At the cupola furnace operation, exhaust the gas includes much carbon monoxide (CO)gas originated cokes.By burning CO gas collected through the filter, it is converted into so much heats.
Then the generated heat is converted around 500-600℃ hot blast and reused as hot blast air as burning energy for cupola furnace.

This recycle provides excellent effects of reducing cokes ratio and increase the melting efficiency.
Of course the heat can be used as a heating system in the building or boiling water. From current test operation founds that
the system is effective in using the blast coke as well.