2. Experimental
setup
The schematic diagram for observing the flow patterns is shown in Fig.
2. The apparatus is made of transparent acrylic resin to allow
observation of the flow pattern. The experiments are conducted at room
temperature and standard atmospheric pressure, and the air-water system
is chosen in this experiment. The gas and liquid phase are transported
to the spray box by a magnetic pump and blower, respectively. The liquid
and gas phases flow through the channel of the blade unit. The guide
plate eliminates the outside interferences. The sieve plate unit is
positioned at the end of the baffle. The bottom of the unit is connected
to the central bulkhead of the barrel section, which extends to the
bottom of the water tank, dividing the tank into two parts. The
rotational and perforated fluid are separated through a central
separator. The swirling liquid enters the swirling separation chamber.
The gas phase flows out through the left stoma outlet, and the
perforated liquid flows into the perforated flow separation chamber. The
perforated gas flows out through stoma outlet2. Heightsh 1r and h 2p of the
rotating flow and perforated flow can be read from the two separation
chambers, and a hot-wire anemometer is located at the gas phase exits to
measure the gas flow rate, u gr andu gp. The exit aperture is the same and known;
therefore, the corresponding gas flow volume can be calculated based on
the velocity. The pressure measuring points are set at 20 mm on both
sides of the unit, and the pressure changes can be measured by the
differential pressure sensor in real-time.
The liquid phase distribution is uneven on the unit surface owing to the
liquid distributor when the liquid density is small, thereby disagreeing
with the actual working conditions. Therefore, the overflow method of
liquid distribution is adapted. As shown in Fig. 2b, the spray box is
replaced by the overflow box. The liquid phase passes the box through
two overflows and flows along the guide plate connected to the box after
stabilization. The liquid phase flows to the upper edge of the blade
unit in the form of falling film flow (as shown in Fig. 2b inside the
ellipse). Then, the liquid phase is evenly laid on the surface of the
unit, and the gas-phase inlets and other experimental conditions remain
unchanged.
In this experiment, the diameter of the blade unit is 140 mm; the axial
height is 50 mm; the overall height of the device is 1.2 m. The diameter
of the cylinder section where the unit is located is 150 mm. The
structure parameters and shematic of the blade unit are listed and shown
in Table 1 and Fig. 3.