Articles

ARC-1017 (I) XL Catalyzed Oxygen Scavenger / Corrosion Inhibitor

Oxygen Scavenger

    ALBATROSS ARC-1017 XL

    ARC-1017 (I) XL & ARC-1017 (II) XL

Oxygen Scavenger

An Ideal Solution to prevent Corrosion Problem in Boiler

PROBLEM

CORROSION

Corrosion occurs when metals (by acid or electrolytic action) attack metals. The metal is eaten away similar to the generalized rusting of an automobile fender. Corrosion increases maintenance costs, results in premature replacement of equipment and causes unnecessary safety risks.

Corrosion occurs where levels of oxygen or carbon dioxide are high, where pH values are low, where contact occurs between dissimilar metals and in damp environments or corrosive atmospheres.

Basic corrosion in boilers results primarily from the reaction of oxygen with the metal.

Stresses, pH conditions and chemical corrosion have an important influence and produce different forms of attack

Caustic  Stress Corrosion or Caustic Embrittlement

Caustic Stress Corrosion or Caustic Embrittlement : The combination of high stress and high caustic concentrations eventually led to destructive cracking of the boiler vessel. It occurs when hairline cracks appear in highly stressed areas due to high concentrations of alkaline salts that liberate hydrogen, which is then absorbed by the iron in steel, effectively changing its physical properties. This condition is caused largely by boiler water with pH values 11+ and manifests itself in high-temperature areas of the boiler.

Unless embrittlement problems are constantly monitored & controlled, they will take their toll in higher fuel costs, increased safety risks, unnecessary downtime and equipment replacement.

CORROSION CONTROL

Dissolved oxygen in the boiler water can lead to severe corrosion, invariably in the form of pitting attack which can weaken or eventually perforate tubes.

Oxygen is generally removed from boiler feed water in a two-step process which is:

Mechanical Deaearation followed by Chemical Oxygen Scavenging.

Modern deaerators are capable of lowering the oxygen content of feed water to less than 7 parts-per-billion (ppb). Chemical oxygen scavengers are then added to the deaerator storage tank to decrease the oxygen content to lower the detection limit of common test, i.e < l ppb.

The two most commonly used chemical oxygen scavengers are Sulfite & Hydrazine base.

Sulfite base oxygen scavenger when catalyzed reacts with oxygen to form sulfate. The reaction rates are very fast at deaerator temperature however, only catalyzed sulfite should be used at temperatures below 82 degrees C Hydrazine, (N2H4), reacts with oxygen to form nitrogen gas and water. In addition it can passivate metal surfaces by reducing iron and copper to the ferrous and cuprous oxide, respectively.

Hydrazine reacts more slowly than sulfite at low temperature and pressure, and for this reason it is generally not recommended at pressure below 4.l4MPa (600 psig).

Our Products

ARC-1017 (I) XL Sulfite base oxygen scavenger

ARC-1017 (II) XL Hydrazine base oxygen scavenger.

ARC–1017 (I) XL: Although many factors contribute to corrosion in boilers, the chief factor is dissolved oxygen in feed water.  So it is essential to remove the oxygen as far as possible in feed water tank it. ARC–1017 (I) XL is a specially formulated product needed to scavenge oxygen present in feed water.

SPECIFICATION

ARC–1017 (I) XL is an active specialized chemical in powder form for instant oxygen scavenging from boiler

DOSAGE & FEEDING

ARC–1017 (I) XL treatment levels are determined by Oxygen content of feed water  and  its  temperature  i.e.  higher the feed water temperature the lower is the  Oxygen contents  &  hence  lower  dosage  of ARC–1017 (I) XL is required.

Feed ARC–1017 (I) XL continuously for the best results.  Any interruption in feeding may result in corrosion in boiler.

ALBATROSS will provide technical assistance in arriving at optimum dosage for your operating conditions and as per quality of water being used.

ARC-1017 (II) XL steam boiler water treatment, catalyzed oxygen scavenger that combines chemically with dissolved oxygen in feed water or in the boiler to inhibit the formation of oxygen induced corrosion. Fast reacting and, therefore, will effectively remove dissolved oxygen from water, providing excellent corrosion protection of the boiler and the pre-boiler water systems when fed correctly.

ARC-1017 (II) XL will eliminate oxygen pitting and reduce the rate of return line corrosion through the elimination of oxygen being passed through the steam lines.

DOSAGE & FEEDING

Dosages will vary depending upon the feed water temperature, type of boiler operation, type of heater or deaerator, air leakage into the system, etc. application rate should be adjusted to maintain a reading of 0.2-1.0 PPM hydrazine in the boiler, and 1-2 PPM in the feed water. This product should be mixed with soft or condensate water.

Feeding of ARC-1017 (II) XL by chemical metering pump is recommended. The treatment should injected to the deaerator storage section.

ADVANTAGES / BENEFITS

  1. Reduces pitting type corrosion & extends equipments life/reduces down time.
  2. Reduces iron pick-up in the feed water systems & minimizes the iron deposition on heat transfer area.
  3. Contains a high  performance transition metal catalyst for  instant removal of oxygen. The quick oxygen removal  minimizes metal  to oxygen  contact time thus ensuring  minimum  corrosion.
  4. 20-500 times faster removal of oxygen  than commercial unanalyzed oxygen scavengers.
  5. Protects feed water lines and deaerator.
  6. Reduce treatment cost.