Vane packs Vane pack are coalescing internals made of several layers of corrugated plates regularly spaced one from each other by spacers. These vane packs are used to pick up the liquid particles from a gas stream. Vane pack are coalescing internals made of several layers of corrugated plates regularly spaced one from each other by spacers. These vane packs are used to pick up the liquid particles from a gas stream.
Vane pack type V
Vane pack type Y
Operation principle The liquid particles in a gas stream enter the pack with more inertia than the gas molecules. In the changes of direction due to the presence of vane pack, the droplets gather themselves in the corrugations by wetting them to get a sufficient size to drop by their own weight.
Efficiency The vane pack is capable to stop at more than 99.5 % the liquid particles which size is above 20 µm for vane pack type V and 8µm for vane pack type Y.
Operating conditions The above mentioned efficiencies are actual if the operating conditions are within be following limits : - Optimum velocity : The gas velocity inside the vane pack must not exceed a maximum velocity (V max) and must be higher than a minimum velocity (V min) :
with, pL = liquid density at the operating conditions (kg/m 3 ) pG = gas density at the operating conditions (kg/m 3 ) The formula is valid for an horizontal gas stream through a vertical vane pack (the most common case). For different configurations k values are different. - Liquid rate : The ratio of actual volumetric flow rates (liquid/gas) must be high enough to let the vane pack wet. This rate must exceed 10 -5 . If this is not the case, a wetting system must be provided.
Pressure drop When flowing through the vane pack, a very weak pressure drop occurs. It may be expressed as a function of the gas velocity (in m/s) and of its density r G (in kg/m 3 ). The following formula is valid only for a for vane pack of 200 mm thickness (three corrugations). |
