Construction of a heat transfer wall and heat transfer pipe and method of producing heat transfer pipe

Abstract

Abstract A heat transfer wall comprises a heat transfer wall body, a number of fins integrally formed on one surface of the body, extending parallel to each other and having breaks formed therein at predetermined intervals, and a number of beads integrally formed on the other surface of the body. This arrangement may be applied to a heat transfer pipe. Thus, the pipe comprises a heat transfer pipe body, at least one row of spiral fins integrally formed on the outer surface of the body and having breaks formed therein at predetermined intervals, and a number of beads integrally formed on the inner surface of the body. A method of producing such heat transfer pipes comprises the steps of rolling the outer surface of a pipe to form spiral fins integral with the pipe wall, and urging a sharp edged rolling tool against the outer surface of the pipe while rotating the tool on the outer surface of the pipe along a spiral path having a lead angle which is in reverse relation to the lead angle of the fins so as to form breaks in the fins at predetermined intervals while inwardly bulging the inner surface of the pipe at the positions corresponding to the breaks to form beads on the inner surface of the pipe at these positions.

Inventors

• 👤 Yoshiyuki Satoh
• 👤 Tomio Higo

Bibliographic Details