GRETA - value adding heat recovery - report cooling of castings
In the case study at a Swedish iron foundry, the opportunity of recovering waste heat from cooling goods has been studied. Probably, the most reasonable practical solution is to place the goods in a cooling hut/cooling oven after the break away of sand and mould. The cooling hut’s air cools the goods under controlled conditions. The air, in turn, can be cooled with hot cooling water, which in turn would be cooled by district heating. Alternatively, the hot air can be used directly to heat up nearby facilities. The foundry already has heat recovery from induction furnace cooling water and from compressed air units to a district heating network. The need for about 70°C heat is already saturated, while there is a demand for about 100°C heat. There is also plenty of 100°C waste heat, both in goods and sand. An alternative outlet could therefore be heat-driven electricity production. However, the electricity efficiency for this will be low, perhaps 5-10%. The remaining heat needs to be cooled, e.g. with surface water.
Bakom projektet står ett stort antal gjuteriföretag och det statliga forskningsinstitutet RISE. Det pågår 2020-2023 och finansieras av Svenska Gjuteriföreningen och det strategiska innovationsprogrammet Metalliska material, en gemensam satsning av Vinnova, Energimyndigheten och Formas.