Tundish

Eig. 10. Schematic representation of the process of cooling of steel (H) during continuous casting. The tundish is a buffer between the ladle and the mold. 

Normally, zircon sand is readily available as a by-product of mtile and ilmenite mining at ca 150 per metric ton. However, zircon and baddeleyite are obtained as by-products of their operations, and therefore, the supply is limited by the demand for other minerals. In 1974, when a use for zircon in tundish nozzles developed in the Japanese steel industry, a resulting surge in demand and stockpiling raised zircon prices to 500/t. Worldwide production by country is given in Reference 80. 

Alumina—graphite refractories, almost all continuous casting ware, have come into much greater use as continuous casting has spread in steelmaking. These refractories are used in shrouds that conduct the molten metal from the ladle to the tundish, in the subentry tubes that take the metal from the tundish to the mold, in isostatically pressed stopper rods, and in shroud tubes for slab and bloom casters. The alumina—graphite compositions are used in these products because of the thermal-shock resistance and corrosion resistance they impart to the product. 

When a boiler may not be shut down for maintenance of the level control chambers isolating valves can be fitted between the water-level control and the steam space. In this instance, the valves must be capable of being locked in the open position and the key retained by a responsible person. When these valves are closed during maintenance periods the boiler must be under manual attendance. Fitting of these valves should only be with the agreement of the insurance company responsible for the boiler. Drains from the water-level controls and level gauges should be collected at a manifold or sealed tundish before running to the blowdown vessel. 

A tundish, having an area possibly 1% of the cross-sectional area of the tower, is located just above the water level and is led to the drain, forming part of the overflow fitting. This will bleed off 1 % of the water falling through the tower. 

Common practice and a general guide is to prevent combustible vapors from transmitting from one process area to another process area, generally 15.2 meters (50 ft.) or more away. Usually unsealed receptacles, such as drain funnels, tundishes, drain boxes, are routed to the nearest local sealed catch basin and then into the oily water sewer main. The unsealed receptacles are only allowed in the same process area equipment where if vapors where released from an adjacent unsealed receptacle it would be "immaterial" due to the proximity to where the liquid is being drained and would normally emit vapors. 

Melting Crucible (Tundish) Material Ceramics/Refractory... 

A continuous casting line is shown in Fig. 4. Steel is poured via a tundish into a water-cooled copper mold. As casting commences, the bottom of the mold is sealed with a dummy bar onto which the steel solidifies. 

POSTER TITLE Inclusion Behavior of LCAK Steel in Tundish during Continuous Casting Process... 

The Tundish Cover This is an improved sandwich technique, whereby the ladle is covered by a lid after the Mg alloy has been placed at the bottom of the ladle. The metal is poured in the concave lid and flows through a hole in the ladle, where the reaction takes place The plunging method Using a plunger bell, the Mg alloy is submerged in the liquid metal until the reaction is finished. During the treatment the ladle lid is closed, to prevent MgO fume emissions... 

FIGURE 54.22 Tundish dryer in the foundry. (Courtesy of Energy Efficiency Office of the U.K. Department of Energy.)... 

Demonstration of a Single Burner Tundish Dryer, Energy Efficiency Demonstration Scheme, Final Report ED/76/107, Energy Efficiency Office, U.K. Department of Energy (March 1986). 

The liquid metal was cast into 80 mm dia remelt stock by teeming through a tundish fitted with dams, weirs and ceramic filters. Table 1 provides typical analysis of remelt bar stocks. 

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