A method for replacing faulty blowers in a blast furnace without shutting down ventilation.

Abstract

This invention specifically relates to a method for replacing a faulty blower in a blast furnace without shutting down the furnace. The method includes: confirming the blower replacement time; starting the standby blower and putting it into trial operation; after the standby blower is running normally, adjusting the stator angle of the faulty blower while maintaining the air pressure at the first air pressure; adjusting the stator angle of the standby blower, closing the second vent valve, and slowly closing the second anti-surge valve to raise the air pressure to the second air pressure; slowly closing the first air supply valve of the faulty blower and slowly opening the second air supply valve of the standby blower, maintaining air pressure fluctuations less than the third air pressure, until the first air supply valve of the faulty blower is fully closed and the second air supply valve of the standby blower is fully open; after the standby blower is put into blast furnace air supply, informing the blast furnace operator to fully open the second air supply valve, fully close the second anti-surge valve, and open the check valve, and slowly adjusting the stator angle of the standby blower to the angle required by the blast furnace; finally, stopping the faulty blower and completing the replacement. This method solves the problem that faulty blower replacement can only be achieved by shutting down the blast furnace.

Description

Technical Field

[0001] This invention relates to the field of blast furnace blasting technology, specifically a method for replacing a faulty blower in a blast furnace without shutting down blasting. Background Technology

[0002] Blowers are core power equipment in the ironmaking process of steel enterprises. During blast furnace smelting, they are responsible for supplying air to the blast furnace to ensure the oxygen needed for the fuel injected to fuel the burning coke. They also need sufficient air pressure to overcome the resistance of the air supply system and the burden column, and to maintain a certain internal pressure in the blast furnace. In actual production, when the blowers supplying air to the blast furnace malfunction, an emergency shutdown is required to replace the blowers. This shutdown not only increases the risk of incomplete slag and iron removal leading to small tuyeres and burn-through fire tubes, but also increases the safety hazards associated with cutting off ignition gas during the shutdown and restart process. Summary of the Invention

[0003] The purpose of this invention is to provide a method for switching faulty blowers in a blast furnace without shutting down ventilation, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for replacing a faulty blower in a blast furnace without shutting down the furnace, the method comprising: confirming the blower replacement time; starting the standby blower and putting it into trial operation; after the standby blower is running normally, reducing the stator angle of the faulty blower from the normal production angle to the first angle, maintaining the air pressure at the first air pressure to ensure the minimum pressure that prevents slag from entering the blast furnace tuyeres; raising the stator angle of the standby blower from the safe operating angle to the second angle, closing the second vent valve, and slowly closing the second anti-surge valve to raise the air pressure to the second air pressure; slowly closing the first air supply valve of the faulty blower, and slowly opening the second air supply valve of the standby blower, maintaining the air pressure fluctuation less than the third air pressure, until the first air supply valve of the faulty blower is fully closed and the second air supply valve of the standby blower is fully open; after the standby blower is put into blast furnace air supply, informing the blast furnace operator to fully open the second air supply valve, fully close the second anti-surge valve, and open the check valve, and slowly adjusting the stator angle of the standby blower to the angle required by the blast furnace; contacting the dispatcher to shut down the faulty blower, thus completing the blower replacement.

[0005] Preferably, the first angle is 30°, the second angle is 30°, and the safe operating angle is 22°.

[0006] Preferably, the first wind pressure is 100 kPa, the second wind pressure is 100 kPa, and the third wind pressure is 5 kPa.

[0007] Preferably, the fan switching time is after the blast furnace taps iron.

[0008] Preferably, starting the standby fan and putting the standby fan into trial operation includes successfully releasing the standby fan's stator blades, and the indicator light illuminating to show that the standby fan has started successfully; setting the standby fan's stator blade angle to a safe operating angle, and simultaneously opening the second air distribution valve and closing the second air supply valve.

[0009] Preferably, after the standby fan is operating normally, the stator angle of the faulty fan is reduced from the normal production angle to the first angle. After the air pressure is maintained at the first air pressure, the first anti-surge valve and the first vent valve of the faulty fan need to be opened, and the standby fan is operated to shut down the fan.

[0010] Preferably, the step of raising the standby fan's stator blade angle from the safe operating angle to the second angle, closing the second vent valve, and slowly closing the second anti-surge valve to raise the air pressure to the second air pressure involves raising the standby fan's stator blade angle from 22° to 30°, closing the second vent valve, and slowly closing the second anti-surge valve to raise the air pressure to 100 kPa. Based on the relationship between the standby fan's stator blade angle and the air volume and air pressure, raising the standby fan's stator blade angle from the safe operating angle of 22° to 30° ensures that the standby fan pressure is 110 kPa. When the standby fan air pressure is 110 kPa, the main pipe pressure of the blast furnace air supply can meet 100 kPa.

[0011] Preferably, after the standby blower is put into operation for blast furnace air supply, the method further includes the step of opening the first anti-surge valve, so that when the air supply volume of the faulty blower is 0, the first air supply valve is determined to be closed.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] This invention solves the problem that the faulty blower can only be replaced by shutting down the blast furnace, avoiding the risk of small tuyeres and burn-through fire tubes caused by the shutdown. During normal production, the standby blower does not need to operate at low load. The safe stationary blade angle of the blower is determined to be 30°, which is the minimum angle of the blast furnace tuyeres. Attached Figure Description

[0014] Figure 1 This is a system schematic diagram of the faulty fan and the standby fan of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Reference Figure 1 This embodiment provides a method for switching a faulty blower in a blast furnace without shutting down ventilation. The method includes the following steps in sequence:

[0017] S1. Select the time to switch blowers after tapping iron from the blast furnace. Otherwise, if the slag and iron are not completely removed from the blast furnace, the suspended furnace charge above the furnace will suddenly drop, causing slag and iron to backflow into the tuyeres and fire tubes. Stopping the blowers after tapping iron can reduce the risk of slag and iron backflow.

[0018] S2. Start the standby fan to put it into trial operation mode. Specifically: when the standby fan's stationary blades are successfully released, the indicator light will illuminate to show that the standby fan has started successfully; set the standby fan's stationary blade angle to 22°, and simultaneously open the second air distribution valve and close the second air supply valve; when the standby fan starts, open the second air distribution valve corresponding to the blast furnace to reduce the workload when replacing the fan; the second air supply valve is closed to avoid affecting the air volume and air pressure of the malfunctioning fan and the blast furnace after the standby fan starts.

[0019] S3. After the standby blower is running normally, reduce the stationary blade angle of the faulty blower from the normal production angle to 30°, maintain the air pressure at 100 kPa, open the first anti-surge valve and the first vent valve of the faulty blower, and cooperate with the standby blower operation to ensure the minimum pressure that prevents slag from entering the blast furnace tuyeres.

[0020] S4. Based on the relationship between the standby fan's stator blade angle and air volume and pressure, increase the standby fan's stator blade angle from 22° to 30°. This adjustment process is a slow one, and should be carried out according to the actual operating conditions. This ensures that the standby fan pressure is 110 kPa. Then, close the second vent valve and slowly close the second anti-surge valve to increase the air pressure to 100 kPa. Increase the standby fan's stator blade angle from the safe operating angle of 22° to 30°. When the standby fan pressure is 110 kPa, the main pipe pressure of the blast furnace air supply can meet 100 kPa.

[0021] S5. Slowly close the first air supply valve of the faulty fan and slowly open the second air supply valve of the standby fan, keeping the air pressure fluctuation less than 5 kPa, until the first air supply valve of the faulty fan is fully closed and the second air supply valve of the standby fan is fully open.

[0022] S6. After the standby blower is put into the blast furnace for air supply, inform the blast furnace operator to fully open the second air supply valve and fully close the second anti-surge valve. The second check valve will open automatically by relying on the air pressure. Open the first anti-surge valve of the faulty blower. When the air supply volume of the faulty blower is 0, confirm that the first air supply valve of the faulty blower is closed, and slowly adjust the stationary blade angle of the standby blower to the angle required by the blast furnace.

[0023] S7. Contact the dispatcher to shut down the faulty fan and complete the fan replacement.

[0024] Although the illustrative specific embodiments of this application have been described above to enable those skilled in the art to understand this application, this application is not limited to the scope of the specific embodiments. For those skilled in the art, all applications utilizing the concept of this application are protected as long as various variations are within the spirit and scope of this application as defined and determined by the appended claims.

Claims

1. A method of switching off a blast furnace without blowing down a failed fan, characterized in that, The method comprises the following steps: confirming the time for switching the fan; starting the standby fan to make the standby fan in a trial running state; after the standby fan is in normal operation, reducing the static blade angle of the faulty fan from a normal production angle to a first angle, keeping the wind pressure at a first wind pressure, ensuring the minimum pressure for preventing the blast furnace tuyere from being filled with slag, the first angle being 30°, and the first wind pressure being 100 KPa; increasing the static blade angle of the standby fan from a safe operation angle to a second angle, the safe operation angle being 22°, the second angle being 30°, closing the second air release valve, slowly closing the second anti-surge valve to increase the wind pressure to a second wind pressure, the second wind pressure being 100 KPa; slowly closing the first air supply valve of the faulty fan and slowly opening the second air supply valve of the standby fan, keeping the wind pressure fluctuation less than a third wind pressure, until the first air supply valve of the faulty fan is fully closed and the second air supply valve of the standby fan is fully opened, the third wind pressure being 5 KPa; after the standby fan is put into blast furnace air supply, informing the blast furnace operator that the second air supply valve is fully opened, the second anti-surge valve is fully closed, the check valve is opened, and the static blade angle of the standby fan is slowly adjusted to the angle required by the blast furnace; contacting the dispatcher to stop the faulty fan, and the fan switching is completed; the step of starting the standby fan to make the standby fan in a trial running state comprises the following steps: when the standby fan static blade release is successful and the indicator light is on, it indicates that the standby fan is successfully started, the static blade angle of the standby fan is set to the safe operation angle, the second air distribution valve is opened, and the second air supply valve is closed; after the standby fan is in normal operation, the static blade angle of the faulty fan is reduced from the normal production angle to the first angle, the wind pressure is kept at the first wind pressure, the first anti-surge valve and the first air release valve of the faulty fan need to be opened, and the standby fan is operated to stop.

2. A method of switching over a failed fan without blowing down a blast furnace as claimed in claim 1 wherein, The time for switching the fan is after the blast furnace is tapped.

3. The method of claim 1, wherein: The step of increasing the static blade angle of the standby fan from the safe operation angle to the second angle, closing the second air release valve, slowly closing the second anti-surge valve to increase the wind pressure to the second wind pressure comprises the following steps: increasing the static blade angle of the standby fan from 22° to 30°, closing the second air release valve, and slowly closing the second anti-surge valve to increase the wind pressure to 100 KPa; according to the relationship between the static blade angle of the standby fan and the wind pressure and the wind volume, the static blade angle of the standby fan is increased from the safe operation angle of 22° to 30°, so that the standby fan pressure is 110 KPa, and when the standby fan pressure is 110 KPa, the blast furnace air supply main pipe pressure can meet 100 KPa.

4. The method of claim 1, wherein: After the standby fan is put into blast furnace air supply, the method further comprises the step of opening the first anti-surge valve, so that when the air supply volume of the faulty fan is 0, it is determined that the first air supply valve is closed.

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