Anticorrosive for boiler

Abstract

The boiler anti-corrosive of the present invention contains an amine compound represented by formula (1): NH 2 —(CH 2 ) m —O—(CH 2 ) n —OH  (1) (wherein each of m and n is an integer of 1 to 3), or contains an oxygen scavenger and the amine compound represented by formula (1). The anti-corrosive is generally used in a boiler operated with a superheater or a steam turbine, or in such a boiler to which treated water is fed, and can more effectively maintain the pH of boiler water and can prevent corrosion not only of the boiler tank but also in the entire boiler system including a feed-condensate system, without adding a large amount of phosphate salt or elevating the Na/PO 4 mole ratio to 3 or higher.

1 . A boiler anti-corrosive characterized by containing an amine compound represented by formula (1):
   NH 2 —(CH 2 ) m —O—(CH 2 ) n —OH  (1)
   
       (wherein each of m and n is an integer of 1 to 3). 
     
     
         2 . A boiler anti-corrosive according to  claim 1 , which further contains an oxygen scavenger. 
     
     
         3 . A boiler anti-corrosive according to  claim 2 , wherein the oxygen scavenger is at least one species selected from among hydrazine, carbohydrazide, hydroquinone, 1-aminopyrrolidine, 1-amino-4-methylpiperazine, N,N-diethylhydroxylamine, isopropylhydroxylamine, erythorbic acid and a salt thereof, and ascorbic acid and a salt thereof. 
     
     
         4 . A boiler anti-corrosive according to  claim 1 , wherein the amine compound represented by formula (1) is at least one species selected from 2-(2-aminoethoxy)ethanol and 3-(3-aminopropoxy)propanol. 
     
     
         5 . A boiler anti-corrosive according to  claim 1 , which further contains at least one species selected from among ammonia and a neutralizable amine. 
     
     
         6 . A boiler anti-corrosive according to  claim 5 , wherein the neutralizable amine is 3-methoxypropylamine.