Wednesday, May 5, 2010

Tundish Systems

Tundish Gate :
Tundish gates are provided with 3 plates in order to avoid the movement of the sub-entry nozzle in the mold during the flow control by throttling.

Improved air-tightness of tundish gates (R50 or C52).
Tundish gates are operating in automatic control mode, including automatic casting start up.
Laddle Shroud :
Ladle Shroud is a ceramic tube manufactured from isostatic-ally pressed alumina graphite custom designed for immediate connection to the Ladle Slide Gate Nozzle giving maximum protection of the steel stream against oxidation from the atmosphere and minimizing steel splashing.

The shroud can be oxygen cleaned for immediate re-use during sequence casting operations or for subsequent re-use during batch casting.

Custom Ladle Shrouds containing multiple material sections and specialized design features are used to tailor the product to customer casting conditions and operating practices.

A range of argon delivery methods can be incorporated in ladle shrouds as per designed.

Tundish Stopper :

Tundish Stopper Can be alumina graphite or clay graphite, for example :
1) VISO™ range of isostatically pressed Alumina Graphite stoppers
2) VAPEX® range of extruded clay graphite stoppers

ARGOROD™
For instance, in tundish applications where argon injection through the stopper is required, the Argorod™ attachment is designed to give a gas tight connection combined with a rigid assembly for auto-control systems.

For high performance applications, a range of special mixes are available for the stopper head or the slag line, each composition is custom formulated for the particular steel composition or casting conditions. 

Shroud manipulator
Shroud Gasket :

The benefits from incorporating airtight Gaskets are:
  1. Reduce nitrogen pick-up
  2. Improved steel cleanliness by preventing the formation of inclusions due to re-oxidation
  3. Reduced incidences of nozzle blockage due to re-oxidation and alumina formation
  4. Reduce damage to collector nozzles
  5. Better sealing of re-used ladle shrouds, due to the flexibility of the gasket
  6. Easy application and removal after use

Air Tight Gasket Types
    • Ceramic Fibre
    • Cut Fibre
    • Vacuum Formed
    • Impregnated for superior performance
    • VG SEALBIND™ ceramic gasket (with or without anti-stick graphite)
    • Tempseal compressible refractory seals
    • VG Graphite high temperature seals
Tundish slide gate plate :
It is zirconia-inserted plates for casting long sequences of the most aggressive steel grades. Zirconia provides maximum erosion resistance to minimize plate wear and maximize performance.

Plate design features, where required, include argon injection into the bore and argon sealing between plates to minimize bore clogging and air aspiration maximizing performance and steel quality.

Advancing Technology The relationships between clogging, argon injection and air aspiration are complex, and operations have shown that stopping all aspiration between the plates does not entirely eliminate alumina deposits in the flow channel. Through the application of modeling and simulation technologies, the influence of various flow phenomena associated with the flow from tundish-to-mold, slide gate operation and the impact of these phenomena on clogging in the entire flow channel have been uncovered. As a result of these studies, a rethinking of tundish gate configuration has occurred and an innovative "offset bore" design has been developed to improve flow control, greatly retard clogging and enhance product quality. 

Stopper Control System :
         Stoppers systems used to control the molten steel flow from the tundish to the mold by means of stopper.        
  • Use of “Stopper Rigging” with minimized back-lash
  • Electromechanical or hydraulic actuators to provide a very accurate positioning of the stopper and a very short response time
  • New generation of mould level meter sensors not demanding external manipulators disturbing the mold environment
  • Application of the most up-to-date technologies compatible with the highest technical standard demanded by the Steel Industry General Contractors.
     
Mold Level Control

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