A method for continuous blast furnace blower mutual protection air supply

Abstract

This application relates to a method for continuous blast furnace air supply with mutual protection between blowers, belonging to the field of blast furnace smelting technology. It includes opening a quick-cut valve, simultaneously supplying air to blast furnaces #3 and #2 via axial flow blower #3, opening centrifugal blower #1 and inlet air valve #1, closing venting valve #1 and anti-surge valve #1, slowly adjusting flow regulating valve #2, opening venting valve #1, and simultaneously opening connecting valve #2, continuing to slowly adjust flow regulating valve #2, pressurizing operation of centrifugal blower #1, and so on. After the flow regulating valve is fully closed, the No. 3 flow regulating valve and quick-cut valve are closed sequentially, the mutual protection system is deactivated, and the No. 3 blast furnace resumes normal production. The No. 1 centrifugal fan supplies air to the No. 2 blast furnace separately. The No. 1 air inlet valve and the No. 1 anti-surge valve are adjusted so that the No. 1 centrifugal fan reaches the air supply pressure required by the No. 2 blast furnace. When the fault of the No. 2 axial flow fan is cleared, the No. 2 axial flow fan is started and runs to build up pressure. The No. 2 axial flow fan and the No. 1 centrifugal fan perform a reverse air operation to restore the air supply of the No. 2 axial flow fan. This application has the effect of saving a large amount of raw materials and fuels.

Description

Technical Field

[0001] This application relates to the field of blast furnace smelting technology, and in particular to a method for mutual protection of blast furnace blowers during continuous blast furnace operation. Background Technology

[0002] Blast furnace smelting requires that, under certain furnace volume and raw material conditions, the blast velocity and blast energy of the blast furnace must reach certain values; otherwise, the blast furnace condition may be unsatisfactory, resulting in poor production, technical and economic indicators. Therefore, the blast system is a key factor affecting the initial gas flow distribution of the blast furnace. In particular, a reasonable blast system in the early stage of blast furnace start-up will promote the recovery of furnace condition.

[0003] In the relevant technology, during normal blast furnace production, axial flow fans #2 and #3 supply air to blast furnaces #2 and #3 respectively, with air pressures around 300 kPa. In the fan interoperability system, flow regulating valves #2 and #3 are both open. When one of the axial flow fans fails and trips, taking the trip of fan #2 as an example, the quick-cut valve in the interoperability system quickly opens the pipeline connection within 2 seconds. While fan #3 supplies air to blast furnace #3, a portion of the air is diverted to blast furnace #2 to prevent a sudden air outage from blast furnace #2, which could cause a major accident of slag charging at the blast furnace tuyeres. At this time, the air pressure from fan #3 is shared equally between the two blast furnaces, with each maintaining a pressure of around 150 kPa.

[0004] In the subsequent handling process, the original operation required a smooth shutdown of blast furnace #2, followed by the return of air to blast furnace #3, disengaging the mutual protection system, and simultaneously restarting centrifugal fan #1 to resume air supply to blast furnace #2 to restore production. After the malfunction of axial fan #2 was resolved, a reverse air operation was performed between axial fan #2 and centrifugal fan #1. During this process, the fan mutual protection system and centrifugal fan #1 were completely separated. Only after the mutual protection system was disengaged could centrifugal fan #1 supply air independently. Moreover, the blast furnace needed to shut down, wasting some raw materials and fuels and reducing the production efficiency of the blast furnace. Therefore, this process needs to be improved. Summary of the Invention

[0005] To address the problem of blast furnace shutdown and waste of raw materials and fuel when axial flow fans malfunction, this application provides a method for continuous blast furnace ventilation with interconnected blowers.

[0006] The technical solution for the blast furnace continuous blast fan mutual protection air supply method provided in this application is as follows:

[0007] A method for mutual protection of blowers during continuous blast furnace operation, addressing a tripping fault in the No. 2 axial flow blower, includes the following steps:

[0008] S1. Open the quick-cut valve. While the No. 3 axial flow fan supplies air to the No. 3 blast furnace, it also allocates a portion of the air to the No. 2 blast furnace. At the same time, the No. 1 centrifugal fan is turned on, the No. 1 air inlet valve is opened, and the No. 1 venting valve and the No. 1 anti-surge valve are closed. The No. 1 centrifugal fan runs and pressurizes.

[0009] S2. Slowly adjust the No. 2 flow regulating valve to reduce the flow rate of the air sent into the No. 2 blast furnace by the No. 3 axial flow fan, and adjust the pressure of the No. 2 blast furnace to 120KPa-130KPa. During this period, the air pressure of the No. 3 blast furnace will rise slightly.

[0010] S3. Open the No. 1 air supply valve and simultaneously open the No. 2 connecting valve to enable the No. 3 axial flow fan and the No. 1 centrifugal fan to simultaneously supply air to the No. 2 blast furnace and the No. 3 blast furnace, ensuring the air supply pressure;

[0011] S4. Continue to slowly adjust the No. 2 flow regulating valve to reduce the flow rate of the air sent to the No. 2 blast furnace by the No. 3 axial flow fan. At the same time, the No. 1 centrifugal fan will pressurize to ensure that the pressure sent to the No. 2 blast furnace is maintained between 130KPa and 150KPa.

[0012] After the S5 and 2# flow regulating valves are slowly closed until fully closed, the 3# flow regulating valve and quick-cut valve are closed in sequence, the mutual protection system is disengaged, and the 3# blast furnace resumes normal production. At this time, the 1# centrifugal fan is used to send air to the 2# blast furnace separately.

[0013] S6. Adjust the No. 1 air inlet valve and the No. 1 anti-surge valve so that the No. 1 centrifugal fan can reach the air supply pressure required by the No. 2 blast furnace;

[0014] S7. After the fault of axial flow fan #2 is cleared, axial flow fan #2 is started and pressurized to 130 kPa. A reverse fan operation is performed between axial flow fan #2 and centrifugal fan #1 to restore the air supply of axial flow fan #2.

[0015] Furthermore, in step S1, the operating air supply pressure of centrifugal fan #1 is reduced to 120KPa-130KPa.

[0016] Furthermore, in step S1, the axial flow fan No. 3 simultaneously supplies air to blast furnaces No. 2 and No. 3, with the air supply pressure being between 145KPa and 150KPa. Under this premise, the centrifugal fan No. 1 is turned on.

[0017] Furthermore, in step S2, the air supply pressure of blast furnace #3 increases slightly, reaching 175KPa-185KPa. At this time, the air supply pressure of blast furnace #3 can be kept stable by adjusting the stator blades of axial flow fan #3 and anti-surge valve #3.

[0018] Furthermore, in step S6, centrifugal fan #1 reaches the air supply pressure required by blast furnace #2, with a pressure range of 280KPa-300KPa.

[0019] Further, the operation of the reverse air fan in step S7 is as follows: the No. 2 axial flow fan is started and pressurized to 130 kPa, the No. 2 air supply valve is opened, and the No. 2 axial flow fan supplies air to the No. 2 blast furnace. The No. 1 vent valve and the No. 1 anti-surge valve of the No. 1 centrifugal fan are opened. The No. 1 air supply valve, the No. 2 connecting valve, and the No. 1 air inlet valve of the No. 1 centrifugal fan are closed. The No. 1 centrifugal fan stops supplying air to the No. 2 blast furnace. After the air from the No. 1 centrifugal fan has been exhausted, the No. 1 vent valve and the No. 1 anti-surge valve of the No. 1 centrifugal fan are closed. The No. 1 centrifugal fan is shut down and put into standby. The No. 2 axial flow fan resumes its independent air supply to the No. 2 blast furnace.

[0020] Furthermore, the air supply pressure of the No. 2 axial flow fan is increased to 280 kPa-300 kPa, which is required for normal production of the No. 2 blast furnace.

[0021] In summary, this application includes at least one of the following beneficial technical effects:

[0022] Through the optimization of the above operating process, it is possible to achieve that if any one of the two axial flow fans trips, the fan mutual protection system does not need to be shut down, and the blast furnace can perform online reverse fan operation without shutting down the blast furnace. This reduces the impact of blast furnace shutdown due to fan failure, saves a lot of raw materials and fuel and time to restore blast furnace conditions, ensures the continuous production rhythm of the blast furnace, and improves the blast furnace operating rate and technical and economic indicators. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a method for mutual protection of blowers in a blast furnace during continuous operation, as described in an embodiment of this application. Implementation

[0024] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, the present invention provides a method for mutual protection of blast furnace blowers during continuous operation, addressing a tripping fault in the No. 2 axial flow blower, comprising the following steps:

[0026] S1. Open the quick-cut valve. While supplying air to blast furnace #3, the axial flow fan #3 also allocates a portion of the air to blast furnace #2. The air supply pressure is between 145KPa and 150KPa. Under this premise, start centrifugal fan #1, open air inlet valve #1, and close air vent valve #1 and anti-surge valve #1. Centrifugal fan #1 operates under pressure buildup. The air supply pressure of centrifugal fan #1 is built up to 120KPa-130KPa.

[0027] S2. Slowly adjust the No. 2 flow regulating valve to reduce the flow rate of the air supplied to the No. 2 blast furnace by the No. 3 axial flow fan, and adjust the pressure of the No. 2 blast furnace to 120KPa-130KPa. During this period, the air supply pressure of the No. 3 blast furnace will rise slightly and reach 175KPa-185KPa. At this time, the air supply pressure of the No. 3 blast furnace can be kept stable by adjusting the stator blades of the No. 3 axial flow fan and the No. 3 anti-surge valve.

[0028] S3. Open the No. 1 air supply valve and simultaneously open the No. 2 connecting valve to enable the No. 3 axial flow fan and the No. 1 centrifugal fan to simultaneously supply air to the No. 2 blast furnace and the No. 3 blast furnace, ensuring the air supply pressure;

[0029] S4. Continue to slowly adjust the No. 2 flow regulating valve to reduce the flow rate of the air sent to the No. 2 blast furnace by the No. 3 axial flow fan. At the same time, the No. 1 centrifugal fan will pressurize to ensure that the pressure sent to the No. 2 blast furnace is maintained between 130KPa and 150KPa.

[0030] After the S5 and 2# flow regulating valves are slowly closed until fully closed, the 3# flow regulating valve and quick-cut valve are closed in sequence, the mutual protection system is disengaged, and the 3# blast furnace resumes normal production. At this time, the 1# centrifugal fan is used to send air to the 2# blast furnace separately.

[0031] S6. Adjust the No. 1 air inlet valve and the No. 1 anti-surge valve so that the No. 1 centrifugal fan can reach the air supply pressure required by the No. 2 blast furnace, with a pressure range of 280KPa-300KPa.

[0032] S7. After the fault of axial flow fan #2 is cleared, axial flow fan #2 is started and pressurized to 130 kPa. A reverse air operation is performed between axial flow fan #2 and centrifugal fan #1. Axial flow fan #2 is started and pressurized to 130 kPa. Air supply valve #2 is opened and axial flow fan #2 supplies air to blast furnace #2. Air vent valve #1 and anti-surge valve #1 of centrifugal fan #1 are opened. Air supply valve #1, connecting valve #2, and air inlet valve #1 of centrifugal fan #1 are closed. Centrifugal fan #1 stops supplying air to blast furnace #2. After the air from centrifugal fan #1 has been exhausted, air vent valve #1 and anti-surge valve #1 of centrifugal fan #1 are closed. Centrifugal fan #1 is shut down and put on standby. Axial flow fan #2 resumes independent air supply to blast furnace #2. Air supply pressure of axial flow fan #2 is increased to 280 kPa-300 kPa, which is required for normal production of blast furnace #2.

[0033] The present invention will be further described below through specific embodiments. Example 1

[0034] The present invention provides a method for mutual protection of blast furnace blowers during continuous operation, addressing a tripping fault in the No. 2 axial flow blower, comprising the following steps:

[0035] S1. Open the quick-cut valve. While supplying air to blast furnace #3, the axial flow fan #3 also allocates a portion of the air to blast furnace #2. The air supply pressure is 130 kPa. Under this premise, start centrifugal fan #1, open air inlet valve #1, and close air outlet valve #1 and anti-surge valve #1. Centrifugal fan #1 runs under pressure buildup. The air supply pressure of centrifugal fan #1 is built up to 130 kPa.

[0036] S2. Slowly adjust the No. 2 flow regulating valve to reduce the flow rate of the air supplied to the No. 2 blast furnace by the No. 3 axial flow fan, and adjust the pressure of the No. 2 blast furnace to 120 kPa. During this period, the air supply pressure of the No. 3 blast furnace will rise slightly and reach 180 kPa. At this time, the air supply pressure of the No. 3 blast furnace can be kept stable by adjusting the stator blades of the No. 3 axial flow fan and the No. 3 anti-surge valve.

[0037] S3. Open the No. 1 air supply valve and simultaneously open the No. 2 connecting valve to enable the No. 3 axial flow fan and the No. 1 centrifugal fan to simultaneously supply air to the No. 2 blast furnace and the No. 3 blast furnace, ensuring the air supply pressure;

[0038] S4. Continue to slowly adjust the No. 2 flow regulating valve to reduce the flow rate of the air sent to the No. 2 blast furnace by the No. 3 axial flow fan. At the same time, the No. 1 centrifugal fan will pressurize to ensure that the pressure sent to the No. 2 blast furnace is maintained at 130 kPa.

[0039] After the S5 and 2# flow regulating valves are slowly closed until fully closed, the 3# flow regulating valve and quick-cut valve are closed in sequence, the mutual protection system is disengaged, and the 3# blast furnace resumes normal production. At this time, the 1# centrifugal fan is used to send air to the 2# blast furnace separately.

[0040] S6. Adjust the No. 1 air inlet valve and the No. 1 anti-surge valve so that the No. 1 centrifugal fan can reach the air supply pressure of 300 kPa required by the No. 2 blast furnace.

[0041] S7. After the fault of axial flow fan #2 is cleared, axial flow fan #2 is started and pressurized to 130 kPa. A reverse air operation is performed between axial flow fan #2 and centrifugal fan #1. Axial flow fan #2 is started and pressurized to 130 kPa. Air supply valve #2 is opened and axial flow fan #2 supplies air to blast furnace #2. Air vent valve #1 and anti-surge valve #1 of centrifugal fan #1 are opened. Air supply valve #1, connecting valve #2, and air inlet valve #1 of centrifugal fan #1 are closed. Centrifugal fan #1 stops supplying air to blast furnace #2. After the air from centrifugal fan #1 has been exhausted, air vent valve #1 and anti-surge valve #1 of centrifugal fan #1 are closed. Centrifugal fan #1 is shut down and put on standby. Axial flow fan #2 resumes independent air supply to blast furnace #2. Air supply pressure of axial flow fan #2 is increased to 300 kPa, which is required for normal production of blast furnace #2. Example 2

[0042] The present invention provides a method for mutual protection of blast furnace blowers during continuous operation, addressing a tripping fault in the No. 3 axial flow blower, comprising the following steps:

[0043] S1. Open the quick-cut valve. While supplying air to blast furnace #2, the axial flow fan #2 also allocates a portion of the air to blast furnace #3. The air supply pressure is 130 kPa. Under this premise, start centrifugal fan #1, open air inlet valve #1, and close air vent valve #1 and anti-surge valve #1. Centrifugal fan #1 runs under pressure buildup. The air supply pressure of centrifugal fan #1 is built up to 130 kPa.

[0044] S2. Slowly adjust the No. 3 flow regulating valve to reduce the flow rate of the air supplied to the No. 3 blast furnace by the No. 2 axial flow fan, and adjust the pressure of the No. 3 blast furnace to 120 kPa. During this period, the air supply pressure of the No. 2 blast furnace will rise slightly and reach 180 kPa. At this time, the air supply pressure of the No. 2 blast furnace can be kept stable by adjusting the stator blades of the No. 2 axial flow fan and the No. 2 anti-surge valve.

[0045] S3. Open the No. 1 air supply valve and simultaneously open the No. 3 connecting valve to enable the No. 2 axial flow fan and the No. 1 centrifugal fan to simultaneously supply air to the No. 2 blast furnace and the No. 3 blast furnace, ensuring the air supply pressure;

[0046] S4. Continue to slowly adjust the No. 3 flow regulating valve to reduce the flow rate of the air sent to the No. 3 blast furnace by the No. 2 axial flow fan. At the same time, the No. 1 centrifugal fan will pressurize to ensure that the pressure sent to the No. 3 blast furnace is maintained at 130 kPa.

[0047] After the S5 and 3# flow regulating valves are slowly closed until fully closed, the 2# flow regulating valve and quick-cut valve are closed in sequence, the mutual protection system is disengaged, and the 2# blast furnace resumes normal production. At this time, the 1# centrifugal fan is used to send air to the 3# blast furnace separately.

[0048] S6. Adjust the No. 1 air inlet valve and the No. 1 anti-surge valve so that the No. 1 centrifugal fan can reach the air supply pressure of 300 kPa required by the No. 3 blast furnace.

[0049] S7. After the fault of the No. 3 axial flow fan is cleared, the No. 3 axial flow fan is started and pressurized to 130 kPa. The No. 3 axial flow fan and the No. 1 centrifugal fan are switched. The No. 3 axial flow fan is started and pressurized to 130 kPa. The No. 3 air supply valve is opened and the No. 3 axial flow fan supplies air to the No. 3 blast furnace. The No. 1 vent valve and the No. 1 anti-surge valve of the No. 1 centrifugal fan are opened. The No. 1 air supply valve, the No. 3 connecting valve, and the No. 1 air inlet valve of the No. 1 centrifugal fan are closed. The No. 1 centrifugal fan stops supplying air to the No. 3 blast furnace. After the No. 1 centrifugal fan has exhausted its air supply, the No. 1 vent valve and the No. 1 anti-surge valve of the No. 1 centrifugal fan are closed. The No. 1 centrifugal fan is shut down and put on standby. The No. 3 axial flow fan resumes its independent air supply to the No. 3 blast furnace. The air supply pressure of the No. 3 axial flow fan is increased to 300 kPa, which is required for normal production of the No. 3 blast furnace.

[0050] As can be seen from the above embodiments, the method of the present invention, through the optimization of the above operating process, can achieve the following: after any one of the two axial flow fans trips, the fan mutual protection system does not need to be shut down, and the blast furnace can perform online reverse fan operation without shutting down the blast furnace. This reduces the impact of blast furnace shutdown due to fan failure, saves a lot of raw materials and fuel and time to restore the blast furnace condition, ensures the continuous production rhythm of the blast furnace, and improves the blast furnace operating rate and technical and economic indicators.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A method for mutual protection and air supply of blast furnace blowers without interruption, characterized in that: The tripping failure of axial flow fan #2 includes the following steps: S1. Open the quick-cut valve. While the No. 3 axial flow fan supplies air to the No. 3 blast furnace, it also allocates a portion of the air to the No. 2 blast furnace. At the same time, the No. 1 centrifugal fan is turned on, the No. 1 air inlet valve is opened, and the No. 1 venting valve and the No. 1 anti-surge valve are closed. The No. 1 centrifugal fan runs and pressurizes. S2. Slowly adjust the No. 2 flow regulating valve to reduce the flow rate of the air sent into the No. 2 blast furnace by the No. 3 axial flow fan, and adjust the pressure of the No. 2 blast furnace to 120kPa-130kPa. During this period, the air pressure of the No. 3 blast furnace will rise slightly. S3. Open the No. 1 air supply valve and simultaneously open the No. 2 connecting valve to enable the No. 3 axial flow fan and the No. 1 centrifugal fan to simultaneously supply air to the No. 2 blast furnace and the No. 3 blast furnace, ensuring the air supply pressure; S4. Continue to slowly adjust the No. 2 flow regulating valve to reduce the flow rate of the air sent to the No. 2 blast furnace by the No. 3 axial flow fan. At the same time, the No. 1 centrifugal fan will pressurize to ensure that the pressure sent to the No. 2 blast furnace is maintained between 130kPa and 150kPa. After the S5 and 2# flow regulating valves are slowly closed until fully closed, the 3# flow regulating valve and quick-cut valve are closed in sequence, the mutual protection system is disengaged, and the 3# blast furnace resumes normal production. At this time, the 1# centrifugal fan is used to send air to the 2# blast furnace separately. S6. Adjust the No. 1 air inlet valve and the No. 1 anti-surge valve so that the No. 1 centrifugal fan can reach the air supply pressure required by the No. 2 blast furnace; S7. After the fault of axial flow fan #2 is cleared, axial flow fan #2 is started and pressurized to 130kPa. A reverse fan operation is performed between axial flow fan #2 and centrifugal fan #1 to restore the air supply of axial flow fan #2. The operation of the reverse air fan in step S7 is as follows: the No. 2 axial flow fan is started and pressurized to 130 kPa, the No. 2 air supply valve is opened, and the No. 2 axial flow fan supplies air to the No. 2 blast furnace. The No. 1 vent valve and the No. 1 anti-surge valve of the No. 1 centrifugal fan are opened. The No. 1 air supply valve, the No. 2 connecting valve, and the No. 1 air inlet valve of the No. 1 centrifugal fan are closed. The No. 1 centrifugal fan stops supplying air to the No. 2 blast furnace. After the air from the No. 1 centrifugal fan has been exhausted, the No. 1 vent valve and the No. 1 anti-surge valve of the No. 1 centrifugal fan are closed. The No. 1 centrifugal fan is shut down and put into standby. The No. 2 axial flow fan resumes its independent air supply to the No. 2 blast furnace.

2. The method for mutual protection and air supply of blast furnace blowers without interruption as described in claim 1, characterized in that: In step S1, the operating pressure of centrifugal fan #1 is increased to 120kPa-130kPa.

3. The method for mutual protection and air supply of blast furnace blowers without interruption as described in claim 1, characterized in that: In step S1, axial flow fan #3 simultaneously supplies air to blast furnaces #2 and #3, with air pressures ranging from 145kPa to 150kPa. Under this premise, centrifugal fan #1 is turned on.

4. The method for mutual protection and air supply of blast furnace blowers without interruption as described in claim 1, characterized in that: In step S2, the air supply pressure of blast furnace #3 increases slightly, reaching 175 kPa-185 kPa. At this time, the air supply pressure of blast furnace #3 can be kept stable by adjusting the stator blades of axial flow fan #3 and anti-surge valve #3.

5. The method for mutual protection and air supply of blast furnace blowers without interruption according to claim 1, characterized in that: In step S6, centrifugal fan #1 reaches the air supply pressure required by blast furnace #2, with a pressure range of 280kPa-300kPa.

6. The method for mutual protection and air supply of blast furnace blowers without interruption according to claim 1, characterized in that: The air pressure of the No. 2 axial flow fan is increased to 280kPa-300kPa, which is required for normal production of the No. 2 blast furnace.

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