Study On Influence Factors And Pilot Test Of Electrochemical Scale Removal Equipment

Circulating cooling water accounts for about 80%of industrial water consumption.Scaling,corrosion and microbial breeding often occur in the process of circulating cooling water operation,which will not only lead to decreased heat transfer efficiency and blocked pipes,but also increase energy consumption and shorten the service life of equipment.The traditional method of descaling and descaling is to add chemical agents,but the cost is high,which will cause secondary pollution to the water.Electrochemical treatment technology is a new technology,which is known as environmentally friendly technology.It has the characteristics of scale removal and prevention,sterilization and algae killing,corrosion inhibition and COD degradation.This paper deals with the treatment of circulating cooling water by electrochemical technology,discusses the influence rule of operating parameters on the treatment effect,and carries out pilot test research.Based on titanium base iridium ruthenium oxide coating plate as anode,stainless steel plate as cathode,the four factors three levels orthogonal experiment design,under the condition of static operation,comprehensive inspection hardness removal rate and COD removal rate and residual chlorine concentration three indexes,the test results show that the current density of 7 m A/cm~2,initial water hardness is 400 mg/L,electrolytic time for 5 min,plate spacing is 1 cm,the optimum operation conditions for system.The order of the significant influence of the above four factors on the treatment effect is:water hardness>current density>electrolytic time>plate spacing.According to the orthogonal experiment the optimum parameters for running conditions,to further explore the above factors,single factor experiment design a comprehensive treatment effect and energy consumption,it is concluded that under the condition of dynamic test,current density of 5 m A/cm~2,plate spacing is 3 cm,residence time for 5 min,initial water hardness is 500 mg/L treatment effect is good,low energy consumption.On this basis,a 600 m~3/h circulating cooling water system of a steel plant in Handan city,Hebei province was taken as the treatment object,and the electrochemical scale removal equipment was used to carry out the pilot test study.Hardness and COD removal were better when the current density was 3 m A/cm~2 than 5 m A/cm~2.When the circulating flow increased from 6 m~3/h to 18 m~3/h,the hardness removal effect was good,while the COD removal effect was opposite.The results of the study on the energy consumption of the electrochemical method for removing hardness and COD per unit mass show that the energy consumption increases with the increase of current density.The circulation flow has little influence on energy consumption.When it rises from 6 m~3/h to 18 m~3/h,both hardness and COD energy consumption decrease.According to the treatment effect and energy consumption,the optimal operating conditions were determined:circulating flow was 18 m~3/h,and current density was 3 m A/m~2.Through EDS and SEM analysis,it is found that the scale crystal after electrochemical treatment has distortion,which is conducive to cleaning the cathode scale and achieving the purpose of descaling and inhibiting scale.The economic benefit analysis and environmental benefit analysis have been carried out.Compared with the chemical additive method,the electrochemical scale removal device can save the operation cost of 400,800 yuan per year,effectively reduce the treatment cost,and will not cause secondary pollution.It has a good industrial application prospect.