Optimal Piling Network Corrosion Protection System for Al-Zubair Harbor

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Figures 4-6 is more than –800 mV at different paths and

positions of anode with 1.5 voltage of power supply;

therefore, the selected voltage of power supply does not

protect the steel piles because their potential is more than

the desired value. In Figure 7, the voltage of power sup-

ply is 2V and the anode is set on the first path, when the

anode place is in the first position, the distance between

the anode and the piles equals to 17 cm and the value of

protection potential is –796 mV. In position (2) the dis-

tance between the anode and the piles is equal to 16 cm

and the protection potential is –816 mV. At position (3)

the distance between the anode and the piles equals 15

cm and protection potential is –850 mV. There is an in-

verse relationship between protection potential and the

distance between the anode and cathodes, this relation-

ship is given by the following Equation [10]:

the protection potential is less than –800 mV. In Figure

10, voltage of power supply is 2.5 V and the anode is set

on the first path. When the anode is in the first position,

the distance between the anode and the piles is equal to

17cm and protection potential is –1019 mV, in the sec-

ond position the distance between the anode and the piles

is 16 cm and protection potential is –1041 mV, at posi-

tion (3) the distance between the anode and the piles is

15 cm and protection potential is –1091 mV. It can be

observed that protection potential is increased in negative

direction when the distance between the anode and cath-

odes is decreased. In Figure 11, voltage of power supply

is 2.5 V and the anode is set at the second path, the dis-

tance among the anode and the piles in position (1) is 15

cm and protection potential is –1096 mV, the distance

among the anode and the piles in position (2) is 16 cm

and protection potential is –1050 mV, in position (3) the

distance among the anode and the piles is equal to 17 cm

and the protection potential is –1011 mV. In Figure 12,

voltage of power supply is 2.5 V and the anode is set on

the third path, it can be observed that the protection po-

tential at this path is less negative than protection poten-

tial at the first and second path because the length of this

path is larger than the first and second path. The distance

between the anode and the piles in position (1) is 16.6 cm

and protection potential is –978 mV, the distance be-

tween the anode and the piles in position (2) is 16.4 cm

and protection potential is –988 mV, in position (3) the

distance between the anode and the piles is equal to 16.6

cm and the protection potential is –981 mV.

0.171VID

(4.1)

where V represents the potential, ρ is the resistivity of

environment, I represent current density, and D is the

distance between the cathode and anode; therefore, when

the distance between the anode and piles is reduced, this

will lead to a reduction in protection potential to less than

–800 mV. In Figure 8 voltage of power supply is 2V and

the anode is set on the second path, at position (1) and (2)

protection potential is less than –800 mV while at posi-

tion (3) protection potential is more than –800 mV. The

distance between the anode and the piles in the first posi-

tion equals 15 cm and protection potential is –854 mV.

The distance between the anode and the piles in the sec-

ond position equals 16 cm and protection potential is

–825 mV, in position (3) the distance between the anode

and the piles is equal to 17 cm and the protection poten-

tial is –794 mV. These results verify the inverse rela-

tionship between protection potential and the distance

between the anode and cathodes. In Figure 9, voltage of

power supply is 2V and the anode is set at the third path,

at this path the protection potential is more than –800

mV for all positions of anode. This path is represented

hypotenuse in the right-angled triangle so the length of

this path is 10.6 cm longer than the first and second paths,

which the length of each one of them equals 7.5 cm. The

distance between the anode and the piles in position (1)

is 16.6 cm and protection potential is –793 mV, in posi-

tion (2) the distance between the anode and the piles is

16.4 cm and protection potential is –798 mV, in position

(3) the distance between the anode and the piles is equal

to 16.6 cm and the protection potential is –791 mV. As

previously stated, when the distance between the anode

and piles is reduced, it will lead to increase in protection

potential in a negative direction. The protection potential

in Figures 10-12 is less than –800 mV at all paths and

positions of anode with 2.5 voltage of power supply;

therefore, the selected voltage of power supply protects

the steel piles at all paths and positions of anode because

5. Conclusions

1) Full factorial design is a powerful tool to obtain ac-

curate results about the influence of the factors and their

interactions by using experiments including all possible

factors-level combinations in the experimental design.

2) Full protection for three cathodes can be provided

through an electrical circuit connecting them within an

appropriate geometric shape.

3) When the distance between the anode and piles are

reduced, this will lead to increase in the protection poten-

tial in a negative direction.

4) When the distance between the anode and piles are

reduced, this will lead to increase in the protection poten-

tial in negative direction.

It can be noticed that the protection potential at third

path is less than the other paths because the third path

(hypotenuse in the right-angled triangle) is the longest

path among the others.

REFERENCES

[1] West Virginia University, “Appalachian Underground

Corrosion Short Course,” MATCOR, Inc., Morgantown,