EFFECT OF DRAG-REDUCING POLYMERS ON THE RATE OF FLOW-INDUCED CORROSION OF METALS

Rates of diffusion-controlled corrosion of copper rotating cylinders i n acidified chromate solutions containing Polyox WSR-301 drag-reducing polymer, were measured under turbulent flow conditions. The variables studied were the acid concentration, the cylinder rotational speed an d the polymer concentration. The rate of corrosion was found to decrea se in the presence of Polyox, depending on the operating conditions. A t a given polymer concentration, the maximum inhibition efficiency was found to be a decreasing function of the acid concentration and occur red between a Reynolds number of 4500 and 6000, depending on the acid concentration. The maximum observed corrosion inhibition efficiency wa s about 23% for an acid concentration of 0.25 M bearing 250 ppm Polyox . Possible practical applications of drag-reducing polymers in operati ng chemical engineering equipment, to benefit from their dual function as corrosion inhibitors and drag reducers, were highlighted. (C) 1998 Elsevier Science B.V. All rights reserved.