Carbohydrazones as boiler water oxygen scavengers
AssigneeNalco Chemical Company
InventorsDouglas G. Kelley, Deborah M. Rogers, Frederick J. Swiecinski
Life of this patent
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Abstract
The invention is directed generally to controlling corrosion in boiler systems and more particularly to treating boiler water to remove dissolved oxygen and to passivate metal surfaces.
Claims15
A method for removing dissolved oxygen from boiler water having an alkaline pH which comprises adding to said boiler an oxygen scavenging amount of at least one carbohydrazone compound selected from the group of carbohydrazone compounds consisting of:
- ##STR3## in which R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are, individually, hydrogen, an alkyl group, a substituted alkyl group, an aryl group, and a substituted aryl group.
A method of removing dissolved oxygen from boiler water having alkaline pH and passivating boiler surfaces, the method comprising the step of adding to the boiler water at least 0.5 moles of a carbohydrazone per mole of dissolved oxygen along with from 0.2 to about 20% by weight based on the carbohydrazone of a catalyst capable of undergoing oxidation-reduction reactions.
Dependencies are inferred from the claim text.