Electromagnetic (BOF & EAF)
The EMLI BOF and EAF Detection 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
EMLI-SIE Electric Arc Furnace Slag Detection System:
The EMLI III Electric Arc Furnace (EAF) slag detection system uses state-of-the-art electronics and custom designed sensors to detect the presence of slag in the taphole area of the furnace during tapping.
The proprietary sensor design and sensor placemen allows the EMLI system to generate a reliable and accurate slag alarm far in advance of the slag detection of a human operator.
This allows the user to maximize yield while greatly minimizing slag carryover.
The EMLI EAF slag detection system utilizes two sensor coils, placed on opposite sides of the taphole in the bottom of the furnace. One coil is used as a transmitter and the other is used as a receiver.
The transmitter is excited with a controlled AC current. This current causes the formation of an electromagnetic field that is detected by the receiver.
When the taphole is empty, maximum signal transfer occurs and the receiver detects a strong signal.As tapping begins and the taphole is totally filled with steel, maximum signal shielding occurs and the receiver detects the minimum signal.
Near the end of the tapping, slag begins to become entrained in the stream and appears in the taphole. Since slag does not shield electromagnetic signals, the signal in the receiver begins to increase toward maximum. The received signal is directly proportional to the amount of slag in the taphole.
When the received signal reaches a certain predetermined set-point level, a slag alarm is activated a slag alarm is activated
System Benefits:
The EMLI EAF Slag Detection System accurately and reliably detects the onset of slag during the tapping phase of an Electric Arc Furnace or a Basic Oxygen Furnace. The system offers the following benefits to the modern steelmaker:
- The unique design and placement of the EMLI sensor coils allows the system to detect the presence of slag at the earliest possible moment. This a major advantage competing technologies..
- The slag alarm can be adjusted based on the type of steel being produced.
- Sensor coils can often be ocated and installed in such a manner that they are accessible from the outside of the furnace without disturbing the furnace refractory.