Figure 3. The variations of pressure drop and standard deviation
with liquid mass flow rate (G = 0.126
kg·m-2·s-1) (a)us = 1 mm·s-1, (b)us = 2 mm·s-1, (c)us = 3 mm·s-1, (d)us = 5 mm·s-1
In order to establish the transition boundary between trickle flow and
pulse flow in the three-phase moving bed, several combinations of gas
and liquid mass flow rate in a broad range were adopted at different
solid flow rates. Based on the standard deviation and the visual
observation methods, the transition boundary between the trickle flow
and the pulse flow in the three-phase
moving bed was distinguished and shown in Figure 4. As can be seen from
Figure 4 that the transition boundary between the trickle flow and pulse
flow tends to decrease as the liquid mass flow rate increases at any
given solid flow rate. This result is coherent with the observations in
the trickle bed reported by several
authors18,21,40,41.
It is worth noting in Figure 4 that the transition depends strongly on
the solid flow rate. At the constant gas mass flow rate, the increase of
the solid flow rate makes the transition boundary shift rightwards to a
higher liquid mass flow rate.