Study On Electrolytic Scale Inhibition Method Of Open Circulating Cooling Water System

Scaling,corrosion and microbial growth are major problems in the operation of industrial circulating cooling water systems.These problems will reduce the heat exchange efficiency,which in turn will cause system blockage,which is not conducive to safe production.Regarding the treatment of system scaling,the existing methods are mainly based on chemical agents,but this method causes secondary pollution.Therefore,there is a need to develop an efficient,pollution-free and lowcost descaling technology.In this paper,the open circulating cooling water is treated by electrolytic scale inhibition method,and the electrochemical properties of water and scale ions under the action of low-voltage electric field are used to reduce the hardness of water and achieve the purpose of scale inhibition.In this thesis,an electrolytic scale inhibition system was constructed.In this paper,four kinds of three-level orthogonal experiments were designed based on the existing common titanium plate coated with ruthenium and iridium as the anode and cathode.The results show that the influent water hardness is 600mg/L,the system voltage is 10 V,the hydraulic retention time is 10.5min,and the plate spacing is 12 mm,which is the best combination of system electrolysis scale inhibition.The degree of influence of four factors on the scale inhibition effect is: water hardness > voltage > hydraulic retention time > plate spacing.The optimal conditions obtained above are combined into the operating conditions of the system,and the cathode plates of different material structures are compared.The scale inhibition ability of the three plates is obtained: titanium plate coated with ruthenium and iridium > stainless steel plate > titanium plate.The scale inhibition effect of three kinds of cathode plates of the same material is: titanium mesh coated with ruthenium and iridium(mesh size 3 mm × 6 mm)> titanium mesh coated with ruthenium and iridium(mesh size 4.5 mm × 12.5 mm)>titanium plate coated with ruthenium and iridium.Moreover,the small-hole network structure titanium mesh coated with ruthenium and iridium has the strongest deposition ability.Finally,in this thesis,through the study of four single factor experiments,the calcium hardness removal rate and the deposition rate of the scale layer are taken as the evaluation indexes,and the electricity is obtained by using the ruthenium and iridium coated titanium plate as the anode and the ruthenium and iridium coated small pore titanium mesh as the cathode.The optimum level of the influent water quality of electrolytic scale inhibition system is 375 mg/L,the optimum voltage level is 13 V,the optimum hydraulic retention time is 10.5 min,and the optimum plate spacing is 17 mm.The calcium hardness removal rate under this optimal operating condition is 61.62%,the water temperature is changed to 3.3?,and the conductivity is on a downward trend.In summary,this paper selects the high-efficiency plate to construct the electrolytic scale inhibition system,the effect is remarkable,and the comprehensive benefits are good.