Patent ID: 7574981

Claim:
A method for reduction of film boiling in a cooling tube having a first tube end, a second tube end, and an interior surface with an inner tube diameter that is constant, the method comprising the steps of: fabricating an internal overlay about the interior surface as a layer that is spaced a distance from the first tube end, the layer having a first layer end with an annular inner recess thereabout, the layer internally diverging from the first layer end to a second layer end to provide a continuous transition from the first layer end to the interior surface; inserting a second ferrule end of a ferrule also with a first ferrule end into the first tube end, the second ferrule end sized to extend from the first tube end to be received in abutting relationship with the annular inner recess at the first layer end, wherein a smooth transition is provided between the ferrule and the overlay; providing a cooling fluid about the cooling tube to remove heat therefrom; and allowing a hot fluid to flow from the first tube end to the second tube end through the ferrule and the internal overlay so that heat is removed from the hot fluid through the cooling tube to the cooling fluid; wherein the ferrule and the overlay prevent film boiling of the cooling fluid along a portion of the cooling tube containing the ferrule and the overlay when the cooling tube is at an operating temperature.