| 摘要 |
PURPOSE: A coil tube for the hot water of a boiler, capable of securing the strength against external impact by forming outer recessed surfaces and outer protruded surfaces, is provided to prevent the sticking of scales to the inner wall of a coil pipe due to the successive beating of hot water vortex. CONSTITUTION: A coil tube for the hot water of a boiler comprises an outer recessed surface(12) and an outer protruded surface(11). The outer recessed surfaces are formed on the outer circumference of the tube at a regular interval. The outer recessed surfaces cross each other in a diagonal direction The outer protruded surface is gently projected among the outer recessed surfaces The inner circumference waved surface is formed. An inner waved-shaped surface produces the turbulent current of hot water. |
