Furnace sensor irons out waste energy

A new type of high-temperature sensor could help increase the efficiency of steelmaking furnaces and reduce greenhouse gas emissions, according to its developers at the

. The sensor, which monitors the concentration of oxides of carbon inside the furnace, could also improve the quality of steel.

Steelmaking furnaces operate at about 1600

C — too hot for most sensors. This means there is no way to monitor in detail what is happening inside the furnace, which can le

ad to inefficiency. Blast furnaces work by using oxygen to remove carbon from pig iron; the gas is injected into the furnace, where it oxidises the carbon in the metal. This produces carbon monoxide and carbon dioxide. But once the carbon is exhausted, the iron itself starts to burn.

Research leader Murray Thomson said about half of the energy used in the process is wasted and generates unnecessary carbon dioxide emissions. 'If they knew what the CO