Fig. 5 Continuous perforated flow. (a) The front side; (b) The reverse side; (c) Diagram of CPF.
Fig. 5 shows the flow pattern of the CPF. The operating conditions areF s = 0.8 (m/s*(kg/m3)0.5),L W = 104 m3/(m2*h). As shown in Fig. 5a, the liquid spray density is increased. The liquid film on the surface and sieve holes of the blade unit is significantly thickened. With the centripetal and centrifugal force at the internal and external blade unit, the liquid film on the inside of the unit (near the inner cylinder) and outside of the unit (near the outside cylinder) thickens and is thin in the middle. On the reverse side of the unit, continuous droplets and multiple streams flow through the sieve holes near the inner cylinder because the slope is large on the inside. The downward component of the velocity is increased. The liquid film thickens, and the cumulative mass increases simultaneously, which increases the flow velocity of the liquid film. The liquid cannot coat the sieve holes under the influence of surface tension. The liquid phase flows through the holes continuously. The slope of the middle and outer sides of the unit is smaller than that of the internal unit, and the downward component velocity is smaller. The flow rate of the liquid film decreases, and the influence of the surface tension becomes significant. The liquid film coats the sieve holes again and sinks and forms droplets that adhere to the back of the blade unit, presenting a dispersed fluid film flow. The flow mechanism is similar to that of the BFF.
3.1.1.3. DMF