In today’s manufacturing market, aluminum is increasingly becoming the material of choice being lighter, safer and more sustainable. With estimated growth in global aluminum demand of 4-5% in 2018, both primary and secondary processors of aluminum are rapidly looking to improve the efficiency of their operations. Manufacturers looking to replace existing materials with aluminum need new methodology to prove that new thermal processing of aluminum parts and products is done to specification both efficiently and economically.
Helping with this need, PhoenixTM offers a range of temperature profiling solutions designed specifically for applications in the aluminum manufacturing market. Whether reheating aluminum slabs/ingots or log homogenization in a continuous pusher or walking-beam furnace or solution reheating (T6) aluminum automotive parts, a unique system solution is available. In many situations, PhoenixTM has worked directly with key industry players to develop bespoke solutions for unique process challenges.
Temperature Profiling Solutions
The PhoenixTM temperature profiling system is designed to travel through the thermal process measuring the product and or furnace environment. A high-accuracy, waterproof, multichannel datalogger records temperature from thermocouple inputs, located at points of interest on, in or around the product being thermally treated. To protect the datalogger as it travels through the hostile furnace, a thermal barrier "hot box" is employed to keep the logger at a safe working temperature to prevent damage and guarantee accuracy of measurement.
The design and choice of barrier is strongly influenced by the demands of the process. PhoenixTM offers a comprehensive, flexible and durable range of barriers to suit even the highest of temperatures and longest soak times. Employing the PhoenixTM system, a complete thermal record of the product throughout the entire process can be collected. A popular enhancement to the system is the use of two-way RF telemetry, providing real-time process monitoring direct from the furnace. The product temperature can be viewed live and downloaded at any point in the furnace. Raw temperature data collected from the process can be converted into useful information using one of the custom-designed PhoenixTM Thermal View software packages available.
The thermal graph can be reviewed and analyzed to give a traceable, certified record of the process performance. Such information is critical to satisfy CQI-9, AMS 2750 and other regulatory demands. Fully TUS-compliant reports can be produced in moments from the intuitive software, making accurate TUS a simple and quick task. Information can be used to not only prove product quality but provide the means to confidently change process characteristics to improve productivity and process efficiency.
Datalogger Range
Dataloggers can be provided in a variety of configurations to suit the specific demands of the process being monitored. Models ranging from 6 to 20 channels can be provided with a variety of thermocouple options (types K, N, R, S, B) to suit measurement temperature and accuracy demands (AMS 2750 and CQI-9). The loggers can be offered in either standard (<80 °C/176°F) or high-temperature operating temperature variants to allow use of either standard thermal barrier designs or high-performance designs. Built to cope with hostile industrial environments, the IP67 logger is capable of managing even the most demanding water quench process.
Provided with Bluetooth wireless connection for short range localized download and reset (direct from within the barrier), the logger memory of 3.8M allows even the longest processes to be measured with highest resolution. An optional two-way telemetry package offers live real-time logger control and process monitoring.
Live Radio Communication
The logger is available with a unique two-way RF system option, allowing live monitoring of temperatures as the system travels with the product through the furnace. Furthermore, it is possible to communicate with the logger, installed in the barrier, to reset/download at any point pre-, during and post-run using the RF system.
Provided with a "Lwmesh" networking protocol, the RF signal can be transmitted through a series of routers linked back to the main coordinator connected to the monitoring PC. The routers being wirelessly connected are located at convenient points in the process to capture all live data without any inconvenience of routing communication cables as needed on other commercial RF systems. The operator, from the convenience of his/her control room/office, can see what is happening in the process live. For an 11-hour process such live data gives the operator confidence that the process is working.
In many processes there will be locations where it is physically impossible to get an RF signal out of the furnace. With conventional systems this results in process-data gaps. For the PhoenixTM system this is prevented using a fully automatic catch-up feature. Any data that is missed will be sent when the RF signal is re-established, guaranteeing 100% in-process data review in most applications.
Aluminum Processing
Preheat of Aluminum Slabs/Ingots Prior to Hot Rolling (Pusher Furnace)
A thermal barrier is embedded into the slab (machined or milled out) to allow safe transit of the test slab through pusher furnace (typically 550°C/1022°F). Thermocouples are set deep into the core of the slab/ingot. A water tank is designed to give capacity (volume of water) to allow protection of logger running safely at 100°C (212°F) as water boils and evaporates off. A filling mechanism is designed so that even during slab rotation entering and exiting furnace water is not lost from the tank. Employing RF, the soak process can be monitored to guarantee that the correct rolling temperature is achieved to avoid excessive roll wear. From live monitoring, halving of soak times have been achieved.
Aluminium Log Homogenization (Walking-Beam Furnace)
After casting, aluminum logs are homogenized before being supplied to extrusion companies. The walking-beam process is demanding not only due to the excessive durations (12-13 hours at 580°C/1076°C) but due to the fact that the profiling system has to rotate with the log and therefore needs to be the same form as the log with the same diameter or less.
The PhoenixTM rotating cylindrical barrier design meets the demands of the process. The barrier is attached to a shortened log, and thermocouples are routed along the log in a machined channel to prevent problems during movement through the furnace. The design of the barrier water tank, providing thermal protection, guarantees that water capacity is maximized with no loss of water during continuous process rotation.
T6 Solution Reheat of Aluminum Automotive Products
The solution reheat process (T6) comes with many technical challenges where temperature profiling is concerned. The need to monitor solution treatment, quench and then the age-hardening process requires not only a system that will protect against heat over a long process duration but also withstand the rigors of being plunged into a water quench between the two heating phases.
The PhoenixTM HTS06 system has been designed specifically for the T6 process. The datalogger is installed in the water tank cavity of the thermal barrier, with a water-tight seal comprising of heavy-duty gaskets and compression glands through which the thermocouples exit. This protection, along with the logger's IP67 rating, ensures that the logger is protected from water damage during the quench. Providing significant thermal protection, the outer cage containing the thermal-insulation-blanket-wrapped water tank is capable of running continuously through all three processes without interruption. In the quench, the water tank is replenished and the blanket will absorb water providing further protection during the age-hardening process. The TS06 can provide protection at 550°C (1022°F) for up to 20 hours.
AMS 2750/CQI-9 Furnace Temperature Uniformity Surveys (TUS)
PhoenixTM is able to offer fully AMS 2750 and CQI-9 compliant temperature uniformity survey (TUS) solutions. Combining the thermal barrier or external logger offerings, the system can be used to validate that the furnace setpoints defined in the TUS are within specified limits. The Thermal View Survey software package provides full review, analysis and reporting to satisfy the strict requirements of regulatory standards.
Aluminum Brazing (CAB and Vacuum)
Monitoring controlled atmosphere brazing (CAB) processes used in the manufacture of radiators and condensers comes with its own specific challenges. Mesh-belt furnaces often have limited accesses requiring the use of low-profile barrier designs. Chemicals in the flux used in the process can chemically attack the glass cloth used in most thermal barrier constructions.
To overcome this issue, the CAB barrier is designed with a front-loading draw to minimize the amount of exposed cloth. As its name suggests, the CAB process can be compromised by the degassing of oxygen from the barrier. To eliminate such problems, the barrier insulation is pretreated with a vacuum heated/nitrogen purge procedure.
Conclusion
PhoenixTM offers complete, reliable, through-process temperature profiling solutions for use across the aluminum processing industry. Offering unique solutions to meet specific application challenges, PhoenixTM provides tried-and-tested systems used globally by key market players to understand, control and improve their manufacturing operations.
