Patent ID: 6446565
Filing Date: 2002-09-10
Classification: C21B,F27B

Abstract:
A blast tuyere for shaft furnaces, comprising:a conical hollow main body defined by a longitudinal axis and defining an upper apex and a lower apex, said main body having an inner casing, an outer casing, and a tuyere nose interconnecting the inner and outer casings, with hot air conducted to the shaft furnace through the inner casing, wherein the outer casing is formed by a single-piece base body having a vertically axially symmetrical cross section and terminating smoothly in the tuyere nose, wherein the inner casing is formed by a conical weld-in part; wherein the inner and outer casings define a hollow space through which a coolant stream is conducted during operation, said hollow space divided in an antechamber, adjacent the tuyere nose, and a main chamber, which are completely separated hydraulically from one another and include separate coolant circuits, wherein the coolant circuit for the antechamber includes two passages of substantially constant cross section, said passages arranged in parallel relationship to the longitudinal axis for supply and return flow of coolant, said passages located in an area of the upper apex of the main body outside a cross section of the main chamber as relating to the longitudinal axis and terminating in a ring channel, which is arranged in the tuyere nose in a direction transversely to the passages, and wherein the coolant circuit for the main chamber includes a helical cooling passageway of substantially constant cross section, as viewed in length direction of an extension of the helical cooling passageway, with the weld-in part forming an inner wall of the helical cooling passageway of the main chamber, wherein the helical cooling passageway of the main chamber has a two-threaded configuration to define a first cooling channel provided for supply of coolant, and a second cooling channel provided for return of coolant, and a 180Â° bend for interconnecting the first and second cooling channels.