Aluminum alloy casting machine crystallizer aluminum leakage monitoring system adopting sensing optical fibers

Abstract

An aluminum alloy casting machine crystallizer aluminum leakage monitoring system adopting sensing optical fibers is characterized in that a temperature measuring ring is fixedly arranged at the lower part of each crystallizer, each temperature measuring ring is provided with a sensing optical fiber, and one end of each sensing optical fiber is connected with a temperature detection system; in the aluminum alloy deep well casting production process, the surface of a cast aluminum ingot radiates infrared rays to enable the temperature of the sensing optical fiber or the temperature measuring ring to rise, and accurate detection of the temperature of the outer surface of each aluminum ingot is achieved; before an aluminum leakage accident of the aluminum ingot occurs, the distance between the semi-solid high-temperature molten aluminum in the aluminum ingot and the surface of the aluminum ingot is reduced, and the surface temperature of the aluminum ingot is increased, so that the temperature of the sensing optical fiber or the temperature measuring ring is increased; when the sensing optical fiber detects that the temperature abnormally rises, it is judged that the aluminum ingot may have an aluminum leakage accident, and at the moment, measures are taken to enable the semi-solid area in the aluminum ingot to recover to the normal state again, so that the aluminum leakage accident is avoided; the utility model has the advantages of simple structure, few sensors, low cost, high reliability and simple maintenance.

Description

Technical Field

[0001] This utility model relates to the field of aluminum alloy casting technology, specifically to an aluminum alloy casting machine crystallizer leakage monitoring system using optical fiber sensing. Background Technology

[0002] In the deep-well casting and melting production of aluminum alloys, molten high-temperature aluminum liquid enters the crystallizer through a distribution plate and solidifies into ingots. The solidified aluminum ingots are then pulled downwards by an ingot derrick at a set speed to ultimately produce the desired aluminum ingots. During this production process, if the solidified area of ​​the molten high-temperature aluminum liquid in the crystallizer is too thin, leakage may occur at the bottom of the crystallizer. This leakage not only affects the forming quality of the aluminum ingots, but also poses a serious threat to the safety of workers if a large amount of high-temperature aluminum liquid leaks into the coolant in the deep well, causing an explosion due to the instantaneous generation of a large amount of steam.

[0003] To address the aforementioned issues, National Utility Model Patent Application No. 202411199056.4 discloses a crystallizer aluminum leakage detection device. This device includes a heat insulation ring installed at the bottom of a cooling water pipe, a mounting bracket installed at the bottom of the heat insulation ring, an annular flexible tube embedded within the mounting bracket, and a pressure monitoring system for monitoring the pressure of the annular flexible tube. During aluminum ingot production, if a high-temperature molten aluminum leaks, the leaking molten aluminum will melt the annular flexible tube, causing it to leak. When the annular flexible tube leaks, its pressure changes. By detecting the pressure change within the annular flexible tube using a sensor, the high-temperature molten aluminum leakage can be detected, triggering an alarm signal and allowing for appropriate measures to be taken to reduce production safety risks. However, this crystallizer aluminum leakage detection device has an overly complex structure, resulting in high costs. Furthermore, after each high-temperature molten aluminum leakage incident, the device must be replaced and repaired, thus increasing maintenance costs.

[0004] National Utility Model Patent Application No. 202410550303.4 discloses a device for monitoring aluminum leakage during the casting process. This device includes several monitoring components located at the bottom of the crystallizer. Each monitoring component includes a connector, a sensor, and a sensing element, with the sensor connected to the sensor. When the sensing element comes into contact with leaking high-temperature molten aluminum, the sensor triggers an alarm, thus monitoring the aluminum leakage. The problem with this device is that to improve monitoring accuracy, multiple sensors need to be installed on the sensor at the bottom of each crystallizer. However, deep-well aluminum alloy casting equipment often has dozens of crystallizers, resulting in a large number of sensors (up to hundreds), making the cost of the aluminum leakage monitoring device excessively high. Furthermore, the connection between the numerous sensors and the monitoring terminal (PLC cabinet) leads to low reliability and is prone to connection failures (due to the harsh working environment of the sensors), thus increasing maintenance costs.

[0005] In addition, the two utility model patents mentioned above can only trigger alarms when an aluminum leakage accident occurs, and cannot provide warnings before an aluminum leakage accident occurs. Therefore, they cannot completely prevent aluminum leakage accidents from happening, and further improvements are needed. Utility Model Content

[0006] To overcome the shortcomings of the prior art, this utility model discloses an aluminum leakage monitoring system for an aluminum alloy casting machine crystallizer using optical fiber sensing, in order to solve the problems of existing aluminum leakage monitoring devices in the prior art, such as complex structure, high cost, low reliability, high use and maintenance costs, and inability to provide early warning.

[0007] To achieve the aforementioned objective, this utility model adopts the following technical solution: a crystallizer leakage monitoring system for an aluminum alloy casting machine using optical fiber sensing, comprising a distribution plate disposed above the casting well; a plurality of distribution channels are evenly distributed on the upper part of the distribution plate, and a plurality of gates are symmetrically arranged on both sides of the distribution channels, with a crystallizer fixedly disposed below each gate; a temperature measuring ring is fixedly disposed below each crystallizer, and an optical fiber sensing element is wound around the temperature measuring ring, with one end of the optical fiber sensing element connected to a temperature detection system.

[0008] Furthermore, each temperature measuring ring is independently equipped with a sensing optical fiber, or a sensing optical fiber is sequentially and continuously installed on each temperature measuring ring; the sensing optical fiber is wound around the inner or outer circular surface of the temperature measuring ring.

[0009] Furthermore, the sensing fiber wound around the crystallizer has more than one turn.

[0010] Furthermore, the other end of the sensing fiber is placed in a constant temperature chamber, or a section of the sensing fiber between the distribution plate and the temperature detection system is placed in a constant temperature chamber.

[0011] Furthermore, the length of the sensing fiber installed in the constant temperature chamber is over 20 meters.

[0012] Furthermore, the inner or outer circular surface of the temperature measuring ring is provided with an optical fiber groove, and the root of the optical fiber groove is provided with an R-angle with a radius of 5.0-10.0mm; the sensing optical fiber is wound and arranged in the optical fiber groove.

[0013] Furthermore, the temperature measuring ring is made of ordinary structural steel or Invar steel.

[0014] Furthermore, a heat insulation ring is installed between the crystallizer and the temperature measuring ring.

[0015] Preferably, a cooling water ring and a heat insulation ring are arranged sequentially between the crystallizer and the temperature measuring ring.

[0016] Preferably, a cooling water ring is fixedly installed at the lower part of the temperature measuring ring; a heat insulation ring is installed between the temperature measuring ring and the crystallizer and the cooling water ring.

[0017] Due to the adoption of the above-described technical solution, this utility model has the following beneficial effects: This utility model discloses an aluminum alloy casting machine crystallizer leakage monitoring system using optical fiber sensing. A temperature measuring ring is fixedly installed at the bottom of each crystallizer, and an optical fiber sensing device is installed on each temperature measuring ring. One end of the optical fiber sensing device is connected to a temperature detection system. During the deep-well casting production process of aluminum alloy, the infrared radiation emitted from the surface of the aluminum ingot causes the temperature of the optical fiber sensing device or temperature measuring ring to rise. Accurate detection of the outer surface temperature of each aluminum ingot is achieved through the optical fiber sensing device. Before a potential aluminum leakage accident occurs in an aluminum ingot, the distance between the semi-solid high-temperature aluminum liquid inside the ingot and the surface of the ingot will decrease, thereby increasing the surface temperature of the ingot. This increased surface temperature will then cause the optical fiber sensing device or temperature measuring ring to leak. When the temperature of the temperature sensing ring rises, and the optical fiber sensor detects an abnormal increase in the temperature of the temperature sensing ring, it can be determined that the aluminum ingot may be leaking aluminum. At this time, by controlling the reduction of the traction speed of the ingot drawing machine or increasing the cooling water flow rate, the cooling time of the aluminum ingot can be extended or the cooling rate can be accelerated, so that the semi-solid high-temperature aluminum liquid area inside the aluminum ingot can be restored to a normal state, thereby avoiding the aluminum leakage accident. The aluminum leakage monitoring system of the aluminum alloy casting machine crystallizer using optical fiber sensor of this utility model has the advantages of simple structure, few sensors, low cost, high reliability, simple maintenance, and early warning of aluminum leakage accidents. It lays a solid technical foundation for the promotion and application of aluminum leakage monitoring system of aluminum alloy casting machine crystallizer using optical fiber sensor. Attached Figure Description

[0018] Figure 1 Top view of the distribution disk;

[0019] Figure 2 Lower exterior view of the distribution disk;

[0020] Figure 3Schematic diagram of the aluminum leakage monitoring system for an aluminum alloy casting machine crystallizer using optical fiber sensing. Figure 1 ;

[0021] Figure 4 This is a schematic diagram of the appearance of the temperature measuring ring in Example 1;

[0022] Figure 5 This is a side view of the distribution disk in Embodiment 1;

[0023] Figure 6 For the appendix Figure 5 Enlarged schematic diagram of section A in the middle;

[0024] Figure 7 Schematic diagram of the aluminum leakage monitoring system for an aluminum alloy casting machine crystallizer using optical fiber sensing. Figure 1 ;

[0025] Figure 8 Schematic diagram of the aluminum leakage monitoring system for an aluminum alloy casting machine crystallizer using optical fiber sensing. Figure 2 ;

[0026] Figure 9 These are schematic diagrams of the appearance of the temperature measuring rings in Examples 2, 3, and 4;

[0027] Figure 10 This is a side view of the distribution disk in Embodiment 2;

[0028] Figure 11 for Figure 6 Enlarged schematic diagram of section B in the middle section;

[0029] Figure 12 This is a partial enlarged cross-sectional view of Example 3;

[0030] Figure 13 This is a partial enlarged cross-sectional view of Example 4;

[0031] Figure 14 A schematic diagram of the internal structure of an aluminum ingot before an aluminum leakage accident occurs.

[0032] In the diagram: 1. Distribution plate; 1.1. Distribution channel; 1.2. Gate; 2. Crystallizer; 3. Insulation ring; 4. Temperature sensing ring; 4.1. Temperature sensing ring body; 4.1.1. Fiber optic channel; 4.1.2. Fiber optic mounting hole; 4.2. Temperature sensing ring flange; 5. Sensing fiber optic cable; 6. Temperature detection system; 6.1. Laser source; 6.2. Wavelength division multiplexer; 6.3. APD photoelectric converter; 6.4. Data acquisition card; 6.5. Data processing equipment; 6.6. Alarm device; 7. Constant temperature chamber; 8. Cooling water ring; 9. High-temperature aluminum liquid; 10. Semi-solid high-temperature aluminum liquid; 11. Aluminum ingot Detailed Implementation

[0033] The present invention will be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0034] Example 1, see appendix to the instruction manual. Figure 1 , 2 :

[0035] A system for monitoring aluminum leakage in the crystallizer of an aluminum alloy casting machine using optical fiber sensing includes a distribution plate 1 located above the casting well; several distribution channels 1.1 are evenly distributed on the upper part of the distribution plate 1, and several through gates 1.2 are symmetrically arranged on both sides of the distribution channels 1.1; a crystallizer 2 is fixedly installed below each gate 1.2; a temperature measuring ring 4 is fixedly installed below each crystallizer 2; see the attached instruction manual. Figure 3 Each temperature measuring ring 4 has an independently wound sensing optical fiber on its inner circular surface, and one end of each sensing optical fiber 5 is connected to a temperature detection system 6.

[0036] See the instruction manual appendix Figure 4 The temperature sensing ring 4 is circular, made of ordinary structural steel, with an optical fiber groove 4.1.1 on its inner surface. An optical fiber mounting hole 4.1.2 is provided tangentially along the groove 4.1.1. The sensing optical fiber 5 is wound around the optical fiber groove 4.1.1 of the temperature sensing ring 4, with one end passing through the mounting hole 4.1.2 and connecting to the temperature detection system 6. The number of turns of the sensing optical fiber 5 is more than one turn, specifically determined by the spatial resolution of the temperature detection system 6 and the diameter of the optical fiber groove 4.1.1. The specific calculation formula is Q=R / (πD), where Q is... The number of turns of the sensing fiber 5 around the temperature measuring ring 4 (the result should be rounded up to the nearest whole number, and any turns less than one should be rounded up to one whole turn), R is the spatial resolution of the temperature detection system 6, and D is the diameter of the fiber optic slot 4.1.1; for example, when the spatial resolution of the temperature detection system 6 is 1.0 meter and the outer diameter of the fiber optic slot 4.1.1 is 0.2 mm, the length of each turn of the sensing fiber 5 around the fiber optic slot 4.1.1 is 0.628 meters. Therefore, the sensing fiber 5 is wound 1.59 times around the temperature measuring ring 4, which is less than two turns, so it is rounded up to two turns;

[0037] See the instruction manual appendix Figure 5 , 6 The temperature measuring ring 4 is fixedly installed at the lower part of the crystallizer 2. A heat insulation ring 3 is installed between the temperature measuring ring 4 and the crystallizer 2. The heat insulation ring 3 prevents the heat of the crystallizer 2 from being transferred to the temperature measuring ring 4, thus affecting the accuracy of the temperature measurement by the sensing fiber 5.

[0038] See the instruction manual appendix Figure 3The temperature detection system 6 includes a laser source 6.1, a wavelength division multiplexer 6.2, an APD photoelectric converter 6.3, a data acquisition card 6.4, a data processing device 6.5, and an alarm device 6.6. The laser source 6.1, wavelength division multiplexer 6.2, and APD photoelectric converter 6.3 are connected via optical fibers; the APD photoelectric converter 6.3 is connected to the data acquisition card 6.4 via wires; and the laser source 6.1, data acquisition card 6.4, data processing device 6.5, and alarm device 6.6 are connected via wires. One end of the sensing optical fiber 5 is connected to the wavelength division multiplexer 6.2. The working principle of the temperature detection system 6 is as follows: the laser source 6.1 emits laser pulses which are sent to the wavelength division multiplexer 6.2. The wavelength division multiplexer 6.2 couples the laser pulses to the sensing optical fiber 5. When the sensing optical fiber 5 is placed in a temperature field, the laser pulses are scattered at various points on the sensing optical fiber 5. The scattered light travels back along the sensing optical fiber 5 to the wavelength division multiplexer 6.2, where it is then multiplexed. Device 6.2 filters out most of the Rayleigh and Brillouin scattered light, leaving Raman scattered light which is then separated into Stokes and anti-Stokes beams. The two separated beams of Stokes and anti-Stokes light are input into two channels of the APD photoelectric converter 6.3 for photoelectric conversion. The converted electrical signals are transmitted to the data acquisition card 6.4 for analog-to-digital conversion into digital signals. The digital signals are input into the data processing device 6.5, where, after demodulation and noise reduction, the temperature information distributed along the length of the corresponding sensing fiber 5 is measured. The data processing device 6.5 determines whether an aluminum ingot 11 may be experiencing an aluminum leakage accident by detecting an abnormal increase in temperature of the sensing fiber 5 wound on each temperature measuring ring 4 that exceeds a set threshold. When the data processing device 6.5 detects a possible aluminum leakage accident in an aluminum ingot 11, it controls the alarm device 6.6 to issue an audible and visual alarm signal to notify the operators to handle the situation promptly.

[0039] The aluminum alloy casting machine crystallizer leakage monitoring system of this embodiment, which uses sensing optical fiber, can be realized by setting a temperature measuring ring 4 and sensing optical fiber 5 at the bottom of the existing aluminum alloy casting machine crystallizer, thus having the advantage of simple structure.

[0040] The working process of the aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber in this embodiment is as follows: When the aluminum alloy casting machine is working, the molten high-temperature aluminum liquid flows into the crystallizer 2 through the distribution channel 1.1 and gate 1.2 of the distribution plate 1. After being cooled and solidified in the crystallizer 2, the solidified aluminum ingot is pulled downward by the ingot traction machine at a set speed to produce the required aluminum ingot 11. The surface of the aluminum ingot 11 that has just been pulled out of the crystallizer 2 still has a high temperature and radiates infrared rays outward, which directly raises the temperature of the sensing optical fiber 5 set in the optical fiber groove 4.1.1 of the temperature measuring ring 4, thereby realizing the accurate detection of the outer surface temperature of each aluminum ingot 11.

[0041] Example 2, see appendix to the instruction manual. Figure 1 , 2 :

[0042] A system for monitoring aluminum leakage in the crystallizer of an aluminum alloy casting machine using optical fiber sensing includes a distribution plate 1 located above the casting well; several distribution channels 1.1 are evenly distributed on the upper part of the distribution plate 1, and several through gates 1.2 are symmetrically arranged on both sides of the distribution channels 1.1; a crystallizer 2 is fixedly installed below each gate 1.2; a temperature measuring ring 4 is fixedly installed below each crystallizer 2; see the attached instruction manual. Figure 7 , 8 A sensing fiber 5 is sequentially wound around the outer surface of each temperature measuring ring 4. One end of the sensing fiber 5 is connected to the temperature detection system 6, and the other end, which is no less than 20 meters long, is placed in a constant temperature chamber 7. In this aluminum alloy casting machine crystallizer leakage monitoring system using sensing fiber optics, the purpose of placing the other end of the sensing fiber 5 in the constant temperature chamber 7 is to experimentally calibrate the temperature measurement benchmark before the system is set up and put into formal use. Alternatively, the constant temperature chamber 7 can be placed 200 meters away from the temperature detection system 6 (the length of the sensing fiber 5), and the length of the sensing fiber 5 in the constant temperature chamber 7 can be 20 meters. In the above arrangement of the sensing fiber 5, its length wound around each temperature measuring ring 4 and the distance between each temperature measuring ring 4 are known. Therefore, the distance between the sensing fiber 5 wound around each temperature measuring ring 4 and the temperature detection system 6 is also known.

[0043] See the instruction manual appendix Figure 9The temperature measuring ring 4 includes an annular temperature measuring ring body 4.1, with temperature measuring ring flanges 4.2 at both ends. An optical fiber groove 4.1.1 is provided on the outer circumference of the temperature measuring ring body 4.1, with an R-angle at the root of the groove 4.1.1 and a radius of 8mm. A sensing optical fiber 5 is wound in the optical fiber groove 4.1.1 of the temperature measuring ring 4, with more than one turn. The specific number of turns is determined by the spatial resolution of the temperature detection system 6 and the outer diameter of the optical fiber groove 4.1.1, using the formula Q = R / (πD), where Q is the number of turns of the sensing optical fiber 5 on the temperature measuring ring 4 (the result must be rounded up to the nearest integer, and any less than one turn must be rounded up to one turn), and R is the temperature... The spatial resolution of the temperature detection system 6 is defined by D, where D is the outer diameter of the fiber optic slot 4.1.1. For example, if the spatial resolution of the temperature detection system 6 is 1.0 meter and the outer diameter of the fiber optic slot 4.1.1 is 0.6 mm, the length of each turn of the sensing fiber 5 wound on the fiber optic slot 4.1.1 is 1.884 meters. Therefore, the sensing fiber 5 is wound 0.53 times on the temperature measuring ring 4, which is less than one turn, so it is rounded up to one turn. The temperature measuring ring 4 is made of Invar steel, which has a very small coefficient of thermal expansion. This prevents the temperature measuring ring 4 from expanding and deforming due to heat during operation, which would cause tensile stress on the sensing fiber 5 wound around its outer circumference and affect the accuracy of temperature measurement.

[0044] See the instruction manual appendix Figure 10 , 11 The temperature measuring ring 4 is fixedly installed at the lower part of the crystallizer 2. A heat insulation ring 3 is installed between the temperature measuring ring 4 and the crystallizer 2. The heat insulation ring 3 prevents the heat of the crystallizer 2 from being transferred to the temperature measuring ring 4, thus affecting the accuracy of the temperature measurement by the sensing fiber 5.

[0045] See the instruction manual appendix Figure 7 , 8The temperature detection system 6 includes a laser source 6.1, a wavelength division multiplexer 6.2, an APD photoelectric converter 6.3, a data acquisition card 6.4, a data processing device 6.5, and an alarm device 6.6. The laser source 6.1, wavelength division multiplexer 6.2, and APD photoelectric converter 6.3 are connected via optical fibers; the APD photoelectric converter 6.3 is connected to the data acquisition card 6.4 via wires; and the laser source 6.1, data acquisition card 6.4, data processing device 6.5, and alarm device 6.6 are connected via wires. The sensing optical fiber 5... The end is connected to wavelength division multiplexer 6.2; the working principle of temperature detection system 6 is as follows: laser pulses emitted by laser source 6.1 are sent to wavelength division multiplexer 6.2, which couples the pulsed laser to sensing fiber 5; when sensing fiber 5 is placed in a temperature field, the laser pulses will be scattered at various points on sensing fiber 5, and the scattered light will return along sensing fiber 5 to wavelength division multiplexer 6.2. Wavelength division multiplexer 6.2 will filter out most of the Rayleigh scattering and Brillouin scattering light that is scattered back, and the remaining Raman scattering light will be separated into Stokes light. The two separated beams of Stokes light and anti-Stokes light are input into two channels of the APD photoelectric converter 6.3 for photoelectric conversion. The converted electrical signals are transmitted to the data acquisition card 6.4 for analog-to-digital conversion into digital signals. The digital signals are input into the data processing device 6.5. After demodulation and noise reduction processing, the temperature information distributed along the length of the sensing fiber 5 is measured. The distance between the sensing fiber 5 wound on each temperature measuring ring 4 and the temperature detection system 6 (i.e., the distance along the length of the sensing fiber 5) is known. Therefore, the temperature of the sensing fiber 5 wound on each temperature measuring ring 4 can be obtained based on the measured temperature information along the length of the sensing fiber 5. The data processing device 6.5 determines whether an aluminum ingot 11 may have a leakage accident by detecting an abnormal increase in the temperature of the sensing fiber 5 wound on each temperature measuring ring 4 that exceeds a set threshold. When the data processing device 6.5 detects that an aluminum ingot 11 may have a leakage accident, it controls the alarm device 6.6 to issue an audible and visual alarm signal to notify the operators to handle the situation in time.

[0046] The aluminum alloy casting machine crystallizer leakage monitoring system of this embodiment, which uses a sensing fiber, can be implemented by setting a temperature measuring ring 4 at the bottom of the existing aluminum alloy casting machine crystallizer and a sensing fiber 5. Therefore, it has many advantages such as simple structure, few sensors, low cost, high reliability and simple maintenance, which makes it easy to promote and use in aluminum alloy casting machines.

[0047] The working process of the aluminum alloy casting machine crystallizer leakage monitoring system using optical fiber sensing in this embodiment is as follows: When the aluminum alloy casting machine is working, the molten high-temperature aluminum liquid flows into the crystallizer 2 through the distribution channel 1.1 and the gate 1.2 of the distribution plate 1. After being cooled and solidified in the crystallizer 2, the solidified aluminum ingot is pulled downward by the ingot traction machine at a set speed to produce the required aluminum ingot 11. The surface of the aluminum ingot 11 that has just been pulled out of the crystallizer 2 still has a high temperature and radiates infrared rays outward, which raises the temperature of the temperature measuring ring 4. The temperature of each temperature measuring ring 4 measured by the optical fiber sensing 5 indirectly realizes the accurate detection of the outer surface temperature of each aluminum ingot 11.

[0048] See the instruction manual appendix Figure 14 Before a potential aluminum leakage accident occurs in an aluminum ingot 11, the area of ​​semi-solid high-temperature aluminum liquid 10 inside the ingot will expand and extend downwards. As a result, the distance between the semi-solid high-temperature aluminum liquid 10 and the surface of the aluminum ingot 11 will decrease, thus causing the surface temperature of the aluminum ingot 11 to rise. The rise in the surface temperature of the aluminum ingot 11 will in turn cause the temperature of the temperature measuring ring 4 to rise. When the sensing fiber optic 5 detects an abnormal rise in the temperature of the temperature measuring ring 4 and exceeds the set threshold, it can be determined that the aluminum ingot 11 may have a potential aluminum leakage accident. At this time, by controlling the reduction of the traction speed of the ingot drawing machine or increasing the cooling water flow rate in the crystallizer 2, the area of ​​semi-solid high-temperature aluminum liquid 10 inside the aluminum ingot 11 will shrink and return to the normal state, thereby avoiding the occurrence of an aluminum leakage accident.

[0049] Example 3, see appendix to the instruction manual. Figure 12 :

[0050] In this embodiment, a cooling water ring 8 is added between the crystallizer 2 and the temperature measuring ring 4. The cooling water ring 8 further cools the aluminum ingot 11 pulled out from the crystallizer 2 to prevent aluminum leakage accidents.

[0051] Example 4, see appendix to the instruction manual. Figure 13 :

[0052] In this embodiment, the temperature measuring ring 4 is positioned between the crystallizer 2 and the cooling water ring 8, and heat insulation rings 3 are provided between the temperature measuring ring 4 and both the crystallizer 2 and the cooling water ring 8. This positioning of the temperature measuring ring 4 can prevent the cooling water sprayed from the cooling water ring 8 from affecting the temperature measuring ring 4, thereby further improving the accuracy of the surface temperature measurement of the aluminum ingot 11.

[0053] The specific method for setting the sensing fiber in the temperature measuring ring 4 is as follows: The temperature measuring ring 4 is fixedly set at the lower part of the crystallizer 2 in the manner described in Examples 2, 3, and 4; a sensing fiber 5 is sequentially wound around the fiber groove 4.1.1 of each temperature measuring ring 4; before winding the sensing fiber 5 on the outer circumference of the temperature measuring ring 4, a 0.2mm layer of paraffin wax is coated on the surface of the fiber groove 4.1.1 of the temperature measuring ring 4. This layer of paraffin wax creates a gap between the sensing fiber 5 and the surface of the fiber groove 4.1.1. This gap prevents the temperature measuring ring 4 from expanding and deforming due to heat during operation, thus avoiding tensile stress on the sensing fiber 5 wound around the outer circumference of the fiber groove 4.1.1 and affecting the accuracy of temperature measurement; in addition, this gap can also compensate for the change in distance between adjacent crystallizers 2 during the operation of the aluminum alloy casting machine crystallizer, avoiding tensile stress on the sensing fiber 5 between adjacent crystallizers 2 and affecting the accuracy of temperature measurement; furthermore, when the temperature measuring ring 4 is working, the paraffin layer will melt and flow downwards due to heat, and the sensing fiber 5 will move downwards with the paraffin layer. The layers move downwards together, causing the sensing fiber 5 wound in the fiber groove 4.1.1 to fall onto the R-angle at the lower root of the fiber groove 4.1.1, ensuring good contact between the sensing fiber 5 and the temperature measuring ring 4, thereby ensuring the accuracy of the temperature detection by the sensing fiber 5. After the sensing fiber 5 is wound in the fiber groove 4.1.1 of one temperature measuring ring 4, it is coated with paraffin wax again to fix the sensing fiber 5, preventing the tightness of the sensing fiber 5 wound on the previous temperature measuring ring 4 from being affected when the sensing fiber 5 is wound on the next temperature measuring ring 4. When the sensing fiber 5 is wound on the temperature measuring ring 4, the sensing fiber 5 between adjacent temperature measuring rings 4 is in a loose state, avoiding the change in the distance between adjacent crystallizers 2 when the aluminum alloy casting machine crystallizer is working, which would cause tensile stress in the sensing fiber 5 between adjacent crystallizers 2 and affect the accuracy of temperature measurement. One end of the sensing fiber 5, with a length of not less than 20 meters, is set in the constant temperature chamber 7, and the other end is connected to the temperature detection system 6. The constant temperature chamber 7 and the detection system 6 are both set in the control room.

[0054] Alternatively, the sensing fiber 5, which is 20 meters long and located 200 meters away from the temperature detection system, can be placed in the constant temperature chamber 7.

[0055] The parts of this utility model not described in detail are existing technologies.

Claims

1. A system for monitoring aluminum leakage in an aluminum alloy casting machine crystallizer using optical fiber sensing, comprising a distribution plate (1) disposed above the casting well; the distribution plate (1) has several distribution channels (1.1) evenly distributed on its upper part, and several gates (1.2) symmetrically arranged on both sides of the distribution channels (1.1), with a crystallizer (2) fixedly disposed below each gate (1.2); characterized in that: Each crystallizer (2) is fixedly equipped with a temperature measuring ring (4) at the bottom, and a sensing optical fiber (5) is wound on the temperature measuring ring (4). One end of the sensing optical fiber (5) is connected to a temperature detection system (6).

2. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber as described in claim 1, characterized in that: Each temperature measuring ring (4) is independently provided with a sensing optical fiber (5), or a sensing optical fiber (5) is sequentially and continuously provided on each temperature measuring ring (4); the sensing optical fiber (5) is wound around the inner or outer circular surface of the temperature measuring ring (4).

3. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber as described in claim 1, characterized in that: The sensing fiber (5) wound around the crystallizer (2) has more than one turn.

4. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber as described in claim 1, characterized in that: The other end of the sensing fiber (5) is placed in the constant temperature chamber (7), or a section of the sensing fiber (5) between the distribution plate (1) and the temperature detection system (6) is placed in the constant temperature chamber (7).

5. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber as described in claim 2, characterized in that: The length of the sensing fiber (5) installed in the constant temperature chamber (7) is more than 20 meters.

6. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber as described in claim 1, characterized in that: The inner or outer circular surface of the temperature measuring ring (4) is provided with an optical fiber groove. 4.1.1), the root of the fiber optic groove (4.1.1) is provided with an R-angle, the radius of which is 5-10mm; the sensing fiber (5) is wound in the fiber optic groove (4.1.1).

7. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber as described in claim 1, characterized in that: The temperature measuring ring (4) is made of ordinary structural steel or Invar steel.

8. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber as described in claim 1, characterized in that: A heat insulation ring (3) is provided between the crystallizer (2) and the temperature measuring ring (4).

9. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber as described in claim 1, characterized in that: A cooling water ring (8) and a heat insulation ring (3) are sequentially arranged between the crystallizer (2) and the temperature measuring ring (4).

10. The aluminum alloy casting machine crystallizer leakage monitoring system using sensing optical fiber according to claim 1, characterized in that: A cooling water ring (8) is fixedly installed at the lower part of the temperature measuring ring (4); a heat insulation ring (3) is installed between the temperature measuring ring (4), the crystallizer (2), and the cooling water ring (8).

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