Cathodic protection system of wet desulfurized funnel

Abstract

The invention relates to a cathodic protection system for a wet desulfurized funnel, which is used for the treatment of corrosion on the wet desulfurized funnel in a thermal power plant. The wet desulfurized funnel comprises a basal body surrounding the funnel, wherein the basal body is provided with an inner wall and an outer wall, an outlet of the wet desulfurized funnel is formed at the end part of the basal body. The cathodic protection system of the wet desulfurized funnel comprises an acid resisting layer which is arranged along the inner wall, an anode screen which is laid in the acid resisting layer, a reference electrode which is embedded in the acid resisting layer, and a measurement grounding device, a cathode and a constant potential rectifier which are arranged on the outer wall of the wet desulfurized funnel, wherein the reference electrode, the measurement grounding device, the cathode, and the anode screen are respectively led out by cables and are connected with the constant potential rectifier. Since the cathodic protection is combined based on the acid resisting layer, corrosion can be effectively resisted, and the acid resisting property is excellent; and meanwhile, the acid resisting layer is compact, flaws are not easy to occur, and the leakage resisting property is good, the load of the funnel can be reduced after the cathodic protection is applied, the service life of the funnel is long, and economic benefits are significant.

Description

technical field [0001] The invention relates to a cathodic protection system used for corrosion control of wet desulfurization chimneys in thermal power plants. Background technique [0002] The corrosion control of wet desulfurization chimney is one of the major problems affecting the safety of thermal power plant operation. There is a large amount of condensed acid in the wet desulfurization chimney without flue gas heat exchanger, which is extremely corrosive. The main reason for the serious corrosion of the wet desulfurization chimney is that the flue gas temperature is lower than the sulfuric acid dew point temperature, and a large amount of acid liquid condenses on the inner wall of the chimney, which will severely corrode the steel inner cylinder or reinforced concrete cylinder. At present, there are nearly a dozen kinds of corrosion control schemes in China, mainly including coatings, lining materials and new polymer materials. None of these schemes has achieved a go...

AI Technical Summary

Problems solved by technology

Due to the harsh working conditions of strong corrosive residual liquid and alternating high and low temperatures, most of the current anti-corrosion coatings have aging, cracking, and peeling. There are a large number of cracks or peeling in cement and lining materials. FRP glass fiber reinforced plastics have poor fire resistance. Titanium The alloy has many problems such as poor resistance to dilute acid and high price

[0007] Traditional acid-resistant cement (castable) is the most commonly used method for acid-resistant linings. Compared with coatings, lining sleeves and other composite chimney anti-corrosion methods, it has excellent acid resistance, long service life, and is not easy to age. It has the advantages of fire resistance and low price, but it also has certain shortcomings. Its thickness is thick (about 8-10cm), and its temperature shock resistance is poor, and it is prone to cracks, and it is not dense enough, and its impermeability is poor, resulting in condensation Liquid penetration, corrosion of chimney substrates

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