Through walls or wear ground pipeline anti-corrosion structure
Technical field
The present invention relates to a kind of anticorrosive measure of fluid-transporting tubing, relate in particular to a kind of through walls or wear ground pipeline anti-corrosion structure.
Background technique
At present in many occasions, the pipeline of conveyance fluid need pass wall or ground, the seawater conveyance conduit of nuclear power station for example, its pipeline many places are in dark moist gallery or melt pit, these environment have very strong corrosivity, especially pipeline passes the through hole on wall or ground, and Korrosionsmedium is assembled easily, and the risk that crevice corrosion takes place is arranged.Crevice corrosion be meant when metal and metal or metal and nonmetal between when having very little slit (being generally 0.25-0.1mm), medium is difficult for flowing and forms and is detained the phenomenon of the metal accelerated corrosion in the promotion slit in the slit in.
Most of industrial metals or alloy all may produce crevice corrosion, with the seawater of nuclear power station through walls or wear ground pipeline be example, the anticorrosive measure that nuclear power station adopts at present is the inner line with rubber of carbon steel, outside anti-corrosion method with corrosion-inhibiting coating is at wall-through hole or wear place, hole, ground and adopt fireproof blocking or clay sealing.Seawater through walls or wear the residing corrosive environment of working time, equipment of ground Corrosion of Pipeline degree and equipment and the factors such as anti-corrosion measure that adopted relevant.Seawater through walls or wear ground Corrosion of Pipeline, show as at wall-through hole or wear the effective thickness attenuate of hole place, ground tube wall, serious meeting causes the corrosive pipeline perforation, influences the normal operation of equipment, if the seawater pipeline corrosion failure of the system relevant with nuclear safety also can cause unit outage.
At present the nuclear power station wall-through hole or the structure of wearing place, hole, ground respectively as shown in Figures 1 and 2, pipeline 10 is arranged in wall 20 or the ground 30, liquid 100 is easily at wall-through hole or wear place, hole, ground and gather, and might infiltrate in the environment of slit the generation of the corrosion that gaps.Above-mentioned seawater is through walls or wear ground pipeline generation reason for corrosion, and the one, because seawater is through walls or wear the ground pipeline and mostly be in the dark moist gallery or melt pit, have a large amount of stronger Korrosionsmediums in the environment, as O
2, Cl
-Deng; The 2nd because wall-through hole or wear the concrete at hole place, ground or the combination force of clay and metallic conduit relatively poor, perhaps concrete is because phenomenons such as cracking, efflorescence have taken place in the operation time limit for a long time, like this at wall-through hole or wear hole place, ground and will produce the slit, for entering of Korrosionsmedium provides condition.The source of Korrosionsmedium is: underground water of sparge water, water of condensation and the seepage hydrophobic, that use when remaining in seawater in the equipment, repair apparatus of equipment etc., and the complicated component of water in the melt pit, corrosivity is strong.
After above-mentioned Korrosionsmedium enters wall-through hole or wears the slit in hole, ground; though there is the corrosion-inhibiting coating protection outside of pipeline 10; but because the solvent evaporates in the coating in the Dry run after construction; be easy in coating, form pin hole; Korrosionsmedium enters in the environment of slit and can contact with metallic matrix by pin hole, causes the metallic matrix corrosion.The corrosion primary stage, the inside and outside homogeneous corrosion that oxygen depolarization takes place in slit.Because the medium in the slit can not convective flow, the diffusion of oxygen replenishes difficult, and oxygen reduction reaction progressively stops.Just having constituted macroscopical oxygen concentration cell subsequently, is to be negative electrode outside anode, the seam in the seam of anoxic.Because much smaller, so at the solubilizing reaction Fe → Fe of anode generation metal as the seam internal area ratio of anode seam outer area
2++ 2e; And take place at negative electrode
Reaction.The corrosion products of cathode and anode meets the formation secondary product and deposits the metal cations Fe that produce in the slit this moment at sealing
2+Be difficult to the interior positive charge of seam be increased, Cl must be arranged toward the slit external diffusion
-Migration is come in to keep charge balance (electronegative OH
-Also may move into, but their migration velocity compares Cl
-Slowly many).Metal chloride concentration in the result stitches constantly increases, and hydrolysis reaction (Fe further takes place chloride
2++ 2H
2O → Fe (OH)
2↓+2H
+) insoluble hydroxide of generation and free acid.The existence of free acid can destroy the passivating film of metal surface, and quickens the corrosion of metallic matrix.The final seawater that just caused is through walls or wear the ground pipeline at wall-through hole or wear the heavy corrosion at place, hole, ground.
How to improve through walls or wear the ground pipeline at wall-through hole or wear the corrosion protection design at hole place, ground, become and avoid through walls or wear the ground corrosive pipeline losing efficacy and being badly in need of a key issue solving.
Summary of the invention
It is a kind of through walls or wear the anti-corrosion structure of ground pipeline that technical problem to be solved by this invention is to provide, and it can prevent effectively that Korrosionsmedium from entering the slit, thereby avoids corrosion pipeline.
The present invention is achieved in that a kind of through walls or wear the anti-corrosion structure of ground pipeline, and described pipeline is arranged in wall or the ground, is provided with in the position near wall or ground in the outer wall of pipeline and avoids fluid accumulation at wall-through hole or wear the deflector at place, hole, ground.
Owing to set up deflector at pipeline near the position on wall or ground, described deflector can avoid liquid at wall-through hole or wear place, hole, ground and gather, thereby prevents that effectively Korrosionsmedium from entering the slit, avoids taking place crevice corrosion.
For the pipeline through walls that no fireproof blocking requires, described pipeline is arranged in the wall, and described deflector can be the gap that is arranged at pipeline and between the walls.Like this, liquid can unhinderedly flow away from this gap, can not gather.
For the through walls of fireproof blocking requirement being arranged or wearing the ground pipeline, described deflector can be sheathed on pipeline outer wall, one of them ora terminalis and the tube contacts of deflector, the outer surface of deflector extends to the direction on wall or ground from this ora terminalis, extends to the direction away from the pipeline medial axis simultaneously.Like this, deflector can flow away by sharp its outer surface guiding liquids, makes liquid away from wall-through hole or wear the hole, ground.
Description of drawings
Fig. 1 is that existing pipeline through walls is in the structural representation at wall-through hole place.
Fig. 2 is that the existing ground pipeline of wearing is in the structural representation of wearing place, hole, ground.
Fig. 3 be in the present invention's first preferred embodiment pipeline through walls in the structural representation at wall-through hole place.
Fig. 4 wears the ground pipeline in the structural representation of wearing place, hole, ground in the present invention's second preferred embodiment.
Fig. 5 be in the present invention's the 3rd preferred embodiment pipeline through walls in another structural representation at wall-through hole place.
Embodiment
In order to make technical problem to be solved by this invention, technological scheme and beneficial effect clearer,, the present invention is further elaborated below in conjunction with drawings and Examples.Should be appreciated that specific embodiment described herein only in order to explanation the present invention, and be not used in qualification the present invention.
See also Fig. 3, be in first preferred embodiment of the present invention pipeline through walls in the structural representation at wall-through hole place.Pipeline 1 is arranged in the wall 2, for the pipeline through walls that the fireproof blocking requirement is arranged, is filled with fire-proof sealing material 3 in the gap of pipeline 1 and wall 2.Be arranged with a deflector 4 in the outer wall of pipeline 1 in position near wall 2, described deflector 4 can by have water proofing property and adhesiveness preferably material make, sealer etc. for example, its material can be identical with above-mentioned fire-proof sealing material 3.The outer surface 41 of deflector 4 is the inclined-plane, one of them ora terminalis of deflector 4 (being the edge of outer surface 41) contacts with pipeline 1 outer wall, the outer surface of deflector 4 extends to the direction of wall 2 from above-mentioned ora terminalis, extend simultaneously to direction away from the medial axis of pipeline 1, and extend to wall 2 surfaces, promptly another ora terminalis that deflector 4 is relative with above-mentioned ora terminalis is attached at wall 2 surfaces.
Because the outer surface 41 of deflector 4 is the inclined-plane, therefore, deflector 4 can utilize its outer surface 41 guiding liquids flow away (as the direction of arrow among Fig. 3), make liquid away from wall-through hole, avoid liquid to gather at the wall-through hole place, thereby prevent that effectively Korrosionsmedium from entering the slit, avoid taking place crevice corrosion.
Occasion for pipeline is worn ground can be provided with above-mentioned deflector near the position on ground at pipeline outer wall equally, flows away with guiding liquids, avoids liquid to gather wearing place, hole, ground.Be appreciated that, the form of the outer surface 41 of above-mentioned deflector 4 is not limited to the inclined-plane, it also can be designed to cambered surface or other curved surfaces, as long as ora terminalis of this deflector and tube contacts, and its outer surface extends to wall or ground direction from this ora terminalis, gets final product to extending away from the direction of pipeline medial axis simultaneously.
Further improvement as above-mentioned mode of execution sees also Fig. 4, is to wear the ground pipeline in the present invention's second preferred embodiment in the structural representation of wearing place, hole, ground.Pipeline 1 is arranged in the ground 5, and 5 are provided with a step 6 in ground, and described step 6 is sheathed on pipeline 1 outer wall, further is provided with a deflector 4 on step 6.Described step 6 can be by having certain elasticity, not easy to crack, have impermeability, can prevent the corrosive liquids infiltration, and make with the material that metal or coating surface binding ability are good, for example neoprene mortar, asphalt mortar, bituminous mortar etc., in this enforcement, this step 6 is made by the neoprene mortar, what promptly a certain amount of neoprene of adding was made in the mortar.The material of described deflector 4 is identical with the material of middle deflector 4 embodiment illustrated in fig. 3, its outer surface 41 also is the inclined-plane, one of them ora terminalis of deflector 4 contacts with pipeline 1, outer surface 41 is from the 5 directions extension earthward of this ora terminalis, extend to direction simultaneously, and extend to step 6 surfaces away from the pipeline medial axis.
In the foregoing description, owing to set up step 6, its dash is higher, and pipeline 1 is difficult for being soaked by the ponding on the ground 2, can prevent the contacting point on ponding corrosion pipeline 1 and ground 2 on the ground 2.On the other hand, the intensity of step 6 is higher, and is not fragile, and step 6 has impermeability and elasticity preferably, can prevent that pipeline 1 vibration etc. from causing mortar to crack.In addition, step 6 also has stronger warning effect.
Above-mentioned first, second preferable enforcement all is applicable to the through walls of fireproof blocking requirement or wears the ground pipeline, see also Fig. 5, it is the 3rd preferred embodiment of the present invention, it is applicable to the pipeline through walls of no fireproof blocking requirement, between pipeline 1 and wall 2, has gap 7, liquid can unhinderedly flow away from this gap 7, and Korrosionsmedium forms crevice corrosion with regard to not gathering in the slit like this.
The above only is preferred embodiment of the present invention, not in order to restriction the present invention, all any modifications of being done within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.