Before hot rolling, it is necessary that the billets / blooms /slabs be homogeneously reheated at a temperature between 1.100ºC and 1.250ºC. This is achieved in the Reheating Furnace specialized in working with both hot and cold material at furnace entry.
Our list of references for this type of installation covers all types of furnaces:
- Walking hearth & Pusher furnaces, for low investment processes,
- Walking-beam and refractory beam furnace, for more special applications,
- Tunnel furnaces for thin and semi-thin slabs in mini-mill processes,
- Rotary hearth furnaces, for reheating round ingots for the production of non- welded tubes or pipes,
- Rototherm furnaces for hardening and tempering tubes and pipes,
- Handling systems associated to the above mentioned furnaces:
o roller tables,
o transfer tables,
o transfer cars,
o kick-on and kick-off devices for charge and discharge,
o Automatic positioning systems with fixed and movable stoppers….etc.
Within the framework of a Reheating Furnace Control, Ingeteam has developed up to three different applications implemented in different control systems, either PC’s or PLC’s, covering the entire control and regulation of a Furnace: from level 0 instrumentation to 1.5 level optimization, through to level 1 sequential and technologic control.
The Reheating Furnace Technological Control System –TCS- is mainly conceived to handle furnace regulation loops as well as metallurgical, energetic and productive strategies such as the ignition/switch-off control of the furnace.
The regulation loops and tasks controlled by this application are as follows:
- Zone temperature regulation,
- Cross-control air flow and gas flow regulation. There are up to two thermocouples per zone that allow a plausibility control as well as an automatic commutation of the feedback element in case of failure,
- New strategies of temperature regulation based in 100% sequential impulse firing (no cross-control needed neither associated instruments).,
- Air/ Gas efficiency correction,
- Furnace pressure regulation,
- Combustion air pressure regulation,
- Combustion air recuperator protection: fume dilution or hot air leakage,
- Cooling circuit regulation and control: flow, level and temperature,
- Solenoid valve control and ON/OFF of combustion ventilators,
- Indication and monitoring of the process values, trending and logging,
- Furnace startup strategies / stoppage time control
- Material tracking,
- Reports by lot, shift, daily and weekly