Abstract: A lance including: a central pipe having a wear-resistant ceramic layer coated on an inner wall thereof; a central casing pipe having a casing pipe groove in an outer wall thereof, in which the central casing pipe is fitted over the central pipe; an intermediate pipe fitted over the central casing pipe, in which a combustion-supporting gas chamber is formed between a front part of the central pipe and the intermediate pipe, and an intermediate pipe groove is formed in an outer wall of the rear part; and an outer casing pipe fitted over the intermediate pipe, in which a cooling medium chamber is formed between a front part of the intermediate pipe and the outer casing pipe, and a cooling medium injection channel is defined by an inner wall of the outer casing pipe and the intermediate pipe groove.

Abstract: The invention provides a lance including: a central pipe having a wear-resistant ceramic layer coated on an inner wall thereof; a central casing pipe having a casing pipe groove in an outer wall thereof, in which the central casing pipe is fitted over the central pipe and has a length less than that of the central pipe; a central pipe fitted over the intermediate pipe, in which a combustion-supporting gas chamber is formed between a front part of the central pipe and the intermediate pipe, an external diameter of a rear part of the intermediate pipe is greater than an external diameter of a front part of the intermediate pipe, and an intermediate pipe groove is formed in an outer wall of the rear part; and an outer casing pipe fitted over the intermediate pipe, in which a cooling medium chamber is formed between the front part of the intermediate pipe and the outer casing pipe, and a cooling medium injection channel is defined by an inner wall of the outer casing pipe and the intermediate pipe groove.