Water Injection vs. Steam Injection

Much higher energy consumption, because the water will absorb a lot of heat to turn into steam first.

Er, isn't that the same amount of energy needed to make the steam elsewhere?

yes, same amout of energy, the only diiffernce I would see is what would be more efficent?

I'm not a steel guy; but it seems like the big issue in blast furnace operation is concentrating enough energy in a small volume to maintain the temperatures necessary for the reduction reactions to take place. Next is getting the whole operation to a steady state. Introducing an unnecessary energy loss to the process such as that needed to change the state of water to a vapor sounds to me like a means to unnecessarily burden the process. Better to have that phase change happen away from the blast furnace at lower temperatures using waste energy from some source. Sort of like a boiler fueled by a waste heat source. I suspect that function is built into modern blast furnace systems in conjuction with the hot stoves for heating air.

So let's hear from someone who is well versed in the steel making process to tell us what the real world on this might be.

Ed Weldon

Produce the same amount of hydrogen. Whether any draw back or not depends on the source of steam. if the steam is generated from a fired boiler then no difference from specific energy consumption. However, if the steam is generated from waste heat recovery then the option of injecting water directly will be less energy efficient.

I believe, in your case the steam is generated from the furnace flue gas. Thus you will expect higher energy consumption.

However, the biggest issue will be sudden expansion of water into steam. Water should be atomized otherwise sudden expansion of steam may results in explosion in the furnace.