An online monitoring device for the level of molten aluminum in a furnace

Abstract

The present invention belongs to the technical field of aluminum alloy ingot production, and discloses an online monitoring device for the liquid aluminum level in a furnace, including a holding furnace, a laser distance measuring component, a detection port opening and closing component, and an air cooling component; a furnace top detection port is arranged on the top of the holding furnace, and the upper end face of the furnace top detection port is inclined; the detection port opening and closing component is used to block or open the furnace top detection port; the laser distance measuring component includes a laser distance meter arranged just above the furnace top detection port, and the outer sleeve of the laser distance meter is provided with a detection sleeve with a circulating cooling function; the lower end face of the detection sleeve is parallel to the upper end face of the furnace top detection port and inclined, and forms an inclined ventilation channel with the upper end face of the furnace top detection port; the air cooling component is arranged at the upper air outlet of the ventilation channel, and is used to provide cooling wind obliquely downward along the ventilation channel, and the wind direction of the cooling wind is parallel to the inclined direction of the ventilation channel. The present invention can improve the ranging accuracy of the laser distance meter, and has reliable operation, long service life, and efficient and easy-to-operate detection method.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy ingot production, and in particular relates to an online monitoring device for aluminum liquid level in a furnace. Background Art

[0002] Aluminum alloy ingots are made of pure aluminum and recycled aluminum, and some other alloying elements (such as silicon, copper, magnesium, iron, etc.) are added according to international standards or special requirements to improve the deficiencies of pure aluminum in castability, chemical properties and physical properties. Aluminum alloys have good casting properties and plastic processing properties, good electrical and thermal conductivity, as well as good corrosion resistance and weldability. They can be used as structural materials and are widely used in aerospace, aviation, transportation, construction, electromechanical, light chemicals and daily necessities.

[0003] In the aluminum alloy ingot production line, the following process flows are sequentially followed: first, different raw materials are screened, and the screened raw materials are put into the preheating kiln. After preheating, they enter the upper furnace to melt the aluminum products, and then enter the lower furnace to add molten alloys. Finally, they enter the holding furnace to remove slag. The slag produced in the holding furnace enters the rotary furnace, and the aluminum liquid (i.e., aluminum water) that meets the production standards enters the aluminum ingot mold to generate aluminum alloy ingots. In the above production process, how to accurately measure and control the filtrate level in the holding furnace to determine whether the aluminum liquid in the furnace body is at the lower and upper limits of the liquid level, and to ensure the stability and safety of the aluminum liquid supply management production, is a difficult problem that needs to be solved in the aluminum alloy ingot production technology.

[0004] Chinese patent CN217877967U discloses an online monitoring alarm device for the weight of aluminum liquid in a furnace, including an aluminum liquid supply box, which is located on one side of the aluminum liquid insulation furnace, the aluminum liquid supply box is connected to the aluminum liquid insulation furnace through a connecting piece, the aluminum liquid supply box and the connecting piece are detachably connected, a through hole is opened on the top of the aluminum liquid supply box, a sealing plate is arranged above the through hole, and the sealing plate is rotatably connected to the aluminum liquid supply box; a collecting part is arranged on one side of the aluminum liquid supply box, the collecting part is connected to the aluminum liquid supply box, a temperature measuring part is fixedly connected to the collecting part, and the temperature measuring part is located in the aluminum liquid supply box; a supporting part is located above the aluminum liquid supply box, the supporting part is fixedly connected to the aluminum liquid supply box, a transmission part is arranged on the supporting part, and the transmission part is fixedly connected to the sealing plate; a distance measuring part is arranged on the supporting part, the distance measuring part is arranged corresponding to the aluminum liquid in the aluminum liquid supply box through the through hole, and the distance measuring part is electrically connected to an alarm light. This patent realizes timely monitoring of the height of aluminum liquid in the insulation furnace and improves the accuracy of monitoring.

[0005] However, during detection, the above-mentioned patent opens the port to allow outside air to enter, which will cause the temperature of the aluminum liquid in the furnace to drop and the aluminum liquid to solidify, affecting the distance measurement. The patent uses a liquid extraction pump to extract and recover the semi-solidified aluminum liquid, and it is difficult to extract the semi-solidified aluminum liquid with high temperature and poor fluidity, resulting in high investment costs and complex structure. At the same time, the temperature of the aluminum liquid in the furnace is generally 700-900℃. After the port is opened, the high-temperature gas rises, resulting in greater heat radiation to the laser rangefinder above, and it is prone to malfunction and damage when it is in a high-temperature environment for a long time, which reduces the accuracy of laser ranging. The entire technical solution needs further improvement. Summary of the invention

[0006] The present invention aims to solve the technical problems existing in the background technology and provide an online monitoring device for the aluminum liquid level in a furnace, which can improve the ranging accuracy of a laser rangefinder, has reliable operation, long service life, and an efficient and easy-to-operate detection method.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] An online monitoring device for the level of aluminum liquid in a furnace, comprising a holding furnace, a laser distance measuring component, a detection port opening and closing component and an air cooling component;

[0009] A furnace top detection port is provided on the top of the insulation furnace, and the upper end surface of the furnace top detection port is inclined;

[0010] The detection port opening and closing component is used to block or open the furnace top detection port;

[0011] The laser distance measuring assembly comprises a laser distance measuring device arranged just above the furnace top detection port, and the laser distance measuring device is externally sleeved with a detection sleeve having a circulating cooling function; the lower end surface of the detection sleeve is arranged in an inclined manner parallel to the upper end surface of the furnace top detection port, and forms an inclined ventilation channel with the upper end surface of the furnace top detection port;

[0012] The air cooling component is arranged at the upper air outlet of the ventilation channel, and is used for providing cooling air obliquely downward along the ventilation channel, and the wind direction of the cooling air is parallel to the oblique direction of the ventilation channel.

[0013] Furthermore, the furnace top detection port arranged at the top of the insulation furnace is a cylindrical structure protruding upward, and the cylinder wall of the furnace top detection port is filled with heat insulation material.

[0014] Furthermore, the heat insulating material filled in the cylinder wall of the furnace top detection port is ceramic fiber insulation cotton.

[0015] Furthermore, the detection port opening and closing assembly includes a cylinder, a connecting rod and a support rod;

[0016] The cylinder is fixedly installed on one side of the holding furnace through a mounting seat. The cylinder is installed vertically. The upper end of the cylinder is hinged to the first end of the connecting rod. Oval slots are provided in the middle of the connecting rod and the upper part of the support rod. The two oval slots are arranged in a cross-corresponding manner. At the same time, the directions of the two oval slots are parallel to the axis directions of their respective components. The connecting rod and the support rod are movably hinged through the two cross-set oval slots, so that the hinge point can slide along the direction of the connecting rod and the direction of the support rod;

[0017] A plugging portion is provided at the second end of the connecting rod. The plugging portion is pressed or covered on the furnace top detection port.

[0018] Furthermore, a layer of heat-insulating flexible material structure is provided on the pressing or covering end face of the plugging portion.

[0019] Further, the laser distance measurement assembly further includes a bracket. The laser rangefinder is installed on the bracket and is located directly above the furnace top detection port;

[0020] A detection sleeve is sleeved outside the laser rangefinder; a coolant inlet is provided below the pipe wall of the detection sleeve, and a coolant outlet is provided above the pipe wall of the detection sleeve; a cooling pipe is provided inside the pipe wall of the detection sleeve. The cooling pipe is spiral, and the two ends of the cooling pipe are respectively communicated with the coolant inlet and the coolant outlet.

[0021] Furthermore, the air-cooling assembly is a fan or a blower;

[0022] The air-cooling assembly is inclined and fixedly arranged on the bracket. The air supply cross-section of the air-cooling assembly is perpendicular to the inclined axis of the ventilation channel.

[0023] Further, the inclination angle of the ventilation channel is set to 30°-60°.

[0024] Further, a pressure sensor is further provided at the bottom of the holding furnace; at the same time, a controller is further included. The pressure sensor and the laser rangefinder are both connected to the controller; the controller automatically detects the liquid level of the molten aluminum in the furnace according to the following method:

[0025] First, preset the lower limit h1 and the upper limit h2 of the molten aluminum liquid level in the holding furnace according to the operation requirements, and h1 < h2; at the same time, preset the safe liquid level interval [h3, h4], and h1 < h3 < h4 < h2;

[0026] Secondly, keep the furnace top detection port closed, and sequentially measure the weight G1 of the molten aluminum in the holding furnace at the liquid level height of h3 and the weight G2 of the molten aluminum at the liquid level height of h4 through the pressure sensor;

[0027] Then, keep the furnace top detection port closed. When the pressure sensor detects that the current weight G < G1 or G > G2, immediately open the air cooling component and the furnace top detection port in sequence, start the laser rangefinder to perform laser ranging, and obtain the current height h of the molten aluminum level in the furnace;

[0028] Finally, compare the current height h of the molten aluminum level in the furnace with the preset upper and lower limits of the liquid level:

[0029] If h < h1, it means that the current molten aluminum level is lower than the preset lower limit of the liquid level, and molten aluminum needs to be supplemented;

[0030] If h > h2, it means that the current molten aluminum level is higher than the preset upper limit of the liquid level, and the supply of molten aluminum needs to be stopped, and the molten aluminum is discharged until the discharge stops when the filtrate level h = h2;

[0031] If h1 ≤ h ≤ h2, that is, h is in the liquid level height interval [h1, h2], it means that the current molten aluminum level is within the safe interval and no treatment is required.

[0032] Furthermore, two laser ranging components are provided for one holding furnace, namely the first laser ranging component and the second laser ranging component;

[0033] A pressure sensor is also provided at the bottom of the holding furnace; at the same time, a controller is further included. The pressure sensor is connected to the controller, and the laser rangefinders in the first laser ranging component and the second laser ranging component are also connected to the controller. The controller automatically detects the molten aluminum level in the furnace according to the following method:

[0034] First, preset the lower limit h1 and the upper limit h2 of the molten aluminum level in the holding furnace according to the operation requirements, and h1 < h2; at the same time, preset the safe liquid level interval [h3, h4], and h1 < h3 < h4 < h2;

[0035] Secondly, keep the furnace top detection port closed, and measure the weight G1 of the molten aluminum in the holding furnace at the liquid level height of h3 and the weight G2 of the molten aluminum at the liquid level height of h4 in sequence through the pressure sensor;

[0036] Then, keep the furnace top detection port closed. When the pressure sensor detects that the weight G < G1 or G > G2, immediately open the air cooling component and the furnace top detection port in sequence, start the laser rangefinders of the first laser ranging component and the second laser ranging component to perform laser ranging simultaneously, and respectively obtain the first height H1 of the molten aluminum level in the furnace measured by the first laser ranging component and the second height H1 of the molten aluminum level in the furnace measured by the second laser ranging component, and compare and analyze the difference △H between H1 and H2 to obtain the current height h of the molten aluminum level in the furnace, specifically including:

[0037] If △H > 2mm, a fault alarm prompt is issued to prompt the staff to troubleshoot the two laser ranging components;

[0038] If △H≤2mm, the current aluminum liquid level h in the furnace is taken as the average value of the measurement values ​​of the two laser ranging components, that is:

[0039] h=(H1+H2) / 2;

[0040] Finally, compare the current aluminum liquid level h in the furnace with the preset upper and lower limits:

[0041] If h

[0042] If h>h2, it means that the current aluminum liquid level is higher than the preset upper limit, and it is necessary to stop supplying aluminum liquid and discharge the aluminum liquid until the filtrate level is h=h2;

[0043] If h1≤h≤h2, that is, h is in the liquid level height interval [h1, h2], it means that the current aluminum liquid level is in the safe range and no processing is performed.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] (1) The on-line monitoring device for the level of aluminum liquid in a furnace of the present invention can reduce the influence of the heat radiation of the rising high-temperature gas on the laser rangefinder by arranging a detection sleeve with a circulating cooling function on the outside of the laser rangefinder, thereby avoiding inaccurate distance measurement or easy damage; an inclined ventilation channel is formed by the lower end surface of the detection sleeve and the upper end surface of the furnace top detection port, and cooling air is provided obliquely downward through an air cooling component. On the one hand, the cooling air blows the rising high-temperature gas downward along the vertical wind direction to avoid the rising heat radiation of the high-temperature gas to the laser rangefinder; on the other hand, the cooling air provides a lateral airflow along the horizontal wind direction, which can take away the hot air blown downward and guide the hot air to the laser rangefinder. The flow effect prevents external gas from entering the furnace top detection port and contacting the aluminum liquid in the furnace, and prevents the high-temperature aluminum liquid in the furnace from solidifying after contacting the external air, resulting in a smaller volume and inaccurate liquid level measurement; at the same time, the lower end face of the detection sleeve and the upper end face of the furnace top detection port form an inclined ventilation channel. Compared with the situation where both the upper and lower end faces are horizontal or one is inclined and the other is horizontal, the ventilation channel with both the upper and lower end faces inclined is more conducive to the horizontal and vertical air flow, and is more conducive to the above-mentioned suppression of the adverse effects of the high-temperature gas in the furnace and the external gas; the above-mentioned designs jointly ensure the ranging accuracy, working reliability and long service life of the device of the present invention;

[0046] (2) The furnace top detection port arranged on the top of the insulation furnace is a cylindrical structure protruding upward. The cylinder wall of the furnace top detection port is filled with heat insulation material, which can further block the influence of external gas on the high-temperature aluminum liquid in the furnace when the detection port is opened, and avoid inaccurate distance measurement caused by solidification of aluminum liquid;

[0047] ​(3) The inspection port opening and closing assembly adopts a cylinder-driven connecting rod, utilizing the lever principle and the long circular groove movable hinge structure cross-connected and correspondingly arranged in the middle of the connecting rod and the upper part of the support rod, so that the sealing part at the second end of the connecting rod can open or close the furnace top inspection port. The operation is simple and labor-saving, and the cylinder can be used to lift and press down to ensure the sealing of the furnace top inspection port when it is closed during non-inspection. At the same time, a layer of heat-insulating flexible material structure layer can be arranged on the pressed or covered end surface of the sealing part, which can further improve the sealing of the furnace top inspection port when it is closed, and increase the end surface resistance to avoid sliding of the inclined sealing part, thereby reducing the force required to be applied by the cylinder and protecting the cylinder.

[0048] (4) The inclination angle of the inclined ventilation channel formed by the lower end face of the detection sleeve and the upper end face of the furnace top detection port can be adjusted according to the actual situation. The wind direction of the cooling air is parallel to the inclination direction of the ventilation channel. If the temperature in the furnace is very high, you can choose to tilt downward by 60°, so that the downward branch airflow is larger, which is more conducive to suppressing the high-temperature rising gas; if the outside temperature is relatively low, you can choose to tilt downward by 30°, so that the horizontal branch airflow is larger, which is more conducive to forming a shielding airflow and isolating the outside gas from entering the furnace and affecting the ranging accuracy; if the adverse effects of the furnace temperature and the outside temperature are equivalent, you can choose to tilt downward by 45°, so that the downward branch airflow is equivalent to the horizontal branch airflow, suppressing the adverse effects of the two factors to the same extent, and the operation and use method is flexible;

[0049] (5) A pressure sensor is also provided at the bottom of the holding furnace. The pressure sensor roughly detects the weight of the safety interval corresponding to the upper and lower limits of the liquid level of the holding furnace. When the weight exceeds the safety interval, the laser rangefinder is automatically started to measure the distance. The current aluminum liquid level h in the furnace obtained by the distance measurement is compared with the preset upper and lower limits of the liquid level, and measures are taken to increase the supply, discharge or do no processing. In this way, automatic and efficient distance measurement can be achieved to ensure that the aluminum liquid level is within the preset liquid level interval, thereby ensuring production quality and safety.

[0050] (6) By arranging two laser distance measuring components on a heat preservation furnace to measure distance at the same time, on the one hand, it is possible to roughly determine whether the two laser distance measuring components have measurement failures through the measurement error, and timely alarm to prompt the staff to conduct troubleshooting, thereby avoiding production accidents caused by inaccurate distance measurement due to equipment failure; on the other hand, within the measurement error accuracy range, by averaging the distance measurement values ​​of the two laser distance measuring components, the measurement error can be further reduced, achieving more accurate liquid level measurement, and being more conducive to improving production quality and safety assurance. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1This is a schematic diagram of the structure of the on-line monitoring device for the aluminum liquid level in the furnace in Example 1 of the present invention when no detection is performed;

[0052] Figure 2 This is a schematic diagram of the structure of the on-line monitoring device for the aluminum liquid level in the furnace during detection in Example 1 of the present invention;

[0053] Figure 3 This is a schematic diagram of the structure of the on-line monitoring device for the aluminum liquid level in the furnace during detection in Example 2 of the present invention;

[0054] Description of the markings in the figure:

[0055] 1-heat-keeping furnace; 2-aluminum liquid; 3-detection port opening and closing assembly; 4-furnace top detection port; 5-long round groove; 6-bracket; 7-air cooling assembly; 8-detection sleeve; 9-laser rangefinder; 10-pressure sensor; 11-first laser distance measurement assembly; 12-second laser distance measurement assembly;

[0056] 3.1-mounting seat; 3.2-cylinder; 3.3-connecting rod, 3.31-sealing part; 3.4-support rod; 4.1-thermal insulation material; 8.1-coolant inlet; 8.2-coolant outlet; 8.3-cooling pipe. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0059] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0060] Example 1

[0061] Combination Figure 1-2 As shown, an embodiment of the present invention provides an online monitoring device for the aluminum liquid level in a furnace, comprising a holding furnace 1, a laser ranging component, a detection port opening and closing component and an air cooling component 7;

[0062] A furnace top detection port 4 is provided on the top of the insulation furnace 1, and the upper end surface of the furnace top detection port 4 is inclined;

[0063] The detection port opening and closing component is used to block or open the furnace top detection port 4;

[0064] The laser distance measuring assembly comprises a laser distance measuring instrument 9 arranged directly above the furnace top detection port 4, and the laser distance measuring instrument 9 is externally sleeved with a detection sleeve 8 with a circulating cooling function, which can reduce the heat radiation effect of the rising high-temperature gas on the laser distance measuring instrument 9, and avoid inaccurate distance measurement or easy damage; the lower end face of the detection sleeve 8 is arranged to be parallel to the upper end face of the furnace top detection port 4 and form an inclined ventilation channel with the upper end face of the furnace top detection port 4;

[0065] The air cooling component 7 is arranged at the upper air outlet of the ventilation channel, and is used to provide cooling air obliquely downward along the ventilation channel, and the wind direction of the cooling air is parallel to the inclination direction of the ventilation channel. By providing oblique downward cooling air, on the one hand, the cooling air blows the rising high-temperature gas downward along the vertical wind direction to avoid the rising heat radiation laser rangefinder 9 of the high-temperature gas, and on the other hand, the cooling air provides a lateral airflow along the horizontal wind direction, which can take away the hot air blown downward, and prevent the outside gas from entering the furnace top detection port 4 to contact the aluminum liquid 2 in the furnace through the drainage effect, so as to avoid the high-temperature aluminum liquid in the furnace from solidifying after contacting the outside air, resulting in a smaller volume and inaccurate liquid level measurement.

[0066] Specifically, the furnace top detection port 4 provided on the top of the insulation furnace 1 is a cylindrical structure protruding upward, and the cylinder wall of the furnace top detection port 4 is filled with a heat insulation material 4.1, which can further block the influence of external gas on the high-temperature aluminum liquid in the furnace when the detection port is opened, and avoid inaccurate distance measurement caused by solidification of the aluminum liquid. The heat insulation material 4.1 can be specifically selected from ceramic fiber insulation cotton, which has the characteristics of high temperature resistance (high temperature resistance above 1000°C) and good heat insulation performance.

[0067] The detection port opening and closing assembly includes a cylinder 3.2, a connecting rod 3.3 and a support rod 3.4; the cylinder 3.2 is fixedly installed on one side of the insulation furnace 1 through a mounting seat 3.1, the cylinder 3.2 is vertically installed, the upper end of the cylinder 3.2 is hinged to the first end of the connecting rod 3.3, the middle part of the connecting rod 3.3 and the upper part of the support rod 3.4 are both provided with an oblong groove 5, the two oblong grooves 5 are cross-arranged and corresponding, and at the same time, the directions of the two oblong grooves 5 are parallel to the axial direction of the components where they are located, the connecting rod 3.3 and the support rod 3.4 are movably hinged through the two cross-arranged oblong grooves 5, so that the hinge point can slide along the connecting rod direction and the support rod direction; the second end of the connecting rod 3.3 is provided with a blocking portion 3.31, and the blocking portion 3.31 is pressed or covered on the furnace top detection port 4. The pressing or covering end face of the blocking portion 3.31 is an inclined surface adapted to the upper end face of the furnace top detection port 4.

[0068] In some embodiments, the pressed or covered end surface of the sealing portion 3.31 can be provided with a layer of high-temperature resistant heat-insulating flexible material structure, which can further improve the sealing performance of the furnace top detection port when it is closed on the one hand, and increase the end surface resistance on the other hand to prevent the inclined sealing portion from sliding, thereby reducing the force required to be applied to the cylinder and protecting the cylinder.

[0069] When the liquid level is not detected, the cylinder 3.2 extends to the top, provides a supporting torque upward, and amplifies the supporting torque by using the lever principle through the intersection point at the upper end of the support rod 3.4, so that the second end of the blocking part 3.31 is pressed downward, and the blocking part 3.31 can be easily sealed and pressed or covers the furnace top detection port 4 by the downward pressure applied by the second end of the connecting rod and the gravity of the blocking part 3.31 itself;

[0070] When the liquid level is detected, the cylinder 3.2 retracts to the bottom end, providing a downward pull torque, which is amplified by the lever action, so that the second end of the blocking portion 3.31 tilts upward, thereby opening the furnace top detection port 4 and exposing the internal detection channel. Figure 2 As shown, it is convenient for the laser rangefinder 9 to emit laser downward to reach the furnace to measure the filtrate level.

[0071] The laser distance measuring assembly also includes a bracket 6, and the laser distance measuring instrument 9 is installed on the bracket 6 and is located directly above the furnace top detection port 4 to ensure that the distance measuring laser emitted by the laser distance measuring instrument 9 can pass through the detection channel of the furnace top detection port 4 to reach the furnace; the laser distance measuring instrument 9 is externally sleeved with a detection sleeve 8 with a circulating cooling function, specifically, a coolant inlet 8.1 is provided below the tube wall of the detection sleeve 8, a coolant outlet 8.2 is provided above the tube wall of the detection sleeve 8, and a cooling pipe 8.3 is provided inside the tube wall of the detection sleeve 8, the cooling pipe 8.3 is spiral, and the two ends of the cooling pipe 8.3 are respectively connected to the coolant inlet 8.1 and the coolant outlet 8.2, which is used to realize the circulating cooling function by circulating cooling water or other coolants, thereby cooling the laser distance measuring instrument 9, and avoiding the thermal radiation of the high temperature gas during the detection to affect the accuracy of the laser distance measuring instrument 9 and its reliability in use. In this embodiment, the coolant is water, and other existing coolants such as ethylene glycol-water solution can also be selected according to the situation.

[0072] The air cooling component 7 is a fan or a blower, and the air cooling component 7 is fixedly arranged on the bracket 6 at an angle. The air supply section of the air cooling component 7 is perpendicular to the inclined axis of the ventilation channel formed by the lower end surface of the detection sleeve 8 and the upper end surface of the furnace top detection port 4, so that the air cooling component 7 provides cooling air obliquely downward along the ventilation channel, and the wind direction of the cooling air is parallel to the inclined direction of the ventilation channel. As shown in the previous analysis, the oblique downward cooling wind has downward and horizontal branch airflows. The downward branch airflow can blow the high-temperature gas rising from the detection port downward to avoid the high-temperature gas rising to radiate the laser rangefinder 9; the horizontal branch airflow can take away the hot air blown downward, and through the drainage effect, prevent the outside gas from entering the furnace top detection port 4 to contact the aluminum liquid 2 in the furnace, and avoid the high-temperature aluminum liquid in the furnace from solidifying after contacting the outside air, resulting in a smaller volume and inaccurate liquid level measurement.

[0073] The inclination angle of the ventilation channel is set to 30°-60°, which can be adjusted according to actual conditions. If the temperature in the furnace is very high, you can choose to tilt downward by 60°, so that the downward branch airflow is larger, which is more conducive to suppressing the rising high-temperature gas; if the outside temperature is relatively low, you can choose to tilt downward by 30°, so that the lateral branch airflow is larger, which is more conducive to forming a shielding airflow, isolating the outside gas from entering the furnace and affecting the ranging accuracy; if the adverse effects of the furnace temperature and the outside temperature are equivalent, you can choose to tilt downward by 45°, so that the downward branch airflow is equivalent to the lateral branch airflow, and the adverse effects of the two factors are suppressed to the same extent.

[0074] In addition, the lower end face of the detection sleeve 8 and the upper end face of the furnace top detection port 4 form an inclined ventilation channel. Compared with the situation where both the upper and lower end faces are horizontal or one is inclined and the other is horizontal, the ventilation channel with both upper and lower end faces inclined is more conducive to the horizontal and vertical air flow, and is more conducive to suppressing the adverse effects brought by the high-temperature gas in the furnace and the external gas as described above.

[0075] Embodiment 2

[0076] On the basis of Embodiment 1, the following improvements are made in this embodiment:

[0077] A pressure sensor 10 is further provided at the bottom of the holding furnace 1; at the same time, a controller is further included. The pressure sensor 10 and the laser rangefinder 9 are both connected to the controller, and the controller automatically detects the liquid level of the molten aluminum in the furnace according to the following method:

[0078] First, preset the lower limit h1 and the upper limit h2 of the liquid level of the molten aluminum in the holding furnace according to the operation requirements, and h1 < h2; at the same time, preset the safe liquid level range [h3, h4], and h1 < h3 < h4 < h2;

[0079] Secondly, keep the furnace top detection port closed, and sequentially measure the weight G1 of the molten aluminum in the holding furnace 1 at the liquid level height of h3 and the weight G2 of the molten aluminum at the liquid level height of h4 through the pressure sensor 10, where: h1 < h3 < h4 < h2. Specifically, the safe liquid level range [h3, h4] is located in the liquid level height range [h1, h2], and specifically, it can be moved 3 - 5 mm closer to the center line of the liquid level height range [h1, h2] according to the actual situation. The purpose is to roughly obtain the weight range [G1, G2] corresponding to the safe liquid level range through the pressure sensor 10. Without measuring the liquid level distance within the weight range [G1, G2], it can be ensured that the liquid level is stable within the safe range. After exceeding the weight range [G1, G2], then transfer to the next step to enable the laser rangefinder to accurately measure the liquid level of the molten aluminum in the furnace; at the same time, in some embodiments, in order to avoid measurement errors, when measuring G1 and G2, the average value of multiple measurements can be taken;

[0080] Then, keep the furnace top detection port 4 closed during the working process. When the pressure sensor 10 detects that the weight G < G1 or G > G2, that is, G exceeds the weight range [G1, G2], immediately turn on the air-cooling component and the furnace top detection port 4 in sequence, and start the laser rangefinder 9 to measure the distance to obtain the current liquid level height h of the molten aluminum in the furnace;

[0081] Finally, compare the current liquid level height h of the molten aluminum in the furnace with the preset upper and lower limits of the liquid level:

[0082] If h < h1, it means that the current liquid level of the molten aluminum is lower than the preset lower limit of the liquid level, and molten aluminum needs to be replenished;

[0083] If h > h2, it means that the current molten aluminum level is higher than the preset upper limit of the liquid level, and it is necessary to stop supplying molten aluminum and discharge the molten aluminum until the discharge stops when the filtrate level h = h2;

[0084] If h1 ≤ h ≤ h2, that is, h is within the liquid level height range [h1, h2], it means that the current molten aluminum level is within the safe range and no treatment is required.

[0085] Embodiment 3

[0086] On the basis of Embodiment 2, the following improvements are made in this embodiment:

[0087] As Figure 3 shown, for a holding furnace 1 in this embodiment, two laser ranging components are provided for the in-line monitoring device of the molten aluminum level in the furnace, namely the first laser ranging component 11 and the second laser ranging component 12.

[0088] Same as Embodiment 2, a pressure sensor 10 is provided at the bottom of the holding furnace 1; at the same time, a controller is further included. The pressure sensor 10 is connected to the controller, and the laser rangefinder 9 in the first laser ranging component 11 and the second laser ranging component 12 is also connected to the controller. The controller automatically detects the molten aluminum level in the furnace according to the following method:

[0089] First, preset the lower limit h1 and the upper limit h2 of the molten aluminum level in the holding furnace according to the operation requirements, and h1 < h2; at the same time, preset the safe liquid level range [h3, h4], and h1 < h3 < h4 < h2;

[0090] Secondly, keep the furnace top detection port closed, and measure the weight G1 of the molten aluminum in the holding furnace 1 at the liquid level height of h3 and the weight G2 of the molten aluminum at the liquid level height of h4 in sequence through the pressure sensor 10, where: h1 < h3 < h4 < h2. Specifically, the safe liquid level range [h3, h4] is located within the liquid level height range [h1, h2], and specifically, it can be close to the center line of the liquid level height range [h1, h2] by 3 - 5 mm. The purpose is to roughly obtain the weight range [G1, G2] corresponding to the safe liquid level range through the pressure sensor 10. Without performing liquid level ranging within the weight range [G1, G2], it can ensure that the liquid level is stable within the safe range. After exceeding the weight range [G1, G2], then transfer to the next step to enable laser ranging to accurately measure the molten aluminum level in the furnace; at the same time, in some embodiments, in order to avoid measurement errors, when measuring G1 and G2, the average value of multiple measurements can be taken;

[0091] Then, during the working process, keep the furnace top detection port 4 closed. When the pressure sensor 10 detects that the current weight G < G1 or G > G2, that is, G exceeds the weight range [G1, G2], immediately turn on the air-cooling component in sequence, open the furnace top detection port 4, and start the laser rangefinders 9 of the first laser ranging component 11 and the second laser ranging component 12 to perform ranging simultaneously, respectively obtain the first molten aluminum liquid level height H1 measured by the first laser ranging component 11 and the second molten aluminum liquid level height H1 measured by the second laser ranging component 12, and compare and analyze the difference △H between H1 and H2 to obtain the current molten aluminum liquid level height h in the furnace, specifically including:

[0092] If △H > 2mm, it indicates that the ranging errors of the two laser ranging components are relatively large, and a fault alarm prompt is issued to prompt the staff to conduct a fault check on the two laser ranging components;

[0093] If △H ≤ 2mm, then take the current molten aluminum liquid level height h in the furnace as the average value of the measurement values of the two laser ranging components, that is:

[0094] h = (H1 + H2) / 2;

[0095] Finally, compare the current molten aluminum liquid level height h in the furnace with the preset liquid level upper and lower limits:

[0096] If h < h1, it means that the current molten aluminum liquid level is lower than the preset liquid level lower limit, and molten aluminum needs to be replenished;

[0097] If h > h2, it means that the current molten aluminum liquid level is higher than the preset liquid level upper limit, and the supply of molten aluminum needs to be stopped, and the molten aluminum is discharged until the discharge stops when the filtrate liquid level h = h2;

[0098] If h1 ≤ h ≤ h2, that is, h is within the liquid level height range [h1, h2], it means that the current molten aluminum liquid level is within the safe range and no treatment is required.

[0099] In this embodiment, by setting two laser ranging components to perform ranging simultaneously, on the one hand, it can roughly judge whether the two laser ranging components have measurement failures through the measurement error, and promptly alarm to prompt the staff to conduct a fault check, avoiding production accidents caused by inaccurate ranging due to equipment failures; on the other hand, within the measurement error accuracy range, by averaging the ranging values of the two laser ranging components, the measurement error can be further reduced, realizing more accurate liquid level measurement, which is more conducive to improving production quality and safety guarantee.

[0100] The above are only the embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the scope of the application of the present invention shall be included in the protection scope of the present invention.

Claims

1. An online monitoring device for the level of aluminum liquid in a furnace, characterized in that: It includes a holding furnace, a laser distance measuring component, a detection port opening and closing component and an air cooling component; A furnace top detection port is provided at the top of the holding furnace, and the upper end face of the furnace top detection port is inclined; The detection port opening and closing component is used to block or open the furnace top detection port; The laser distance measuring component includes a laser rangefinder arranged directly above the furnace top detection port, and a detection sleeve with a circulating cooling function is sleeved outside the laser rangefinder; the lower end face of the detection sleeve is inclined parallel to the upper end face of the furnace top detection port, and forms an inclined ventilation channel with the upper end face of the furnace top detection port; The air cooling component is arranged at the upper air inlet of the ventilation channel, and is used to obliquely provide cooling air downward along the ventilation channel, and the wind direction of the cooling air is parallel to the inclined direction of the ventilation channel.

2. The on-line monitoring device for the aluminum liquid level in the furnace according to claim 1 is characterized in that: The furnace top detection port provided at the top of the holding furnace is a cylindrical structure protruding upward, and a heat insulating material is filled in the cylinder wall of the furnace top detection port.

3. The on-line monitoring device for the aluminum liquid level in the furnace according to claim 2, characterized in that: The heat insulating material filled in the cylinder wall of the furnace top detection port is ceramic fiber heat insulating cotton.

4. The on-line monitoring device for the aluminum liquid level in the furnace according to claim 1, characterized in that: The detection port opening and closing component includes a cylinder, a connecting rod and a support rod; The cylinder is fixedly installed on one side of the holding furnace through a mounting seat, the cylinder is vertically installed, the upper end of the cylinder is hinged to the first end of the connecting rod, long circular grooves are provided in the middle of the connecting rod and the upper part of the support rod, the two long circular grooves are arranged in a cross-corresponding manner, and at the same time, the directions of the two long circular grooves are parallel to the axis directions of their respective parts, and the connecting rod and the support rod are movably hinged through the two cross-arranged long circular grooves, so that the hinge point can slide along the direction of the connecting rod and the direction of the support rod; A blocking part is arranged at the second end of the connecting rod, and the blocking part is pressed or covered on the furnace top detection port.

5. The on-line monitoring device for the aluminum liquid level in the furnace according to claim 4, characterized in that: A layer of heat insulating flexible material structure is arranged on the pressing or covering end face of the blocking part.

6. The on-line monitoring device for aluminum liquid level in a furnace according to claim 1, characterized in that: The laser distance measuring component further includes a bracket, and the laser rangefinder is installed on the bracket and is located directly above the furnace top detection port; A detection sleeve is sleeved outside the laser rangefinder; a coolant inlet is provided below the tube wall of the detection sleeve, and a coolant outlet is provided above; a cooling tube is arranged in the tube wall of the detection sleeve, the cooling tube is spiral, and the two ends of the cooling tube are respectively communicated with the coolant inlet and the coolant outlet.

7. The on-line monitoring device for the aluminum liquid level in the furnace according to claim 6, characterized in that: The air cooling component is a fan or a blower; The air cooling component is obliquely and fixedly arranged on the bracket, and the air supply section of the air cooling component is perpendicular to the inclined axis of the ventilation channel.

8. The on-line monitoring device for aluminum liquid level in a furnace according to claim 1, characterized in that: The inclination angle of the ventilation channel is set to 30°-60°.

9. The on-line monitoring device for the aluminum liquid level in a furnace according to any one of claims 1 to 8, characterized in that: A pressure sensor is further provided at the bottom of the holding furnace; at the same time, a controller is further included, and the pressure sensor and the laser rangefinder are both connected to the controller; the controller automatically detects the liquid level of the molten aluminum in the furnace according to the following method: First, preset the lower limit h1 and the upper limit h2 of the molten aluminum liquid level in the holding furnace according to the operation requirements, and h1 < h2; at the same time, preset the safe liquid level interval [h3, h4], and h1 < h3 < h4 < h2; Secondly, keep the furnace top detection port closed, and measure the weight G1 of the molten aluminum in the holding furnace at the liquid level height of h3 and the weight G2 of the molten aluminum at the liquid level height of h4 through the pressure sensor in turn; Then, keep the furnace top detection port closed. When the pressure sensor detects that the current weight G < G1 or G > G2, immediately turn on the air-cooling component and the furnace top detection port in sequence, start the laser rangefinder to perform laser ranging, and obtain the current height h of the molten aluminum level in the furnace; Finally, compare the current height h of the molten aluminum level in the furnace with the preset upper and lower limits of the liquid level: If h < h1, it means that the current molten aluminum level is lower than the preset lower limit of the liquid level, and molten aluminum needs to be supplemented; If h > h2, it means that the current molten aluminum level is higher than the preset upper limit of the liquid level, and the supply of molten aluminum needs to be stopped, and the molten aluminum is discharged until the discharged liquid level h = h2 and then the discharge is stopped; If h1 ≤ h ≤ h2, that is, h is within the liquid level height range [h1, h2], it means that the current molten aluminum level is within the safe range and no treatment is required.

10. The on-line monitoring device for aluminum liquid level in a furnace according to any one of claims 1 to 8, characterized in that: For one holding furnace, two laser ranging components are provided, namely the first laser ranging component and the second laser ranging component; A pressure sensor is also provided at the bottom of the holding furnace; at the same time, a controller is further included. The pressure sensor is connected to the controller, and the laser rangefinders in the first laser ranging component and the second laser ranging component are also connected to the controller. The controller automatically detects the molten aluminum level in the furnace according to the following method: First, preset the lower limit h1 and the upper limit h2 of the molten aluminum level in the holding furnace according to the operation requirements, and h1 < h2; at the same time, preset the safe liquid level range [h3, h4], and h1 < h3 < h4 < h2; Secondly, keep the furnace top detection port closed, and measure the weight G1 of the molten aluminum in the holding furnace at the liquid level height h3 and the weight G2 of the molten aluminum at the liquid level height h4 in sequence through the pressure sensor; Then, keep the furnace top detection port closed. When the pressure sensor detects that the weight G < G1 or G > G2, immediately turn on the air-cooling component and the furnace top detection port in sequence, start the laser rangefinders of the first laser ranging component and the second laser ranging component to perform laser ranging simultaneously, and respectively obtain the first height H1 of the molten aluminum level in the furnace measured by the first laser ranging component and the second height H1 of the molten aluminum level in the furnace measured by the second laser ranging component, and compare and analyze the difference △H between H1 and H2 to obtain the current height h of the molten aluminum level in the furnace, specifically including: If △H > 2mm, a fault alarm prompt is issued to prompt the staff to troubleshoot the two laser ranging components; If △H ≤ 2mm, take the current height h of the molten aluminum level in the furnace as the average value of the measurement values of the two laser ranging components, that is: h = (H1 + H2) / 2; Finally, compare the current height h of the molten aluminum level in the furnace with the preset upper and lower limits of the liquid level: If h < h1, it means that the current molten aluminum level is lower than the preset lower limit of the liquid level, and molten aluminum needs to be supplemented; If h > h2, it means that the current molten aluminum level is higher than the preset upper limit of the liquid level, and the supply of molten aluminum needs to be stopped, and the molten aluminum is discharged until the discharged liquid level h = h2 and then the discharge is stopped; If h1 ≤ h ≤ h2, that is, h is within the liquid level height range [h1, h2], it means that the current molten aluminum level is within the safe range and no treatment is required.

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