Detection of Dummy Bar System at Continuous Casters
Customer / Field / Equipment manufacture
Vallourec Sol. Tubulares do Brasil – Steelworks in Jeceaba. Continuous Casting - Long products
Blooms or billets are formed in the strands of the continuous casting machine. After passing through the mold, oscillator, straightening and secondary cooling, the semi-finished product is ready to be pushed out onto the rolls. During this process the head must be guided; a dummy bar system or starter bar is used to guide the billet. Customer wants to detect the hot material as well as its head, that is to say the dummy bar system, or starter bar (or false bar), which is cold. This provides early information on material approaching, as wells as position control of the dummy bar system, which must then me removed.
The position of the dummy bar system can be detected only by means of an optical sensor, i. e. a barrier working on the light interruption principle. Casting machines usually consist of several strands, but barrier must control only the relevant strand, so it has to be installed very close to the material. Processing and ambient temperatures are both very high.
Previous solution / Competitor product
Optical system with fibre optics. An electronic box with two fibre optic cable in transmitter-receiver function. Model CLS-K from MICRO-EPSILON. It was a barrier for general purposes so customer had to provide complex mechanical protection for fibre optic cables against radiated heat. Subject to failure. Unstable function with hot blooms.
Light barrier (transmitter-receiver mode) with separate fibre optic cables and optics. Fibre optic cable withstands up to 290 °C. Front part of the optic (lens side) up to 600 °C. Cable protection hose set for fibre optic cable.
Advantages compared to previous solution or competition
High material temperature has no impact on correct functioning. Equipment long lifetime. We provide solutions tailored for the steel industry. Safe detection also in contaminated areas thanks to high functional reserve. We provide fitting accessories for mounting and protection. We have consolidated references among plant constructors: Danieli, for example, uses Proxitron light barriers for dummy bar detection in their Minimills.
Competitor solution, product series CLS-K