Once-through cooling system protection

Continuous ferrous sulphate addition has been used for many years to reduce water side corrosive attack of steam condenser tubes. It is usually applied to once through cooling water systems because of its low cost, to provide an iron-rich protective film on the tube surface. For recirculation systems other more expensive, corrosion inhibitors are generally employed. Two phases of the ferrous sulphate treatment programme may be recognised. The first phase involves the initial laying down of the protective film. The second phase involves the maintenance of the film, which would be otherwise destroyed by the shear effects of flow. 

This simple use of a fire protection connection in a once-through cooling mode provides additional defence in depth capability for cooling the residual heat removal system. This solution was chosen using a process that promoted satisfying design requirements with lowest change to... 

The advantage of using a fire protection connection in a once-through cooling mode is increased reliability of the residual heat removal system. 

One can characterize DBNPA as a potent but not persistant microbicide the application of which does not cause waste water problems. Formulations containing 40%, 20% or 5% a.i., are available. They may be used to inhibit biofouling in recirculating water (cooling towers) and once-through industrial water systems, in pulp, paper and paperboard mills, in enhanced oil recovery systems, in aqueous metalworking fluids. As a preservative DBNPA is efficient only for the short term protection of aqueous products. 

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