Tubular elements Assemblies of tubular elements

FMECHANICAL ENGINEERING LIGHTING HEATING WEAPONS BLASTING ENGINES OR PUMPS F28Heat exchange F28FDETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION

F28F1/00Tubular elements Assemblies of tubular elements

F28F1/003Multiple wall conduits F28F1/006with variable shape F28F1/02Tubular elements of cross-section which is non-circular F28F1/022with multiple channels F28F1/025with variable shape. F28F1/04polygonal F28F1/045with assemblies of stacked elements F28F1/06crimped or corrugated in cross-section F28F1/08Tubular elements crimped or corrugated in longitudinal section F28F1/10Tubular lements and assemblies thereof with means for increasing heat-transfer area F28F1/105the means being corrugated elements extending around the tubular elements F28F1/12the means being only outside the tubular element F28F1/122and being formed of wires F28F1/124and being formed of pins F28F1/126consisting of zig-zag shaped fins F28F1/128Fins with openings F28F1/14and extending longitudinally F28F1/16the means being integral with the element F28F1/18the element being built-up from finned sections F28F1/20the means being attachable to the element F28F1/22the means having portions engaging further tubular elements F28F1/24and extending transversely F28F1/26the means being integral with the element F28F1/28the element being built-up from finned sections F28F1/30the means being attachable to the element F28F1/32the means having portions engaging further tubular elements F28F1/325Fins with openings F28F1/34and extending obliquely F28F1/36the means being helically wound fins or wire spirals F28F1/38and being staggered to form tortuous fluid passages F28F1/40the means being only inside the tubular element F28F1/405and being formed of wires F28F1/42the means being both outside and inside the tubular element F28F1/422with outside means integral with the tubular element and inside means integral with the tubular element F28F1/424Means comprising outside portions integral with inside portions F28F1/426the outside portions and the inside portions forming parts of complementary shape F28F1/44and being formed of wire mesh