|Abstract: ||In the aquaculture, the dissolved oxygen rate becomes a critical factor for
the intensive fish production. Dissolved oxygen (DO) means the oxygen rate (mg/l
or ppm) dissolved in the water. Stickney (1979), as quoted in Andan (2003),
admits that the oxygen inadequacy put the fish in danger because it causes stress,
disease, and even death among fishes. Therefore, in the highly dense embankment,
aeration tool may be important to improve air dissolution rate in the water.
The main objective of research is to examine the performance of paddle
wheel aerator driven by savonius type-L windmill for embankment water aeration.
The secondary goal of this research may be to understand the speed, torque, paddle
wheel power and windmill power; to acknowledge the efficiency, to acknowledge
the paddle wheel depth for optimum aeration to supply dissolved oxygen in the
Research has been conducted for 15 days. It observes various data such as
water sample (dissolved oxygen), wind speed, windmill rotor rotation and paddle
wheel rotation to examine the power and the torque of windmill and paddle wheel,
and the efficiency of this aerator system. In this research, paddle wheel has 70 cm
diameter and 450
slope. Several treatments of paddle wheel angle deep are used,
such as 1 cm, 3 cm, 6 cm, 9 cm, and 12 cm.
Results of research indicate that the mill rotates and moves the paddle wheel
in the different minimum wind speeds, such as 1.1 m/s at 1 cm angle deep, 2 m/s at
6 cm angle deep, 2.7 m/s at 9 cm angle deep, and 3.2 m/s at 12 cm angle deep.
During 15 days of observation, the average wind speed rate is 2.577 m/s with the
power and torque produced by windmill reaching for 1.18 watt and 0.898 Nm. The
average power and torque of the paddle wheel are 0.888 watt and 0.433 Nm.
Considering these results, the lost power is 0.291 watt. Energy conversion
efficiency equals to 15.76 %, while aerator system efficiency remains as 75.3 %.
The results of examination against embankment water sample, collected
from the observation pool, before and after aeration, indicate that DO content
before aeration attains to 4.7 mg/l, while after aeration it achieves 8.05 mg/l. The
other point in the embankment without aeration shows DO content for 4.758 mg/l.
Considering the results of the before-aeration treatment in the embankment after
15 days aeration with various paddle wheel angle deep treatments, research finds
average dissolved oxygen improvement to 3.292 mg/l. The highest dissolved
oxygen increase about 4.65 mg/l is occurred at 3 cm deep with 32.5 rpm rotations
of paddle wheel. The lowest dissolved oxygent increase about 2.37 mg/l is
developed at 12 cm paddle wheel angle deep treatment with 13.66 rpm average
rotations of paddle wheel|