The EMLI Furnace Bath Level Measurement System
EMLI System Description
The EMLI™ (Electro Magnetic Level Indication) system utilizes state-of-the-art technology in the measurement and detection of liquid metal levels. The basic EMLI system architecture consists of a MANAGEMENT UNIT, a CONTROL UNIT and a PREAMPLIFIER UNIT. In multiple system applications, one MANAGEMENT UNIT can monitor up to eight (8) CONTROL UNITS.
The MANAGEMENT UNIT is used to monitor the system, log data, and for set-up and troubleshooting. If enabled the system can be remotely evaluated through the MANAGEMENT UNIT via an Internet connection.
The CONTROL UNIT is the heart of the system. It generates the transmitter signal and receives and evaluates the measurement signal.
The PREAMPLIFIER UNIT increases the level of the measurement signal before it is fed to the CONTROL UNIT
The MANIPULATOR unit inserts the lance into the hot bath to enable the level measurement.
EMLI - FBL Furnace Bath Level Measurement System
The EMLI Furnace Bath Level Measurement System is a robust instrument that reliably and consistently measures the level of the liquid metal in an Electric Arc Furnace (EAF). A unique feature of the system is that it can take measurements when the furnace is dormant or when the furnace is arcing.
In most cases the system is adapted to work with the existing furnace door manipulator. (If the plant does not have a manipulator MPE-US can assist in the acquisition of a unit). The manipulator must have a position encoder. A specially designed proprietary EMLI sensor is installed in the end of a modified lance. The addition of the EMLI sensor does not interfere with the other functions on the lance.
An IMPORTANT feature of the EMLI Furnace Bath Level Measurement System is that the system is not affected by slag and therefore measures the actual level of liquid metal in the furnace.
Principle of Operation
The special EMLI Furnace Bath Level Measurement System sensor emits an electromagnetic field that surrounds the tip of the lance. When the lance is in the retracted position there is no metal in the immediate vicinity of the sensor and therefore the signal output from the system is minimal. When the manipulator begins the insertion cycle and the lance enters the bath, the sensor is initially surrounded by slag. Since the sensor is unaffected by slag there is no change in the system output signal. As the insertion cycle continues the sensor will pass the slag/steel interface and become immersed in the liquid metal. At this instant the metal has a major effect on the electromagnetic field surrounding the sensor and the signal output increases dramatically. At this point the system notes the reading from the lance position encoder and uses this reading as the metal bath level.
The fact that the EMLI Furnace Bath Level Measurement System accurately measures the true level of the metal in the Electric Arc Furnace (EAF) and offers the following benefits: