Study On The Water Quality Protection Technology Of Recirculating Cooling Water In Corn Deep Processing Enterprises

Water quality preservation technology of circulating cooling water system,is not only benefit the enterprise energy saving and emission reduction,but also has a far-reaching influence on water environment protection.With the increasing sense of environment protection,corrosion and scale inhibitors,starting in low phosphorus,phosphorus-free direction.The development of low phosphorus,phosphate-free,corrosion,scale,and microorganism inhibitor has practical engineering significance.This paper rely on a typical corn deep-processing enterprises,solves the problems of pipeline corrosion,scaling,and microbial growth in the circulating cooling water system.With the actual circulating cooling water as experimental water,inhibition efficiencies were studied by rotaring coupon corrosion test,calcium carbonate deposition and flat colony counting method.The inhibitor we studied were zinc sulfate,polyepoxysuccinic acid(PESA),polyaspartic acid(PASP),hydroxyl-ethylidene diphosphonic acid(HEDP),amino trimethylene phosphonic acid(ATMP),sodium hypochlorite,isothiazolone,glutaraldehyde.Selected the best concentration ratio of corrosion,scale,and microorganism inhibitor by orthogonal test method for carbon steel and stainless steel,explored the corrosion and scale mechanism by electrochemical experiment and scanning electron microscope.In this stydy,corrosion,scale,and microorganism inhibitor:(1)When the dosage was 37.8mg/L,Zn2+(1mg/L),PESA(1.5mg/L),HEDP(8mg/L),ATMP(10mg/L),sodium hypochlorite(3mg/L),isothiazolone(0.8mg/L),the corrosion rate for carbon steel material is 0.004428mm/a,the scale inhibition rate exceeded 97.42%,and the bactericidal rate reached above 99.48%.(2)When the dosage was 21.8mg/L,PESA(8mg/L),HEDP(5mg/L),ATMP(5mg/L),sodium hypochlorite(3mg/L),isothiazolone(0.8mg/L),the corrosion rate for stainless steel is 0.001646mm/a,the scale inhibition rate exceeded 96.82%,and the bactericidal rate reached above 99.31%.(3)The results of electrochemical experiment showed that the inhibitor mainly inhibit the anodic reaction.(4)The result of scanning electron microscopy analysis showed that a protective film was formed on the surface of the carbon steel to inhibit the corrosion,damage the lattice structure of calcium carbonate,inhibit the crystal growth.The economic analysis shows that,the inhibitor treatment cost for circulating cooling water is 1.47 yuan /(tons?d),lower than the similar agents’ prices at home and abroad,less phosphorus,higher ratio of performance to price,which provide alternative solutions for the enterprise with the promotion of significance.