A blast furnace iron tapping dust removal system and speed regulation method thereof

Abstract

The present invention discloses a blast furnace iron-tapping dust removal system and a speed regulation method thereof, comprising an exhaust chimney, a first fan, a second fan, a first dust collector, a second dust collector, a first dust removal main line, a second dust removal main line, a first iron mouth dust suction branch line, a second iron mouth dust suction branch line, a third iron mouth dust suction branch line, a fourth iron mouth dust suction branch line and a furnace top dust suction branch line. The present invention adopts a multi-channel smoke source point strong suction and a parallel double dust collector negative pressure dust removal measure with switchable pipelines. When a certain point in the multiple iron mouths is about to or is generating smoke, the corresponding air outlet pipeline valve is opened; at a point where no smoke is generated, the air outlet pipeline valve is closed, and then the frequency of the double dust collector fan inverter is automatically adjusted by logical judgment of the valve state to maintain the air volume and wind speed required to open the air outlet. In this way, the dust removal effect is guaranteed and the power consumption can be kept in an optimal state.

Description

Technical Field

[0001] The present invention relates to a dust removal system and a speed regulation method thereof, in particular to a blast furnace iron tapping dust removal system and a speed regulation method thereof, belonging to the technical field of steel smelting. Background Art

[0002] Blast furnace production in the steel smelting process will produce a large amount of toxic and harmful smoke during the iron-making process, and raw material ash will also overflow when the furnace top is loaded. Therefore, the iron-making blast furnace will be equipped with a dust removal device in the iron-making yard to purify the above-mentioned environmental smoke.

[0003] Currently, large and medium-sized blast furnaces typically have three to four tapholes, each of which takes turns tapping iron. In addition to the taphole currently tapping, which requires continuous suction and dust removal, the taphole awaiting tapping or the taphole where a blocked molten iron ladle is still located also requires a certain amount of suction airflow. Therefore, the dust removal system in the tapping yard is usually designed based on the airflow required by both tapholes. To meet high environmental standards, roof-mounted suction dust removal has been largely abandoned, with localized, point-based, high-intensity suction dust removal being increasingly adopted. Therefore, during the taphole unloading process, different tuyere valves need to be opened and closed. Specifically, the number of open tuyere valves required for tapping from a single taphole and for simultaneous dust removal from two tapholes varies. Assuming the dust removal system fan operates continuously at a high speed, this clearly wastes ineffective energy expenditure during the single-taphole dust removal phase.

[0004] Typically, tuyere valve switching is performed at the blast furnace, while the dust removal system operates as a separate, independent system. To ensure effective dust removal while saving unnecessary electricity, the only way to achieve this is through an automatic control system that adjusts the operating frequency of the dust removal system's high-voltage inverter.

[0005] In order to ensure the dust removal effect, the design capacity of the dust removal device is relatively large. Usually, one blast furnace requires two dust collectors to operate in conjunction. Generally, a dust collector is designed to independently correspond to two of the four iron holes, and then a connecting pipe is set on the dust removal main pipe, and a connecting valve is installed. When there are three iron holes, one dust collector corresponds to one iron hole. In the above configuration, the connecting valve will be opened only when the two iron holes corresponding to a certain dust collector need air volume at the same time. In other states, the connecting valve is closed. This design requires the fans of the two dust collectors to be adjusted independently, which not only increases the complexity and unreliability of the adjustment, but also when a pure single iron hole requires air, the fan of the other dust collector faces a state of no wind to absorb, or keeps the air hole valve open and operates at a low frequency, which still wastes electricity expenditure. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a blast furnace iron tapping dust removal system and a speed regulation method thereof, which can ensure the dust removal effect and keep the power expenditure in an optimal state.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0008] A blast furnace iron tapping dust removal system is characterized in that it includes an exhaust chimney, a first fan, a second fan, a first dust collector, a second dust collector, a first dust collection main line, a second dust collection main line, a first iron mouth dust suction branch line, a second iron mouth dust suction branch line, a third iron mouth dust suction branch line, a fourth iron mouth dust suction branch line and a furnace top dust suction branch line, one end of the first fan and the second fan is connected to the exhaust chimney, the other end of the first fan is connected to one end of the first dust collector, the other end of the second fan is connected to one end of the second dust collector, the other end of the first dust collector is connected to the first dust collection main line, the other end of the second dust collector is connected to the second dust collection main line, the first iron mouth dust suction branch line and the second iron mouth dust suction branch line are connected to the second dust collection main line, the third iron mouth dust suction branch line and the fourth iron mouth dust suction branch line are connected to the first dust collection main line, the furnace top dust suction branch line is connected to the first dust collection main line and the second dust collection main line respectively, the first dust collection main line and the second dust collection main line are connected by a connecting pipe, and a connecting shut-off valve is provided on the connecting pipe.

[0009] Furthermore, the first iron mouth dust suction branch, the second iron mouth dust suction branch, the third iron mouth dust suction branch, and the fourth iron mouth dust suction branch respectively include an iron mouth top suction branch and an iron mouth bottom suction branch.

[0010] Furthermore, the iron mouth top suction branch includes an iron mouth top suction branch pipe, one end of the iron mouth top suction branch pipe is provided with a top suction dust collecting hood, the other end of the iron mouth top suction branch pipe is connected to the first dust removal main line or the second dust removal main line and the other end of the iron mouth top suction branch pipe is provided with an iron mouth top suction cut-off valve.

[0011] Furthermore, the taphole lower suction branch comprises a taphole lower suction branch pipe, a taphole side suction left air duct, a taphole side suction right air duct, a swing chute left air duct, a swing chute right air duct, a slag skimmer air duct, an iron ditch air duct and a slag ditch air duct, the taphole side suction left air duct, the taphole side suction right air duct, the swing chute left air duct, the swing chute right air duct, the slag skimmer air duct, the iron ditch air duct and the slag ditch air duct are arranged in sequence along one end of the taphole lower suction branch pipe to the other end, and one end of the taphole side suction left air duct, the taphole side suction right air duct, the swing chute left air duct, the swing chute right air duct, the slag skimmer air duct, the iron ditch air duct and the slag ditch air duct are connected to the iron The taphole lower suction branch pipe is connected, and the other ends of the taphole side left suction air duct, the taphole side right suction air duct, the swing chute left air duct, the swing chute right air duct, the slag skimmer air duct, the iron ditch air duct and the slag ditch air duct are provided with a lower suction dust collecting hood, the other ends of the taphole side left suction air duct, the taphole side right suction air duct, the slag skimmer air duct, the iron ditch air duct and the slag ditch air duct are provided with a manual regulating valve, the other ends of the swing chute left air duct and the swing chute right air duct are provided with an electric regulating valve, the other end of the taphole lower suction branch pipe is connected to the first dust removal main line or the second dust removal main line and the other end of the taphole lower suction branch pipe is provided with an taphole lower suction cut-off valve.

[0012] Furthermore, the other end of the swing chute left air duct is provided with a swing chute left air duct electric regulating valve, and the other end of the swing chute right air duct is provided with a swing chute right air duct electric regulating valve.

[0013] Furthermore, the furnace top dust suction branch includes a furnace top dust suction branch pipe, one end of the furnace top dust suction branch pipe is provided with two furnace top dust suction hoods, the other end of the furnace top dust suction branch pipe is connected to the second dust removal main pipe through a first furnace top dust suction shut-off valve, and the other end of the furnace top dust suction branch pipe is connected to the first dust removal main pipe through a second furnace top dust suction shut-off valve.

[0014] Furthermore, a first air mixing pipe is provided on the first dust removal main line, and a first air mixing shut-off valve is provided on the first air mixing pipe; a second air mixing pipe is provided on the second dust removal main line, and a second air mixing pipe is provided on the second air mixing shut-off valve.

[0015] Furthermore, a first inlet main pipe shut-off valve is provided at one end of the first dust removal main pipe connected to the first dust collector, and a second inlet main pipe shut-off valve is provided at one end of the second dust removal main pipe connected to the second dust collector.

[0016] A speed regulation method for a blast furnace iron tapping dust removal system comprises the following steps:

[0017] Perform logic judgment on whether the top suction cut-off valve and the bottom suction cut-off valve of the first, second, third and fourth taphole dust suction branches are fully closed;

[0018] According to the pressure value PI1 at the inlet of the first dust collector and the pressure value PI2 at the inlet of the second dust collector, the frequency value of the inverter is adjusted: when either the pressure value of PI1 or PI2 is greater than -1.9kPa, the reset block SR is set to S, and SEL is selected to output +1; when the pressure values ​​of PI1 and PI2 are both less than -2.1kPa, the output is -1, and the output number is defined as HZ UPSET1;

[0019] According to the wind temperature value TI1 at the inlet of the first dust collector and the wind temperature value TI2 at the inlet of the second dust collector, the frequency value of the inverter is adjusted upward: when either the wind temperature value TI1 or TI2 is greater than 70°C, the reset block SR is set to S, and SEL output 2 is selected; when the wind temperature values ​​TI1 and TI2 are both less than 60°C, the output is 0, and the output number is defined as HZ UP SET2;

[0020] Set the theoretical maximum frequency of the fan motor to X1, assume the commonly used maximum frequency is 45HZ, and set the initial frequency reduction number X2; perform the subtraction operation SUB on X1 and X2, subtract HZ DOWN SET from the result, add HZ UP SET1 and HZ UP SET2, and then set the limit through the limit block LIMIT to output a value between the minimum MIN and maximum MAX; this value minus the fine-tuning number X3 is defined as the inverter setting value FAN1 HZ SET for the first fan; this value minus the fine-tuning number X4 is defined as the inverter setting value FAN2 HZ SET for the second fan.

[0021] Furthermore, the process of the closed position logic judgment is: if the closed limit signal is present and the open position signal is absent, the logic is true, then a frequency reduction number is output through the selection block SEL; if the logic is false, 0 is output; then the output numbers of the iron mouth top suction cut-off valve and the iron mouth bottom suction cut-off valve status of the first iron mouth dust suction branch, the second iron mouth dust suction branch, the third iron mouth dust suction branch, and the fourth iron mouth dust suction branch are added ADD. Since at most two iron mouths require air volume at the same time, the output number of the above addition block ADD is subtracted from the minimum base number SUB, and the result is the actual frequency reduction number; then, by connecting the open position 010 OPEN permission SEL of the cut-off valve, it is proved that the two dust collectors are working in parallel, otherwise 0 is output and the frequency reduction strategy is not executed; then the frequency reduction number passes through an upper and lower limit block LIMIT to limit the output value to between 0 and 15HZ, forming the actual frequency reduction number HZ DOWN SET during automatic control.

[0022] Compared with the prior art, the present invention has the following advantages and effects:

[0023] 1. The present invention adopts a point-type enhanced suction structure design to ensure that there is no dust in the iron removal port, and the investment and power consumption are lower than the traditional roof-type suction dust removal;

[0024] 2. The air duct valve at the smoke-free point of the present invention can be closed at any time, saving diversion, ensuring the air volume of the air outlet while providing a basis for the fan to slow down;

[0025] 3. The two dust collectors operate in parallel, eliminating the problem of periodic lack of air intake or constant opening of the air inlet valve, which causes waste of electricity, when a single dust collector operates independently.

[0026] 4. The present invention automatically calculates the required speed of the fan based on the status of the air inlet valve and the wind temperature and pressure, thereby ensuring the dust removal effect while optimizing the power expenditure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the blast furnace iron-tapping dust removal system of the present invention.

[0028] Figure 2 It is a schematic diagram of the taphole down-suction branch of the present invention.

[0029] Figure 3 The invention discloses a logic diagram of valve state conversion and frequency reduction of a speed regulation method for a blast furnace iron-tapping and dust-removing system.

[0030] Figure 4 The invention discloses a frequency modulation logic diagram of wind pressure state conversion of a speed regulation method for a blast furnace iron-tapping dust removal system.

[0031] Figure 5 The present invention is a logic diagram of the frequency increase and conversion of the wind temperature state of the speed regulation method of the blast furnace iron-tapping dust removal system.

[0032] Figure 6 The present invention is a frequency instruction output logic diagram of the speed regulation method of the blast furnace iron tapping and dust removal system. DETAILED DESCRIPTION

[0033] In order to elaborate on the technical solutions adopted by the present invention to achieve the predetermined technical purpose, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments, and the technical means or technical features in the embodiments of the present invention can be replaced without creative work. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0034] like Figure 1As shown, a blast furnace iron-tapping dust removal system of the present invention comprises an exhaust stack 001, a first fan 002, a second fan 003, a first dust collector 004, a second dust collector 005, a first dust removal main line, a second dust removal main line, a first iron mouth dust suction branch line, a second iron mouth dust suction branch line, a third iron mouth dust suction branch line, a fourth iron mouth dust suction branch line and a furnace top dust suction branch line, one end of the first fan 002 and the second fan 003 is connected to the exhaust stack 001, the other end of the first fan 002 is connected to one end of the first dust collector 004, and the other end of the second fan 003 is connected to the exhaust stack 001. It is connected to one end of the second dust collector 005, the other end of the first dust collector 004 is connected to the first dust collection main line, the other end of the second dust collector 005 is connected to the second dust collection main line, the first iron mouth dust suction branch line and the second iron mouth dust suction branch line are connected to the second dust collection main line, the third iron mouth dust suction branch line and the fourth iron mouth dust suction branch line are connected to the first dust collection main line, the furnace top dust suction branch line is connected to the first dust collection main line and the second dust collection main line respectively, the first dust collection main line and the second dust collection main line are connected by a connecting pipe and the connecting pipe is provided with a connecting shut-off valve 010. The present invention includes two sets of dust removal devices and dust removal air ducts and valves and dust collection hoods at each air outlet. When the fan is running, negative pressure is generated in the dust removal air duct. Air containing smoke and dust will be sucked into the dust collection hood, filtered by the bag dust collector, and the smoke and dust are collected. The filtered air is discharged to the atmosphere through the exhaust pipe, thereby forming a dust removal cycle. When the present invention is working, when the communication cut-off valve 010 is in a closed state, the two dust collectors only correspond to their respective dust removal points; when the communication cut-off valve 010 is in a normally open state, the two dust collectors operate in parallel.

[0035] It should be noted that, since some blast furnaces have only three tapholes, the present invention Figure 1 The structural diagram of the fourth iron mouth dust suction branch is omitted.

[0036] The first iron mouth dust suction branch, the second iron mouth dust suction branch, the third iron mouth dust suction branch, and the fourth iron mouth dust suction branch respectively include an iron mouth top suction branch and an iron mouth bottom suction branch.

[0037] The iron mouth top suction branch includes an iron mouth top suction branch pipe, one end of which is provided with a top suction dust collecting hood 012. The structural design of the dust collecting hood can facilitate the collection of smoke from the smoke source. The other end of the iron mouth top suction branch pipe is connected to the first dust removal main line or the second dust removal main line and the other end of the iron mouth top suction branch pipe is provided with an iron mouth top suction cut-off valve. Among them, the other end of the iron mouth top suction branch pipe of the first iron mouth dust suction branch is provided with a first iron mouth top suction cut-off valve 101, the other end of the iron mouth top suction branch pipe of the second iron mouth dust suction branch is provided with a second iron mouth top suction cut-off valve 201, the other end of the iron mouth top suction branch pipe of the third iron mouth dust suction branch is provided with a third iron mouth top suction cut-off valve 301, and the other end of the iron mouth top suction branch pipe of the fourth iron mouth dust suction branch is provided with a fourth iron mouth top suction cut-off valve 401.

[0038] like Figure 2 As shown, the taphole lower suction branch includes the taphole lower suction branch pipe, the taphole side suction left air duct 601, the taphole side suction right air duct 602, the swing chute left air duct 603, the swing chute right air duct 604, the skimmer air duct 605, the iron ditch air duct 606 and the slag ditch air duct 607. The taphole side suction left air duct 601, the taphole side suction right air duct 602, the swing chute left air duct 603, the swing chute right air duct 604, the skimmer air duct 605, the iron ditch air duct 606 and the slag ditch air duct 607 are arranged in sequence from one end to the other end of the taphole lower suction branch pipe, wherein the taphole side suction left air duct 601 is arranged at one end of the taphole lower suction branch pipe. One end of the taphole side suction left air duct 601, the taphole side suction right air duct 602, the swing chute left air duct 603, the swing chute right air duct 604, the slag skimmer air duct 605, the iron ditch air duct 606 and the slag ditch air duct 607 is connected to the taphole lower suction branch pipe, and the other end of the taphole side suction left air duct 601, the taphole side suction right air duct 602, the swing chute left air duct 603, the swing chute right air duct 604, the slag skimmer air duct 605, the iron ditch air duct 606 and the slag ditch air duct 607 is set There is a downward suction dust collecting hood, and the other ends of the left air duct 601 on the iron outlet side, the right air duct 602 on the iron outlet side, the slag skimmer air duct 605, the iron ditch air duct 606 and the slag ditch air duct 607 are provided with a manual regulating valve 013, and the other ends of the swing chute left air duct 603 and the swing chute right air duct 604 are provided with an electric regulating valve 014, and the other end of the iron outlet downward suction branch pipe is connected to the first dust removal main line or the second dust removal main line and the other end of the iron outlet downward suction branch pipe is provided with an iron outlet downward suction cut-off valve. Among them, the other end of the iron mouth lower suction branch pipe of the first iron mouth dust suction branch is provided with a first iron mouth lower suction shut-off valve 102, the other end of the iron mouth lower suction branch pipe of the second iron mouth dust suction branch is provided with a second iron mouth lower suction shut-off valve 202, the other end of the iron mouth lower suction branch pipe of the third iron mouth dust suction branch is provided with a third iron mouth lower suction shut-off valve 302, and the other end of the iron mouth lower suction branch pipe of the fourth iron mouth dust suction branch is provided with a fourth iron mouth lower suction shut-off valve 402. In the present invention, the manual regulating valve 013 is used for the required air volume change of the iron mouth side suction left air duct 601, the iron mouth side suction right air duct 602, the swing chute left air duct 603, the swing chute right air duct 604, the slag skimmer air duct 605, the iron ditch air duct 606 and the slag ditch air duct 607 when the required air volume change is small, and the electric regulating valve 014 is used when the required air volume change is large. The stroke of the electric control valve is from half open to fully open. When in automatic control, it is interlocked with the swing chute stroke limit. When the left limit of the swing chute is connected, the left branch electric control valve opens and the right branch electric control valve closes. The same action occurs when the right limit of the swing chute is connected.

[0039] Given that the swing chute is the main source of smoke and dust during iron tapping, the air volume required by its two tank positions accounts for more than 40% of the total air volume of a taphole. There is a process conversion process where the left tank is connected to iron or the right tank is connected to iron, and the amount of smoke and dust generated by the two tank positions in the two states is different. In addition, because the air volume required there is large, the diameters of the two air outlet branches are relatively thick, and the main pipes are relatively small. Therefore, when the two air outlets are fully open, the negative pressure of the air outlets is relatively small, which makes it easy for dust to overflow. For the tank positions that do not receive iron, the amount of smoke and dust is very small, and fully opening the air outlets is not very meaningful. Therefore, it is necessary to close the valves corresponding to the air outlets of the tank positions that do not receive iron to increase the air volume and wind speed of the iron-connected air outlets to ensure that dust does not overflow to the outside. Therefore, the two air outlets are set as remotely operated electric regulating valves, with the lower limit of the valve set to half open and the upper limit set to fully open. When the swing chute switches the tank position, the two air inlet valves are opened and closed synchronously. When manual, they can be opened first on the valve operation box matched with the swing chute operation box, and then closed after switching. Automatically, it can be interlocked with the swing chute's in-place limit to automatically execute the opening and closing actions.

[0040] The other end of the swing chute left air duct 603 is provided with a swing chute left air duct electric regulating valve 608, and the other end of the swing chute right air duct 604 is provided with a swing chute right air duct electric regulating valve 609.

[0041] The furnace top dust suction branch includes a furnace top dust suction branch pipe 011, one end of which is provided with two furnace top dust suction hoods, and the other end of the furnace top dust suction branch pipe 011 is connected to the second dust removal main line through the first furnace top dust suction shut-off valve 501, and the other end of the furnace top dust suction branch pipe 011 is connected to the first dust removal main line through the second furnace top dust suction shut-off valve 502.

[0042] The first dust collection main line is equipped with a first air mixing duct, which is connected to the first dust collection main line via a tee. A first air mixing shut-off valve 008 is installed on the first air mixing duct. The second dust collection main line is equipped with a second air mixing duct, which is connected to the second dust collection main line via a tee. A second air mixing shut-off valve 009 is installed on the second air mixing duct. During normal operation, if the intake air temperature is too high, the air mixing shut-off valve automatically opens to draw in cooler air for cooling. The air mixing shut-off valve automatically opens when the dust collector inlet temperature exceeds 110°C and automatically closes when it is below 100°C.

[0043] The first inlet main pipe shut-off valve 006 is provided at one end of the first dust removal main line connected to the first dust collector 004, and the second inlet main pipe shut-off valve 007 is provided at one end of the second dust removal main line connected to the second dust collector 005. In normal operation, both shut-off valves remain normally open.

[0044] When the two dust removal fans are working normally, the two dust collector inlet shut-off valves, the connecting shut-off valve, and the two shut-off valves for the furnace top dust removal are all placed in the normally open position and are prohibited from being closed.

[0045] To remove dust generated during top charging and tapping at the tapholes of large and medium-sized ironmaking blast furnaces, a dual-dust collector negative pressure dust removal system with multiple, high-pressure suction points and switchable piping is employed. When dust is about to or actually being generated at a particular taphole, the corresponding tuyere pipe valve opens. At points where dust is not being generated, the tuyere pipe valve closes. Based on logical analysis of the valve status, the frequency converters for the dual-dust collector fans are automatically adjusted to maintain the required air volume and speed for the tuyere opening. This ensures effective dust removal while optimizing energy consumption.

[0046] like Figure 3 、 Figure 4 、 Figure 5 and Figure 6 As shown, the operating logic of the control frequency required by the high-voltage inverter for two dust removal fans running in parallel is automatically calculated. When the fan adjustment is manual, the set frequency value is manually input to adjust the fan to the required speed. When it is automatic, the above calculated data is transmitted to the inverter, and the fan speed is automatically adjusted to match the appropriate air volume required on site.

[0047] Following the design principle of prioritizing environmental protection and energy conservation, the first step is to ensure that dust collection points are free of overflow. However, if the shutoff valve signal at the air inlet fails, the fan will be operated at a higher speed if the signal is fully opened. This will cause the fan to operate at its lowest speed, creating a risk of dust overflow. Therefore, the actual design strategy must be to increase the speed in the event of a fault and decrease the speed when the valve signal is normal.

[0048] A speed regulation method for a blast furnace iron tapping dust removal system comprises the following steps:

[0049] like Figure 3 As shown, the iron mouth top suction cut-off valve and the iron mouth bottom suction cut-off valve of the first iron mouth dust suction branch, the second iron mouth dust suction branch, the third iron mouth dust suction branch, and the fourth iron mouth dust suction branch are subjected to a logic judgment of whether they are in the closed position. The process of the logic judgment of the closed position is: if the close limit signal is present and the open position signal is absent, the logic is true, then a frequency-reducible number, such as 4HZ or 7HZ, is output through the selection block SEL; if the logic is false, 0 is output. Then the output numbers of the iron mouth top suction cut-off valve and the iron mouth bottom suction cut-off valve states of the first iron mouth dust suction branch, the second iron mouth dust suction branch, the third iron mouth dust suction branch, and the fourth iron mouth dust suction branch are added ADD, as shown Figure 3The minimum added value of the data of the 8 valves is 0, and the maximum added value is 44. Since in actual operation, at most two iron ports require air volume at the same time, that is, at least two air port valves are fully closed, the output number of the above addition block ADD is subtracted from the minimum base number 22 of SUB, and the result is the actual frequency reduction number; then, by connecting the cut-off valve to the open position 010 OPEN permission SEL, it is proved that the two dust collectors are working in parallel, otherwise the output is 0 and the frequency reduction strategy is not executed; then the frequency reduction number passes through an upper and lower limit block LIMIT, and the output value is limited to between 0 and 15HZ, forming the actual frequency reduction number HZ DOWN SET during automatic control.

[0050] like Figure 4 As shown, the frequency of the inverter is slightly adjusted based on the pressure values ​​PI1 and PI2 at the inlet of the first and second dust collectors, respectively. Assuming that a negative pressure of 2 kPa at the dust collector inlet ensures sufficient airflow at all air outlets, the inverter frequency is increased by 1 Hz when the actual negative pressure is insufficient, and reduced by 1 Hz when the actual negative pressure is too high. The specific logic is as follows: When either the pressure value PI1 or PI2 is greater than -1.9 kPa, the reset block SR is set to S, selecting SEL to output +1. When both the pressure values ​​PI1 and PI2 are less than -2.1 kPa, the output is -1. The output number is defined as HZ UP SET1.

[0051] like Figure 5 As shown, the frequency of the inverter is adjusted upward based on the air temperature values ​​TI1 at the inlet of the first dust collector and TI2 at the inlet of the second dust collector. Assuming that the air temperature at the dust collector inlet is high, it indicates that certain dust collection points are receiving high-temperature smoke and dust, which reduces the air density and theoretical air volume. There is a risk of dust overflow, and it is necessary to increase the air flow to absorb the dust. Only when the air temperature of the dust collection duct is lower than a certain value, indicating that the air outlet can absorb a certain amount of cold air, can the hot air and smoke be completely sucked away, eliminating the risk of dust overflow. When the air temperature is high, the inverter speed is increased by 2HZ; otherwise, the speed will not be increased. The specific logic is as follows: When either the air temperature value TI1 or TI2 is greater than 70°C, the reset block SR is set to S, and SEL output 2 is selected. When the air temperature values ​​of TI1 and TI2 are both less than 60°C, the output is 0. The output number is defined as HZ UP SET2.

[0052] like Figure 6As shown in the example, the theoretical maximum frequency of the fan motor is set to X1, assigned a value of 50. The commonly used maximum frequency is assumed to be 45 Hz, and the initial frequency reduction factor X2 is assigned a value of 5. A subtraction operation (SUB) is performed on X1 and X2, and the result is subtracted from the HZ DOWN SET value, then added to the HZ UPSET1 and HZ UP SET2 values. This value is then limited by the LIMIT block to output a value between MIN = 30 and MAX = 45. This value, minus the fine-tuning factor X3 (assigned a value of 0), is defined as the inverter setpoint FAN1 HZ SET for the first fan. This value, minus the fine-tuning factor X4 (assigned a value of 0.5), is defined as the inverter setpoint FAN2 HZ SET for the second fan. Fine-tuning factors X3 and X4 are used to balance the operating conditions of two fans operating in parallel. The actual values ​​assigned are optimized based on the operating parameters of the two fans on site.

[0053] The present invention adopts a point-type enhanced suction structure design to ensure that there is no environmental dust at the iron removal port, and has lower investment and power consumption than traditional roof-type suction dust removal; the air duct valve at the smoke-free point of the present invention can be closed at any time, saving diversion, and providing a basis for fan deceleration while ensuring the air volume of the air outlet; the two dust collectors run in parallel, eliminating the phenomenon of no wind to be sucked in stage by stage or the waste of electricity caused by the often-open air outlet valve when a single dust collector operates independently; the present invention automatically calculates the required rotation speed of the fan based on the air outlet valve status and wind temperature and pressure, ensuring the dust removal effect while optimizing the power expenditure.

[0054] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A blast furnace iron tapping dust removal system, characterized by: It comprises an exhaust chimney, a first fan, a second fan, a first dust collector, a second dust collector, a first dust collection main line, a second dust collection main line, a first iron mouth dust suction branch line, a second iron mouth dust suction branch line, a third iron mouth dust suction branch line, a fourth iron mouth dust suction branch line and a furnace top dust suction branch line, one end of the first fan and the second fan are connected to the exhaust chimney, the other end of the first fan is connected to one end of the first dust collector, the other end of the second fan is connected to one end of the second dust collector, the other end of the first dust collector is connected to the first dust collection main line, the other end of the second dust collector is connected to the second dust collection main line, the first iron mouth dust suction branch line and the second iron mouth dust suction branch line are connected to the second dust collection main line, the third iron mouth dust suction branch line and the fourth iron mouth dust suction branch line are connected to the first dust collection main line, the furnace top dust suction branch line is connected to the first dust collection main line and the second dust collection main line respectively, the first dust collection main line and the second dust collection main line are connected by a connecting pipe and a connecting shut-off valve is provided on the connecting pipe; Perform logic judgment on whether the top suction cut-off valve and the bottom suction cut-off valve of the first, second, third and fourth taphole dust suction branches are fully closed; Adjust the frequency value of the inverter according to the pressure value PI1 at the inlet of the first dust collector and the pressure value PI2 at the inlet of the second dust collector: when either the pressure value of PI1 or PI2 is greater than -1.9kPa, set the reset block SR to S and select SEL to output +1; when the pressure values ​​of PI1 and PI2 are both less than -2.1kPa, output -1, and the output number is defined as HZ UPSET1; According to the wind temperature value TI1 at the inlet of the first dust collector and the wind temperature value TI2 at the inlet of the second dust collector, the frequency value of the inverter is adjusted upward: when either the wind temperature value TI1 or TI2 is greater than 70°C, the reset block SR is set to S, and SEL output 2 is selected; when the wind temperature values ​​TI1 and TI2 are both less than 60°C, the output is 0, and the output number is defined as HZ UP SET2; Set the theoretical maximum frequency of the fan motor to X1, assume the commonly used maximum frequency to be 45HZ, and set the initial frequency reduction number X2; perform the subtraction operation SUB on X1 and X2, subtract the actual frequency reduction number HZ DOWN SET from the result, add HZ UP SET1 and HZUP SET2, and then set the limit through the limit block LIMIT to output a value between the minimum MIN and maximum MAX; this value minus the fine-tuning number X3 is defined as the inverter setting value FAN1 HZ SET for the first fan; this value minus the fine-tuning number X4 is defined as the inverter setting value FAN2 HZ SET for the second fan.

2. A blast furnace iron tapping dust removal system according to claim 1, characterized in that: The first iron mouth dust suction branch, the second iron mouth dust suction branch, the third iron mouth dust suction branch, and the fourth iron mouth dust suction branch respectively include an iron mouth top suction branch and an iron mouth bottom suction branch.

3. A blast furnace iron tapping dust removal system according to claim 2, characterized in that: The iron mouth top suction branch includes an iron mouth top suction branch pipe, one end of which is provided with a top suction dust collecting hood, the other end of which is connected to the first dust removal main pipe or the second dust removal main pipe, and the other end of which is provided with an iron mouth top suction cut-off valve.

4. A blast furnace iron tapping dust removal system according to claim 2, characterized in that: The taphole lower suction branch comprises a taphole lower suction branch pipe, a taphole side suction left air duct, a taphole side suction right air duct, a swing chute left air duct, a swing chute right air duct, a slag skimmer air duct, an iron ditch air duct and a slag ditch air duct, and the taphole side suction left air duct, the taphole side suction right air duct, the swing chute left air duct, the swing chute right air duct, the slag skimmer air duct, the iron ditch air duct and the slag ditch air duct are arranged in sequence along one end of the taphole lower suction branch pipe to the other end, and one end of the taphole side suction left air duct, the taphole side suction right air duct, the swing chute left air duct, the swing chute right air duct, the slag skimmer air duct, the iron ditch air duct and the slag ditch air duct is connected to the taphole lower suction branch pipe. The suction branch pipe is connected, and a down-suction dust collecting hood is provided at the other end of the left suction air duct on the iron outlet side, the right suction air duct on the iron outlet side, the left air duct of the swing chute, the right air duct of the swing chute, the air duct of the slag skimmer, the iron ditch air duct and the slag ditch air duct; a manual regulating valve is provided at the other end of the left suction air duct on the iron outlet side, the right suction air duct on the iron outlet side, the air duct of the slag skimmer, the iron ditch air duct and the slag ditch air duct; an electric regulating valve is provided at the other end of the left air duct of the swing chute and the right air duct of the swing chute; the other end of the iron outlet down-suction branch pipe is connected to the first dust removal main line or the second dust removal main line and an iron outlet down-suction cut-off valve is provided at the other end of the iron outlet down-suction branch pipe.

5. A blast furnace iron tapping dust removal system according to claim 4, characterized in that: The other end of the swing chute left air duct is provided with a swing chute left air duct electric regulating valve, and the other end of the swing chute right air duct is provided with a swing chute right air duct electric regulating valve.

6. A blast furnace iron tapping dust removal system according to claim 1, characterized in that: The furnace top dust suction branch includes a furnace top dust suction branch pipe, one end of the furnace top dust suction branch pipe is provided with two furnace top dust suction dust collecting hoods, the other end of the furnace top dust suction branch pipe is connected to the second dust removal main pipe through a first furnace top dust suction cut-off valve, and the other end of the furnace top dust suction branch pipe is connected to the first dust removal main pipe through the second furnace top dust suction cut-off valve.

7. The blast furnace iron tapping dust removal system according to claim 1, characterized in that: The first dust removal main line is provided with a first air mixing pipe, the first air mixing pipe is provided with a first air mixing shut-off valve, the second dust removal main line is provided with a second air mixing pipe, the second air mixing pipe is provided with a second air mixing shut-off valve.

8. A blast furnace iron tapping dust removal system according to claim 7, characterized in that: The end of the first dust removal main line connected to the first dust collector is provided with a first inlet main line cut-off valve, and the end of the second dust removal main line connected to the second dust collector is provided with a second inlet main line cut-off valve.

9. The blast furnace iron tapping dust removal system according to claim 1, characterized in that: The process of the described closing position logic judgment is: if the closing limit signal is present and the opening position signal is absent, the logic is true, then a frequency reduction number is output through the selection block SEL; if the logic is false, 0 is output; then the output numbers of the iron mouth top suction cut-off valve and the iron mouth bottom suction cut-off valve status of the first iron mouth dust suction branch, the second iron mouth dust suction branch, the third iron mouth dust suction branch, and the fourth iron mouth dust suction branch are added ADD. Since at most two iron mouths require air volume at the same time, the output number of the above-mentioned addition ADD is subtracted from the minimum base number SUB, and the result is the actual frequency reduction number; then, by connecting the open position 010 OPEN permission SEL of the cut-off valve, it is proved that the two dust collectors are working in parallel, otherwise 0 is output and the frequency reduction strategy is not executed; then the frequency reduction number passes through an upper and lower limit block LIMIT, and the output value is limited to between 0 and 15Hz, forming the actual frequency reduction number HZ DOWN SET during automatic control.

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