Blowing out

Cleaning of a mold or mold cavity with pressurized air.

In sand casting, this process is applied to remove sand grain or coatingchips from the mold cavity.

In gravity die casting, coatingchips or lose burrs are removed from the die.

In die casting, potential residues of separating agents or water drops from the upstream spraying process are blown out as these would otherwise lead to increased gas porosity due to vapor formation in contact with the liquid metal in the downstream filling. Simultaneously, also adhesive burrs and flakes are removed from the mold surface.

When furnaces are blown out for complete discharge, the fine ore content is increased in the last charges before the blowing out process. The carbon dioxide content and the temperature increase. If the temperature gets too high, the gas supply to the furnace has to be disconnected, charging has to be deactivated and water has to be introduced for cooling and to prevent explosions. The remaining charge has to be removed from the frame and the rest.