Apparatus employing an aqueous solution

An apparatus having a flow path for an aqueous solution, the aqueous solution including water and iron based compounds which deposit on the interior of the apparatus, the water being capable of reacting with its environment to form iron based compounds, wherein the improvement comprises:

• water having a pH which is at least 5.5, having an electrical conductivity which is less than or equal to five-tenths of a micromho per centimeter, having a solids content which is less than one part per million (1 ppm), the solids content including an amount of iron based compounds other than ferric hydrous oxide;
• and,
• means for disposing ferric hydrous oxide in the water wherein said ferric hydrous oxide is of a character that retards the deposition of said iron based compounds on the interior of the apparatus.

A method of operating a boiler which uses feedwater to form an aqueous solution, the boiler having at least one flow path for the aqueous solution which extends through the boiler and at least one conduit for the aqueous solution through which the flow path extends, the aqueous solution including water and iron based compounds which deposit on the interior of the conduit, the water being capable of reacting with its environment to form iron based compounds, the improvement which comprises:

• providing the boiler with feedwater having a pH which is at least 5.5, an electrical conductivity which is less than or equal to one micromho per centimeter, a solids content which is less than one part per million (ppm),
• disposing in the feedwater ferric hydrous oxide of a character and of an amount which blocks the deposition of iron based compounds from said aqueous solution in said conduit of the boiler and which promotes the formation of a protective wall layer of iron deposit without evidence of corrosion greater than equivalent systems which do not have said ferric hydrous oxide.