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Safety guideline for boiler operations in machinery spaces on board cargo ship

Working with marine boiler
: Use of Boiler Gauge Glasses
Boiler water is to be kept within the upper and lower limits at all times. If the water level disappears from either the top or the bottom of the glass and does not return immediately, then all burners are to be shut off until the water level has been restored in the gauge glass. Any such loss of water must be recorded in the Engine Log Book and reported to the Chief Engineer.



Whenever the water level indicated is suspect it is essential that the remote water level indications are not used in place of the readings from the water level gauge glass. Low pressure water level gauge glasses are to be "blown down" by an approved method for the type of gauge glass at least once per watch or whenever the water level indication is suspect. High pressure water level gauge glasses are to be blown through only when necessary.

Testing of Boiler Water Controls, Regulators, Alarms and Trips.

All boiler controls, regulators, alarms and trips must be tested regularly in accordance with the applicable Planned Maintenance System and makerís recommendations. Each test is to be recorded with the signature of the Engineer Officer who conducted the test.

Boiler level alarms or trip defects are to be rectified immediately. The boiler should not normally be operated with any such safeguards inoperative unless under the supervision of the Chief Engineer. In this circumstance the boiler must be continuously monitored.

The appropriate Management office is to be advised of details of any defects, remedial measures taken, and confirmation of satisfactory re-tests which are also to be recorded in the Engine Room Log Book.


Boiler Water Tests and Treatment

Water in the boilers, steam/steam generators together with samples from their feed water systems is to be tested daily. Testing is to be carried out in accordance with procedures laid down by the suppliers of the water treatment systems. Completion of tests is to be recorded in Engine Room logbook and the full results entered on the appropriate forms and sent to the laboratory for evaluation. Test results indicating contamination or loss of chemical reserve are to be investigated immediately.

Departures from normal operating conditions are to be recorded, and the relevant Management Office immediately advised.


Storage and Handling of Boiler Chemicals

Attention is drawn to the spontaneous combustion properties of certain oxygen scavenging materials such as hydrazine. Any material (e.g. cleaning material, rags, cotton waste, sawdust etc.) contaminated with chemicals of this type, must be washed or destroyed immediately, to avoid the risk of self ignition.


Blowing Down Boilers

Boilers are to be blown down at least once per week dependent upon the frequency required to control the level of dissolved solids contained in the boiler water. Ideally blowdown should be carried out under light load conditions with at least one tonne being blown down from each boiler, the actual quantity being recorded in the ER log book and the boiler water report forms.

Blowing down is to be carried out irrespective of the salinity or chemical reserve readings. Use is also to be made of the surface blow down valve to remove scum from the boiler.


Boiler Maintenance at Sea

Should it become necessary to shut a boiler down for repairs or routine maintenance, and if this results in a reduction in speed or adversely affects operational requirements, the appropriate Management Office must be informed. Details concerning the reason for the shutdown and the likely delay should be advised. For main propulsion boilers, wherever possible, routine maintenance should be carried out during ballast rather than loaded passages.


Cleaning of Gas Side Surfaces

During cargo operations, in the interests of safety, and in particular to avoid the possible emission of sparks, the use of soot blowers or other devices for cleaning the gas side surfaces is prohibited.


Safety Precautions during Boiler Operation, Maintenance and Cleaning

During the operation, cleaning and maintenance of boilers safe working practices are of paramount importance. Qualified personnel are to be familiar with correct operational procedures and manufacturers recommendations.

Where these operations involve personnel entering the gas or water spaces, the full safety precautions outlined in the Company Safety and Environmental Manual are to be adhered to. In particular, respirators, protective clothing, and low voltage lamps are to be used.


Spark and Smoke Emission

You should be aware that under various regulations applicable to the area your vessel is in, it may be an offence to emit dark smoke. The Master should therefore request appropriate detailed information from the local agent concerning the area emission regulations and pass the information to the Chief Engineer. Careful consideration should be given to the location and operational circumstance of the vessel before soot blowing. Permission should be sought from the bridge before soot blowing.

Soot blowing or cleaning of turbochargers should not be carried out when gas freeing cargo tanks, when bunkering or transferring fuel or when working cargo alongside a terminal or during ship to ship transfer. In order to ensure that sparks are not generated from the funnel flame arrestors and screens they must be regularly checked and replaced when required. High back pressures can be generated if these devices become blocked. Flame screens must not be painted.

Emissions of smoke, soot and exhaust gases such as COx, NOx and SOx (Carbon, nitrogen and sulphur) is minimised by controlled running, systematic maintenance and inspection routines of machinery, boilers and funnel. The emissions of exhaust gases contribute to pollution and environmental problems such as acidification and global warming. We aim to focus on control and reduction of the emission of these harmful gases. Reference is made to MARPOL Annex VI and of the Companyís Safety and Environmental Procedures.

Some of the ships are equipped with funnel filters to prevent large emissions from occurring. Special care shall be exercised during port stays and when starting main and auxiliary engines and lighting boilers.


General precautions

A notice should be displayed at each boiler setting out operating instructions. Information provided by the manufacturers of the oil-burning equipment should be displayed in the boiler room.

To avoid the danger of a blowback when lighting boilers, the correct flashing up procedure should always be followed:

(i) there should be no loose oil on the furnace floor;

(ii) the oil should be at the correct temperature for the grade of oil being used; if not, the temperature of the oil must be regulated before lighting is attempted;

(iii) the furnace should be blown through with air to clear any oil vapour; (iv) the torch, specially provided for the purpose, should always be used for lighting a burner unless an adjacent burner in the same furnace is already lit; other means of ignition, such as introducing loose burning material into the furnace, should not be used. An explosion may result from attempts to relight a burner from the hot brickwork of the furnace;

(v) if all is in order, the operator should stand to one side, and the lighted torch inserted and fuel turned on. Care should be taken that there is not too much oil on the torch which could drip and possibly cause a fire;

(vi) if the oil does not light immediately, the fuel supply should be turned off and the furnace ventilated by allowing air to blow through for two or three minutes to clear any oil vapour before a second attempt to light is made. During this interval the burner should be removed and the atomizer and tip inspected to verify that they are in good order;

(vii) if there is a total flame failure while the burner is alight, the fuel supply should be turned off.

The avenues of escape from the boiler fronts and firing spaces should be kept clear.

Where required to be fitted, the gauge glass cover should always be in place when the glass is under pressure. If a gauge glass or cover needs to be replaced or repaired, the gauge should be shut off and drained before the cover is removed.


Summarized below marine boiler detail Info pages:

  1. Requirement for various boiler types - water tube boilers and more
  2. The watertube boiler is employed for high-pressure, high-temperature, high-capacity steam applications, e.g. providing steam for main propulsion turbines or cargo pump turbines. Firetube boilers are used for auxiliary purposes to provide smaller quantities of low-pressure steam on diesel engine powered ships.....

  3. Fire tube boilers working principle and operational procedure
  4. The firetube boiler is usually chosen for low-pressure steam production on vessels requiring steam for auxiliary purposes. Operation is simple and feedwater of medium quality may be employed. The name 'tank boiler is sometimes used for firetube boilers because of their large water capacity. The terms 'smoke tube' and 'donkey boiler are also in use....

  5. Exhaust Gas Boilers And Economisers working procedure
  6. The use of exhaust gases from diesel main propulsion engines to generate steam is a means of heat energy recovery and improved plant efficiency.The auxiliary steam installation provided in modern diesel powered tankers usually uses an exhaust gas heat exchanger at the base of the funnel and one or perhaps two watertube boilers .....

  7. The use of boiler mountings
  8. Watertube boilers, because of their smaller water content in relation to their steam raising capacity, require certain additional mountings: Automatic feed water regulator. Fitted in the feed line prior to the main check valve, this device is essential to ensure the correct water level in.the boiler during all load conditions. Boilers with a high evaporation rate will use a multiple-element feed water control system ....

  9. Purity of boiler feedwater
  10. Most 'pure' water will contain some dissolved salts which come out of solution on boiling. These salts then adhere to the heating surfaces as a scale and reduce heat transfer, which can result in local overheating and failure of the tubes. Other salts remain in solution and may produce acids which will attack the metal of the boiler. An excess of alkaline salts in a boiler, together with the effects of operating stresses, will produce a condition known as 'caustic cracking'. This is actual cracking of the metal which may lead to serious failure.....

  11. The steam-to-steam generator working principle and operational procedure
  12. Steam-to-steam generators produce low-pressure saturated steam for domestic and other services. They are used in conjunction with watertube boilers to provide a secondary steam circuit which avoids any possible contamination of the primary-circuit feedwater. The arrangement may be horizontal or vertical with coils within the shell which heat the feedwater.....

  13. How to control combustion in a marine boiler
  14. The essential requirement for a combustion control system is to correctly proportion the quantities of air and fuel being burnt. This will ensure complete combustion, a minimum of excess air and acceptable exhaust gases. The control system must therefore measure the flow rates of fuel oil and air in order to correctly regulate their proportions.....

  15. Safe boiler operation - Preparations & raising steam
  16. All boilers have a furnace or combustion chamber where fuel is burnt to release its energy. Air is supplied to the boiler furnace to enable combustion of the fuel to take place. A large surface area between the combustion chamber and the water enables the energy of combustion, in the form of heat, to be transferred to the water.....

  17. Fuel oil burning process - various design burners
  18. Marine boilers currently burn residual low-grade fuels. This fuel isstored in double-bottom tanks from which it is drawn by a transfer pump up to settling tanks. Here any water in the fuel may settle out and be drained away.

  19. Boiler arrangement - combustion process - supply of air
  20. Combustion is the burning of fuel in air in order to release heat energy. For complete and efficient combustion the correct quantities of fuel and air must be supplied to the furnace and ignited. About 14 times as much air as fuel is required for complete combustion....

  21. Ordinary spring-loaded safety valve and improved high-lift safety valve for a marine boiler
  22. Safety valves are fitted in pairs, usually on a single valve chest. Each valve must be able to release all the steam the boiler can produce without the pressure rising by more than 10% over a set period.....

  23. Correct working level for marine boilers - use of water level gauges
  24. The water level gauge provides a visible indication of the water level in the boiler in the region of the correct working level.

  25. How to maintain water level in a marine boiler ?
  26. A modern high-pressure, high-temperature watertube boiler holds a small quantity of water and produces large quantities of steam. Very careful control of the drum water level is therefore necessary. The reactions of steam and water in the drum are complicated and require a control system based on a number of measured elements......

  27. Safety precautions for working with marine boiler
  28. All boiler controls, regulators, alarms and trips must be tested regularly in accordance with the applicable Planned Maintenance System and makerís recommendations. Each test is to be recorded with the signature of the Engineer Officer who conducted the test....




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