An arc furnace bottom construction for maintaining the outer surface temperature of the bottom construction essentially at least on the lower part of the arc furnace essentially close to the temperature surrounding the arc furnace. The bottom construction contains at least two constructions to be cooled and being positioned to each other in different heights seen from the side view.

A powder feeder system for a foundry system having a mixing hearth includes a housing assembly, and a feeder assembly in the housing assembly having a moveable barrel feeder for feeding a pre-weighed charge of metal powder into the mixing hearth of the foundry system during operation thereof. A method for recycling metal powder includes the steps of melting a content of the mixing hearth completely; and then feeding the metal powder into the mixing hearth while the contents of the mixing hearth are still molten using the powder feeder system.

The invention relates to a melting method, in which method unmelted charges form a bank 30 resting on one side against the upstream wall 11 of the furnace 10 and having, on the opposite side, a free surface 40; the unmelted charges are heated by means of at least three flames 51, 52, 53 at a regulated power and momentum and are directed towards the free surface 40 so as to define impact zones 41, 42, 43 on this free surface 40 over at least three different distances I1, I2, I3 of one of the side walls 13, 13 of the furnace 10.

A system for melting metals includes a heating chamber configured to contain a molten metal, a wet hearth melting chamber, and a pump. The wet hearth melting chamber includes a wet hearth inlet, a wet hearth outlet, and a refractory shelf having a top surface. The refractory shelf has a plurality of rails disposed on top of the top surface and spaced apart from one another to form flow channels. The wet hearth melting chamber has an inlet channel fluidly coupling the wet hearth inlet to the top surface of the refractory shelf and an outlet channel fluidly coupling the top surface of the refractory shelf to the wet hearth outlet. The pump is in an inlet flow path between the heating chamber and the wet hearth melting chamber and is configured to pump molten metal from the heating chamber through the wet hearth melting chamber.