A launder is used for molten aluminum casting has a steel jacket and which is lined with refractory material, is provided with an insulating cover. The extra heating of the launder is implemented by a gas burner. A discharge system for the gases from the launder is arranged in the launder cover. The cover of the launder also works as insulation for the radiation heat released from the launder.
A launder and trough is used to transfer molten metal from the melting furnace to the casting machine reliably and tolerant to interruptions in casting. In particular, the objective is a reliable transfer of aluminum from the furnace to the casting machine in the aluminum casting process.
The heating covers can be fitted to be used, for example, in the molten metal launders, the intermediate troughs, from which the melt is dosed into casting troughs, and the casting troughs, from which the melt is dosed into the casting molds.
The launder for molten aluminum casting provides considerable advantages. The launder enables the heating of the launder construction with less power compared with traditional burner solutions. The heat production is easy to adjust and local thermal stress is avoided, whereby the cracking of the launder embeddings is also avoided. The tendency to downtime of the casting equipment is reduced, as the casting can be interrupted without a risk of the metal solidifying in the launders and troughs. The launder extends the working life of the embeddings of the troughs and the launders and especially of the anode furnace.
In the launder construction, molten metal, such as molten aluminum, is arranged to flow under gravity in an inclined launder that is lined with refractory material and has a metal jacket, and at least part of the launder and troughs are covered with an insulating cover.
At least one electrical resistor element is arranged in the cover of the launder to heat the launder and to keep the metal melted, and a burner of a hot gas blower is arranged at the upper end of the covered launder portion to provide a stagnation pressure in the launder channel to decelerate the flowing gas or to prevent it from flowing or even make it flow downwards.
The covers that are arranged on top of the troughs are used during casting and during the periods between castings and during any breaks in casting. The covers of the troughs are easy to fit in place and remove because of their light structures.
The heating elements can be placed in the cover of the troughs so that the heating elements extend to the area in the pit of the trough, where the melt flows during the process.