Patent ID: 6872344

Claim:
A manufacturing method for a gas blowing plug, said method comprising the steps of: (a) forming a plane-shaped combustible sheet into a tubular body, (b) cutting the combustible sheet at predetermined intervals along the longitudinal axis of the tubular body, said cuts generally located in a plane that is normal to the longitudinal axis of the tubular body, (c) projecting the cut portion from the inside to the outside to form a band-shaped convex portion of said tubular body; (d) disposing said tubular body in a mold; (e) filling the mold with a monolithic refractory material; (f) compressing the monolithic refractory material; and (g) sintering the compressed, monolithic refractory material to burn the combustible sheet and form a discontinuous slit-shaped gas passage in the refractory material, where the shape of said discontinuous slit-shaped gas passage corresponds to the shape of the tubular body that is disposed in the mold.