompanying drawings.

According to an embodiment of the present invention, the metal smelting apparatus includes: a main duct through which combustion gas generated in an electric furnace flows; It is formed on one side and has an inlet through which the combustion gas flows in and an outlet through which the combustion gas flows through the inlet and the inlet through which the combustion gas flows, and has an internal flow path through which the combustion gas flows. A dust collecting block having an acceleration section, the cross-sectional area gradually decreasing from the inlet to the acceleration section and gradually increasing in cross-sectional area from the acceleration section to the outlet; At least one filter disposed between the acceleration section and the outlet section of the internal flow path; At least one adsorption screen and at least one oxidation screen are spaced apart in the interior space, the adsorption screen is an illite material and the oxidation screen is a reaction block coated with an oxidation catalyst; And includes a chimney for discharging the combustion gas that has passed through the reaction block, the dust collecting block has a recovery passage and a supply passage connected to the acceleration section, a portion of the combustion gas moving to the chimney is the recovery passage Through it, it is possible to flow into the internal flow path and external air can flow into the internal flow path through the supply flow path.

The metal smelting apparatus, a concentration detection sensor for detecting the carbon dioxide concentration of the combustion gas passing through the reaction block; A recovery valve capable of adjusting the flow rate of the combustion gas flowing through the recovery passage; And it may further include a controller that is electrically connected to the concentration sensor and the recovery valve to increase the opening degree of the recovery valve when the carbon dioxide concentration is below a reference value.

According to another embodiment of the present invention, the metal smelting apparatus includes: a main duct through which combustion gas generated in an electric furnace flows; It is formed on one side and has an inlet through which the combustion gas flows in and an outlet through which the combustion gas flows through the inlet and the inlet through which the combustion gas flows, and has an internal flow path through which the combustion gas flows. A dust collecting block having an acceleration section, the cross-sectional area gradually decreasing from the inlet to the acceleration section and gradually increasing in cross-sectional area from the acceleration section to the outlet; At least one filter disposed between the acceleration section and the outlet section of the internal flow path; One or more adsorption screens and one or more oxidation screens are spaced apart in the interior space, the adsorption screen is an illite material and the oxidation screen is a reaction block coated with an oxidation catalyst; A cooling block cooled in a process in which the combustion gas passing through the reaction block passes; And includes a chimney for discharging the combustion gas that has passed through the cooling block, the dust collecting block has a recovery passage connected to the acceleration section, a part of the combustion gas moving to the chimney through the recovery passage It is possible to flow into the internal flow path, and the metal smelting apparatus includes: a concentration sensor for detecting the carbon dioxide concentration of the combustion gas that has passed through the cooling block; A recovery valve capable of adjusting the flow rate of the combustion gas flowing through the recovery passage; And it is electrically connected to the concentration detection sensor and the recovery valve, and if the carbon dioxide concentration is below the reference value, the opening degree of the recovery valve is increased, and a controller capable of adjusting the cooling performance of the cooling block is further included.

According to an embodiment of the present invention, a part of the combustion gas discharged through the chimney is re-introduced into the dust collection block and re-purified to purify and discharge the combustion gas sufficiently.

In addition, it is possible to sufficiently purify the combustion gas by controlling the flow rate of the combustion gas re-entered into the dust collecting block according to the carbon dioxide concentration of the combustion gas discharged through the chimney.

In addition, depending on the temperature of the combustion gas flowing into the dust collecting block, by introducing external air into the dust collecting block or by increasing the cooling performance of the cooling block, the combustion gas flowing into the dust collecting block is sufficiently cooled, thereby preventing damage to the screen, etc. can do.

1 is a view schematically showing a metal smelting apparatus according to an embodiment of the present invention.
2 is a cross-sectional view schematically showing the dust collecting block shown in FIG. 1.
3 is a view schematically showing a metal smelting apparatus according to another embodiment of the present invention.
4 is a cross-sectional view schematically showing the dust collecting block shown in FIG. 3.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to FIGS. 1 to 4. The embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be interpreted as being limited to the embodiments described below. These embodiments are provided to explain the present invention in more detail to those of ordinary skill in the art. Therefore, the shape of each element shown in the drawings may be exaggerated to emphasize a clearer description.

1 is a view schematically showing a metal smelting apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view schematically showing the dust collecting block shown in FIG. 1. The metal smelting apparatus includes an electric furnace 100, a combustor 110, a cooler 120, and the like.

The electric furnace 100 melts a metal material such as iron with arc heat, and the combustor 110 re-burns incompletely burned components among the combustion gases discharged from the electric furnace 100, and the cooler 120 is a combustor ( 110) followed by cooling the combustion gas with water and air.

Steelmaking space 10 is a place where electric furnace 100 and combustor 110 are installed to perform steelmaking, and combustion gas containing various dusts generated in steelmaking space 10 is installed in a canopy. It is discharged through the main duct 101.

The electric furnace 100 and the combustor 110 are connected to the noduct 105, and the combustor 110 and the cooler 120 are also connected to the high temperature duct 115. The combustion gas discharged from the cooler is discharged through the cooling duct 125 connected to the main duct 101. The auxiliary fan 130 controls the flow of combustion gas discharged from the cooler 120 to the main duct 101.

Since the electric furnace 100 melts a metal material by using electricity of a strong intensity, a lot of dust is generated together with the combustion gas, and a considerable amount of dust remains in the steelmaking space 10, and the worker must remove the dust Can safely work on steelmaking. It is preferable to filter out these dusts because a large amount of useful components are contained in the combustion gas generated from the electric furnace 100. Therefore, it is necessary to filter useful materials in the combustion gas discharged from the electric furnace 100 together with dust generated in the steelmaking space 10, and the dust collecting block is main in the cooler 120 and the steelmaking space 10. The dust of the combustion gas introduced through the duct 101 is filtered and the purified air is discharged.

Normally, the steelmaking space 10 is a space where an operator works, so the temperature of the air containing dust is not so high, and thus it may be filtered directly from the dust collecting block through the main duct 101. However, since the combustion gas discharged directly from the electric furnace 100 and the combustor 110 is high enough to melt the metal, if it is discharged without cooling, it may damage members such as piping and filters of the dust collection block.

Accordingly, a cooler 120 is installed at the rear ends of the electric furnace 100 and the combustor 110, and the combustion gas flows into the dust collecting block through the main duct 101 while the temperature is lowered in the cooler 120. .

The cooler 120 sprays cold water with internal combustion gas, and at this time, the water vaporizes and absorbs the thermal energy of the combustion gas to cool the combustion gas. When water is in the liquid state, it exists at 100 ° C or lower, but since the combustion gas flowing into the cooler 120 flows at a high temperature of about 600 ° C to 1,000 ° C, the water in the sprayed liquid state absorbs the heat of the combustion gas. However, it goes through the process of vaporization over 100 ℃. During this process, water is heated, but the combustion gas is cooled to a low temperature in a short time. The temperature of the combustion gas may be changed according to the steelmaking conditions in the electric furnace 100, and may be changed according to the amount of material, the continuous steelmaking time, the temperature inside the electric furnace, and the like.

As shown in FIG. 2, the dust collecting block includes a filter (shown in shaded) that filters and collects dust contained in the combustion gas, and the filter is made of a material such as non-woven fabric or polyester. Accordingly, the filter filters out dust contained in the combustion gas, but discharges air and gas to the outside. Here, if the temperature of the exhaust gas flowing into the dust collecting block is too high, the filter is damaged, so the temperature of the incoming combustion gas is preferably lower than the allowable limit temperature of the filter. However, if the cooling temperature of the combustion gas is too low, the vaporized water in the combustion gas changes to a liquid state, which means that some water vapor is eventually filtered by the filter. When the liquid water adheres to the filter together with the dust, the performance of the filter is deteriorated, and secondary problems such as corrosion of the filter and dust collecting members due to dust and moisture may occur.

Therefore, the temperature of the combustion gas flowing into the dust collecting block through the main duct 101 from the cooler 120 is maintained at 100 ° C or higher, but the filter is preferably in a temperature range that is not damaged. In the case of a filter such as polyester, the combustion gas flowing into the dust collecting block is preferably in the range of 100 ° C. to 130 ° C.

1 and 2, the combustion gas discharged from the main duct 101 flows into the dust collecting block through the fan. The dust collecting block has an internal flow path, and an inlet is formed on one side (left side based on FIG. 2) and an outlet is formed on the other side (right side based on FIG. 2).

The internal flow path has an acceleration section formed in the central portion, and the diameter (d) of the acceleration section is smaller than the diameter (D) of the inlet and outlet. Specifically, the cross-sectional area of the internal flow passage has a shape of a venturi tube that gradually decreases from the inlet to the accelerating section and gradually increases from the accelerating section to the outlet, and the combustion gas increases the flow velocity in the accelerating section.

The recovery flow path and the supply flow path are formed at the upper and lower portions of the acceleration section, respectively. The combustion gas that has passed through the reaction block may be re-introduced into the internal flow channel through the recovery flow channel, and external air may be introduced into the internal flow channel through the supply flow channel. The combustion gas flowing along the internal passage through the inlet increases the flow rate in the acceleration section, and as a result, the combustion gas or external air that has passed through the reaction block may flow into the internal passage. Detailed description thereof will be described later.

As described above, at least one filter (indicated by shade) for filtering and collecting dust contained in the combustion gas is installed between the acceleration section and the outlet, and the filter is made of a material such as non-woven fabric or polyester.

The reaction block has an internal space through which the combustion gas passes through the dust collection block, and one or more adsorption screens and one or more oxidation screens are installed in the internal spaces to be spaced apart so as to be perpendicular to the moving direction of the combustion gas. The adsorption screen is made of illite and has a number of through holes. Illite (illite) is a natural clay mineral, defined as a porous mica mineral, and has a flexible and elastic property with a thin sheet structure, so it has excellent properties compared to other minerals. Specifically, the combustion gas passes through the adsorption screen, and in this process, the adsorption screen adsorbs and deodorizes toxic gases harmful to the human body.

In addition, the oxidation screen is coated with an oxidation catalyst such as platinum (Pt), rhodium (Rh), and palladium (Pd) on the surface, and has a number of through holes. The oxidation screen oxidizes harmful gases (eg, CO, HC) contained in the combustion gas and converts them into CO2 or H2O. Specifically, the combustion gas passes through the oxidation screen, and in the process, the oxidation screen oxidizes the harmful gas and converts it into CO2 or H2O.

On the other hand, the oxidation process described above is performed at about 200 to 400 ° C, but as described above, the combustion gas flowing into the dust collecting block maintains 100 ° C to 130 ° C while passing through the cooler 120. Therefore, it is necessary to heat the combustion gas in order to smoothly oxidize the combustion gas, and as shown in FIG. 2, a heater is installed between the dust collection block and the reaction block, and a temperature suitable for oxidizing the combustion gas before entering the reaction block. Can be heated.

Thereafter, the combustion gas purified through the reaction block should be discharged through a chimney, but if the combustion gas is not sufficiently oxidized in the process of passing through the reaction block, harmful gases are released into the atmosphere, causing air pollution. Since it can be an issue of environmental pollution, it is necessary to check the degree of oxidation of the combustion gas.

Specifically, as described above, since the combustion gas generates carbon dioxide in the oxidation process, when measuring the concentration of carbon dioxide, it is possible to confirm the degree of oxidation of the combustion gas. The carbon dioxide concentration sensor is installed on the pipe connecting the reaction block and the chimney to detect the concentration of carbon dioxide, and a recovery valve is installed on the branch pipe branched from the pipe connecting the reaction block and the chimney and connected to the recovery passage. You can.

The controller is electrically connected to the concentration sensor and the recovery valve. The controller measures the carbon dioxide concentration of the combustion gas that has passed through the reaction block through the carbon dioxide concentration detection sensor, and if the concentration of carbon dioxide is less than a predetermined reference value, it is determined that sufficient oxidation has not been performed, thereby increasing the opening degree of the recovery valve. In this case, since the internal flow path is the shape of a Venturi tube, the pressure in the internal flow path is relatively low, and a part of the combustion gas that has passed through the reaction block may flow into the internal flow path through the recovery flow path. The controller can increase or decrease the opening degree of the recovery valve according to the concentration of carbon dioxide, and through this method, a part of the combustion gas can be recovered as a dust collecting block without a separate fan or pump. The recovered combustion gas can be moved back to the reaction block and re-oxidized.

On the other hand, in general, the combustion gas flowing from the cooler 120 to the dust collecting block through the main duct 101 is lower than the allowable limit temperature of the filter, but when the electric furnace is in the warm temperature period, the combustion gas flowing into the dust collecting block allows the filter. In some cases, it is necessary to cool the combustion gas further.

The temperature sensor is installed on the internal flow path, and may be disposed between the inlet and the acceleration section or between the acceleration section and the filter. The temperature sensor can detect the temperature of the combustion gas, and a supply valve may be installed on the pipe connected to the supply flow path.

The controller is electrically connected to the temperature sensor and the supply valve. The controller measures the temperature of the combustion gas through a temperature sensor, and increases the opening of the supply valve when the temperature of the combustion gas is higher than a predetermined reference value (for example, 130 degrees). In this case, since the internal flow path is the shape of a Venturi tube, the pressure in the internal flow path is relatively low and external air may flow into the internal flow path through the supply flow path. The external air flows into the internal flow path through the supply flow path, and is mixed with the combustion gas to cool the combustion gas. The controller may increase or decrease the opening degree of the supply valve according to the temperature of the combustion gas, and through this method, the outside gas may be supplied to the dust collecting block without a separate fan or pump to cool the combustion gas.

3 is a view schematically showing a metal smelting apparatus according to another embodiment of the present invention, and FIG. 4 is a cross-sectional view schematically showing the dust collecting block shown in FIG. 3. As described above, the supply passage of the dust collection block may be omitted, and the combustion gas supplied to the internal passage may be cooled through the cooling block.

A cooling block is installed between the reaction block and the chimney to cool the combustion gas that has passed through the reaction block. The controller is electrically connected to the cooling block, and when the temperature of the combustion gas is equal to or greater than a predetermined reference value (for example, 130 degrees), the combustion gas that has passed through the reaction block through the cooling block may be cooled to a predetermined temperature. The controller increases the opening degree of the recovery valve, and the cooled combustion gas can be re-supplied to the internal flow path through the recovery flow path according to the method described above to cool the combustion gas. The controller can increase or decrease the opening degree of the supply valve and the cooling performance of the cooling block (for example, the temperature or flow rate of the cooling water supplied to the cooling block) according to the temperature of the combustion gas. The combustion gas can be cooled by re-supplying the combustion gas without a pump. At this time, the opening degree of the supply valve is preferably selected from a larger value of the opening degree determined according to the concentration of carbon dioxide and the opening degree determined according to the temperature of the combustion gas. Can be sufficiently cooled.

Although the present invention has been described in detail through preferred embodiments, other types of embodiments are possible. Therefore, the technical spirit and scope of the claims set forth below are not limited to the preferred embodiments.

10: heating device 11: heating housing
13: discharge fan 21: filter housing
22: inlet 31: main housing
42a: support block 42b: coil
50: discharge unit 51: hopper
52: connector 55: nozzle

Claims (3)

A main duct through which combustion gas generated in an electric furnace flows;
It is formed on one side and has an inlet through which the combustion gas flows in and an outlet through which the combustion gas flows through the inlet and the inlet through which the combustion gas flows, and has an internal flow path through which the combustion gas flows. A dust collecting block having an acceleration section, the cross-sectional area gradually decreasing from the inlet to the acceleration section and gradually increasing in cross-sectional area from the acceleration section to the outlet;
At least one filter disposed between the acceleration section and the outlet section of the internal flow path;
At least one adsorption screen and at least one oxidation screen are spaced apart in the interior space, the adsorption screen is an illite material and the oxidation screen is a reaction block coated with an oxidation catalyst; And
It includes a chimney for discharging the combustion gas that has passed through the reaction block,
The dust collecting block has a recovery passage and a supply passage connected to the acceleration section,
A metal smelting apparatus in which a part of the combustion gas moving to the chimney is able to flow into the internal flow path through the recovery flow path and external air can flow into the internal flow path through the supply flow path. According to claim 1,
The metal smelting device,
A concentration sensor for detecting the carbon dioxide concentration of the combustion gas that has passed through the reaction block;
A recovery valve capable of adjusting the flow rate of the combustion gas flowing through the recovery passage; And
And a controller for electrically connecting the concentration detecting sensor and the recovery valve to increase the opening degree of the recovery valve when the carbon dioxide concentration is below a reference value. In the metal smelting apparatus,
A main duct through which combustion gas generated in an electric furnace flows;
It is formed on one side and has an inlet through which the combustion gas flows in and an outlet through which the combustion gas flows through the inlet and the inlet through which the combustion gas flows, and has an internal flow path through which the combustion gas flows. A dust collecting block having an acceleration section, the cross-sectional area gradually decreasing from the inlet to the acceleration section and gradually increasing in cross-sectional area from the acceleration section to the outlet;
At least one filter disposed between the acceleration section and the outlet section of the internal flow path;
At least one adsorption screen and at least one oxidation screen are spaced apart in the interior space, the adsorption screen is an illite material and the oxidation screen is a reaction block coated with an oxidation catalyst;
A cooling block cooled in a process in which the combustion gas passing through the reaction block passes; And
It includes a chimney for discharging the combustion gas that has passed through the cooling block,
The dust collecting block has a recovery passage connected to the acceleration section, so that some of the combustion gas moving to the chimney can flow into the internal passage through the recovery passage,
The metal smelting device,
A concentration sensor for detecting the carbon dioxide concentration of the combustion gas that has passed through the cooling block;
A recovery valve capable of adjusting the flow rate of the combustion gas flowing through the recovery passage; And
A metal smelting apparatus further comprising a controller that is electrically connected to the concentration sensor and the recovery valve to increase the opening degree of the recovery valve when the carbon dioxide concentration is below a reference value, and to adjust the cooling performance of the cooling block.

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