Depending on mill size and purpose, a steel mill may carry out all steps of steelmaking from smelting iron ore to rolled product. Or it may melt semi-finished casting products such as blooms, ingots, slabs and billets, made from molten pig iron or scrap.
There are two types of steel mills, integrated and mini. Integrated plants usually make large structural sections, such as heavy plate, strip, wire rod, railway rails, and occasionally long products such as bars and pipe. A mini-mill is traditionally a secondary steel producer, with most of the iron it uses coming from recycled scrap steel.
Temperature measurement and control throughout the steel production process helps improve worker safety, protects equipment, and maintains product quality.
Molten pouring streams are found in several locations within the steel plant. Arc and blast furnaces melt iron ore producing molten streams which fill ladles and torpedo cars that move the liquid steel to tundishes which are filled by molten pouring streams from the transport vessels. The liquid metal needs to be consistently monitored to ensure it remains at an ideal temperature. If it does not, the liquid metal may cool too quickly, causing damage to equipment and creating a defective end product.
Thermal imaging cameras and infrared (IR) temperature sensors from Process Sensors Corporation (PSC) are routinely used for monitoring molten steel.
Ladles and torpedo cars are a critical component of the steel production process used to transport molten metal from the arc or blast furnace to another location within the plant for further processing.
The refractory lining of these vessels is susceptible to damage over time due to high molten steel temperatures. Ladle and torpedo car shells require routine temperature and hotspot monitoring to identify the risk of a breakout.
The Surveyor thermal imaging camera series from Process Sensors Corporation allows for precise detection of defects or depletions in the refractory lining across a large camera viewing area. With a Surveyor thermal imaging camera, a profile of the entire shell can be generated to automatically detect hotspots before a breakout can occur, protecting the safety of workers and preventing facility damage. Multiple thermal imaging cameras can also be used to monitor the integrity of the entire shell to identify defects before they become critical.
For ladle or torpedo car transport that does not follow a fixed path, portable handheld IR thermometers from PSC can be used to detect single spots on the shell or car surface on a routine basis.
Usually present in integrated steel mills, continuous casting is the process in which molten metal is poured from the ladle into a tundish. A tundish feeds molten metal into a water-cooled vibrating mold where it begins to solidify into billets or slabs. It is then drawn through a die, creating the desired shape. Once shaped, the metal cast enters a spray chamber where water jets spray the metal to cool and harden it.
Before the molten metal cast is cooled with water, it gains a thin layer of cooled skin, strong enough to hold shape but susceptible to a “breakout” if not properly cooled. The cooling rate of the metal must be carefully controlled or it can clog the tundish, cause an expensive molten metal breakout, or adversely affect product quality.
Specially engineered fiber optic 2-color pyrometers from PSC can be used to provide important temperature data to the operators who supervise the cooling rate, preventing any damage, loss of production and downtime.
To learn more about how PSC can optimize your molten steel handling and casting operation, please fill out the contact form below.
The Process Sensors Surveyor camera series offers a comprehensive range of imaging and line scanning camera systems to continuously monitor and control industrial processes.
The Process Sensors Metis M3 Series pyrometers are available in single and dual wavelength versions and feature advanced design and feature sets.
Rich in features, the self-contained two-color model PSC-SR56N and one-color models PSC-G56N/PSC-S56N pyrometers offer a choice of four sighting methods.