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Electrics & Automation for Special Melting & Remelting

IREC REMELTING CONTROL

The IREC is a specially developed unit designed to control ESR, VAR and Ti-VAR processes with nonlinear advanced controllers. Electrode control is performed by a servo frequency converter or via fast-response hydraulic cylinders. Power control is provided by transformers and saturable reactors. All the components are powered by MCC cabinets and controlled from a PLC cabinet.

In manual mode, the system also accepts local commands from local operator panels. Various different ESR, VAR and Ti-VAR plant types can be equipped with this system, for plants operating with 1-65 t ingots.

The open interface enables a process control system (PCS) to communicate with the IREC where different process values and process setpoints can be exchanged. In addition to the communication with the PCS, some signals are connected directly for faster signal filtering and more precise control. The controller is equipped with a memory card that incorporates the entire configuration and control. 

 

IREC Features
  • High-performance management system for the ESR process
  • Advanced nonlinear PID control
  • Fast melt rate and swing calculation algorithm
  • Interface layer to all common Process Control Systems (PCS)
  • Highly reliable 

The IREC System includes all the functions required for automatic ESR operation, such as:

  • Melting voltage control
  • Melting current control
  • Electrode immersion depth control (slag resistance control) 

The melting parameters are as follows:

  • Melting current
  • Melting voltage
  • Melting power
  • Electrode feed rate
  • Electrode weight
  • Controller setpoints
  • Resistance variation (swing)
  • Electrode (ram) position
  • Melt rate control
  • Pre-setting of controller setpoints
  • Drip short control – optional 
IREC SYSTEM DATA
Item Data
CPU Intel® Atom D410 ® 1,66GHz, 2 GB RAM, System Memory Compact Flash
Interfaces 4 x Ethernet (10/100 BaseT)
2 x USB
Profibus-DP-Master (max. 2 units)
2 x RS232/422/485
1 x VGA connector (15 po. Sub-D-socket w.)
Operating system Windows 7 embedded
Power supply +~36VDC
(e.g. 24 V @ 2A, min. 48 W)
Dimensions 111 x 152 x 139 mm
Protection class IP 20
Ambient area working temperature -10°C to +65°C
Storage temperature -20°C to +80°C
Relative humidity 20 ~ 95 % not condensed
IREC CONTROLLER ARCHITECTURE
IDRIP - Drip short measurement of the VAR

Two measurement cards in parallel mode are used to measure the VAR voltage. This means the voltage values can be obtained at a sampling rate of 200 kHz. These raw values are used to evaluate the drip short frequency and produce the time categorization of single drip shorts. 

If the input voltage falls below a defined trigger level, then a single drip will be triggered. The drips are categorized according to their duration. The unit features values for the trigger level, voltage hysteresis and duration times for categorization. 

IDRIP - CONTROLLER ARCHITECTURE