CN201136898Y - Sacrificial anode of profiled cross section - Google Patents

Abstract

The utility model provides a profiled cross section sacrificial anode, which comprises an anode body and a circular anode core. The profiled cross section sacrificial anode has the improvement that the shape of the cross section of the anode body is a profiled body formed in a way that a station-shaped body extends from the bottom part of a trapezoid body; the polarization of the cathode in the early protection stage can be rapidly reached, the use effect of the cathode protecting device can be enhanced, the using amount of the sacrificial anode can be saved, and the manufacturing cost of the ocean engineering cathode protecting system can be reduced.

Description

Special-shaped cross section sacrificial anode

Technical field

The utility model relates to cathodic protector, relates in particular to the special-shaped cross section sacrificial anode that uses in a kind of ocean engineering structure galvanic protection.

Background technology

That the sacrificial anode that uses in the ocean engineering structure cathodic protector mostly is is aluminium base, zinc-base or magnesium base anode.Because corrosion in various degree all can take place the different zones in the ocean environment of being in ocean engineering structure, these corrosion are most of to be galvanic corrosion.For example, all bear different zones, corrosion in various degree at the ocean structure of tidal range district, splash zone and atmospheric zone.

In order to protect marine structure to avoid corrosion, nearly all marine structure all adopts the galvanic protection mode to prevent that corrosive from taking place and development.Submerged zone in ocean environment; cathodic protector generally is divided into two kinds of impressed current cathodic protection and galvanic anode protections; a large amount of employings is sacrificial anode cathodic protection devices at present; sacrificial anode cathodic protection devices mainly is made up of the sacrificial anode that is evenly arranged on the works; sacrificial anode is soldered on the protected works, and the consumption by sacrificial anode itself provides protection for works.Its advantage is that design and construction are simple, does not need to safeguard, protects effective.

The protective current density of ocean engineering structure cathodic protector design is to design different numerical value respectively according to the different steps in initial stage, mid-term and the later stage of works galvanic protection.At the galvanic protection initial stage, the works surface is naked steel, this time, body structure surface did not also form the calcium deposition layer, therefore the initial stage polarization needs sacrificial anode can produce the polarization of big electric current with the accelerating structure thing, accelerate the formation of calcium deposition layer, so that works can be polarised to protection potential within a short period of time; Be the phase of keeping during the stable galvanic protection after the initial stage polarization, the protective current density that this phase of keeping needs is less, because after the big current polarizing in the early stage, the works surface has formed the calcium deposition layer, at this moment needed protective current density is less.

Conventional cross section sacrificial anode mostly is trapezoid cross section or square-section; the anode surface area in this cross section is very little in different protection phase table area change; can not provide electric current according to the requirement of different steps current density; and the anode of profiled-cross-section; surface-area is bigger in the early stage, and bigger electric current can be provided, and shortens the polarization time at initial stage; improve sacrificial anode in whole service efficiency during one's term of military service, guarantee effective protection of works.

Shown in Fig. 1, Figure 1A; be the sacrificial anode structure used in the existing Cathodic Protection System for Marine Structure device and the cross-sectional shape of anode bodies; mainly comprise anode bodies and circular anode core, anode bodies and circular anode core are combined into sacrificial anode by casting, and the cross-sectional shape of this anode bodies is trapezoidal.The anode surface area in this cross section is less, and is therefore very little in the different protection phase table area change of galvanic protection, particularly can not provide big electric current to quicken polarization effectively at the galvanic protection initial stage, therefore haves much room for improvement.

The utility model content

Main purpose of the present utility model is to overcome the above-mentioned shortcoming that existing anode exists; a kind of special-shaped cross section sacrificial anode is provided; the anode bodies and the circular anode core that comprise profiled-cross-section; because the anode of profiled-cross-section has increased the surface-area of anode in the initial polarization stage significantly; make heterotypic positive pole can produce bigger electric current in the starting stage; can make protected structure reach polarization in the early stage fast; simultaneously because profiled-cross-section anodic bench-type structure division is thinner relatively; after the acceleration initial stage, polarization was consumed, thereby the anodic cross section returns to the stable polarization that mid-term is kept in the trapezoid cross section basically.By the polarization of acceleration initial stage, make the works surface form the calcium deposition layer fast, make the protective current of middle and later periods reduce, thereby reduced the consumption of sacrificial anode on the whole, reduce the cost of oceanographic engineering cathodic protection system.

The utility model special-shaped cross section sacrificial anode comprises anode bodies and circular anode core; It is characterized in that described anode bodies cross-sectional shape is the shaped body that truncated cone is extended in the prismatoid bottom.

Aforesaid special-shaped cross section sacrificial anode, wherein the truncated cone of prismatoid bottom extension is formed in one.

Aforesaid special-shaped cross section sacrificial anode, wherein anode bodies is aluminium base, zinc-base or magnesium base anode bodies.

The beneficial effect of the utility model special-shaped cross section sacrificial anode; it comprises the anode bodies and the circular anode core of profiled-cross-section; increased the surface-area of the anode bodies of profiled-cross-section; therefore can make the galvanic protection initial stage reach polarization fast; improve works cathodic protector result of use; save the consumption of sacrificial anode, reduce the cost of oceanographic engineering cathodic protection system.

Description of drawings:

Fig. 1 is existing conventional sacrificial anode structural representation.

Figure 1A is existing conventional sacrificial anode cross-sectional structure synoptic diagram.

Fig. 2 is the utility model special-shaped cross section sacrificial anode structural representation.

Fig. 2 A is the utility model special-shaped cross section sacrificial anode cross-sectional structure synoptic diagram.

Fig. 3 is existing conventional cross section sacrificial anode and special-shaped cross section sacrificial anode sectional dimension comparison diagram.

Major label description in figure: bottom width, the conventional anode of c and heterotypic positive pole trapezoid cross section height under bottom width, b ' the heterotypic positive pole trapezoid cross section under bottom width, the conventional anode of the b trapezoid cross section on bottom width, a ' the heterotypic positive pole trapezoid cross section on the conventional anode of 1 sacrificial anode body, 2 anode cores, 3 conventional sacrificial anode cross sections, 3 ' special-shaped sacrificial anode cross section, a trapezoid cross section, c ' heterotypic positive pole cross section upper base are wide to the height of platform shape bottom surface, d ' heterotypic positive pole platform shape bottom surface.

Embodiment

Consult shown in Fig. 2, Fig. 2 A, the utility model special-shaped cross section sacrificial anode, it comprises anode bodies 1 and circular anode core 2; Its improvements are that the cross-sectional shape of this anode bodies 1 is the shaped body that truncated cone is extended in the prismatoid bottom; The truncated cone that extend this prismatoid bottom is formed in one; Anode bodies 1 is aluminium base, zinc-base or magnesium base anode bodies.

The preparation of the utility model special-shaped cross section sacrificial anode, prefabricated cross-sectional shape is the anode bodies mould that truncated cone is extended in the prismatoid bottom earlier, in ready-formed anode bodies mould, place the anode core of tubular again, cast then, anode core and anode bodies are combined into one, and the cross-sectional shape of anode bodies is the profiled-cross-section that truncated cone is extended in the prismatoid bottom; Cast material can be aluminium, zinc material or magnesium material, is prepared into the anode bodies of aluminium base, zinc-base or magnesium base.

The utility model special-shaped cross section sacrificial anode is fixed on the protected works by welding process, when protected works is installed in the ocean environment, plays the galvanic protection effect thereby sacrificial anode will make works polarize.

According to electrochemical principle, the generation electric current of sacrificial anode is to be directly proportional with the surface-area of anode bodies.In order to send bigger polarizing current at the galvanic protection initial stage; the design of the utility model special-shaped cross section sacrificial anode is according to this principle; under the constancy of volume situation of anode bodies; increased the surface-area at anode bodies initial stage; the surface-area of determining anode bodies by design calculation can send bigger polarizing current at the galvanic protection initial stage, reaches the purpose of acceleration initial stage polarization speed.As shown in Figure 3, for convenience the anode core is not considered in contrast, because identical anode core is under the constant situation of length, volume is identical to the influence of polarizing current.

Each minimizing part (anode top dash area as shown in Figure 3) of anodic both sides, conventional cross section is put into the edge of a wing, two ends, bottom forms the lower stage tee section, under all constant situation of conventional cross section anode and the utility model profiled-cross-section anodic volume V and length L, increase the surface-area of special-shaped cross section sacrificial anode, increase the purpose that satisfies the quickening mws polarization thereby make the anode initial stage that electric current take place, prove as follows:

Promptly (a-a ') * c '=(d '-b) * (c-c ')

Conventional anode girth: $S=a+b+2\sqrt{c^2+{\left[\frac{(b-a)}{2}\right]}^2}$

The heterotypic positive pole girth: $S^{\&prime;}=a^{\&prime;}+(2d^{\&prime;}-b^{\&prime;})+2\sqrt{{\mathrm{<figure-callout\; id="2"\; label="c"\; filenames="Y20072018720900091.png"\; state="\{\{state\}\}">c</figure-callout>}}^2+{\left[\frac{(b-a)}{2}\right]}^2}$

Conventional anode water receiving resistance: $R=\frac{\mathrm{\&rho;}}{2\mathrm{\&pi;L}}[\mathrm{Ln}\frac{4L}{r}-1]=K_1[\mathrm{Ln}\frac{8\mathrm{L\&pi;}}{S}-1]=K_1[\mathrm{Ln}\frac{K_2}{S}-1]$

Heterotypic positive pole water receiving resistance: $R^{\&prime;}=\frac{\mathrm{\&rho;}}{2\mathrm{\&pi;L}}[\mathrm{Ln}\frac{4L}{r^{\&prime;}}-1]=K_1[\mathrm{Ln}\frac{8\mathrm{L\&pi;}}{S^{\&prime;}}-1]=K_1[\mathrm{Ln}\frac{K_2}{S^{\&prime;}}-1]$

Because ρ, L is constant, then ${\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="Y20072018720900101.png"\; state="\{\{state\}\}">K</figure-callout>}}_1=\frac{\mathrm{\&rho;}}{2\mathrm{\&pi;L}}$ K ₂＝8πL

Then $\frac{R^{\&prime;}}{R}=\frac{\mathrm{Ln}\frac{K_2}{S^{\&prime;}}-1}{\mathrm{Ln}\frac{K_2}{S}-1}$

In the above formula:

V: anode volume,

L: anode length

A: bottom width on the conventional anode trapezoid cross section

B: bottom width under the conventional anode trapezoid cross section

C: conventional anode and heterotypic positive pole trapezoid cross section height

S: conventional anode girth

R: conventional anode water receiving resistance

A ': bottom width on the heterotypic positive pole trapezoid cross section

B ': bottom width under the heterotypic positive pole trapezoid cross section

C ': heterotypic positive pole cross section upper base is to the height of platform shape bottom surface

D ': heterotypic positive pole platform shape bottom surface wide

S ': profiled-cross-section anode girth

R ': profiled-cross-section anode water receiving resistance

ρ: seawater resistivity

K ₁, K ₂: be constant

Ln: logarithm.

Specifically be exemplified below:

Be provided with a conventional cross section sacrificial anode, be of a size of:

a＝30cm?b＝40cm?c＝24cm?L＝200cm

The special-shaped cross section sacrificial anode of same length and volume is of a size of:

a’＝22cm?b’＝32cm?d’＝80cm?c’＝20cm?L＝200cm

The resistivity of seawater is: ρ=25 Ω cm

Then

(a-a′)×c′＝(30-22)×20＝160cm ²

(d′-b)×(c-c′)＝(80-40)×(24-20)＝160cm ²

Satisfy the requirement of cross section constant (being constancy of volume);

Conventional anode girth: $S=30+40+2\sqrt{{24}^2+{\left(\frac{40-30}{2}\right)}^2}=119.03\mathrm{cm}$

The heterotypic positive pole girth: $S^{\&prime;}=22+(2\&times;80-32)+2\sqrt{{24}^2+{\left(\frac{40-30}{2}\right)}^2}=199.03\mathrm{cm}$

Conventional anode and heterotypic positive pole girth ratio: $\frac{S}{S^{\&prime;}}=0.598$

Conventional anode water receiving resistance: $R=0.0199[\mathrm{Ln}\frac{5024}{119.03}-1]=0.05458$

Heterotypic positive pole water receiving resistance: $R^{\&prime;}=0.0199[\mathrm{Ln}\frac{5024}{199.03}-1]=0.04435$

Heterotypic positive pole and conventional anode water receiving resistance ratio: $\frac{R^{\&prime;}}{R}=0.8126$

From shown in Figure 3 and formula calculation result as can be known, the utility model special-shaped cross section sacrificial anode is under the constant prerequisite of length and weight, it is nearly 60% that surface-area has increased, and water receiving resistance has reduced 18.7%, and special-shaped cross section sacrificial anode generation electric current has increased by 23.07%.

The above, it only is preferred embodiment of the present utility model, be not that the utility model is done any pro forma restriction, every foundation technical spirit of the present utility model all still belongs in the scope of technical solutions of the utility model any simple modification, equivalent variations and modification that above embodiment did.

Claims (3)

1, a kind of special-shaped cross section sacrificial anode comprises anode bodies and circular anode core; It is characterized in that described anode bodies cross-sectional shape is the shaped body that truncated cone is extended in the prismatoid bottom.

2, special-shaped cross section sacrificial anode according to claim 1 is characterized in that, the truncated cone that extend described prismatoid bottom is formed in one.

3, special-shaped cross section sacrificial anode according to claim 1 is characterized in that, described anode bodies is aluminium base, zinc-base or magnesium base anode bodies.

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