HEAT-TRANSFER TUBE Russian patent published in 2003 - IPC

FIELD: thermal engineering; heat-transfer apparatuses. SUBSTANCE: grooves are made on outer surface of tube and respective projections are formed on its inner surface; grooves are disposed over helical line at pitch varying between 0.25 D and 0.75D, where D is inner diameter of plain section of tube. Pitch variation period is between 5D and 15D. Proposed heat-transfer tube is noted for improved relationship between augmenting of heat transfer and growth of hydraulic pressure. EFFECT: enhanced reliability and facilitated manufacture of tube with grooves. 1 cl, 1 dwg