Automatic adjusting method for dust removal device of LF (Ladle Furnace)

Abstract

The invention discloses an automatic adjustment method for a dust removal device of an LF furnace, relates to the technical field of ferrous metallurgy, in particular to a rotating electrode double-station type LF furnace, and realizes accurate dust removal by controlling the rotating speed of a fan in a segmented manner and adjusting the opening degree of a valve in a differentiated manner. The method specifically comprises the steps that the rotating speed of a draught fan is adjusted in a segmented mode according to the smelting power-on state, the speed of the draught fan is increased to 830-850 r / min through a steel ladle station entering signal during first-time power-on, and the speed of the draught fan is decreased to 400 r / min after power-on is completed And the fan is triggered to operate at a medium speed through current signals in the second to fourth times of power-on. Meanwhile, interlocking adjustment is conducted on the opening degree of the double-station valve through an automatic control program, the opening degree of the top suction valve and the side suction valve of the smelting station is set to be 90%, the opening degree of the non-smelting station is set to be 45%, and it is guaranteed that the suction force of the smelting station is sufficient. According to the method, through linkage control of a steel ladle entering signal, a current signal and a station state signal, the dust removal effect is guaranteed, meanwhile, energy consumption is remarkably reduced, and the problems that a traditional dust removal device is high in energy consumption and does not reach the environmental protection standard are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of iron and steel metallurgy, and in particular to an automatic adjustment method for a LF furnace dust removal device. Background Art

[0002] In the field of iron and steel metallurgy, the LF furnace is a key equipment for molten steel refining, and the efficiency of its dust removal system directly affects the production environment and energy consumption. At present, the LF furnace for refining in the new area of ​​Beiying Steel Plant adopts a rotating electrode double-station design, and the two stations share a set of dust removal devices, including two dust removal methods: side suction and top suction. In the existing technology, in order to ensure that smoke and dust do not overflow, the dust removal fan needs to maintain high-speed operation throughout the process (for example, 850r / min), resulting in extremely high energy consumption per unit time; at the same time, the opening of the top suction and side suction valves of the two stations are fixed at 95%. Even if a certain station is not carrying out smelting, its valve remains fully open. This design has the following defects: 1. Excessive energy consumption: The continuous high-speed operation of the fan causes electricity waste, increasing daily power consumption by approximately 3,000 kWh and significantly increasing long-term operating costs; 2. Limited dust removal efficiency: When the two workstations are in alternating production, the valve opening of the non-smelting workstation is too high (95%), resulting in dispersed suction of the dust removal system and a decrease in the actual dust removal effect of the smelting workstation. In particular, the phenomenon of smoke and dust overflow is serious during the slagging stage, affecting environmental protection indicators and the working environment; 3. Rigid control logic: The existing technology lacks a dynamic adjustment mechanism and cannot adjust the fan speed and valve opening in real time according to the smelting stage and workstation status, resulting in irrational resource allocation. The root cause of the above problems is that the existing technology does not link production signals with dust removal control and does not adjust the valve opening differently according to the characteristics of the two workstations.

[0003] Therefore, there is an urgent need for a control method that can automatically optimize the fan speed and valve opening based on the smelting sequence and workstation status, so as to significantly reduce energy consumption while ensuring the dust removal effect. Summary of the Invention

[0004] In response to the above technical problems, a method for automatically adjusting a dust removal device in an LF furnace is provided. The method improves dust removal efficiency and reduces energy consumption by automatically adjusting the fan speed and valve opening at different workstations and production stages of the LF furnace.

[0005] To achieve the above object, the present invention provides an automatic adjustment method for a LF furnace dust removal device, comprising the following steps:

[0006] S1. According to the smelting power-on status of the LF furnace station, the dust removal fan speed is controlled in sections;

[0007] S2. Depending on whether the workstation is in the smelting state, the valve openings of the top suction dust removal port and the side suction dust removal port are adjusted differently.

[0008] Furthermore, in step S1, for the working condition of the first power smelting:

[0009] Use the ladle entry signal as the start signal and increase the fan speed to 830-850r / min within 3 minutes after the ladle enters the station to ensure that the fan is in high-speed operation when the power is turned on for the first time;

[0010] After the first power-on, reduce the fan speed to 400r / min and keep running at low speed.

[0011] Furthermore, in step S1, for the working conditions of the 2nd to 4th power smelting:

[0012] The current signal at power-on is used as the fan speed-up trigger signal to increase the fan speed from 400r / min to 700r / min;

[0013] After the power is turned on, reduce the fan speed to 400r / min and keep running at low speed.

[0014] Furthermore, in step S2, differential adjustment of valve opening is achieved through an automatic control program:

[0015] When a certain workstation is in the smelting workstation state, the valve opening of the top suction dust removal port of the workstation is set to 90%, and the valve opening of the side suction dust removal port is set to 90%;

[0016] When a certain workstation is in a non-smelting state, the valve opening of the top suction dust removal port of the workstation is set to 45%, and the valve opening of the side suction dust removal port is set to 45%.

[0017] Furthermore, the segmented control of the fan speed and the differentiated adjustment of the valve opening are both achieved through a preset automatic control program, which performs logical operations and command outputs based on the LF furnace's workstation status signal, ladle entry signal and power-on current signal.

[0018] Furthermore, the time interval between the ladle entry signal and the first power-on start signal is controlled to be 3 minutes to ensure that the fan speed-up process is synchronized with the power-on smelting process.

[0019] Furthermore, the valve openings of the top suction dust removal port and the side suction dust removal port are automatically adjusted by an electric actuator, and the electric actuator is communicated with the automatic control program to receive and execute opening adjustment instructions.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The present invention provides an automatic adjustment method for an LF furnace dust removal device, which dynamically adjusts the fan speed to achieve high and low speed segmented control of the fan, reduce daily power consumption, and effectively solve the high energy consumption problem of the fan running at high speed throughout the whole process in traditional technology.

[0022] 2. The present invention provides an automatic adjustment method for the LF furnace dust removal device, which adopts differential opening adjustment of double-station valves to concentrate suction resources on the smelting station, avoid suction dispersion, significantly reduce smoke and dust overflow in the slagging stage, reduce on-site dust concentration, meet environmental protection standards and improve the working environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 This is a flow chart of an automatic adjustment method for an LF furnace dust removal device according to an embodiment of the present invention;

[0025] Figure 2 This is a flow chart of an automatic adjustment method S1 of an LF furnace dust removal device in an embodiment of the present invention;

[0026] Figure 3 This is a flow chart of an automatic adjustment method S2 for an LF furnace dust removal device in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0030] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0031] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0032] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0033] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0034] Example

[0035] like Figures 1 to 3 As shown, the present invention provides an automatic adjustment method for the LF furnace dust removal device. Based on the refining LF furnace rotating electrode double-station equipment, the dust removal fan speed segmented control and the differential adjustment of the valve opening are achieved through the automatic control program. The specific steps are as follows:

[0036] S1. During the first power-on smelting, the ladle is detected by the ladle entry detection sensor, and the ladle entry signal is used as the starting signal. After the ladle enters the station, the automatic control program starts a 3-minute countdown to ensure that the time interval from the ladle entering the station to the first power-on is 3 minutes. During this period, the fan speed is gradually increased from the initial state of 400r / min to 830-850r / min, and maintained at high speed until the end of the first power-on and the power-on current signal returns to zero. After the first power-on is completed, the automatic control program detects the power-off state, and the fan speed automatically drops to 400r / min and maintains low speed operation until the next power-on trigger;

[0037] For the 2nd to 4th power-on smelting, the current signal at power-on was used as the speed-increasing trigger condition. After the current signal was triggered, the fan speed increased from 400r / min to 700r / min and maintained medium speed operation during the power-on period. After the power-on ended, the current signal returned to zero and the fan speed dropped to 400r / min again.

[0038] S2. Differentiated adjustment of valve opening. The station status sensor provides real-time feedback on the working status of the current smelting station. The automatic control program distinguishes smelting stations from non-smelting stations based on this signal. When a station is in the smelting station state, the automatic control program sets the valve opening of the top suction dust removal port and the side suction dust removal port of the station to 90%. This setting ensures that the dust removal suction force of the smelting station is maximized and effectively suppresses the overflow of smoke and dust;

[0039] When another workstation is not in the smelting workstation state, the valve opening of its top suction dust removal port and side suction dust removal port are automatically adjusted to 45%. By reducing the valve opening of the inactive workstation, the ineffective air volume loss is reduced, while ensuring that the dust removal effect of the smelting workstation is not disturbed;

[0040] If the LF furnace switches from one station to another for smelting, the automatic control program will complete the switching of the valve openings of the two stations within 5 seconds after receiving the status signal of the new station, ensuring uninterrupted connection of the dust removal suction at the smelting station.

[0041] Furthermore, when the station switching command and the power-on signal are triggered simultaneously, valve opening adjustment takes precedence over fan speed adjustment because the valve response time is shorter and the switching must be completed within 5 seconds, while the fan speed adjustment takes 15 seconds, ensuring that the suction configuration of the new smelting station is completed before power is turned on;

[0042] The valve opening at non-smelting stations is set to 45% instead of being completely closed to prevent valve deformation caused by excessive negative pressure in the pipeline. Fluid mechanics simulation shows that the pipeline resistance coefficient is 0.68 at a 45% opening, which not only reduces air volume loss but also ensures system stability.

[0043] Furthermore, the segmented control of the fan speed and the differentiated adjustment of the valve opening are both achieved through a preset automatic control program, which performs output control based on the LF furnace's workstation status signal, ladle entry signal and power-on current signal.

[0044] Specifically, the automatic control program collects the following signals in real time through the preset sensor module: ladle entry signal, power-on current signal, and workstation status signal. The automatic control program outputs control instructions based on the signal combination to form a closed-loop control.

[0045] Furthermore, if no power-on signal is detected within 3 minutes after the ladle enters the station, the program automatically reduces the fan speed to 400r / min and issues an alarm signal.

[0046] Furthermore, if the valve opening adjustment fails, the automatic control program resends the opening command to the electric actuator and retries up to 3 times. If the retry fails, the automatic control program maintains the current smelting station opening at 90% and the non-smelting station opening at 45% to prevent smoke and dust from overflowing due to a single-station valve failure and trigger the fault alarm process.

[0047] Furthermore, the electric actuator has a built-in torque sensor. When the torque is greater than the rated value, it is judged to be stuck. The rated value can be set by the user according to actual conditions. The automatic control program switches to manual mode, allowing the on-site operation box to control the valve locally; at the same time, the backup pneumatic valve is started to ensure that the system function is restored within 5 minutes.

[0048] Furthermore, when the fan stops running, all station valves are forced to close to a minimum opening of 10% to prevent backflow in the pipeline.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for automatically adjusting a LF furnace dust removal device, characterized in that: The following steps are involved: S1. According to the smelting power-on status of the LF furnace station, the dust removal fan speed is controlled in sections; S2. Depending on whether the workstation is in the smelting state, the valve openings of the top suction dust removal port and the side suction dust removal port are adjusted differently.

2. The automatic adjustment method of a LF furnace dust removal device according to claim 1, characterized in that: In step S1, for the first power-on smelting operation: Use the ladle entry signal as the start signal and increase the fan speed to 830-850r / min within 3 minutes after the ladle enters the station to ensure that the fan is in high-speed operation when the power is turned on for the first time; After the first power-on, reduce the fan speed to 400r / min and keep running at low speed.

3. The automatic adjustment method of a LF furnace dust removal device according to claim 1, characterized in that: In step S1, for the working conditions of the 2nd to 4th power-on smelting: The current signal at power-on is used as the fan speed-up trigger signal to increase the fan speed from 400r / min to 700r / min; After the power is turned on, reduce the fan speed to 400r / min and keep running at low speed.

4. The automatic adjustment method of a LF furnace dust removal device according to claim 1, characterized in that: In step S2, differential adjustment of valve opening is achieved through an automatic control program: When a certain workstation is in the smelting workstation state, the valve opening of the top suction dust removal port of the workstation is set to 90%, and the valve opening of the side suction dust removal port is set to 90%; When a certain workstation is in a non-smelting state, the valve opening of the top suction dust removal port of the workstation is set to 45%, and the valve opening of the side suction dust removal port is set to 45%.

5. The automatic adjustment method of the LF furnace dust removal device according to claims 1-4, characterized in that: The segmented control of the fan speed and the differentiated adjustment of the valve opening are both achieved through a preset automatic control program, which performs output control based on the workstation status signal, ladle entry signal and power-on current signal of the LF furnace.

6. The automatic adjustment method of a LF furnace dust removal device according to claim 2, characterized in that: The time interval between the ladle entry signal and the first power-on start signal is controlled to be 3 minutes to ensure that the fan speed-up process is synchronized with the power-on smelting process.

7. The automatic adjustment method of a LF furnace dust removal device according to claim 4, characterized in that: The valve openings of the top suction dust removal port and the side suction dust removal port are automatically adjusted by an electric actuator, and the electric actuator is communicated with the automatic control program to receive and execute an opening adjustment instruction.

Images