Study On The Characteristic Of CaCO₃Fouling Of Wing-Type Votrex Generators

Vortex generators have a wide range of applications as a passive heat transferenhancement device in the heat transfer area. The characteristics of CaCO₃fouling ofwing-type vortex generators were studied in the paper.During a number of experiments, basing on the off-line weighing method in theoperating conditions（the velocity v=0.2m/s, concentration C=1000mg/L andtemperature T=50℃）, each influence of three kinds of distances （s=30,40,80mm）and two kinds of attack angles （β=30°,90°） on the fouling characteristics in arectangular pipe was investigated. Several curves of deposition quantity per unit areaon every specimen increased with airfoils, distances, and attack angles, contrastingwith naked ones were obtained, then a relationship between airfoils, distances andattack angles and the deposit quantity per unit area was summed up in the following:deposition quantity per unit area on wing-type vortex generators specimens issignificantly smaller than that on naked ones；the former is inversely proportional tothe flow cross-sectional area；during the vortex generators, what whose angle ofattack is30°, has better anti-fouling performance than that is90°.In order to extend the study, establishing physical and mathematical models,distances of wing-type vortex generators were extended in calculations throughnumerical simulation. Distances were extended to8kinds （s=10,20,30,40,50,60,70,80mm）,the relationship between deposition quantity per unitarea and distances, by comparing simulation results, was demonstrated as follows:the deposition quantity is the least when the distance is10mm, then increases as thedistance increases；As is the most when the distance is60mm, then has a downwardtrend.