Steel slabs, beams, tubes and bars usually need to be re-heated after they have come out of the rolling mill so that they can pass through the final stage of processing. This final processing may be finish rolling or annealing to complete the processing of the product to meet the required specification. A re-heat furnace is used in these cases to raise the steel temperature to around 1200 degrees C (around 2190 degrees Fahrenheit).
There are two basic types of furnace: batch type or continuous type. The continuous type of furnace is generally the most popular, and there can be a variety of methods and mechanisms to transport the tubes, beams or bars through the furnace. There is often a critical need for high temperature cameras to provide a continuous view into the furnace to monitor the safe progress of bars through the furnace (for product tracking purposes), or to look for possible defective or bent bars which may block the furnace or cause a stoppage.
The Mirion R640 Ventus camera offers a wide field of view so often only a single camera may be required to monitor the entire width of the furnace. In addition, it is water-cooled and uses only a small amount of purge gas (which can be compressed air or nitrogen), so it does not disturb the oxygen balance in the furnace with its lens cooling purge.