Sulphite Oxygen Controller
SULPHITE OXYGEN CONTROLLER is a liquid sodium sulphite product used for oxygen scavenging in low and medium pressure boilers.
How does it work?
SULPHITE OXYGEN CONTROLLER reacts rapidly with dissolved oxygen in the boiler to form inert sodium sulphate. this prevents damage caused by oxygen pitting and corrosion in the boiler. Oxygen Scavenger is a convenient to use liquid oxygen scavenger recommended for the complete removal of oxygen from deaerator heaters, feedwater storage areas, feedwater lines, ship condensate return lines, boiler internals and closed recirculating water systems.
The product is dosed to give a reservoir level of sodium sulphite in the boiler. If the reserve drops below a minimum level then oxygen corrosion will occur. It is therefore essential to maintain a level at all times. The product is used as part of a boiler water treatment programme.
Results of use
The interior of the boiler is protected from oxygen corrosion attack. However please note that extra solids are produced in the process so additional blow-down will be required.
Dosing and Sampling
A reserve of 30-50ppm sulphite (Aalborg recommend 30-60 p.p.m) should be maintained in the boiler. SULPHITE OXYGEN CONTROLLER should be dosed continuously to the boiler by means of a metering pump into the feed line after the recirculation line. Continuous dosing can also be achieved by dosing into the hotwell to a point as close to the feed water pump suction as possible, although efficiency is adversely affected by low hotwell temperatures. A daily analysis sample should be taken after blow-down, cooled and tested immediately. Always take samples from the same location.
A representative sample of boiler water must be obtained, at an interval set by experience in operation of the boiler, usually every 3-5 days. The sample should be taken after the regular blow down and analysed immediately.
The target parameter is 30-50ppm of sulphite. The product should be applied separately to CONDENSATE CONTROLLER and should not be mixed with any alkaline treatment.
18 p.p.m of Oxygen Scavenger are required for each p.p.m of dissolved oxygen, plus a slight excess residual for testing purposes.
Dose per M³ feed = (18 x p.p.m Oxygen) + (________65__________)
Boiler concentration factor
This formula will give 30 p.p.m sulphite as Na²So³
Where Feed temp = 80°C then p.p.m Oxygen = 2.9 p.p.m
Oxygen Scavenger liquid may be fed directly from the shipping container or diluted with clean condensate in a chemical mix tank. It is compatible with most boiler chemical additives except filming amines. Minimum agitation is suggested to prevent premature activation of the oxygen scavenger with oxygen (air) captured by mechanical action at the solution interface. Covered mix tanks or floating plastic plugs are desirable. It may be dosed in conjunction with Liquid Boiler Water Treatment PLEASE TAKE SPECIAL NOTE: DO NOT ADD NEAT LIQUID BOILER WATER TREATMENT AND SULPHITE OXYGEN SCAVENGER TOGETHER. Typically the neat sulphite Oxygen Scavenger should be added to pre-dilute Liquid Boiler Water Treatment in a mixing tank. A typical mix would be for a 100 litres of pre-mixed treatment: 75 litres water, 25 litres Liquid Boiler Water Treatment and 3 litres of Sulphite Oxygen Scavenger.
Oxygen Scavenger is controlled by maintaining a fixed sulphite excess of not less than 30 p.p.m in boilers or 3 p.p.m in feedwater lines, as detectable sulphite using a reagent dropper method or standard titration technique. Aalborg recommendation is 30 -60 p.p.m. Please check specific manufacturer’s instructions as they may vary.
Avoid direct contact with skin and eyes to prevent mild irritation. In case of accidental contact, flush area with water, and seek medical attention. Product should not be ingested. Please refer to Material Safety Data Sheets for detailed handling and storage information.
SULPHITE OXYGEN CONTROLLER is an catalysed sulphite oxygen scavenger used as part of a boiler water treatment programme in low or medium pressure boilers.
Pack Size – 25 litre Drum.
Product Ref. SOC