Launders Runners , Casting Equipment. Elimination of Asbestos-Containing Materials

7 Launders (Runners), Casting Equipment Elimination of Asbestos-Containing Materials 

Depending on a casting machine, the runner may have a small cross section (the surface of the metal 100 sm ), medium (the surface of the metal = 100-200 sm ), or large cross section (the surface of the metal 200 sm ). The molten A1 releases heat in the runner. It has been reported [38] that the temperature drop should not exceed 0.4°/m. The velocity of aluminium in the mnner should not exceed 20 sm/s, which is realized at the slope of a runner of 5-8 mm/m. If the velocity of A1 there is small, the heat release will be larger. It is undesirable for the velocity of A1 to have a possibility of turbulence in the flow (for the quality of the billets). 

In terms of heat losses, the height of the runner should be either equal to or 1.5 times the width. In terms of turbulence, the launder should have no slopes, angles, or knobs. The shape of the launder at Fig. 3.20a is less desirable than the shapes in Fig. 3.20b, c. 

Currently, there are many materials for the launders, but it is difficult to find a material that combines 

The materials used for the launders - alumina silica fiber materials with coatings, fused silica, wollastonite, LCCs and MCCs, heat insulation castables - only partly satisfy the above-listed requirements. 

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