Composition for preventing corrosion using a sulfite-based oxygen scavenger
AssigneeMiura Co., Ltd.
InventorsJunichi Nakajima, Masazumi Yamashita, Kenichi Kimura
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Abstract
The invention effectively prevents occurrence of corrosion in water tubes or the like of boilers. The invention provides a method for operating a boiler, including regulating a concentration of sulfate ions SO42− in boiler water to under 500 ppm, and a method for injecting a sulfite base oxygen scavenger, including setting a concentration of residual dissolved oxygen in boiler feed water to 2-4 ppm. The invention further provides a sulfite base oxygen scavenger composition comprising: 3-30 weight % of at least one selected from a group consisting of Na2SO3, K2SO3, NaHSO3 and KHSO3; 1-20 weight % of NaOH or KOH; 0.2-2 weight % of potassium sorbate; and 5-500 ppm of CoSO4.
Claims6
A boiler feed water containing a sulfite-based oxygen scavenger, comprising:
- the boiler feed water;
- and
- the sulfite based oxygen scavenger in an amount effective to set a level of dissolved oxygen to 2-4 ppm,
- wherein, the sulfite based oxygen scavenger comprises 0.2-2 wt % of potassium sorbate, 5-500 ppm of CoSO4 and 3-30 wt % of at least one K2SO3 or KHSO3.
A boiler feed water containing a sulfite-based oxygen scavenger, comprising:
- the boiler feed water;
- and
- the sulfite based oxygen scavenger in an amount effective to set a level of dissolved oxygen to 2-4 ppm,
- wherein, the sulfite based oxygen scavenger comprises 0.2-2 wt % of potassium sorbate and 3-30 wt % of at least one compound selected from the group consisting of Na2SO3, K2SO3, NaHSO3 and KHSO3.
Dependencies are inferred from the claim text.