| The production of dirt in large industrial equipment can reduce production efficiency or even stop the factory,there may be a vicious incident,causing a series of serious consequences.Chemical cleaning can be applied to petroleum,chemical,paper,textile and other industries.Chemical cleaning is the most common method of removing dirt from industrial equipment,however,cleaning with an acidic cleaning agent will certainly corrode the metal material of the industrial equipment.The corrosion inhibitor can slow down or prevent the corrosion of the metal in the cleaning agent.Chemical cleaning can bring both social and economic benefits.In this paper,a systematic study on the chemical cleaning procedure of refractory fouling is realized.The key steps are:fouling component analysis,determining the cleaning agent and the cleaning temperature and preparation of corrosion inhibitor.In this paper,the scale analysis of Huajin Group heat exchanger scale,Liaohe oil field heat injection furnace scale inhibitor sediment,Fushun Petrochemical Company condenser scale,Beijing paper mill scale,Dongying boiler scale,Beijing steel mill scale and other indissoluble fouling was carried out by chemical analysis and instrumental analysis.I designed a fouling experiment based on the refractory ingredients to determine the cleaning agent and the best cleaning temperature.The dissolution of the insoluble scale does not only require a suitable cleaning agent,but also need to reach 90?cleaning temperature.In high temperature conditions,the acidic cleaning agent is bound to cause serious corrosion of metal equipment,and the general corrosion inhibitor can only be below 60?on the metal corrosion inhibition,therefore,it is necessary to study the high efficiency corrosion inhibitors under high temperature conditions.In this paper,three kinds of high efficiency corrosion inhibitors JA-1,JA-2 and JA-3have been successfully developed in high temperature conditions.Corrosion inhibitor JA-1can inhibit corrosion of stainless steel and carbon steel in hydrochloric acid at 90?,and it also can inhibit corrosion of stainless steel and carbon steel in mud acid at 90?.Corrosion inhibitor JA-2 can inhibit corrosion of stainless steel and carbon steel in hydrofluoric acid at90?.Corrosion inhibitor JA-3 can inhibit corrosion of stainless steel in hydrofluoric acid at90?.In this paper,three kinds of corrosion inhibitors were systematically evaluated by weight loss method,corrosion rate curve method,electrochemical curve method and visual analysis method.Respectively,to change the concentration of JA-1,JA-2,JA-3,calculate the corrosion rate of metal test pieces to determine the best corrosion inhibitor concentration.The corrosion rate of the metal test piece was determined by changing the acidity of the cleaning agent,the temperature of the reaction system and the reaction time,respectively,to determine their acid resistance,temperature resistance and time resistance.Three kinds of corrosion inhibitors have successfully solved the problem of corrosion inhibition of carbon steel and stainless steel in hydrochloric acid,hydrofluoric acid and mud acid under high temperature conditions,and they can make the metal corrosion rate down to 1g·m-2·h-1 below in the cleaning agent at 90?to meet the cleaning requirements of industrial equipment under certain conditions.Electrochemical analysis determines that the three kinds of corrosion inhibitors are mixed corrosion inhibitor in their respective systems. |
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