3.1. Effect of particle size on the percentage of removal efficiency
In Fig. 3 the effect of particle size on the removal efficiency is
depicted for different inlet air flow rates while employing a fixed
water flow rate of 100 l/h. By increasing the particle sizes, higher
removal efficiency has been obtained. This figure shows that the
removal efficiency has a sharp increase by increasing the particle
size. Large particles moving toward the droplets have mass, and
therefore momentum, which causes each particle to travel in a
straight line toward the droplet. The particle leaves the streamline
as the streamline bends to move around the droplet. The greater the
mass of the particle the more likely that it will travel in a straight
line. Also, as the velocity difference between the particle and the
droplet increases, the particle will have increased momentum and
will be more likely to be carried into the droplet. The radius of curvature
of the bend in the streamline has a very important effect on
Particles of roughly 0.1–1m diameter are carried by the gas
streamline sufficiently close to the surface of the droplet that the
particle touches the droplet [18]. These particles have insufficient
inertia to leave the gas streamline and are carried with the streamline.
Some gas will flow very close to the particle. This mechanism
known as interception is a relatively weak mechanism for particle
collection compared to impaction [18]. It is coincidental that
the path of the streamline and the particle happens to be close to
the droplet. It is for this reason that particles in this size range are
difficult to collect compared to larger and smaller particles.
As indicated in Fig. 3 the removal efficiency for PVC particles
larger than 2m becomes approximately 100% while employing
100 l/h water. This results show the very good performance of this
scrubber.