Finned Tube----Types of Fin Tubes
Finned tubes or tubes with extended outer square measurea|area|expanse|extent} are utilized in some device equipments to boost the warmth transfer rate by increasing the effective heat transfer space between the tubes and encompassing fluid.
Types of Finned Tubes
Longitudinal Fins
Figure one - longways finned tube in device
Longitudinal fins on a tube ar best suited to applications wherever the flow outside the tubes is anticipated to be efficient on the tube length, as an example double pipe heat exchangers with extremely viscous fluid outside the finned tube.
Longitudinal fins on a tube line the length of the tubes. The crossed section with shapes of longitudinal fins is either flat or tapered. for various cross sectional geometries, numerous correlations ar out there within the literature to judge the warmth transfer coefficients on outer facet of the tubes.
Transverse Fins
Figure two - transversally finned device tube
Transverse fins ar ordinarily used for gas flows or turbulent flows and for cross flow sort exchangers or shell and tube heat exchangers. For air coolers, tubes with thwartwise fins ar best suited.
Transverse fins ar hollow metal discs spaced from one another and fitted on the length of the finned tubes. The fin discs is tapered or flat . Heat transfers co work on the surface of the fin depend upon the fin disc pure mathematics and ar out there within the literature within the sort of correlations.
Design of finned tube sort exchangers
To design heat exchangers by using finned tubes for increased heat transfer space, heat calculation of needed heat transfer space and optimum spacing of tubes to make the desired square measurea|area|expanse|extent} are 2 components of the matter.
Heat transfer coefficients at surfaces within and outdoors the tubes ar calculated mistreatment through an experiment determined correlations. the warmth transfer potency of fins is calculated mistreatment correlations. totally different sets of correlations ar out there for calculation of fin heat transfer efficiencies of longitudinal and thwartwise fins. The fin space increased by fin heat transfer potency and extra to reveal tube space, provides the effective outer heat transfer space. Overall heat transfer constant is obtained by adding the warmth transfer resistances evaluated at outer and inner surface areas of the tube. For outer space, price of the effective space is employed. Finally the overall heat transfer space needed and thence needed range, length etc. of tubes is calculated.
Effect of range of tubes on the outer fluid flow is checked for changes in fluid speed. If speed of outer fluid changes considerably, the warmth transfer coefficients and needed tube space is reevaluated. therefore during a few iterations and optimum arrangement of finned tubes, to get the specified heat transfer space is determined.
Key Words: Finned Tube, Fin Tubes, Extruded Fin Tubes, Embedded Fin Tube, L Fin tube, Tubos Aletados, Types of Fin Tubes