Cathodic protection system for storage tank outer bottom based on thin-plate zinc alloy anode

Abstract

The invention relates to an outer bottom cathode protection system of a storage tank based on a laminal zinc alloy anode. The outer bottom cathode protection system of the storage tank is arranged at the bottom of an outer bottom plate (1) of the storage tank, and comprises a zinc alloy sheet anode (2), asphaltic sand (3) and a foundation sand layer (4) sequentially from the top down, wherein a housing steel plate (7) of the storage tank is connected with the zinc alloy sheet anode (2) by a cable (6). The system has the advantages that the system avoids the situations that moisture condensation water and underground water rise to be close to the outer bottom plate of the tank due to cracking of the asphaltic sand or water penetration around the tank, or rainwater penetration results in a corrosive environment; and with the adoption of a sacrificial anode mode, the protection period can be up to 20 years. The protection period for a zinc plate can be prolonged if a waterproof effect around the tank is good.

Description

technical field [0001] The invention relates to a cathodic protection system for the outer bottom of a storage tank based on a thin-plate zinc alloy anode, and belongs to the technical field of corrosion and protection for oil and gas storage and transportation systems. Background technique [0002] In the oil and gas storage and transportation system, most steel storage tanks are currently used to store crude oil. During operation, steel storage tanks are bound to be corroded by internal and external environmental media, which will affect their service life. How to solve or alleviate the corrosion of storage tanks with economical measures is particularly important in the design of oil tanks. Cathodic protection is a technology to prevent or inhibit electrochemical corrosion of protected metal structures. [0003] The corrosion of the outer bottom of the storage tank mainly comes from the corrosion of the soil medium at the bottom of the tank. The foundation of most stora...

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Problems solved by technology

[0011] In order to overcome the defects of the prior art, the present invention provides a method to solve the problem that the traditional sacrificial anode method is not suitable for the protection of storage tanks with high resistivity and large diameter, and also to avoid the output current of the applied current system being too small at the initial stage of operation, and the waste of power supply capacity. Problems with relatively large fluctuations in operation

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