Pouring and transfer ladle - Refractory lining and thermal aspects

In foundry casting, the ladle is a piece of equipment historically designed for pouring liquid metal into molds. It is also increasingly used to transport liquid metal between the holding furnace and the automatic casting furnaces.

Composed of a steel casing with its lid, a mechanical tilting system and an insulating refractory lining, the ladle is an essential part of the transfer between equipment. Its use is often short and highly fragmented, so it is rarely the subject of a specific study for refractory lining. However, refractory linings have their own requirements: they must be insulating, suitable for the liquid metal being transported, and resistant to slag corrosion.

The thermal aspects of its use are often ignored or forgotten, yet the pouring or transfer ladle is the site of significant heat loss:

• poor insulation,

• no cover,

• neglected or insufficient preheating,

• temperature drop of liquid metal...

All these losses are far more costly in terms of energy and quality than you might think. They can be easily identified, quantified and combated.

It's important to remember that in a foundry, apart from melting, 30% of the energy consumed is required for holding, handling and pouring the metal.

Despite the large number of ladles available, the foundry does not always make the link between ladle capacity and use. This necessary match is rarely considered from a thermal, and therefore energy, point of view, and in relation to the associated costs.

Generally speaking, the performance of a ladle's refractory lining in service depends on three essential factors:

• the right choice of refractory products for the lining;

• the quality of lining installation and compliance with commissioning instructions;

• how the pouch is preheated, used, monitored and maintained.

The article explains thermal phenomena and suggests solutions for reducing energy consumption.

A glossary is included at the end of the article.