In order for a maximum number of boiler generating and circulating tubes to be installed without weakening the tube sheet, which of the listed procedures should be carried out?
• Boiler drum and tube sheet strength – how holes and tube angles affect metal strength around the ligaments between tubes • Tube entry angle – what happens to stress and spacing when tubes enter at different vs. uniform angles • Definition of “normal” vs. “horizontal” to a surface in mechanical/boiler design
• Which tube arrangement will leave the greatest amount of solid metal (ligament) between adjacent tube holes in the tube sheet? Visualize a pattern of holes in a plate. • How would installing tubes at mixed or arbitrary angles affect spacing, drilling layout, and stress on the tube sheet around each opening? • Think about what designers usually want for stress distribution in a pressure vessel: regular, perpendicular loading, or oblique/angled loading into a curved surface?
• Clarify what “normal to the drum surfaces” means in geometric terms (relation to the surface). • Consider which option allows a regular, closely spaced hole pattern without cutting away too much supporting metal. • Eliminate any options that would reduce uniformity of loading or create irregular spacing of tube holes in the tube sheet.
No comments yet
Be the first to share your thoughts!