الفهرس 
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Abstract
he experiments were carried out at a private farm is Located in
El-Minufiya Governorate, Egypt during of the 2015 season. The main
objective of this work is to study the effect of fish tank design parameters
on water flow pattern, and then the impact on the homogeneity of
rotational velocities and dissolved oxygen concentrations within fish tank,
which is consequently reflected in fish productivity. The first experiment
was devoted to choose the number and diameter orifice entering the water
to fish tank (empty of fish) at different flow rates in order to maintain the
rotational velocity of water suitable for fish. While, the second
experiment was carried out to study the effect of diameter to depth ratio
on the water movement and the impact on the homogeneity of the
rotational velocity, dissolved oxygen and fish productivity.
The obtained results can be summarized as follows:
First Experiment:
- The rotational velocity increases with increasing flow rates from 5
to 75 m3h-1 by using 10 and 15 mm hole diameter with holes
number of 5, 10, 15, 20, 25 and 30 at 45°, 90° and 135° jet angles .
The same also when we used 20 and 25 mm hole diameter with
holes number of 3, 6, 9, 12 and 15 at 45°, 90° and 135° jet angles.
- The highest velocities were obtained at 90° jet angle, when the
lowest velocities were obtained at 135° jet angle.
- The rotational velocity decreases with increasing holes diameter
from 10 to 15 mm with holes number of 5, 10, 15, 20, 25 and 30 at
different flow rates from 5 to 75 m3h-1 at 45°, 90° and 135° jet
angles. The same results also obtained when we increased the
holes diameter from 20 to 25 mm with holes number of 3, 6, 9, 12
and 15 at 45°, 90° and 135° jet angles. We can conclude that the
rotational velocity decreases with increasing holes diameter from
109
SUMMARY AND CONCLUSION
Ahmed M. Ragab, (2016), M.Sc., Fac. Agric., Ain Shams Univ.
10 to 25 mm with holes number of 15 at different flow rates from
30 to 75 m3h-1 at 45°, 90° and 135° jet angles.
- The rotational velocity decreases with increasing holes number
from 5 to 30 when we use 10 and 15 mm hole diameter at different
flow rates from 5 to 75 m3h-1 at 45°, 90° and 135° jet angles. The
same results also obtained when we increased the hole diameter
from 3 to 15 when we use 20 and 25 mm hole diameter at 45°, 90°
and 135° jet angles.
- The results indicate that the pressure of water increases with
increasing flow rates from 5 to 75 m3 h-1, The results also indicate
that the highest value of the pressures of water were 9.3, 56.9,
111.0, 151.0 and 211.0 kPa were found for 5 holes and 10 mm
hole diameter at 5, 15, 30, 45, 60 and 75 m3 h-1flow rate,
respectively.
- The results indicate that the pressure of water decreases with
increasing holes diameter. The results indicate that when the hole
diameter increased from 10.0 to 15.0 mm with 5, 10, 15, 20, 25
and 30 holes and from 20.0 to 25.0 mm with 3, 6, 9, 12 and 15
holes. The same relationship was obtained when the hole diameter
increased from 10 to 25 mm with 15 holes.
- The average velocity of water decreases with increasing holes
diameter from 10.0 to 15.0 mm with 5, 10, 15, 20, 25 and 30 holes
and from 20.0 to 25.0 mm with 3, 6, 9, 12 and 15 holes. When the
hole diameter increased from 10 to 25 mm the average velocity
decreased with 15 holes.
- The impulse force of water decreases with increasing hole
diameter from 10.0 to 15.0 mm with 5, 10, 15, 20, 25 and 30 holes
and from 20.0 to 25.0 mm with 3, 6, 9, 12 and 15 holes. When the
hole diameter increased from 10 to 25 mm the impulse force of
water decreased with 15 holes.
110
SUMMARY AND CONCLUSION
Ahmed M. Ragab, (2016), M.Sc., Fac. Agric., Ain Shams Univ.
To obtain the rotational velocity in the optimum range suitable for tilapia
fish and for tank self-cleaning we recommended that the optimum jet
angle is 90° with the next tank configuration:-
At 5 m3h-1: 5 holes with diameter of 10 mm.
At 15 m3h-1: 5 to 15 holes with diameter of 10 mm, 5 holes with diameter
of 15 mm, 3 holes with diameter of 20 mm or 3 to 6 holes with diameter
of 25 mm .
At 30 m3h-1: 5 to 30 holes with diameter of 10 mm, 5 to 15 holes with
diameter of 15 mm, 3 to 9 holes with diameter of 20 mm or 3 to 9 holes
with diameter of 25 mm.
At 45 m3h-1: 10 to 30 holes with diameter of 10 mm, 5 to 25 holes with
diameter of 15 mm, 6 to 12 holes with diameter of 20 mm or 3 to 12
holes with diameter of 25 mm.
At 60 m3h-1: 15 to 30 holes with diameter of 10 mm, 10 to 30 holes with
diameter of 15 mm, 9 to 15 holes with diameter of 20 mm or 6 to 15
holes with diameter of 25 mm.
At 75 m3h-1: 15 to 30 holes with diameter of 10 mm, 10 to 30 holes with
diameter of 15 mm, 9 to 15 holes with diameter of 20 mm or 6 to 15
holes with diameter of 25 mm.
Second Experiment:
The experiment was carried out to study the effect of the tank
diameter: depth ratio on the rotational velocity homogeneity, dissolved
oxygen homogeneity and productivity of fish tank to reach the optimum
tank diameter: water depth ratio
We availed from the first experiment recommendation and choice
the optimum hole diameter and the holes number with each flow rate to
maintain the rotational velocity inside the tilapia optimum range. The
obtained results can be summarized as follows:
111
SUMMARY AND CONCLUSION
Ahmed M. Ragab, (2016), M.Sc., Fac. Agric., Ain Shams Univ.
Rotational velocity:-
- According to the first tank: the average of rotational
velocities was 10.8 1.75 cm s-1 when the tank
configuration is (flow rate is 6.5 m3h-1, hole diameter is 10
mm and holes number is 5), 19.6 2.97 cm s-1 when the
tank configuration is (flow rate is 12.2 m3h-1, hole diameter
is 10 mm and holes number is 5) and 23.4 3.77 cm s-1
when the tank configuration is (flow rate is 19.2 m3h-1,
hole diameter is 10 mm and holes number is 5).
- According to the second tank: the average of rotational
velocities was 22.5 2.65 cm s-1 when the tank
configuration is (flow rate is 17.1 m3h-1, hole diameter is
10 mm and holes number is 5), 21.3 3.63 cm s-1 when the
tank configuration is (flow rate is 30.1 m3h-1, hole diameter
is 10 mm and holes number is 10) and 20.6 3.77 cm s-1
when the tank configuration is (flow rate is 49.4 m3h-1,
hole diameter is 20 mm and holes number is 9).
- According to the third tank: the average of rotational
velocities was 18.9 1.94 cm s-1 when the tank
configuration is (flow rate is 26.7 m3h-1, hole diameter is
20 mm and holes number is 6), 20.5 3.46 cm s-1 when the
tank configuration is (flow rate is 44.1 m3h-1, hole diameter
is 10 mm and holes number is 15) and 21.4 3.56 cm s-1
when the tank configuration is (flow rate is 76.5 m3h-1,
hole diameter is 20 mm and holes number is 12).
The rotational velocity homogeneity decreased with increasing
flow rates inside the same tank and the best homogeneity was in the first
tank of 4:1 diameter: depth ratio, while the worst homogeneity was in the
second tank of 6.4:1 diameter: depth ratio.
112
SUMMARY AND CONCLUSION
Ahmed M. Ragab, (2016), M.Sc., Fac. Agric., Ain Shams Univ.
Dissolved oxygen:-
- According to the first tank: the average of dissolved oxygen was
6.6 0.50 mg l-1 when the tank configuration is (flow rate is 6.5
m3h-1, hole diameter is 10 mm and holes number is 5), 6.6 0.49
mg l-1 when the tank configuration is (flow rate is 12.2 m3h-1, hole
diameter is 10 mm and holes number is 5) and 6.6 0.49 mg l-1
when the tank configuration is (flow rate is 19.2 m3h-1, hole
diameter is 10 mm and holes number is 5).
- According to the second tank: the average of dissolved oxygen
was 6.1 0.95 mg l-1 when the tank configuration is (flow rate is
17.1 m3h-1, hole diameter is 10 mm and holes number is 5),
6.1 0.96 mg l-1 when the tank configuration is (flow rate is 30.1
m3h-1, hole diameter is 10 mm and holes number is 10) and
6.1 0.97 mg l-1 when the tank configuration is (flow rate is 49.4
m3h-1, hole diameter is 20 mm and holes number is 9).
- According to the third tank: the average of dissolved was 6.1 1.1
mg l-1 when the tank configuration is (flow rate is 26.7 m3h-1, hole
diameter is 20 mm and holes number is 6), 6.1 1.07 mg l-1 when
the tank configuration is (flow rate is 44.1 m3h-1, hole diameter is
10 mm and holes number is 15) and 6.1 1.07 mg l-1 when the
tank configuration is (flow rate is 76.5 m3h-1, hole diameter is 20
mm and holes number is 12).
The best homogeneity was in the first tank of 4:1 diameter: depth ratio
while the worst homogeneity was in the second tank of 8:1 diameter:
depth ratio.
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SUMMARY AND CONCLUSION
Ahmed M. Ragab, (2016), M.Sc., Fac. Agric., Ain Shams Univ.
Productivity:-
- The mean weight of fish increased from 18 to 148, 18 to 136 and 18 to
114 g after 14 weeks with the diameter: depth ratios 4.0, 6.4 and 8.0,
respectively.
- The average weight gain of fish increased from 2 to 21, 8 to 13 and 3
to 6 g after 14 weeks with the diameter: depth ratios 4.0, 6.4 and 8.0,
respectively.
- The average of specific growth rate was 2.29, 2.20 and 2.01 at 4.0, 6.4
and 8.0 diameter depth ratio, respectively during the experiment
period.
- The average of feed conversion rate was 1.70, 1.83 and 2.10 kg
feed/kg fish at 4.0, 6.4 and 8.0 diameter: depth ratio, respectively
during the experiment period.
- The average of feed efficiency was 0.59, 0.55 and 0.48 kg fish/kg feed
at 4.0, 6.4 and 8.0 diameter: depth ratio, respectively during the
experiment period.
- The mean daily mortality rates were 0.048, 0.058 and 0.064 % at 4.0,
6.4 and 8.0 diameter: depth ratio, respectively during the experiment
period.
It could be concluded that:
The optimum diameter: depth ratio is the first tank of 4:1
diameter: depth ratio because it was the most homogenous tank with
respect to rotational velocities and dissolved oxygen concentrations in the
tank in addition to it was the most productivity was obtained from it