Important Factors to Consider When Cleaning a Ship’s Boiler
One of the most important processes that must be performed on a ship’s marine boilers is boiler cleaning. Boiler cleaning is done to prevent and remove carbon and particle deposits from the boiler.
However, there are some critical points to remember when cleaning a boiler. These crucial points are discussed in this article.
Important Considerations for Cleaning Boiler Parts
- If the boiler water is properly treated with chemicals and the chemical concentration is within the acceptable range, the deposits on the water and steam side of the boiler will be minimal.
- If the boiler uses fresh water rather than heavy water, the deposits inside the tubes will be minimal and can be removed by boiling. The upper drum scrubber and brush are used to remove the hard deposits inside the tubes.
- If the boiler oil burner is working properly and proper maintenance is performed on a regular basis, soot deposits inside the oil-fired boiler will be minimal. However, soot deposits cannot be completely avoided because soot formation is greater during boiler startup and accumulates inside the boiler space over time.
- Water washing with a 10% soda solution through the inlet door in the uptake with a water hose can remove soot deposits.
- Water washing must be done with caution. It should be noted that the refractory contained within the boiler does not become wet.
- During water washing, cover the refractory with a plastic sheet and drain the water continuously through the drain at the bottom.
- If the refractory becomes wet, the boiler should be lit slowly; otherwise, the refractory will crack and fall down, resulting in overheating and deformation inside.
The aforementioned points are the fundamental things to remember when doing boiler work, regardless of the type of boiler or ship.
Boiler Parts Maintenance
Boiler maintenance should always be performed with skill and in accordance with valid rules and regulations from the authorities, and some recommendations for periodic inspections and maintenance are provided below.
Every day, during normal boiler operation, some work and check procedures must be considered.
- Examine the boiler’s steam pressure and water level.
- Check that the feed water control system is working properly.
- Examine the boiler water condition and take any necessary countermeasures for feed and boiler water treatment. Blow down the boiler if necessary.
- Examine the operation of the oil burner at various capacities using the inspection holes on the boiler.
- After that, check the flue gas temperature and/or the draft loss across the boiler. The pin-tube section must be cleaned if either the temperature or the draft loss is too high.
Weekly Routine Checks
- For about 10-15 seconds, drain each water level glass.
- In the event of contaminated boiler water or insufficient water treatment, the water level glasses must be drained more frequently.
- Examine the water level safety device.
- The boiler was blown down based on the boiler water tests. Open the blow-down valves quickly for a few seconds, then close and reopen for 5-10 seconds.
- Repeat this operation as needed based on the boiler water tests.
- When necessary, use the scum valve to blow out the scum. The scum blow out process must be repeated until the drained water is clean.
Monthly Routine Checks
- All backup pumps should be tested.
- Examine all boiler mountings for damage or leaks, and repair/replace as needed.
- Check the operation of the high steam pressure switch by lowering the set point or increasing the steam pressure, for example, by slowly closing the main steam valve. The burner must be turned off automatically.
If the boiler becomes contaminated with foreign substances such as oil, chemicals, corrosion products, and so on, it is critical to act quickly to avoid boiler damage.
Layers of thin oil films, mud, and other materials exposed to the heating surfaces disrupt heat transfer in the boiler, resulting in overheating and burned-out pressure parts. A boiling out or acid cleaning must be performed immediately to remove such contamination.
Corrosion products from the pipe system or inadequate boiler water treatment may cause corrosion in the boiler. As a result, it is critical to note that such situations do not occur in the system.