Patent ID: 6428863
Filing Date: 2002-08-06
Classification: C23C,F28F

Abstract:
A process for selected adjustment of dropwise condensation on a surface comprising implanting nitrogen ions with a theoretically predicted minimum dose concentration of 1015 cmâˆ’2 to adjust the wetting characteristic of the surface without need for cleaning or other preparation steps such that stable dropwise condensation is formed on the surface and the intensity of the condensation and heat transfer performance can be selected using the size of the dose concentration, and further comprising calculating the minimum dose from a calculated distance of doping elements (L=2r) according to the following formula: r=2&CenterDot;M~&CenterDot;(-0.2&CenterDot;TTr&af;(Â°&it;â€ƒ&it;C.)+78)R&CenterDot;TTr&af;(K)&CenterDot;(-0.7&CenterDot;TTr&af;(Â°&it;â€ƒ&it;C.)+1028)&CenterDot;ln&it;PTr,D0.03&CenterDot;TTr&af;(Â°&it;â€ƒ&it;C.)-2wherein r is the drop radius, {tilde over (M)} is the molar volume, Ttr is the drop temperature, and Ptr,D is the drop vapor pressure.