Patent ID: 8550811

Claim:
Method for feeding hot gas to a shaft furnace, comprising: feeding a first portion of a first gas flow to a mixing chamber, said first gas flow having a first volumetric fluid flow rate, a first temperature and a first pressure; feeding a second portion of the first gas flow into said shaft furnace; feeding a second gas flow to the mixing chamber, said second gas flow having a second volumetric fluid flow rate, a second temperature and a second pressure; allowing said first portion of said first gas flow to mix with said second gas flow in said mixing chamber, thereby forming a third gas flow, said third gas flow having a third volumetric fluid flow rate, a third temperature and a third pressure; and feeding said third gas flow to said shaft furnace; wherein: said first temperature is higher than said second temperature and said first pressure is lower than said second pressure; said third temperature is regulated by adjusting said second pressure by a pressure regulating device arranged in said second gas flow; and said first gas flow is exempt of pressure regulating devices.