Pressure-stabilizing air supply equipment for blast furnace and control method of pressure-stabilizing air supply equipment

Abstract

The invention discloses pressure-stabilizing air supply equipment for a blast furnace and a control method of the pressure-stabilizing air supply equipment, and relates to the technical field of blast furnace air supply, and the pressure-stabilizing air supply equipment is additionally provided with a pressure-stabilizing fan, a check valve and a pressure-stabilizing valve on the basis of traditional air supply equipment. In the hot-blast stove changing process, air flow distribution of a main air supply fan is not needed, the load of the main air supply fan is not changed, the pressure stabilizing fan automatically pressurizes the hot-blast stove to reach the air supply pressure, and the air supply pressure of the blast furnace is not disturbed in the cold air valve opening and hot air valve stove changing process. In addition, under the condition that the main fan breaks down, the air distributing system does not need to act, the pressure stabilizing fan automatically supplies air to the blast furnace corresponding to the broken-down main fan, and the air volume requirement of the blast furnace without slag filling is met. The cold air flow of other blast furnaces does not need to be shunted in the process, production of other blast furnaces is not affected, and the system is obviously superior to a traditional air distribution system.

Description

Technical Field

[0001] This invention relates to the field of blast furnace air supply technology, and more specifically, to a pressure-stabilizing air supply device for blast furnaces and its control method. Background Technology

[0002] During the traditional hot blast stove replacement process, the blast furnace airflow will temporarily decrease. This is because the traditional replacement operation requires switching the hot blast stove's operating state (combustion → air supply or air supply → combustion). During this switching process, a portion of the air flow from the main blast fan will be diverted to the hot blast stove that is about to supply air. While pressurizing this hot blast stove, the hot air supplied to the blast furnace will experience a brief drop in airflow or pressure fluctuation, leading to a decrease in blast furnace air volume and pressure, which may affect the stability of the furnace operation. Traditional hot blast stoves typically number 3-4, employing a "two-burner-one-supplier" or "parallel air supply" mode, with a high replacement frequency (approximately once every 1-2 hours). This frequent disturbance to the blast furnace operation severely impacts normal production. Furthermore, due to human error or misjudgment, delays or misoperations may cause a sudden drop in blast furnace pressure, potentially leading to accidents such as material collapse or suspension.

[0003] Traditional blast furnace blast diversion systems (also known as "stealing air" or "diverted air supply") divert a portion of the air volume from the cold blast ducts of adjacent blast furnaces during furnace replacement or sudden shutdowns. This is typically 5% to 15% of the rated air volume to maintain the blast pressure of the malfunctioning blast furnace and prevent its condition from deteriorating. However, this operation can have a certain impact on the blast furnace supplying air (the blast furnace that diverts the air). The reduced air volume may lead to the development of airflow at the furnace's edges and a weakening of the airflow in the center. If adjustments are not made in time, this could result in thickening of the furnace walls or accumulation in the center. At the moment of diversion, the cold blast pressure in the blast furnace supplying air will drop briefly. If the blower parameters are not adjusted in time, this may affect the permeability of the furnace.

[0004] Traditional hot blast stove non-disruptive furnace changeover or constant pressure / flow control technologies all increase the air supply capacity of the blower during the hot blast stove changeover process, i.e., by widening the blower's stator angle, to compensate for the air flow diverted during the hot blast stove pressurization process. The drawback of this control technology is that the sudden increase in the blower's stator angle during the changeover causes excessive fluctuations in blower operation, which can easily lead to blower operation safety accidents. Furthermore, the air flow and pressure fluctuate significantly, making it impossible to achieve stable blast furnace air flow and pressure during the hot blast stove changeover process.

[0005] Traditional blast furnace diversion systems require diverting part of the air supply to another blast furnace that is in normal operation, which affects the production of that blast furnace and can easily lead to production accidents. Summary of the Invention

[0006] The purpose of this invention is to provide a pressure-stabilizing blast furnace equipment and its control method to solve the problems caused by the reduction in blast furnace blast flow, pressure drop, and instantaneous increase in blast fan capacity during the traditional blast furnace hot blast stove replacement process, which can lead to blast fan accidents. It also addresses the problem of reduced blast furnace output and blast furnace accidents caused by a decrease in blast flow from another blast furnace during the traditional blast rotation process.

[0007] The embodiments of the present invention are implemented as follows: A pressure-stabilizing air supply device for a blast furnace includes a main blower for supplying air to the blast furnace and multiple hot blast stoves for heating the air supplied by the main blower. The hot air outlets of the multiple hot blast stoves are connected to a hot blast main pipe via hot blast branch pipes, and the hot blast main pipe is connected to the air inlet of the blast furnace. Each hot blast branch pipe is equipped with a hot blast valve. The cold air inlets of the multiple hot blast stoves are connected to a cold air main pipe via cold air branch pipes, and the cold air main pipe is connected to the main blower. Each cold air branch pipe is equipped with a cold air valve. The pressure-stabilizing air supply device also includes a pressure-stabilizing blower. The cold air inlet of each hot blast stove is connected to a make-up air main pipe via a make-up air branch pipe, and the make-up air main pipe is connected to the pressure-stabilizing blower. Each make-up air branch pipe is equipped with a pressure-stabilizing valve. The make-up air main pipe is equipped with a check valve.

[0008] Furthermore, in other preferred embodiments of the present invention, the pressure stabilizing and air supply device also includes a backup fan, which is connected to the cold air main pipe through a backup air duct.

[0009] Furthermore, in other preferred embodiments of the present invention, the main fan and the standby fan are axial flow fans, and the voltage stabilizing fan is a centrifugal fan.

[0010] Furthermore, in other preferred embodiments of the present invention, a mixing duct is connected between the cold air main duct and the hot air main duct, and the mixing duct is equipped with a mixing valve.

[0011] Furthermore, in other preferred embodiments of the present invention, each cold air branch pipe is provided with a bypass pipe that can bypass the cold air valve, and the bypass pipe is provided with a pressure equalization valve.

[0012] Furthermore, in other preferred embodiments of the present invention, the cold air main pipe is provided with a deflector pipe, which is connected to the cold air main pipe of another set of pressure stabilizing and air supply equipment, and the deflector pipe is provided with a deflector valve group.

[0013] A control method for the aforementioned pressure-stabilizing air supply equipment for a blast furnace, wherein, under normal air supply conditions, a plurality of hot blast stoves include at least one hot blast stove I in air supply condition, at least one hot blast stove II in smoldering condition, and at least one hot blast stove III in combustion condition; the cold air valve and hot air valve corresponding to hot blast stove I are both in the open state, and the pressure stabilizing valve is in the closed state; the cold air valve, hot air valve, and pressure stabilizing valve corresponding to hot blast stove II and hot blast stove III are all in the closed state; The following steps are included when performing a furnace changeover operation: S1. Open the pressure regulating valve corresponding to hot blast stove II, keep the cold air valve and hot air valve closed, and pressurize hot blast stove II through the pressure regulating fan; S2. When the pressure difference between hot blast stove II and cold air header is ≤0.05 MPa, close the pressure stabilizing valve corresponding to hot blast stove II; S3. Open the cold air valve and hot air valve corresponding to hot air furnace II, and hot air furnace II will switch from the closed state to the air supply state; S4. Close the hot air valve and cold air valve corresponding to hot air furnace I in sequence, and hot air furnace I will switch from the air supply state to the combustion state; S5. Hot blast stove III transitions from combustion to shut-down state, awaiting the next furnace replacement operation.

[0014] Furthermore, in other preferred embodiments of the present invention, each cold air branch pipe is provided with a bypass pipe that can bypass the cold air valve, and the bypass pipe is provided with a pressure equalization valve. If the pressure stabilizing blower fails to work properly during furnace replacement, the pressure stabilizing valve corresponding to hot blast stove II shall be closed and the pressure equalizing valve corresponding to hot blast stove II shall be opened. A portion of the cold air shall be diverted from the cold air main pipe to replace the pressure stabilizing blower in pressurizing hot blast stove II through the pressure equalizing valve.

[0015] Furthermore, in other preferred embodiments of the present invention, the pressure stabilizing and air supply device also includes a standby fan, which is connected to the cold air main pipe through a standby air duct; the air outlet of the main fan is provided with an air supply valve I, and the air outlet of the standby fan is provided with an air supply valve II. The following steps are included when performing wind turbine replacement work: S1. Close the air supply valve I; S2. Open the pressure stabilizing valve corresponding to hot blast stove I, and supply air to hot blast stove I through the pressure stabilizing blower to meet the minimum air demand of the blast furnace and ensure that the blast furnace does not get slag. S3. Close the cold air valve corresponding to hot blast furnace I, start the standby fan, open the air supply valve II, and supply air to the cold air main pipe through the standby fan; S4. Open the cold air valve corresponding to hot blast stove I, and supply air to hot blast stove I by the standby fan; S5. Close the pressure regulating valve corresponding to hot blast furnace I.

[0016] Furthermore, in other preferred embodiments of the present invention, the cold air main pipe is provided with a deflector pipe, which is connected to the cold air main pipe of another set of pressure stabilizing and air supply equipment, and the deflector pipe is provided with a deflector valve group. If the pressure-stabilizing blower cannot work properly during blower replacement, the pressure-stabilizing valve corresponding to hot blast stove I is closed, the air deflector group is opened, and some cold air is diverted from the cold air header of another set of pressure-stabilizing and air-making equipment to replace the pressure-stabilizing blower and meet the minimum air demand of the blast furnace.

[0017] The beneficial effects of the embodiments of the present invention are: This invention provides a pressure-stabilizing blast furnace equipment and its control method. This equipment, based on traditional blast furnace equipment, adds a pressure-stabilizing fan, a check valve, and a pressure-regulating valve. During hot blast stove switching, there is no need for main blast fan airflow diversion; the main blast fan load remains unchanged, and the pressure-stabilizing fan automatically pressurizes the hot blast stove to reach the required blast pressure. During the switching process involving opening the cold blast valve and hot blast valve, the blast pressure supplied to the blast furnace remains undisturbed. Furthermore, in the event of a main blast fan failure, the blast diversion system does not need to operate; the pressure-stabilizing fan automatically supplies air to the blast furnace corresponding to the failed main blast fan, meeting the blast volume requirements for that blast furnace without slag charging. This process does not require diverting cold blast flow from other blast furnaces and has no impact on their production, significantly outperforming traditional blast diversion systems. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a pressure-stabilizing air supply device for a blast furnace provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of a traditional air supply system.

[0020] Icons: 100-Pressure-stabilizing air supply equipment; 110-Main blower; 111-Air supply valve I; 120-Hot blast stove; 1201-Hot blast stove I; 1202-Hot blast stove II; 1203-Hot blast stove III; 121-Hot blast valve; 122-Cold blast valve; 123-Pressure equalizing valve; 130-Pressure-stabilizing blower; 131-Pressure-stabilizing valve; 132-Check valve; 140-Standby blower; 141-Air supply valve II; 150-Mixing air valve; 160-Air deflector valve assembly; 200-Blast furnace. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0022] The following is a detailed description of a pressure-stabilizing air supply device 100 for a blast furnace and its control method according to an embodiment of the present invention.

[0023] The features and performance of the present invention will be further described in detail below with reference to embodiments. Example

[0024] This embodiment provides a pressure-stabilizing air supply device 100 for a blast furnace, such as... Figure 1 As shown, it includes a main blower 110 for supplying air to the blast furnace, and a plurality of hot blast stoves 120 for heating the air supplied to the main blower 110.

[0025] Furthermore, the hot air outlets of multiple hot blast stoves 120 are all connected to the hot blast main pipe through hot blast branch pipes, and the hot blast main pipe is connected to the air inlet of the blast furnace. Each hot blast branch pipe is equipped with a hot blast valve 121. The cold air inlets of multiple hot blast stoves 120 are all connected to the cold blast main pipe through cold blast branch pipes, and the cold blast main pipe is connected to the main blower 110. Each cold blast branch pipe is equipped with a cold blast valve 122.

[0026] Under normal air supply conditions, the plurality of hot blast stoves 120 include at least one hot blast stove I 1201 in air supply condition, at least one hot blast stove II 1202 in closed condition, and at least one hot blast stove III 1203 in combustion condition. Figure 1 Taking the minimum of three hot blast stoves 120 as an example, more hot blast stoves 120 can be added as needed during actual production. Specifically, the cold air valve 122 and hot air valve 121 corresponding to hot blast stove I 1201 are both open, while the pressure regulating valve 131 is closed; the cold air valve 122, hot air valve 121, and pressure regulating valve 131 corresponding to hot blast stoves II 1202 and III 1203 are all closed. The cold air output from the main blower 110 passes through the cold air header and enters the cold air branch pipe corresponding to hot blast stove I 1201, where it is heated and then flows from the hot air branch pipe back to the hot air header, ultimately reaching the blast furnace.

[0027] Furthermore, such as Figure 1 As shown, the pressure-stabilizing air supply equipment also includes a pressure-stabilizing blower 130. The cold air inlet of each hot blast stove 120 is connected to the main air supply pipe via a branch pipe. The main air supply pipe is connected to the pressure-stabilizing blower 130. Each branch pipe is equipped with a pressure-stabilizing valve 131; the main air supply pipe is equipped with a check valve 132. When furnace replacement is required, or in the event of a failure of the main air blower 110, the pressure-stabilizing blower 130 can supply air to the hot blast stove 120 through the main air supply pipe and branch pipes, thus replacing some of the functions of the main air blower 110 for air supply. The independent air supply mechanism of the pressure-stabilizing blower 130 ensures that the load of the main air blower 110 remains unchanged and the air pressure supplied to the blast furnace remains undisturbed, thereby ensuring production stability and extending the service life of the main air blower 110.

[0028] Furthermore, the pressure stabilizing and air supply equipment also includes a standby fan 140, which is connected to the main cold air duct via a standby air pipe. When the main fan 110 malfunctions or requires maintenance, the standby fan 140 can replace the function of the main fan 110. The main fan 110 is equipped with an air supply valve I 111 at its outlet, and the standby fan 140 is equipped with an air supply valve II 141 at its outlet.

[0029] The main blower 110 and the standby blower 140 are axial flow blowers, whose large air volume can meet the operating requirements of the blast furnace. The pressure stabilizing blower 130 is a centrifugal blower, with an adjustable airflow rate via guide vanes. While the centrifugal blower's airflow is smaller and cannot independently meet the blast furnace's airflow requirements, it is more than sufficient for pressurizing the hot blast stove 120 and ensuring minimum airflow to prevent slag buildup. Furthermore, its low energy consumption and rapid start-up characteristics give it a flexibility that axial flow blowers lack, allowing for a quick response in case of a main blower 110 failure, thus buying time for the standby blower 140 to be activated.

[0030] Furthermore, such as Figure 1 As shown, a mixing duct connects the cold air main duct and the hot air main duct, and the mixing duct is equipped with a mixing valve 150. When the temperature in the hot air main duct exceeds a threshold, the mixing valve 150 is opened to introduce cold air into the hot air main duct, thereby reducing the hot air temperature. The amount of cold air introduced can be controlled by adjusting the opening degree of the mixing valve 150.

[0031] In addition, each cold air branch pipe is equipped with a bypass pipe that can bypass the cold air valve 122, and the bypass pipe is equipped with a pressure equalization valve 123. Under normal operation of the pressure stabilizing fan 130, the bypass pipe and pressure equalization valve 123 are redundant designs. However, when the pressure stabilizing fan 130 malfunctions or needs maintenance, the bypass pipe and pressure equalization valve 123 can be used to allow the pressure stabilizing air supply equipment 100 to revert to the traditional air supply mode, that is, to divert part of the air volume of the main fan 110 to pressurize the hot blast furnace 120.

[0032] Furthermore, such as Figure 1 As shown, the cold air main duct is equipped with a deflector pipe, which connects to the cold air main duct of another set of pressure-stabilizing and makeup air equipment. The deflector pipe is equipped with a deflector valve assembly 160. Similarly, when the pressure-stabilizing blower 130 is working normally, the deflector pipe and the deflector valve assembly 160 are also redundantly designed. When the pressure-stabilizing blower 130 malfunctions or needs maintenance, the deflector pipe and the deflector valve assembly 160 can be used to allow the pressure-stabilizing and makeup air equipment 100 to revert to the traditional deflector mode, that is, to divert part of the air volume of another blast furnace system to maintain the minimum air volume required by the blast furnace. Example

[0033] This embodiment provides a control method for a pressure-stabilizing blast furnace air supply device 100, which is mainly for furnace changeover operations and includes the following steps: S1. Open the pressure regulating valve 131 corresponding to the hot blast furnace II 1202, keep the corresponding cold air valve 122 and hot air valve 121 closed, and pressurize the hot blast furnace II 1202 through the pressure regulating fan 130.

[0034] S2. When the pressure difference between hot blast furnace II 1202 and the cold air header is ≤0.05 MPa, close the pressure regulating valve 131 corresponding to hot blast furnace II 1202.

[0035] S3. Open the cold air valve 122 and hot air valve 121 corresponding to the hot air furnace II 1202 in sequence, and the hot air furnace II 1202 will switch from the closed state to the air supply state.

[0036] S4. Close the hot air valve 121 and cold air valve 122 corresponding to the hot air furnace I 1201 in sequence, and the hot air furnace I 1201 will switch from the air supply state to the combustion state.

[0037] S5. Hot blast stove III 1203 changes from combustion state to shut-down state, awaiting the next furnace replacement operation.

[0038] Furthermore, during furnace replacement operations, if the pressure stabilizing blower 130 malfunctions, such as due to equipment failure or maintenance, the pressure stabilizing valve 131 corresponding to hot blast stove II 1202 is closed, and the pressure equalizing valve 123 corresponding to hot blast stove II 1202 is opened. A portion of the cold air is diverted from the cold air header to replace the pressure stabilizing blower 130 in pressurizing hot blast stove II 1202 via the pressure equalizing valve 123. This reverts to the traditional make-up air mode.

[0039] In contrast, Figure 2 Based on the pressure-stabilizing air supply equipment 100 provided in Embodiment 1 of the present invention, the pressure-stabilizing fan 130, pressure-stabilizing valve 131, check valve 132, make-up air branch pipe, and make-up air main pipe are omitted, i.e., the conventional air supply equipment. Its boiler replacement operation is carried out according to the following steps: S1. Open the equalizing valve 123 corresponding to the hot blast furnace II 1202, keep the corresponding cold air valve 122 and hot air valve 121 closed, and pressurize the hot blast furnace II 1202 by diverting part of the air volume through the cold air main pipe.

[0040] S2. When the pressure difference between the hot blast furnace II 1202 and the cold air header is ≤0.05 MPa, open the cold air valve 122 corresponding to the hot blast furnace II 1202 and close the pressure equalization valve 123 corresponding to the hot blast furnace II 1202.

[0041] S3. Open the hot air valve 121 corresponding to hot air furnace II 1202, and hot air furnace II 1202 changes from the closed state to the air supply state.

[0042] S4. Close the hot air valve 121 and cold air valve 122 corresponding to the hot air furnace I 1201 in sequence, and the hot air furnace I 1201 will switch from the air supply state to the combustion state.

[0043] S5. Hot blast stove III 1203 changes from combustion state to shut-down state, awaiting the next furnace replacement operation.

[0044] During the furnace replacement process, the air volume diverted from the cold air main pipe is pressurized, causing the air volume delivered by the main blower 110 to the hot blast stove I1201 to be constantly changing. This results in a continuous decrease in the hot air pressure delivered to the blast furnace, affecting the stability of production. Example

[0045] This embodiment provides a control method for a pressure-stabilizing air supply device 100 in a blast furnace, mainly addressing the issue of main blower 110 malfunctioning and requiring blower replacement. The method includes the following steps: The following steps are included when performing wind turbine replacement work: S1. Close the air supply valve I 111.

[0046] S2. Open the pressure regulating valve 131 corresponding to the hot blast stove I 1201, and supply air to the hot blast stove I 1201 through the pressure regulating blower 130 to meet the minimum air demand of the blast furnace and ensure that the blast furnace does not get slag.

[0047] S3. Close the cold air valve 122 corresponding to the hot air furnace I 1201, start the standby fan 140, open the air supply valve II 141, and supply air to the cold air main pipe through the standby fan 140.

[0048] S4. Open the cold air valve 122 corresponding to the hot blast furnace I 1201, and supply air to the hot blast furnace I 1201 by the standby fan 140.

[0049] S5. Close the pressure regulating valve 131 corresponding to hot air furnace I 1201.

[0050] Because the standby blower 140 takes at least 30-60 minutes from startup to air supply, a serious accident could occur if the blast furnace has no air available during this period. The method in this embodiment uses a pressure-stabilizing blower 130 to provide the minimum air demand of the blast furnace. On one hand, due to the frequent switching of the three hot blast stoves 120, the pressure-stabilizing blower 130 is mostly in a pressurized state, meaning it doesn't require preheating. When the main blower 110 stops, simply closing the pressure-stabilizing valve 131 corresponding to hot blast stove II 1202 and opening the pressure-stabilizing valve 131 corresponding to hot blast stove I 1201 quickly switches to pressure-stabilizing blower 130 supplying air to the blast furnace. On the other hand, even if the pressure-stabilizing blower 130 is not started, because it uses a more flexible centrifugal blower, it can quickly start and supply air, buying time for the standby blower 140 to start.

[0051] Furthermore, during blower replacement operations, if the pressure-stabilizing blower 130 malfunctions due to equipment failure or maintenance, the pressure-stabilizing valve 131 corresponding to the hot blast stove I 1201 is closed, and the air-diverting valve group 160 is opened. A portion of the cold air is diverted from the cold air main pipe of another set of pressure-stabilizing and makeup air equipment to replace the pressure-stabilizing blower 130 and meet the minimum air demand of the blast furnace. This essentially reverts to the traditional air-diverting mode.

[0052] In contrast, Figure 2 The replacement of fans in traditional air supply equipment is carried out according to the following steps: S1. Close the air supply valve I 111.

[0053] S2. Open the air deflector valve group 160, and divert part of the cold air through the cold air main pipe of another set of pressure stabilizing and air supply equipment to supply air to the hot blast stove I 1201 to meet the minimum air demand of the blast furnace and ensure that the blast furnace does not get slag.

[0054] S3. Activate the standby fan 140 and open the air supply valve II 141 to supply air to the cold air main pipe through the standby fan 140.

[0055] S4. After the standby fan 140 has stabilized, close the deflector valve group 160.

[0056] During the blower replacement process, the cold air from another set of pressure-stabilizing and air-making equipment was diverted, with the air volume being approximately 5% to 15% of the rated air volume. This caused the hot air pressure of another blast furnace, which was connected to the other set of pressure-stabilizing and air-making equipment, to continuously decrease, affecting the normal production of the other blast furnace.

[0057] In summary, this invention provides a pressure-stabilizing blast furnace equipment 100 and its control method. This equipment 100, based on traditional blast furnace equipment, adds a pressure-stabilizing fan 130, a check valve 132, and a pressure-stabilizing valve 131. During the hot blast stove 120 furnace changeover process, there is no need for main blast fan airflow diversion, the main blast fan load remains unchanged, and the pressure-stabilizing fan 130 automatically pressurizes the hot blast stove 120 to reach the required blast pressure. During the furnace changeover process, the blast pressure supplied to the blast furnace remains undisturbed. Furthermore, in the event of a main blast fan 110 failure, the blast diversion system does not need to operate; the pressure-stabilizing fan 130 automatically supplies air to the blast furnace corresponding to the failed main blast fan 110, meeting the blast volume requirements for that blast furnace without slag charging. This process does not require diverting cold blast flow from other blast furnaces and has no impact on the production of other blast furnaces, significantly outperforming traditional blast diversion systems.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pressure-stabilizing air supply device for a blast furnace, characterized in that, The system includes a main blower for supplying air to the blast furnace, and multiple hot blast stoves for heating the air supplied by the main blower. The hot air outlets of the multiple hot blast stoves are connected to a hot blast main pipe via hot blast branch pipes, and the hot blast main pipe is connected to the air inlet of the blast furnace. Each hot blast branch pipe is equipped with a hot blast valve. The cold air inlets of the multiple hot blast stoves are connected to a cold air main pipe via cold air branch pipes, and the cold air main pipe is connected to the main blower. Each cold air branch pipe is equipped with a cold air valve. The pressure-stabilizing and makeup air equipment also includes a pressure-stabilizing blower. The cold air inlet of each hot blast stove is connected to a makeup air main pipe via a makeup air branch pipe, and the makeup air main pipe is connected to the pressure-stabilizing blower. Each makeup air branch pipe is equipped with a pressure-stabilizing valve. The makeup air main pipe is equipped with a check valve.

2. The pressure stabilizing and blast-making equipment for a blast furnace according to claim 1, characterized in that, The pressure stabilizing and air supply equipment also includes a standby fan, which is connected to the cold air main pipe via a standby air duct.

3. The pressure stabilizing and blast-making equipment for a blast furnace according to claim 2, characterized in that, The main fan and the standby fan are axial flow fans, and the voltage stabilizing fan is a centrifugal fan.

4. The pressure stabilizing and blast-making equipment for a blast furnace according to claim 3, characterized in that, A mixing pipe is connected between the cold air main pipe and the hot air main pipe, and the mixing pipe is equipped with a mixing valve.

5. The pressure stabilizing and blast-making equipment for a blast furnace according to claim 4, characterized in that, Each of the aforementioned cold air branch pipes is provided with a bypass pipe that can bypass the cold air valve, and the bypass pipe is provided with a pressure equalization valve.

6. The pressure stabilizing and blast-making equipment for a blast furnace according to claim 5, characterized in that, The cold air main pipe is equipped with a deflector pipe, which is connected to the cold air main pipe of another set of the pressure stabilizing and air supply equipment. The deflector pipe is equipped with a deflector valve assembly.

7. A control method for a pressure-stabilizing blast furnace air supply device as described in claim 1, characterized in that, Under normal air supply conditions, the plurality of hot blast stoves include at least one hot blast stove I in air supply condition, at least one hot blast stove II in smoldering condition, and at least one hot blast stove III in combustion condition; the cold air valve and the hot air valve corresponding to hot blast stove I are both in the open state, and the pressure regulating valve is in the closed state; the cold air valve, the hot air valve, and the pressure regulating valve corresponding to hot blast stove II and hot blast stove III are all in the closed state; The following steps are included when performing a furnace changeover operation: S1. Open the pressure regulating valve corresponding to the hot blast furnace II, keep the cold air valve and the hot air valve closed, and pressurize the hot blast furnace II through the pressure regulating fan; S2. When the pressure difference between the hot air furnace II and the cold air header is ≤0.05 MPa, close the pressure stabilizing valve corresponding to the hot air furnace II; S3. Open the cold air valve and the hot air valve corresponding to the hot air furnace II, and the hot air furnace II changes from the closed state to the air supply state; S4. Sequentially close the hot air valve and the cold air valve corresponding to the hot air furnace I, and the hot air furnace I switches from the air supply state to the combustion state; S5. The hot blast stove III is switched from combustion state to shut-down state, awaiting the next furnace replacement operation.

8. The control method according to claim 7, characterized in that, Each of the aforementioned cold air branch pipes is provided with a bypass pipe that can bypass the cold air valve, and the bypass pipe is provided with a pressure equalization valve; If the pressure stabilizing blower fails to work properly during furnace replacement, the pressure stabilizing valve corresponding to the hot blast stove II is closed, and the pressure equalizing valve corresponding to the hot blast stove II is opened. A portion of the cold air is diverted from the cold air header to replace the pressure stabilizing blower in pressurizing the hot blast stove II via the pressure equalizing valve.

9. The control method according to claim 7, characterized in that, The pressure stabilizing and air supply equipment also includes a standby fan, which is connected to the cold air main pipe through a standby air duct; the air outlet of the main fan is equipped with an air supply valve I, and the air outlet of the standby fan is equipped with an air supply valve II. The following steps are included when performing wind turbine replacement work: S1. Close the air supply valve I; S2. Open the pressure stabilizing valve corresponding to the hot blast stove I, and supply air to the hot blast stove I through the pressure stabilizing blower to meet the minimum air demand of the blast furnace and ensure that the blast furnace does not get slag. S3. Close the cold air valve corresponding to the hot air furnace I, activate the standby fan, open the air supply valve II, and supply air to the cold air main pipe through the standby fan; S4. Open the cold air valve corresponding to the hot blast furnace I, and supply air to the hot blast furnace I by the standby fan; S5. Close the pressure regulating valve corresponding to the hot air furnace I.

10. The control method according to claim 9, characterized in that, The cold air main pipe is equipped with a deflector pipe, which is connected to the cold air main pipe of another set of the pressure stabilizing and air supply equipment. The deflector pipe is equipped with a deflector valve group. If the pressure-stabilizing blower fails to function properly during blower replacement, the pressure-stabilizing valve corresponding to the hot blast stove I is closed, and the air deflector group is opened. A portion of the cold air is diverted from the cold air main pipe of another set of pressure-stabilizing and air-replenishing equipment to replace the pressure-stabilizing blower and meet the minimum air demand of the blast furnace.

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