| 摘要 |
PURPOSE:To prevent sticking of a granular body such as flux to pipe walls by constituting a tuyere of an inside pipe, middle pipe and outside pipe in a concentrical tripple pipe construction, and providing many small-bore through-holes communicating the inside pipe with the middle pipe to the inside pipe over the entire surface thereof. CONSTITUTION:Many through-holes are provided to an inside pipe 1, and O2, N2 or Ar alone or a gaseous mixture composed thereof and a flux such as quicklime are run therein. The same kind of gas as the gas in the pipe 1 contg. no flux, etc. is run in the inside annular flow passage in the clearance between the pipe 1 and a middle pipe 2, and gaseous pressure is maintained higher than the inside pipe pressure. Cooling gas is run as in the prior art in the clearance between the pipe 2 and the pipe 3 to prevent overheating of the tuyere and to protect the same. The gas is therefore admitted through the through-holes provided on the wall of the inside pipe to the inside of the pipe 1 on account of a pressure difference between the central flow of the pipe 1 and the inside annular flow passage. The sticking of the flux to the inside wall surface of the inside pipe wall is thus prevented. |
