Precision sensor manufacturer Micro-Epsilon has introduced a thermal imaging camera with Ethernet interface and automatic hotspot finder function, enabling the camera to be operated autonomously without a PC for automatic monitoring of hot and cold spots in a wide range of applications.
The thermoIMAGER TIM41 is a compact, robust (IP67) thermal imaging camera that is particularly suitable for industrial OEM applications. The camera has an excellent optical resolution (384 x 240 pixels) and provides temperature measurements in the range -20°C to +900°C. With communication and data made available via the Ethernet interface and support for Power-over-Ethernet (PoE), direct cable lengths of up to 100m can be realised. IR video is transferred with a frame rate of up to 25Hz and can be viewed in the freely available TIMConnect software. Measured temperature values can also be output via the camera’s process interface (4-20mA). The camera can also be powered with 5-30 VDC if PoE is not available.
The camera can be operated without a PC using the ‘auto-hotspot-finder’ function, which enables automated detection of hot and cold spots within the camera’s field of view, even on moving objects. Simultaneous monitoring of up to three measuring fields is possible on a continuous basis in autonomous mode. Measurement values can be output to a PLC, for example, which in the event of limit values being exceeded, trigger subsequent actions such as alarms, opening of doors, cooling or switching. This means users can shutdown machines or processes preventively if overheating is detected. Fire monitoring in critical plant, machinery and electronics/electrical equipment are primary areas of use.
Setup is intuitive via the well-established TIMConnect configuration software, available as a free download from the Micro-Epsilon website. When connected with the software an almost unlimited number of inspection areas can be configured, along with IR video recording, snapshots and plots of temperature readings against time.
The TIM41 is available with a choice of 4 lens configurations depending on the distance and field of view required and incorporates a motorised focus for easy adjustments on targets via the software. A range of accessories are also available including air purge collars, protective windows and cooling housings, which enable the TIM41 device to be installed in a wide range of industrial environments.
High Pressure Water Descaling pilot facility in steel manufacturing makes use of Micro-Epsilon thermal imaging cameras
Tata Steel is using a thermoIMAGER TIM M-1 thermal imaging camera from Micro-Epsilon with a short 1µm wavelength, as well as a thermoIMAGER TIM 400T 1500 long wavelength thermal imaging camera, to measure surface temperature before and after descaling to assess descalability and heat loss based on nozzle pressure/flow and descaling speed.
High Pressure Water (HPW) descaling is the process of removing oxide scale by spraying the hot steel surface under a range of moderate-to-high pressure water using stationary (usually flat jet nozzles) or rotary (rotor descaler) systems. The aim is to ideally remove loose to sticky, primary to tertiary scale under optimum impingement and surface chilling, as well as power-water flow rate consumption, for improving the surface quality of rolled products and minimising work roll wear. Complex solid-fluid thermal-mechanical mechanisms are acting through the scale, scale interface and sub-surface of the steel substrate depending on the descaling process parameters of impact pressure, descaling energy and temperature.
The HPW descaling process is a harsh process where, in particular, measurement of temperature and surface state are difficult to achieve (in view of steam/water, oxide scale debris, confined descaling boxes). Measuring surface losses using IR technology can provide benefits to thermo-mechanical processing for difficult to roll steel grades that are prone, for example, to ductility cracking and/or surface defects, and leads to efficient descaling under robust and energy efficient regime maps.
To study and optimise the descaling process, Tata Steel together with the Steel Metal Institute in South Wales (SAMI) https://www.samiswansea.co.uk/ have revamped a HPW descaling rig to optimise the process. The unit can be used in two modes, static or dynamic, with hot or cold material, from steel to simulation material. Reheated samples are typically blocks of 70x70x100 mm thick placed on a carriage which transports the sample at a fixed speed (up to 4m/s). Following descaling, the carriage stops and the sample is transferred to an Argon-filled container to limit further oxidation.
All signals (height, pressure, flow, temperature, etc) are logged via a Windaq data acquisition system. A sophisticated post-analysis procedure has been put in place to characterise descaling efficiency.
Tata Steel is using a thermoIMAGER TIM M-1 thermal imaging camera from Micro-Epsilon with a short 1µm wavelength, as well as the thermoIMAGER TIM 400 T1500 long wavelength thermal imaging camera, to measure surface temperature before and after descaling. The cameras are mounted above the descaling trolley. By utilising both short and long wavelength detectors and the effect of emissivity on the scale at different wavelengths, Tata Steel can assess descalability and heat loss based on nozzle pressure/flow and descaling speed to develop regime maps for the production process.
The thermoIMAGER TIM M-1 camera was supplied with two exchangeable optics, f=25 and 75mm respectively, which allows flexibility in the field of view and camera location. The 1 µm short wavelength detector is most suited to harsh, steamy environments with reduced emissivity error at high temperatures. Included with the cameras is the powerful TIM Connect software, which allows the cameras to be used in a linescan mode or continuous acquisition from a fixed distance and location. The linescan function is particularly helpful when there is restricted viewing space and allows a complete image to be created of the slab as it passes.
As Didier Farrugia, Scientific Fellow, Rolling Finishing & Measurement Department at Tata Steel RD UK commented: “The thermal measurements made, together with surface state during and post-descaling, coupled with the use of a CCD optical camera post-descaling, has enabled the development of key HPW descaling knowledge for direct implementation and optimisation of plant practices.”
Any optimisation of yield, whether in terms of scale or metal loss during reheating, as well as enhancing surface state and defect minimisation, represents a critical cost-performance benefit for the steel industry, in the region of £1million for ~1% yield gain.
Didier Farrugia concludes: “The cameras have proven to be reliable and easy to use, including the possibility to synchronise the two cameras at two specific locations for full temperature traceability. The cameras are also being used in other specific parts of the steel manufacturing process.”
