cos ity ▁and ▁temperature . ▁▁ ▁The ▁geometry ▁of ▁the ▁cy clone ▁involves - in let ▁shape ▁and ▁area , ▁cy clone ▁dimensions ▁( con e ▁angle , ▁length ▁of ▁cyl ind rical ▁section ▁and ▁total ▁length ▁of ▁the ▁cy clone ) ▁and ▁in let , ▁vor tex ▁and ▁a pe x ▁diam eters . ▁ ▁Intern ally , ▁in ert ia ▁is ▁counter ed ▁by ▁the ▁resistance ▁of ▁the ▁liquid , ▁with ▁the ▁effect ▁that ▁larger ▁or ▁dens er ▁particles ▁are ▁transport ed ▁to ▁the ▁wall ▁for ▁event ual ▁exit ▁at ▁the ▁under flow ▁side ▁with ▁a ▁limited ▁amount ▁of ▁liquid , ▁while ▁the ▁fin er , ▁or ▁less ▁dense ▁particles , ▁remain ▁in ▁the ▁liquid ▁and ▁exit ▁at ▁the ▁overflow ▁side ▁through ▁a ▁t ube ▁extending ▁slightly ▁into ▁the ▁body ▁of ▁the ▁cy clone ▁at ▁the ▁center . ▁ ▁For ward ▁hydro cy cl ones ▁remove ▁particles ▁that ▁are ▁dens er ▁than ▁the ▁surrounding ▁fluid , ▁while ▁reverse ▁hydro cy cl ones ▁remove ▁particles ▁that ▁are ▁less ▁dense ▁than ▁the ▁surrounding ▁fluid . ▁In ▁a ▁reverse ▁hydro cy clone ▁the ▁overflow ▁is ▁at ▁the ▁a pe x ▁and ▁the ▁under flow ▁at ▁the ▁base . ▁There ▁are ▁also ▁parallel - flow ▁hydro cy cl ones ▁where ▁both ▁the ▁accept ▁and ▁reject ▁are ▁removed ▁at ▁the ▁a pe x . ▁Par allel - flow ▁hydro cy cl ones ▁remove ▁particles ▁that ▁are ▁l ighter ▁than ▁the ▁surrounding ▁fluid . ▁ ▁H ydro cy cl ones ▁can ▁be ▁made ▁of ▁metal ▁( most