High-pressure water descaling pilot facility uses Micro-Epsilon thermal imaging cameras
04 April 2022
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 the surface temperature before and after descaling. This allows the company 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 remove loose to sticky, primary to tertiary scale under optimum impingement and surface chilling, as well as power-water flow rate consumption. This improves the surface quality of rolled products and minimises work roll wear. Complex solid-fluid, thermomechanical 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, the measurement of the temperature and surface state is difficult to achieve (in view of steam/water, oxide scale debris and confined descaling boxes). Measuring surface losses using IR technology can provide benefits to thermomechanical processing for difficult-to-roll steel grades that are prone, for example, to ductility cracking and/or surface defects. This leads to efficient descaling under robust and energy-efficient regime maps.
To study and optimise the descaling process, Tata Steel, together with the Steel and Metals Institute (SaMI) in South Wales, have revamped an HPW descaling rig to optimise the process.
Read the full article in the April issue of DPA
Contact Details and Archive...