Flue gas treatment system for steel rolling denitration heat compensation furnace

Abstract

The invention provides a steel rolling denitration heat compensation furnace flue gas treatment system which comprises a heat compensation furnace for generating hot flue gas, a soot side flue gas treatment unit and an air flue side flue gas treatment unit, and the air flue side flue gas treatment unit comprises an air flue desulfurization dust remover, an SCR denitration assembly, an induced draft fan and a chimney which are connected in sequence; a flue gas pipeline for transferring hot flue gas is connected to an inlet end flue of the air-flue desulfurization dust remover, and a booster fan is arranged on the flue gas pipeline; in the implementation mode, the hot flue gas firstly exchanges heat with the soot side flue gas treatment unit and then enters the flue at the inlet end of the air-smoke desulfurization dust remover through the drag of the booster fan, and the hot flue gas and the air-smoke flue gas are mixed and then enter the air-smoke desulfurization dust remover together to be subjected to desulfurization and dust removal treatment. The hot flue gas and the empty flue gas are mixed, so that the overall temperature can be increased, heat is provided for the SCR denitration assembly, and therefore, the purification effect of denitration treatment can be ensured.

Description

Technical Field

[0001] The invention relates to the technical field of steel rolling, and in particular to a flue gas treatment system for a steel rolling denitrification heating furnace. Background Art

[0002] Most of the relevant steel rolling flue gas treatment technologies use integrated fixed-bed desulfurization and dust removal and denitrification SCR units, which can achieve efficient removal of multiple pollutants at the same time.

[0003] The SCR unit needs to be heated to above 200°C to reach the reaction temperature of the denitration catalyst. Therefore, a heating furnace is required to provide heat for the SCR unit. However, the heating furnace will inevitably emit flue gas containing pollutants such as nitrogen oxides (NOx), sulfides (SOx), and particulate matter (PM) during the combustion process.

[0004] If the flue gas generated by the supplementary heating furnace is discharged without treatment, it will cause air pollution. Summary of the invention

[0005] The content of the present invention is used to introduce the concepts in a brief form, which will be described in detail in the detailed implementation section below. The content of the present disclosure is not intended to identify the key features or essential features of the technical solution claimed for protection, nor is it intended to limit the scope of the technical solution claimed for protection.

[0006] Some embodiments of the present invention provide a flue gas treatment system for a steel rolling denitrification heating furnace to solve the technical problems mentioned in the above background technology section.

[0007] The system includes a supplementary heat furnace for generating hot flue gas, a flue gas treatment unit on the coal smoke side and a flue gas treatment unit on the air smoke side, wherein:

[0008] The air-to-smoke side flue gas treatment unit comprises an air-to-smoke desulfurization and dust removal device, an SCR denitrification component, an induced draft fan and a chimney connected in sequence;

[0009] A flue gas duct for transmitting hot flue gas is connected to the inlet flue of the air flue gas desulfurization and dust removal device, and a booster fan is arranged on the flue gas duct;

[0010] In the working state, the hot flue gas first exchanges heat with the smoke side flue gas treatment unit, and then enters the air flue gas desulfurization and dust removal device through the traction of the booster fan. After desulfurization and dust removal, the hot flue gas provides heat for the SCR denitrification component.

[0011] Optionally, the SCR denitration component includes an SCR reactor.

[0012] Optionally, the SCR denitration component includes an SCR reactor and a primary heat exchanger with a double flow channel; the flue gas pipeline includes a main pipeline connected to the supplementary heat furnace and a first branch pipeline and a second branch pipeline arranged in parallel;

[0013] The outlet end of the air-smoke desulfurization and dust removal device, the first flow channel of the primary heat exchanger and the first branch pipeline are connected in sequence, and the first branch pipeline is also connected in sequence with the SCR reactor, the second flow channel of the primary heat exchanger, the induced draft fan and the chimney;

[0014] The second branch pipeline is connected to the inlet end flue of the air-gas desulfurization and dust removal device, and the booster fan is arranged on the second branch pipeline.

[0015] Optionally, regulating valves are provided upstream of the position where the first branch pipeline is connected to the first flow channel of the primary heat exchanger and at the flue at the inlet end of the booster fan.

[0016] Optionally, a temperature sensor is provided at the flue at the inlet end of the SCR reactor.

[0017] Optionally, the flue gas treatment system adjusts two regulating valves according to the temperature collected by the temperature sensor.

[0018] Optionally, the SCR denitration component includes an SCR reactor, a primary heat exchanger with dual flow channels, and a secondary heat exchanger;

[0019] The outlet end of the air-smoke desulfurization and dust removal device, the first flow channel of the primary heat exchanger, the first flow channel of the secondary heat exchanger, the SCR reactor, the second flow channel of the primary heat exchanger, the induced draft fan and the chimney are connected in sequence;

[0020] The flue gas duct, the second flow channel of the secondary heat exchanger, the booster fan and the inlet end flue of the air-to-gas desulfurization and dust removal device are connected in sequence.

[0021] Optionally, the flue gas duct is provided with a regulating valve.

[0022] Optionally, a temperature sensor is provided at the flue at the inlet end of the SCR reactor.

[0023] Optionally, the flue gas treatment system adjusts the regulating valve according to the temperature collected by the temperature sensor.

[0024] The above-mentioned embodiments of the present invention have the following beneficial effects: through the steel rolling denitrification supplementary heating furnace flue gas treatment system of the present invention, the flue gas generated by the supplementary heating furnace can be treated to meet the emission standards and avoid pollution to the atmosphere.

[0025] Specifically, in some embodiments of the present invention, the flue gas treatment system of the steel rolling denitrification heating furnace is connected to the flue gas duct at the inlet end of the air-to-air desulfurization dust collector by connecting the flue gas duct that transmits the hot flue gas to the flue gas at the inlet end of the air-to-air desulfurization dust collector, and a booster fan is arranged on the flue gas duct, so that the hot flue gas, under the boosting effect of the booster fan, has a pressure exceeding the pressure at the inlet end of the air-to-air desulfurization dust collector, and thus smoothly enters the flue gas at the inlet end of the air-to-air desulfurization dust collector. In this way, the hot flue gas and the air flue gas enter the air-to-air desulfurization dust collector together for desulfurization and dust removal.

[0026] Since the hot flue gas is mixed with the air flue gas, the overall temperature of the flue gas can be increased, thereby providing heat for the SCR denitrification component to make the SCR denitrification component reach the reaction temperature, thereby ensuring the purification effect of the denitrification treatment.

[0027] In addition, the hot flue gas can increase the reaction temperature of the air-to-gas desulfurization and dust removal device, thereby improving the desulfurization efficiency and further improving the flue gas purification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a structural schematic diagram of an embodiment of a flue gas treatment system for a steel-rolling denitration heating furnace according to the present invention;

[0030] Figure 2 It is a structural schematic diagram of another embodiment of the flue gas treatment system for steel rolling denitration heating furnace of the present invention;

[0031] Figure 3 It is a structural schematic diagram of another embodiment of the flue gas treatment system of the steel rolling denitrification heating furnace of the present invention.

[0032] Description of reference numerals:

[0033] 1: Supplementary heat furnace; 2: Smoke side flue gas treatment unit; 31: Air smoke desulfurization and dust removal device; 321: SCR reactor; 322: Primary heat exchanger; 323: Secondary heat exchanger; 33: induced draft fan; 34: Chimney; 35: Flue gas duct; 351: First branch duct; 352: Second branch duct; 36: Booster fan; 37: Control valve; 38: Temperature sensor. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0036] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The present disclosure will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0038] First see Figure 1 , Figure 1 FIG. 1 is a schematic diagram of the structure of an embodiment of the steel rolling denitrification heating furnace flue gas treatment system of the present invention. Figure 1 As shown, the system includes a supplementary heat furnace 1 for generating hot flue gas, a smoke-side flue gas treatment unit 2, and an air-side flue gas treatment unit. The hot flue gas generated by the supplementary heat furnace 1 provides heat to the denitration catalyst in the smoke-side flue gas treatment unit 2 and the air-side flue gas treatment unit through the flue gas duct 35 to reach the reaction temperature. It should be noted that the smoke-side flue gas treatment unit 2 provides heat to the denitration catalyst by indirect heat exchange with the hot flue gas in the flue gas duct 35. The structure and principle are the same as those of the existing smoke-side flue gas treatment unit, which will not be repeated here.

[0039] The air-smoke side flue gas treatment unit includes an air-smoke desulfurization dust collector 31, an SCR denitrification component, an induced draft fan 33 and a chimney 34 which are connected in sequence. One end of the flue gas duct 35 is connected to the supplementary heat furnace 1, and the other end is connected to the inlet flue of the air-smoke desulfurization dust collector 31. As an example, the air-smoke desulfurization dust collector 31 can be a fixed bed desulfurization dust collector. Furthermore, in order to make the pressure of the hot flue gas exceed the pressure at the inlet end of the air-smoke desulfurization dust collector 31 so that it can enter smoothly, a booster fan 36 is also provided on the flue gas duct 35. By providing the booster fan 36, the pressure of the hot flue gas and the air-smoke flue gas can exceed the pressure at the inlet end of the air-smoke desulfurization dust collector 31, so that they can enter the air-smoke desulfurization dust collector 31 together for desulfurization and dust removal.

[0040] In addition, the hot flue gas is mixed with the air flue gas to increase the overall temperature of the flue gas, thereby providing heat for the SCR denitration component to reach the reaction temperature, thereby ensuring the purification effect of the denitration treatment. Finally, it is discharged from the chimney 34 under the action of the induced draft fan 33.

[0041] Therefore, compared with directly discharging the hot flue gas from the supplementary heat furnace 1, the above-mentioned embodiment of the present application can process the hot flue gas generated by the supplementary heat furnace 1, so as to meet the emission standards and avoid polluting the atmosphere.

[0042] like Figure 1 As shown, the SCR denitration component can be an SCR reactor 321, and a temperature sensor 38 can be set at the inlet flue of the SCR reactor 321. A regulating valve 37 can also be set on the flue gas duct 35. The temperature sensor 38 and the regulating valve 37 can be connected to the control end of the system. The control end can be a PLC (Programmable Logic Controller). The temperature sensor 38 can detect the temperature of the mixed hot flue gas entering the SCR reactor 321 and transmit the temperature to the control end. The control end compares the flue gas temperature with the reaction temperature of the SCR reactor 321. When the flue gas temperature exceeds the reaction temperature of the SCR reactor 321, the control end can reduce the opening of the regulating valve 37, thereby reducing the hot flue gas flow. When the flue gas temperature is lower than the reaction temperature of the SCR reactor 321, the control end can increase the opening of the regulating valve 37, thereby increasing the hot flue gas flow. In this way, it can be ensured that the temperature of the mixed hot flue gas reaches the reaction temperature of the denitration catalyst.

[0043] See also Figure 2 , Figure 2 FIG. 1 is a schematic diagram of another embodiment of the flue gas treatment system for steel rolling denitrification heating furnace of the present invention. Figure 2As shown, the SCR denitration assembly includes an SCR reactor 321 and a primary heat exchanger 322 with dual channels. One end of the flue gas duct 35 is connected to the supplementary heat furnace 1, and the other end of the flue gas duct 35 is divided into a first branch duct 351 and a second branch duct 352 arranged in parallel by a tee or the like.

[0044] In the installed state, the outlet end of the desulfurization dust collector, the first flow channel of the primary heat exchanger 322 and the first branch pipe 351 are connected in sequence. The end of the first branch pipe 351 is also connected in sequence to the SCR reactor 321, the second flow channel of the primary heat exchanger 322, the induced draft fan 33 and the chimney 34. The second branch pipe 352 is connected to the inlet end flue of the desulfurization dust collector, and the booster fan 36 is set to the second branch pipe 352.

[0045] In this way, with the help of the booster fan 36, the hot flue gas and the air flue gas form a mixed hot flue gas that enters the air flue gas desulfurization and dust removal device 31, passes through the first flow channel of the primary heat exchanger 322 and the first branch pipe 351 and enters the SCR reactor 321, and then is discharged from the chimney 34 through the second flow channel of the primary heat exchanger 322 through the induced draft fan 33.

[0046] Therefore, the second branch pipe 352 can make the mixed hot flue gas formed by the hot flue gas and the air flue gas enter the air flue desulfurization and dust removal device 31, and can also make the other hot flue gas merge with the mixed hot flue gas after denitration and dust removal through the first branch pipe 351, and provide heat energy for the SCR reactor 321. In addition, the first flow channel and the second flow channel of the primary heat exchanger 322 exchange heat, so that the mixed hot flue gas passing through the SCR reactor 321 provides heat for the mixed hot flue gas passing through the first flow channel of the primary heat exchanger 322 through the heat exchange of the other hot flue gas before being discharged, thereby avoiding the heat energy loss of the hot flue gas.

[0047] A temperature sensor 38 may also be provided at the inlet flue of the SCR reactor 321, and a regulating valve 37 is provided upstream of the first branch pipe 351 and the first flow channel connection position of the primary heat exchanger 322, as well as at the inlet flue of the booster fan 36. The temperature sensor 38 and the two regulating valves 37 may be connected to the control end for communication. The temperature sensor 38 may detect the temperature of the hot flue gas entering the SCR reactor 321 and transmit the temperature to the control end. The control end compares the hot flue gas temperature with the reaction temperature of the SCR reactor 321, adjusts the opening of the two regulating valves 37, and further adjusts the hot flue gas flow rate. In this way, it can be ensured that the temperature of the mixed hot flue gas passing through the SCR reactor 321 reaches the reaction temperature of the denitration catalyst in the SCR reactor 321.

[0048] See also Figure 3 , Figure 3FIG. 1 is a structural schematic diagram of another embodiment of the flue gas treatment system for steel rolling denitrification heating furnace of the present invention. Figure 3 As shown, the SCR denitration component includes an SCR reactor 321 and a primary heat exchanger 322 and a secondary heat exchanger 323 having double flow channels.

[0049] In the assembled state, the outlet end of the above-mentioned air flue gas desulfurization and dust removal device 31, the first flow channel of the primary heat exchanger 322, the first flow channel of the secondary heat exchanger 323, the SCR reactor, the second flow channel of the primary heat exchanger 322, the induced draft fan 33 and the chimney 34 are connected in sequence. The flue gas duct 35, the second flow channel of the secondary heat exchanger 323, the booster fan 36 and the inlet flue of the desulfurization and dust removal device are connected in sequence.

[0050] In this way, the mixed hot flue gas passing through the first flow channel of the secondary heat exchanger 323 can exchange heat with the hot flue gas passing through the secondary heat exchanger 323, thereby increasing the temperature of the mixed hot flue gas in the first flow channel of the secondary heat exchanger 323 to reach the reaction temperature of the denitration catalyst in the SCR reactor 321. In addition, the mixed hot flue gas passing through the second flow channel of the primary heat exchanger 322 can also exchange heat with the mixed hot flue gas passing through the first flow channel of the primary heat exchanger 322, further increasing the temperature of the mixed hot flue gas passing through the first flow channel of the primary heat exchanger 322 to reach the reaction temperature of the denitration catalyst in the SCR reactor 321. In this way, the utilization efficiency of the hot flue gas can be improved. More importantly, the above embodiment can make the hot flue gas completely undergo the treatment processes of desulfurization, dust removal and denitration, which can greatly improve the purification effect, thereby meeting the emission standards.

[0051] The flue gas duct 35 may be provided with a regulating valve 37, and the inlet flue of the SCR reactor 321 may be provided with a temperature sensor 38. The temperature sensor 38 regulating valve 37 may be connected to the control end for communication. The temperature sensor 38 may detect the temperature of the flue gas entering the SCR reactor 321 and transmit the temperature to the control end. The control end compares the flue gas temperature with the reaction temperature of the SCR reactor 321, adjusts the opening of the regulating valve 37, and further adjusts the hot flue gas flow. In this way, it can be ensured that the temperature of the mixed hot flue gas reaches the reaction temperature of the denitration catalyst.

[0052] The supplementary heat furnace 1 is usually provided with a cooling fan to allow cold air to enter, thereby adjusting the temperature of the hot flue gas. In the above embodiment of the present invention, the cooling fan can be removed, and the cold air is attracted to enter under the negative pressure of the booster fan 36. In addition, the heat energy provided by the hot flue gas can be controlled by controlling the flow rate of the hot flue gas through the regulating valve 37, thereby reducing the manufacturing cost.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flue gas treatment system for steel rolling denitrification heating furnace, characterized in that: It includes a supplementary heat furnace for generating hot flue gas, a flue gas treatment unit on the coal smoke side and a flue gas treatment unit on the air smoke side, wherein: The air-to-smoke side flue gas treatment unit comprises an air-to-smoke desulfurization and dust removal device, an SCR denitrification component, an induced draft fan and a chimney connected in sequence; A flue gas duct for transmitting hot flue gas is connected to the inlet flue of the air flue gas desulfurization and dust removal device, and a booster fan is arranged on the flue gas duct; In the working state, the hot flue gas first exchanges heat with the smoke side flue gas treatment unit, and then enters the flue at the inlet end of the air flue desulfurization and dust removal device through the traction of the booster fan. After desulfurization and dust removal, the hot flue gas provides heat for the SCR denitrification component.

2. The steel rolling denitrification heating furnace flue gas treatment system according to claim 1 is characterized in that: The SCR denitration component includes an SCR reactor.

3. The steel rolling denitrification heating furnace flue gas treatment system according to claim 1 is characterized in that: The SCR denitration assembly includes an SCR reactor and a primary heat exchanger with a double flow channel; the flue gas pipeline includes a main pipeline connected to the supplementary heat furnace and a first branch pipeline and a second branch pipeline arranged in parallel; The outlet end of the air-smoke desulfurization and dust removal device, the first flow channel of the primary heat exchanger and the first branch pipeline are connected in sequence, and the first branch pipeline is also connected in sequence with the SCR reactor, the second flow channel of the primary heat exchanger, the induced draft fan and the chimney; The second branch pipeline is connected to the inlet end flue of the air-gas desulfurization and dust removal device, and the booster fan is arranged on the second branch pipeline.

4. The steel rolling denitrification heating furnace flue gas treatment system according to claim 3 is characterized in that: A regulating valve is provided upstream of the position where the first branch pipeline is connected to the first flow channel of the primary heat exchanger and at the flue at the inlet end of the booster fan.

5. The steel rolling denitrification heating furnace flue gas treatment system according to claim 4 is characterized in that: The inlet flue of the SCR reactor is provided with a temperature sensor.

6. The steel rolling denitrification heating furnace flue gas treatment system according to claim 5 is characterized in that: The flue gas treatment system adjusts two regulating valves according to the temperature collected by the temperature sensor.

7. The steel rolling denitrification heating furnace flue gas treatment system according to claim 1 is characterized in that: The SCR denitration component includes an SCR reactor, a primary heat exchanger with double flow channels, and a secondary heat exchanger; The outlet end of the air-smoke desulfurization and dust removal device, the first flow channel of the primary heat exchanger, the first flow channel of the secondary heat exchanger, the SCR reactor, the second flow channel of the primary heat exchanger, the induced draft fan and the chimney are connected in sequence; The flue gas duct, the second flow channel of the secondary heat exchanger, the booster fan and the inlet end flue of the air-to-gas desulfurization and dust removal device are connected in sequence.

8. The steel rolling denitrification heating furnace flue gas treatment system according to claim 2 or 7, characterized in that: The flue gas duct is provided with a regulating valve.

9. The steel rolling denitrification heating furnace flue gas treatment system according to claim 8, characterized in that: The inlet flue of the SCR reactor is provided with a temperature sensor.

10. The steel rolling denitrification heating furnace flue gas treatment system according to claim 9, characterized in that: The flue gas treatment system adjusts the regulating valve according to the temperature collected by the temperature sensor.

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