Reduced Energy Consumption for Melting in Foundries

3 Abstract By improving the gating technology in traditional g ating systems it is possible to reduce the amount of metal to be re-melted, and hen ce reduce the energy consumption for melting in foundries. Traditional gating systems are known for a straight tapered down runner a well base and 90o bends in the runner system. In the streamli ned gating systems there are no sharp changes in direction and a large effort is do ne t confine and control the flow of the molten metal during mould filling. Experiments in real production lines have proven th at using streamlined gating systems improves yield by decreasing the poured wei ght compared to traditional layouts. In a layout for casting of valve housings in a vertically parted mould the weight of the gating system was reduced by 1,1kg wh ich is a 20% weight reduction for the gating system. In a layout for horizontally par ted moulds the weight of the gating system has been reduced by 3,7kg which is a weight reduction of 60% for the gating system. The experiments casting valve housings in ductile i ron also proved that it is possible to lower the pouring temperature from 1400oC to 1300oC without the risk of cold runs. Glass plate fronted moulds have been used to study the flow of melt during mould filling. These experiments have also been used for studying the flow pattern when ceramic filters are used. The thorough study of the use of filters revealed that the metal passing through the filter is divided into a number of small jets. This proves that filters do not have the claimed positive effect on the flow f metal. The volumes necessary on either side of the filter are not filled till a backpressure is build up and results in formation of pressure shocks when backfilled. These pressure shocks result in more