Patent ID: 7963318
Filing Date: 2011-06-21
Classification: C10G,F28F

Abstract:
1. A finned tube for the thermal cracking of hydrocarbons in the presence of steam, said tube defined by a tube axis and comprising a plurality of helically extending inner fins, said fins being inclined at an angle of 20° to 40° in relation to the tube axis, said inner fins having an undulating structure with adjoining radially outward facing valleys and radially inward facing peaks arranged mirror-symmetrically with respect to one another in cross section and having an identical radius of curvature, and a flank angle of 16° to 25° , said flank angle defined as an angle enclosed between a line tangential to an inscribed circle at a peak and a line tangential at a connecting point of the peaks and the valleys of the undulating structure.