A converter oxygen lance lower limit device resistant to high temperature impact

Abstract

This utility model discloses a high-temperature impact-resistant lower limit device for a converter oxygen lance, belonging to the field of converter steelmaking technology. It includes a protective plate, a spring cylinder, a ejector pin, and a micro switch arranged coaxially along the movement direction of the ejector pin. The protective plate is positioned on the side facing flame radiation, and the spring cylinder is fixed to the un-flame side of the protective plate and fixedly connected to it. The micro switch is positioned on the side away from flame radiation, and its switching lever is located on the axial movement path of the ejector pin. The ejector pin passes through the protective plate and the spring cylinder along the device axis and extends outward from the protective plate. The middle section of the ejector pin is fixedly connected to a compression spring plate inside the spring cylinder. The spring is fitted around the outer circumference of the ejector pin and between the compression spring plate and the spring cylinder. The circumferential and non-moving cavity areas inside the spring cylinder, except for the necessary movement gap between the ejector pin and the spring, are filled with heat-insulating cotton. This utility model can maintain the integrity of the mechanism's shape and reliable operation under high-temperature impact, thereby significantly improving the inherent safety and engineering applicability of the lower limit control.

Description

Technical Field

[0001] This utility model belongs to the field of converter steelmaking technology, and in particular relates to a converter oxygen lance lower limit device that is resistant to high temperature impact. Background Technology

[0002] In the converter steelmaking process of steelmaking plants, the control of the oxygen lance's lifting and lowering movement is crucial, with the lower limit control being particularly critical. The oxygen lance must stop immediately when it descends to the preset lower limit; exceeding this limit could damage the oxygen lance or related equipment, or even cause a safety accident. Furthermore, the area where the oxygen lance's lower limit is installed is in the short-term direct radiation zone of the flame during blowing, experiencing a special condition of instantaneous high-temperature impact, which places even stricter requirements on the reliability of the limit device.

[0003] The common practice in existing technologies is to set a lower limit point at the end of the oxygen lance's stroke. A limiting device immediately outputs a stop or interlock signal when this position is reached, thus achieving the basic safety functions of "stopping upon reaching the limit" and "stopping upon exceeding the limit." In other words, the limiting mechanism serves as the final means of constraining the stroke boundary, meeting the safety control requirements under normal operating conditions. In actual operation, the core of the operation and control strategy revolves around the reliable detection and rapid shutdown of the aforementioned lower limit point to prevent the oxygen lance from continuing to descend and causing risks.

[0004] However, in the special environment of converter blowing, which has instantaneous high temperature impact, the existing commonly used limit mechanism has insufficient heat resistance and is prone to deformation and component damage under short-term flame radiation impact, resulting in the failure of the limit function and making it difficult to meet the high reliability requirements of lower limit control.

[0005] Based on this, the main technical problems currently facing the technology can be summarized (in descending order of importance): 1. Under instantaneous high temperature impact conditions, it is difficult to maintain the reliability of the structure and operation, which can easily lead to the failure or delay of the limit action, and cannot guarantee "stopping immediately when the limit is exceeded"; Second, insufficient heat insulation and thermal shock resistance cause heat to be transferred into the device, leading to performance degradation and drift of key components, and reducing the stability and repeatability of limit actions. Third, under the repeated action of short-term high-temperature radiation for a long period of time, the durability and positional stability of the device are difficult to maintain, which in turn affects the accurate identification of the limit point position and the effectiveness of interlocking. Utility Model Content

[0006] The purpose of this invention is to provide a converter oxygen lance lower limit device that is resistant to high temperature impact, ensuring that the limit device can still maintain its shape and operate stably and reliably under high temperature impact.

[0007] To achieve the above objectives, this utility model provides the following technical solution: A high-temperature impact-resistant converter oxygen lance lower limit device includes a protective plate, a spring cylinder, an ejector pin, and a micro switch arranged coaxially along the movement direction of the ejector pin; wherein... The protective plate is set on the side facing the flame radiation, and the spring sleeve is fixed to the unexposed side of the protective plate and fixedly connected to the protective plate. The micro switch is positioned on the side away from flame radiation, and the switching lever of the micro switch is located on the axial movement path of the ejector pin. The ejector pin passes through the protective plate and the spring cylinder in sequence along the axis of the device and extends outward from the protective plate. The middle section of the ejector pin is fixedly connected to the compression spring plate set inside the spring cylinder. The spring is fitted around the outer periphery of the ejector pin and is located between the compression spring plate and the spring cylinder. The circumferential and non-moving cavity areas inside the spring cylinder, except for the necessary movement gap between the ejector pin and the spring, are filled with heat insulation cotton.

[0008] Preferably, it also includes a fixing hole on the back plate of the device, the fixing hole being an elongated hole parallel to the axis of the device in the length direction; the lower limit device is connected to the mounting bracket through the fixing hole.

[0009] Preferably, the filling of the circumferential and non-moving cavity areas inside the spring cylinder, excluding the necessary movement gap between the ejector pin and the spring, with heat insulation cotton includes filling heat insulation cotton between the compression spring plate and the protective plate.

[0010] Preferably, a roller is mounted on the top of the ejector pin, the rolling direction of the roller is consistent with the movement direction of the limited component, and the roller shaft is perpendicular to the movement direction.

[0011] Preferably, the tail of the ejector pin is provided with a trigger plate, which forms a line contact / surface contact with the switch lever of the micro switch.

[0012] Preferably, the trigger stroke of the pin is within the rated stroke range of the micro switch.

[0013] Preferably, the micro switch uses normally closed contacts, which are connected to the PLC and the emergency stop hard circuit respectively; Preferably, the device is installed on a fixed base or limiting bracket in the lower limit area of ​​the oxygen lance lifting mechanism.

[0014] Preferably, the surface of the protective plate is coated with a high-temperature resistant coating.

[0015] Preferably, the ejector pin is made of 42CrMo steel.

[0016] Compared with the prior art, the beneficial effects of this utility model are: This invention addresses the instantaneous high-temperature radiation impact condition at the lower limit of the oxygen lance in a converter. It proposes a high-temperature alloy limiting device for use in high-temperature environments. This device can stably and reliably output a stop or interlock signal when the oxygen lance descends to the preset lower limit, achieving "stop upon reaching the limit / stop upon exceeding the limit." It also maintains the integrity of the mechanism's shape and the reliability of its operation under high-temperature impact, thereby significantly improving the inherent safety and engineering applicability of the lower limit control.

[0017] This invention creates a dual heat insulation path of "external heat insulation barrier + internal heat insulation filling" by setting a protective plate made of high temperature and high strength alloy at the front end of the limiting device to block heat radiation and filling the spring cylinder with heat insulation cotton. This significantly reduces the conduction of heat to the core electromechanical components and ensures that the limiting device can maintain structural integrity and stable operation under short-term flame radiation.

[0018] This invention uses a high-temperature alloy spring that can maintain good elasticity and mechanical properties even under high temperature conditions. The material can withstand temperatures up to 700–800℃ and can maintain the mechanical consistency and repeatability of limit triggering and resetting even under repeated thermal shocks, avoiding lag or non-action caused by elastic decay, thereby ensuring the timeliness and reliability of the lower limit interlock.

[0019] This invention installs a roller on the top of the ejector pin to reduce friction and impact when in contact with the limited component, making the triggering process smoother and more stable, reducing mechanical wear and improving the repeatability and consistency of the limit signal, which helps to extend the service life of the mechanism and stabilize the lower limit judgment.

[0020] This invention uses chromium-molybdenum steel (42CrMo) with a temperature resistance of 500–600℃ as the ejector pin material. Under the coupled conditions of high temperature and mechanical load, it can still maintain strength and positional stability, ensuring the long-term stability of the limit trigger position and the reliability of force transmission, thereby improving the "hardware backup" capability in case of abnormal overtravel. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the device according to a preferred embodiment of the present invention.

[0022] In the diagram: 1. Protective plate; 2. Spring cylinder; 3. Compression spring plate; 4. Spring; 5. Ejector pin; 6. Roller; 7. Micro switch; 8. Insulation cotton; 9. Fixing hole. Detailed Implementation

[0023] In the converter steelmaking process, the lifting and lowering movement of the oxygen lance system requires precise control, especially the lower limit control. When the oxygen lance descends to the preset lower limit, it must stop immediately; otherwise, it may cause damage to the oxygen lance or equipment, or even lead to a safety accident. However, the area where the oxygen lance lower limit is installed is subjected to short-term direct radiation from the flame during the blowing process, resulting in an instantaneous high-temperature impact. Traditional limit mechanisms are prone to deformation or component damage due to insufficient heat resistance, leading to the failure of the limit function and making it difficult to meet the lower limit control requirements.

[0024] This invention provides a mechanical lower limit device that can maintain its shape and operate stably and reliably in this environment, so as to prevent the oxygen lance from going out of bounds, which could lead to equipment damage and safety accidents.

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0026] like Figure 1 As shown: This embodiment provides a high-temperature impact resistant converter oxygen lance lower limit device, including a protective plate 1, a spring cylinder 2, an ejector pin 5, and a micro switch 7 arranged coaxially along the movement direction of the ejector pin 5; wherein The protective plate 1 is located on the side facing the flame radiation, and the spring cylinder 2 is fixed on the unexposed side of the protective plate 1 and fixedly connected to the protective plate 1. The micro switch 7 is located on the side away from flame radiation, and the switching lever of the micro switch 7 is located on the axial movement path of the ejector pin 5. The ejector pin 5 passes through the protective plate 1 and the spring cylinder 2 in sequence along the axis of the device and extends outward from the protective plate 1. The middle section of the ejector pin 5 is fixedly connected to the compression spring plate 3 set in the spring cylinder 2. The spring 4 is fitted around the outer periphery of the ejector pin 5 and is between the compression spring plate 3 and the spring cylinder 2. The circumferential and non-moving cavity areas inside the spring cylinder 2, excluding the necessary movement gap between the ejector pin 5 and the spring 4, are filled with heat insulation cotton 8.

[0027] The protective plate 1 is located on the outermost side of the device and is fixedly connected to the back plate of the device. Several fixing holes 9 are provided on the back plate of the device. The fixing holes 9 are elongated holes parallel to the axis of the device in the length direction. The lower limit device is connected to the mounting bracket through the fixing holes 9. Radial fine adjustment is achieved by means of the fixing holes 9, so as to realize the relative position correction of key components such as the limit disc, upper / lower limit and roller 6 without disassembling the core mechanism.

[0028] Protective plate 1 is made of high-temperature resistant, high-strength alloy material, possessing excellent heat insulation and protection properties. It is used to block the thermal shock of instantaneous high-temperature radiation to the internal mechanisms, serving as the first line of defense between the device and the furnace side. A high-temperature resistant coating (such as alumina, chromium oxide film, ceramic coating, etc.) is applied to the surface of protective plate 1 to improve its temperature resistance, oxidation resistance, and wear resistance. Supplemented with necessary primer and bonding layers, it ensures the bonding strength between the coating and the substrate, thereby improving the long-term reliability of the limiting device under instantaneous high-temperature impact.

[0029] A circular spring cylinder 2 is located on the unexposed side of the protective plate 1 and is fixedly connected to the protective plate 1. The inside accommodates the high-temperature alloy spring 4 and the travel channel of the ejector pin 5, and is filled with heat insulation cotton 8 to reduce the temperature rise inside the cylinder and ensure that components such as the spring 4 and the micro switch 7 work in an acceptable thermal environment.

[0030] Thermal insulation cotton 8 is filled in the circumferential and non-moving cavity areas of the spring cylinder 2, preferably between the compression spring plate 3 and the protective plate 1; this can improve the thermal insulation of the system, reduce the temperature gradient, and protect the internal elastic and electrical components; thermal insulation cotton 8 is preferably high-temperature resistant fiber cotton, and the filling density is to balance thermal insulation and assembly maintainability, and control the impact of pulverization and drift on the switch.

[0031] The spring 4 is preferably made of a high-temperature alloy, which can maintain good elasticity and mechanical properties in high-temperature environments and can withstand temperatures of up to 700℃~800℃. It provides the mechanical basis for the reset force and stroke feedback of the ejector pin 5, ensuring the reliability of the action after high-temperature impact.

[0032] The trigger stroke of pin 5 is within the rated stroke range of micro switch 7 to ensure reliable operation and reset.

[0033] The material of the ejector pin 5 is preferably 42CrMo steel. As a force transmission component that is in direct contact with the limited part, its temperature resistance can reach 500-600℃. A roller 6 is mounted on the top of the ejector pin 5. The rolling direction of the roller 6 is consistent with the relative movement direction of the limited component. The axis of rotation of the roller 6 is perpendicular to this direction to achieve rolling-based contact, reduce wear, and improve the smoothness and reliability of triggering. The roller 6 features a heat-resistant and wear-resistant structure, which works in conjunction with the limited component to achieve low-friction contact and stroke transmission. This reduces friction during contact with the limited component, resulting in smoother limiting action and lowering the risk of stick-slip and wear.

[0034] The spring plate 3 and the ejector pin 5 are integrally formed, and are used to compress the spring 4 when the ejector pin 5 is pressed, thereby realizing the controllable triggering of the micro switch 7.

[0035] The tail of the ejector pin 5 is equipped with a trigger plate, which is an integral part of the ejector pin 5 / compression spring plate 3 and reciprocates coaxially. The trigger plate forms line contact / surface contact with the switch lever of the micro switch 7 to achieve smooth triggering and reduce impact.

[0036] The micro switch 7 is arranged on the side of the movement trajectory of the ejector pin 5. The position of the switch lever of the micro switch 7 coincides with the movement trajectory of the ejector pin 5. It is used to detect the stroke position of the ejector pin 5 and output an electrical signal, which is linked with the control system to realize the electrical interlocking stop control of the lower limit.

[0037] This device uses the radiation isolation of the protective plate 1 as the first layer of protection, the heat insulation cotton 8 of the spring cylinder 2 as the second layer of protection, and the temperature resistance of the key load-bearing components (high temperature alloy spring 4, 42CrMo ejector pin 5) as the third layer of protection, forming a multi-layer protection system of "heat insulation, buffering, and heat resistance" to ensure the stability and reliability of the mechanism's shape and function under short-term flame impact.

[0038] Working principle: This device is installed on the fixed base or limit bracket in the lower limit area of ​​the oxygen lance lifting mechanism via the fixing hole 9, so that the protective plate 1 faces the furnace side or the flame radiation side. The movement direction of the roller 6 is consistent with the movement direction of the limited component (such as the locking slot or limit cam / stop of the oxygen lance carriage), and the rotation axis of the roller 6 is perpendicular to the movement direction of the limited component. Heat-resistant fasteners are used to reliably connect the protective plate 1 to the mounting surface via the fixing hole 9, allowing for precise on-site adjustment of the stroke contact point and the trigger position of the micro switch 7. The micro switch 7 is connected to the control cabinet via a heat-resistant cable, electrically serving as the lower limit interlock input. It can be connected to the control system using a power-off-safe normally closed contact method to improve fault safety in case of wire breakage / high-temperature degradation.

[0039] When the oxygen lance descends close to the lower limit, the limiting component pushes the roller 6, which in turn moves the ejector pin 5 axially, compressing the high-temperature alloy spring 4. The slight displacement of the ejector pin 5 triggers the switching lever of the micro switch 7. When the tail of the ejector pin 5 / trigger plate reaches the set trigger stroke, the micro switch 7 activates, sending a lower limit signal to the control system. The PLC immediately stops the descent drive and can also activate the brake, achieving reliable protection of the oxygen lance at its lower limit position. The micro switch 7 uses a normally closed contact, connected to both the PLC and the emergency stop hard circuit. When it opens, the PLC alarms and stops the descent, while the hard circuit simultaneously cuts off the main circuit and activates the brake. The lower limit hardware position is lower than the encoder lower limit to achieve overtravel protection.

[0040] Simultaneously, the high-temperature alloy spring 4, subjected to pressure from the compression spring plate 3, releases its elastic potential energy to drive the ejector pin 5 and roller 6 to reset, the switch resets, and the device enters standby mode. The protective plate 1 first shields against instantaneous flame radiation heat, and the heat-insulating cotton 8 inside the spring cylinder 2 further reduces the internal temperature, improving the operational stability of the spring 4 and the switch. This ensures that the device maintains its shape and reliable operation even under high-temperature impact conditions, preventing equipment collisions and accidents caused by limit switch failure. The friction-reducing contact of the roller 6 improves trigger smoothness and reduces wear, extending the maintenance cycle.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-temperature impact-resistant converter oxygen lance lower limiting device, characterized in that, It includes a protective plate (1), a spring cylinder (2), a ejector pin (5), and a micro switch (7) arranged coaxially along the direction of movement of the ejector pin (5); wherein The protective plate (1) is set on the side facing the flame radiation, and the spring cylinder (2) is fixed on the unexposed side of the protective plate (1) and fixedly connected to the protective plate (1); The micro switch (7) is located on the side away from the flame radiation, and the switch lever of the micro switch (7) is located on the axial movement path of the ejector pin (5); The ejector pin (5) passes through the protective plate (1) and the spring cylinder (2) in sequence along the axis of the device and extends outward from the protective plate (1). The middle section of the ejector pin (5) is fixedly connected to the compression spring plate (3) set in the spring cylinder (2). The spring (4) is fitted around the outer periphery of the ejector pin (5) and between the compression spring plate (3) and the spring cylinder (2). The circumferential and non-moving cavity areas inside the spring cylinder (2), except for the necessary movement gap between the ejector pin (5) and the spring (4), are filled with heat insulation cotton (8).

2. The high-impact-resistant lower positioner of the converter oxygen lance according to claim 1, characterized in that, It also includes a fixing hole (9) provided on the back plate of the device. The fixing hole (9) is an elongated hole with its length direction parallel to the axis of the device. The lower limit device is connected to the mounting bracket through the fixing hole (9).

3. The high-impact-resistant lower positioner of the converter oxygen lance according to claim 1, characterized in that, The filling of the circumferential and non-moving cavity areas of the spring cylinder (2), excluding the necessary movement gap between the ejector pin (5) and the spring (4), includes filling the space between the compression spring plate (3) and the protective plate (1) with heat insulation cotton (8).

4. The high-impact-resistant lower stopper for a converter oxygen lance according to claim 1, characterized in that, The top of the ejector pin (5) is equipped with a roller (6), the rolling direction of the roller (6) is consistent with the movement direction of the limited component, and the rotation axis of the roller (6) is perpendicular to the movement direction.

5. The high impact resistant Vessel lance lower stop device of claim 1, wherein, The tail of the pin (5) is provided with a trigger plate, which forms a line contact / surface contact with the switch lever of the micro switch (7).

6. The high impact resistant vessel lance lower stop device of claim 1, wherein, The trigger stroke of the pin (5) is within the rated stroke range of the micro switch (7).

7. The high impact resistant vessel lance lower stop device of claim 1, wherein, The micro switch (7) adopts a normally closed contact and is connected to the PLC and the emergency stop hard circuit respectively.

8. The high impact resistant vessel lance lower stop device of claim 1, wherein, The lower limit device is installed on the fixed base or limit bracket in the lower limit area of ​​the oxygen lance lifting mechanism.

9. The high-temperature impact-resistant converter oxygen lance lower limit device according to claim 1, characterized in that, The protective plate (1) is coated with a high-temperature resistant coating.

10. The high impact resistant vessel lance lower stop device of claim 1, wherein, The ejector pin (5) is made of 42CrMo steel.

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