Mechanical casting is one of the earliest metal heat-treating techniques mastered in modern production and is widely used in the manufacturing of parts and components for industries such as aerospace/aviation, weapons, machinery, electronics, petroleum, chemical, energy, and transportation. Temperature is a critical variable during melting in the casting industry; improper measurement and control can directly affect many quality characteristics.
Limitations of Traditional Temperature Measurement
Thermal Imaging Solution: Addressing Casting Temperature Measurement Limits
- Real-time monitoring of casting temperature: Workers can use thermal cameras to monitor the temperature changes of castings in real-time, allowing for the timely identification and resolution of potential issues, such as overheating or overcooling, thereby improving casting quality.
- Casting process optimization: Based on the temperature data provided by thermal cameras, workers can adjust casting process parameters, such as pouring speed and cooling speed, for better casting results.
- Casting defect prevention: Workers can use thermal cameras to identify potential defects that may occur during casting, such as shrinkage cavities and cracks, enabling timely measures to be taken for prevention or repair.
Industrial Thermal Imaging Application in Mechanical Casting
1. Monitoring of Continuous Casting Process
In the production process of continuous casting of steel, the refined molten steel is transported via a ladle to a turntable, which rotates to the designated pouring position, where the molten steel is poured into the tundish. Then, the molten steel in the tundish is evenly distributed to multiple crystallizers through the water gap. The crystallizer, being one of the core devices of a continuous casting machine, enables the molten steel to rapidly solidify and take shape. Afterward, the tension leveler and the crystallization vibration device work together to pull out the initially solidified billets. After cooling and electromagnetic stirring, the billets are cut into slabs that meet specification requirements.
In traditional processes, temperature monitoring primarily relies on experienced operators observing the color of the billets. This method is fairly subjective with larger errors, making it difficult to meet the requirements of modern continuous casting for product consistency and process controllability.
To achieve intelligent and data-driven temperature monitoring, fixed ultra-high temperature thermal cameras have been widely adopted and deployed at critical “sector” positions of continuous casting machines. They can perform real-time and high-accuracy monitoring of the surface temperature of the billets, generating dynamic thermal images and temperature curves that provide intuitive data support to operators, thus enhancing process control capabilities.
2. Monitoring of Ladle Refractory Materials
Refractory materials are widely applied to ladles and other key devices in an iron and steel plant. They may be damaged due to mechanical vibration, high-temperature corrosion, etc., thus shortening their service life. As phenomena such as peeling, gaps, and cracks gradually occur in the refractory materials, if not detected promptly, they may lead to the leakage of the high-temperature heat source, damaging the device and the environment and posing a threat to worker safety.
To effectively recognize early hazards, fixed thermal cameras can be introduced under such circumstances to monitor in real time the temperature of relevant devices. The system can accurately capture abnormal temperature changes, triggering an immediate warning when the temperature exceeds set thresholds. By analyzing thermal images and temperature distributions, the defect points can be detected and located when the refractory materials are in the early stages of peeling and cracking.
The approach enables proactive fault warning, eliminating safety hazards before they happen. This ensures the safe, continuous, and efficient operation during production in the workshop, effectively preventing device failures and safety accidents.
3. Temperature Measurement on Ladle Surface
In mechanical casting environments, ladles serve as crucial containers for transferring molten iron and are typically replaced every two weeks. Given that ladles are continuously exposed to high-temperature conditions during use, any abnormal temperature rise can lead to serious safety accidents such as the breakdown of the ladle. Therefore, real-time temperature monitoring of the ladle throughout its lifecycle is not only a key safety management measure but also provides data support for optimizing ladle structural design and extending its service life.
To precisely monitor ladles, fixed thermal cameras are usually deployed in critical access areas on-site in the related projects, establishing a comprehensive ladle temperature monitoring system. The system features the following core functions: real-time temperature monitoring of ladles passing through the designated area; recognizing the serial number of the ladles passing through the designated area with algorithms; and recording the serial number of ladles and temperature data at corresponding timestamps in the backstage for overall analysis of temperature data changes of ladles.
4. Temperature Measurement of Shell and Interior of Rotary Kiln
The rotary kiln is a key device for calcining pellets in the casting process. Its internal temperature is typically maintained above 1200°C, while the temperature reaches 1300-1400°C in the burning zone. The high-temperature operation not only affects the lifespan of refractory materials and structural components but is also one of the core factors determining product quality and production efficiency. Improper temperature control may lead to serious safety accidents such as fires or explosions.
Hence, it is particularly critical to perform real-time monitoring and trend diagnosis of the temperatures on the inner and outer walls of the rotary kiln. The fixed thermal camera system can be deployed to continuously monitor the outer wall temperature of the rotary kiln and obtain comprehensive thermal distribution images. Based on that, localized abnormal temperature rises and refractory falls can be recognized on time. Additionally, a historical temperature database can be established to provide data support for the optimization of operational parameters, fault warning, and device maintenance, thereby comprehensively enhancing the safe, stable, and intelligent operation of the rotary kiln.
5. Monitoring Medium Plate in Steel-making and Rolling Production
In steel mills, medium-plate billets remain unfinished before the steel-making and rolling process. Only through stringent heating and rolling procedures can they be transformed into qualified steel plates. During medium plate production, temperature control is decisive for the quality of the medium plate, the service life of the mold, and the production cycle. Thus, it has become an indispensable technological measure in modern steelmaking and rolling technologies. The precision of temperature control during steelmaking and rolling directly affects product consistency, the service life of the rolling mill, and overall production efficiency.
To minimize the temperature difference within the furnace, enhance the temperature uniformity of the slab, extend the service life of the device, and reduce energy consumption as well as oxidation and burning losses, thermal cameras are introduced to the production line to perform non-contact temperature measurement on the slabs exiting the furnace. This approach effectively captures the temperature distribution across areas on the surface of the slabs. By analyzing thermal imaging data, it is possible to accurately identify the causes of uneven temperatures to optimize heating process parameters and ensure stable plate quality, providing robust support for efficient, green, and intelligent steel-making and rolling.
6. Steel Plate Processing Monitoring
On the production line for rolling steel in the steel plant, plates should undergo plastic deformation treatment based on the length, width, and thickness of finished products. During the process, it is necessary to continuously monitor the flatness, geometric dimensions, and surface curvature of the plates to ensure the quality of finished products.
Currently, visible light cameras coupled with exposure adjustments are mainly adopted on-site to assess the flatness and evenness of the plates. However, due to the repeated water-cooling process required after rolling, there is often a significant amount of water vapor and steam on site, which severely obstructs visible light imaging, making it difficult to accurately capture the outline of the plates. Meanwhile, as the plate temperature gradually decreases, the image brightness significantly reduces under fixed exposure parameters, which further affects image clarity and detection accuracy.
Consequently, traditional visible light imaging methods exhibit clear limitations under complex high-temperature and high-humidity conditions. There is an urgent need to introduce visual perception technology that is more suitable for high-temperature industrial scenarios to achieve stable monitoring and intelligent recognition of the plate status.
7. Temperature Measurement of Die-casting Molds
Die casting is a precision metal casting process that is characterized by forcing molten metal under high pressure into a mold cavity with a complex shape. A die-casting machine is a machine used for die casting. Under pressure, molten metal is injected into the mold for cooling and forming, and solid metal castings can be obtained after die sinking. Uneven or improper mold temperature will directly lead to product defects, ejection casting deformation, cracks, mold sticking, surface depressions, shrinkage cavities, and hot bubbles. Significant differences in mold temperature will have different degrees of influence on the filling time, cooling time, and spraying time.
The thermal camera can be used for non-contact temperature monitoring of the temperature for the mold before and after spraying the release agent to ensure the temperature status of the mold. Hidden dangers can be identified by comparing and analyzing monitored historical data.
8. Integrated PLC Monitoring for Die Casting
The manufacturing of vehicle engines and car shells involves hot casting. To ensure the quality of the components, it is necessary to monitor the temperature of the mold before and after the die-casting process, including the temperature of the mold before die-casting and the temperature of the mold after water spray cooling. The on-site device and die-casting PLC linkage realize the real-time monitoring of the mold temperature and the fully automated die-casting production line. At the same time, the complete mold production temperature can be recorded.
The front end is equipped with an online thermal camera, and the data from the thermal camera is obtained through the network protocol. The thermal camera is connected with the PLC through the back-end program to confirm the current status before and after die casting. Then obtain the temperature data from the device end for judgment. The large screen displays the temperature and infrared pictures before and after die casting in the last two periods.
9. Mechanical Power Device Temperature Monitoring
Devices such as motors, fans, pumps, and compressors in the field of mechanical power generally include transmission components such as bearings, gears, belts, and couplings, which transfer mechanical energy through friction. In that case, friction-induced heating will occur after prolonged operation. Once the temperature exceeds a safe threshold, it may not only cause device damage but also result in energy waste and safety accidents.
The thermal camera, being a non-contact temperature monitoring tool, can accurately detect potential faults such as bearing misalignment, poor lubrication, belt slippage, and pulley displacement without downtime. By providing real-time imaging, it helps quickly locate hot spots, offering O&M personnel an intuitive and effective basis for decision-making, thereby effectively reducing friction, improving transmission efficiency, and contributing to energy conservation and emission reduction.
Furthermore, the thermal camera demonstrates significant advantages in several key monitoring processes compared to other traditional methods. In journal temperature monitoring, it overcomes the limitations of being unable to contact and measure temperatures on high-speed rotating components, allowing for the timely identification of fault risks caused by overheating bearings, thus preventing production disruptions. In bearing crack detection, it can identify micro-cracks on the surface that are difficult to discern with the naked eye, enabling early warning. In motor insulation failure monitoring, it can set temperature thresholds for real-time alarm alerts to help address issues such as poor heat dissipation and abnormal insulation, preventing major safety accidents.
10. Friction Welding Temperature Monitoring
Friction welding is a commonly used welding method in the mechanical casting industry. At present, users cannot intuitively and effectively grasp the temperature of welding points during welding, and skilled workers rely solely on their experience for operation and control. It needs workers’ long-term experience accumulation, and it is also prone to significant temperature variations, which cannot guarantee the welding quality. Therefore, it is particularly important to observe the temperature information of the welding point intuitively and grasp the welding temperature in a timely and accurate manner to ensure the welding quality.
By remotely monitoring the welding point temperature in real time with a non-contact thermal camera, accurate temperature control is achieved, leading to optimal welding quality and improved production efficiency. This method avoids the limitations of traditional measurement techniques.
11. Temperature Monitoring of Cooling Chromium-Molybdenum Steel Liners
Chromium-molybdenum steel liners are commonly used key raw materials in the mechanical casting industry. They are widely applied as a reinforcement between the wear-resistant liner and the cylinder of the ball mill to support the cone, protect the device, and cushion the impact of crushed ore. With effective design, those liners can reduce device vibration and extend their service life. After being discharged from the furnace, liners shall be placed in a cooling area for cooling treatment. The traditional manual temperature measurement and spray cooling are inefficient and labor-intensive. Furthermore, prolonged exposure to a high-temperature environment can be harmful to the health of operators.
Compared to traditional point-temperature fixed measurement devices, thermal cameras can provide more intuitive visual temperature distribution images and help operators track the temperature status of the liners in real time. They can perform non-contact temperature monitoring, enabling comprehensive monitoring of temperature changes across all areas on the surface of the liner. In that case, potential overheating or uneven cooling issues can be identified on time, and the cooling process can be optimized to enhance efficiency, reduce labor input, and ensure the safety of operators.
12. 3D Printing Temperature Monitoring
3D printing technology, also called additive manufacturing, is a new type of mechanical casting process. It is a technology that, based on digital model files, employs bondable materials like powdered metal or plastic and constructs objects through layer-by-layer printing. Temperature control during the printing process is crucial for the bonding properties, stacking performance, and printing accuracy of the material. If the printing temperature is too low, the viscosity of the material will increase and the extrusion rate will slow down. If the temperature is too high, the material tends to become liquid, the viscosity decreases, the fluidity increases, and the extrusion rate is too fast, making it impossible to form filaments with accurate control. Therefore, it is particularly important to accurately control temperature during 3D printing.
During the process, the thermal camera, being a non-contact temperature measurement tool, can perform real-time and precise temperature monitoring, thus helping ensure stable and accurate temperature throughout the printing process in the 3D printing industry. The thermal camera can comprehensively monitor temperature changes at critical components such as the print head and print bed, thus preventing printing defects caused by temperature fluctuations and improving product quality and printing efficiency, contributing to the refined and intelligent development of 3D printing technology.
13. Safety Monitoring of Processing Lathes
Devices such as cutting machines and rollers often require operators to manually feed components. During processing, the operators’ hands are often close to the processing area, and the machines cannot automatically determine when to start or stop. Even a slight deviation in feeding can easily lead to injuries for the operators.
To address this issue, multiple sets of raster devices were usually installed on site. When an object enters the detection area of the raster, the emitting and receiving devices identify it and automatically output a control signal to cut off the power of the device. However, those raster devices cannot distinguish between parts and components and the operators’ body parts, resulting in frequent triggering of the raster devices per feeding. It causes the device to stop frequently, affecting production efficiency and failing to effectively protect operators.
To optimize the existing solution, thermal cameras, thanks to their working principle, can effectively replace traditional raster devices. They can monitor the temperature differences between the parts and components and the human body on site and determine whether an operator’s hand is close to a dangerous area. They can set a safety warning area and monitor temperature changes in real time through temperature measurement lines and areas.
If operators mistakenly extend their hands into the measurement area and the temperature exceeds a set safety threshold (e.g., 35°C), the device will trigger an alarm and output a signal through I/O to connect to the PLC control system, thus automatically shutting down the processing device. This measure greatly enhances processing safety, protecting operators during processing to avoid potential injury accidents.
Advantages of Raythink Thermal Camera for Mechanical Casting
1. Smart Inspection and Fault Early Warning
Thermal cameras coupled with professional temperature measurement tools to freely select monitoring areas and automatically obtain the highest temperature point for regular inspection. Thermal image comparison helps discover the damage in the measured devices and notifies staff or links automation devices for management and control.
2. Data Analysis and Predictive Maintenance
The settings of temperature threshold, duration, and sampling interval are available to achieve automatic data collection. Thermal cameras are used to measure the temperature field of the outer wall of the measured device. Then, analysis is conducted for the linear relationship between the outer wall temperature of the mechanical casting boiler and corrosion in the inner lining refractory, and the obtained relationship serves as the reference for making maintenance plans.
3. Flexible and Convenient with Low Maintenance Costs
Thermal cameras feature flexible and convenient operations. Preliminary constructions such as fixed platform installation and cable layout are no longer needed, and the device maintenance cost is relatively low.
4. Self-Developed and Convenient System Integration
Raythink has self-developed all hardware products, from detectors to modules and finished products. Those products support various network protocols such as ONVIF, MODBUS, and MQTT, making system integration more convenient. Meanwhile, Raythink has developed its cloud platform software VIS-3000 for system integration. This software is designed for company device access and management. It comprehensively accesses online monitoring devices developed by Raythink and other manufacturers via Raythink’s private protocols, GB28181, ONVIF, and MQTT, suitable for large-scale LAN device access.
Project Display 1: Enhancing Efficiency for a Die Casting Manufacturer
During die-casting production, temperature control, such as that of die-casting molds, is one of the core process factors. A stable temperature field within the molds directly affects the casting quality, production efficiency, and service life of the molds, thereby influencing production costs and economic benefits. Failure to maintain the mold temperature within the required range can affect the appearance and internal quality of the castings, resulting in decreased production efficiency. Specific issues are as follows:
- Excessively high temperature: Defects such as damage and bubbles will occur, prolonging the cooling time and lowering production efficiency.
- Excessively low temperature: Defects such as cold shut, misrun, and pores will occur, impairing product quality.
In the production of die-casting molds, the molds are often subject to high-temperature and high-pressure environments. The instability of the temperature field causes the molds to be more prone to failure due to periodic thermal expansion and contraction, which not only shortens the service life of the molds but also severely impacts production efficiency.
Customer Demands
- Infrared temperature measurement: Temperature can be measured at the end of the spray process after die sinking. Infrared thermal imaging is used to assess the uniformity of the mold temperature, allowing engineers to conveniently adjust the parameters of the die-casting machine based on the temperature.
- Temperature threshold triggering: Temperature thresholds, time, and duration are set to automatically collect data and generate a temperature curve. In case of abnormal cooling, a temperature alarm is triggered to ensure real-time monitoring during production. Meanwhile, a temperature fluctuation curve is generated, facilitating engineers in tracking temperature changes.
Solution
Infrared thermal imaging technology is used for temperature monitoring, with abnormal temperature alarm signals sent to the PLC system. Upon receiving a high-temperature alarm, the PLC system can automatically control the robot to carry out spraying treatment and extend the spraying time for cooling. The system is superior in its ability to automatically cool, controlling the temperature within the required range without the need for manual intervention. It can significantly improve production efficiency and extend the service life of the molds.
Project Display 2: Temperature Monitoring for a Rotary Kiln
Due to the heating of the burning zone, the inner wall close to the rotary kiln head has the highest temperature in the rotary kiln. With the increasing time of rotary kiln operations, the inner lining will become thinner and even fall off due to the constant high temperature and friction of clinkers. Consequently, the pipe wall temperature changes drastically, and the temperature in the rotary kiln becomes unevenly distributed, hampering stable and reliable operations of rotary kilns. An overly high temperature will cause over-calcination, while a low temperature will cause under-calcination. Neither will produce ideal calcination results.
Traditional manual routine inspection can hardly discover exceptional areas, unable to impose effective safety controls for rotary kilns. Furthermore, the large size and continuous rotation of the kiln make manual inspection difficult and prone to omissions, while single-point temperature measurements can lead to undetected faults and delayed responses.
Thermal Imaging Solution
Thermal cameras enable all-weather temperature monitoring, temperature trend analysis, and alarm prompts for the rotary kiln outer wall to replace manual inspection. The thermal cameras effectively transmit images and temperature data to the control room in real time to prevent, handle, and trigger alarms for problems in advance.
The rotary kiln head sprays fuel into the kiln. The exhaust gas generated through combustion goes to the material and then is let out from the rotary kiln discharge head. The temperature gradually decreases from the rotary kiln head to the rotary kiln discharge head. The temperature at the quenching position of the rotary kiln head can reach 1400°C, but the temperature at the rotary kiln discharge head is only 500 to 800°C. Thermal cameras can monitor the operation status and temperature fields of the combustion in the rotary kiln in real time for real-time visual display of temperature and historical temperature queries.
