The internal surfaces of a new boiler contain deposits of residual oil, grease, and protective coatings inherent in the manufacturing process. These coatings must be removed since they reduce the heat transfer rate and could result in tube rupture from overheating. If a contaminating oil is saponifiable, foaming may occur. Additionally, oil serves as a nucleus and binder for scaling at hot spots and agglomerates boiler sludge and suspended solids into “oil balls,” especially in turbulent sections such as steam drums and water headers. For these reasons, the removal of oil, grease, and mill scale is essential from a new boiler. These deposits can generally be removed by an alkaline boil-out.
H2OTREAT-5601 is an alkaline blend of phosphates, alkalis, surfactants, and dispersants used for pre-operational cleaning of new boilers. H2OTREAT-5601 is suitably inhibited with an appropriate corrosion inhibitor to control caustic embrittlement and stress corrosion cracking of boiler metallurgy. The purpose of an alkaline boil-out is to remove contaminants such as dirt, oil, grease, mill scale, and temporary protective coatings used in the fabrication and installation.
ADVANTAGES:
- Removes Deposits: H2OTREAT-5601 removes greasy and oil-bound deposits from new boilers.
- Increases Efficiency: H2OTREAT-5601 increases the heat transfer efficiency of boilers.
- No Objectionable Odors: H2OTREAT-5601 does not create objectionable odors.
- Prevents Caustic Embrittlement: H2OTREAT-5601 does not cause caustic embrittlement or stress corrosion cracking.
- Ease of Analysis: H2OTREAT-5601 can be readily analyzed at use concentration on-site, ensuring effective cleaning of the system.
DOSAGE AND APPLICATION:
Recommended Boil-Out Procedure:
- Prepare for Firing: Clear the boiler for firing by taking standard precautions.
- Inspect and Clean: Inspect all internal waterside surfaces, including tubes, and remove any debris. It may be necessary to use a high-pressure hose to flush out inaccessible areas.
- Replace Gauge Glass: If the unit is furnished with prismatic type gauge glass, replace it with a temporary one to prevent chemical attack.
- Remove Valves: Water relief valves and steam safety valves must be removed before adding the boil-out solution to avoid contamination. Use care in removing and reinstalling valves.
- Close Valves: Ensure all valves in the piping leading to or from the system are closed to prevent cleaning solution from getting into the system.
- Fill Boiler: Fill the pressure vessel with demineralised, preferably deaerated water until the top of the tubes are covered. Inject H2OTREAT-5601 to give a final strength of 5% w/v in the system and then fill the boiler to the top. The initial fill water should be at ambient temperature.
- Low Firing Rate: Fire the boiler at a very low firing rate to limit flue gases entering the boiler to a maximum of 800°F. Alternatively, introduce 5 psig steam from an outside source through the blowdown nozzles.
- Steam Production: When the boiler begins to produce steam (as seen through the open vents), allow the unit to steam freely for at least four to five hours. Maintain the normal water level (midpoint of the gauge glass) and add more boil-out solution as necessary.
- Close Vents: Close all vents.
- Maintain Pressure: Hold drum steam pressure at 5 to 10 psig while maintaining the water level near the midpoint of the gauge glass. Adjust heat input as required to maintain this pressure.
- Increase Pressure: After eight hours, increase drum pressure to 20% of anticipated operating pressure or to 100 PSI by increasing the firing rate.
- Circulate Solution: Continue to circulate the solution for at least forty-eight hours. Perform hourly blowdowns through intermittent blowdown valve/points lasting for 30 seconds each to remove impurities collected in the header. Replace removed solution with hot treated water to maintain normal water level.
Chemical Analysis and Maintenance:
After each blowdown cycle, draw and analyze a sample of the boil-out solution for pH, alkalinity, conductivity, and phosphate. Add chemical solution when boiler water alkalinity and phosphate levels drop to half the original values. Do not over-add chemicals.
If the blowdown is not clean at the end of forty-eight hours, continue the boil-out for an additional eight-hour cycle until the blowdown is clean. Blowdown is considered clean if free of oil.
Shutdown and Inspection:
- Remove Heat Source: When blowdown is clean, remove the heat source and allow the unit to cool gradually.
- Drain Boiler: Let the boiler cool to 120°F or less, then drain using caution. Dispose of the water and chemicals per local/state environmental regulations.
- Rinse System: Remove inspection covers and rinse the system with treated water at least three to four times.
- Inspect Surfaces: Inspect surfaces and pressure parts internally. If any remnant oil is found, repeat the boil-out procedure.
- Reinstall Components: Reinstall the regular gauge glass and safety or relief valves.
- Post-Boil-Out Operations: If the boiler is to be put into service immediately, fill it with deaerated water and fire until the water is heated to at least 180°F. If the boiler is not going to be put into service, follow proper “Boiler Lay Up Procedures.”
HANDLING AND PRECAUTIONS:
- Do not get H2OTREAT-5601 into eyes, on skin, or clothing. Do not inhale fumes. Wear rubber gloves and goggles or face shield when handling.
- In case of contact with skin, wash well with soap and water. In case of contact with eyes, flush promptly and thoroughly with clear water. Seek immediate medical attention if ingested or in case of eye contact.
- Keep the container closed when not in use.
PACKAGING:
- Normally packed in 50 kg jerry cans.
- For bulk supplies, other convenient packaging can be organized on specific demand.
AFTER SALES SERVICE:
In order to ensure maximum efficiency, H2O Consultant & Engineers provides professional after-sales service, which includes frequent analysis of water and appropriate suggestions from the technical experts of the company.
