Capítulo 3. Formas del conocimiento: filosofía y poesía
3.3 Filosofía, ingenio y el «poder de la fantasía»
3.3.3 El ingenio en Juan Luis Vives
Main engine exhaust gases contain carbon particles, ash and unburnt fuel residues such as soot. The amount being dependent upon the quality of the fuel, the state of the engine and the operating load. Over a period of time deposits accumulate on the tubes, especially after continued operation on low loads. It will then be necessary wash the tubes and remove the accumulated deposits.
A good indicator of the amount of fouling is the pressure loss as the exhaust gas passes through the boiler, if this is more than 20mm H2O above that measured when the boiler was clean the tubes should be cleaned. Other indications are increased exhaust gas temperature after the boiler and/or reduced steam production for the same engine load.
The deposits are mainly insoluble particles bonded together by a water soluble material. Water washing dissolves the bonding material and then flushes the insoluble particles away. Due to the acidic nature of the deposits it is preferable to wash with an alkaline solution (10% washing soda) if possible. If this solution is not available then additional rinsing will be required.
Washing may only be carried out when the boiler is out of service and the shell temperature 100oC or less.
a) Open the two inspection doors to the exhaust spaces, above and below the boiler. Open the drain from the floor of the inlet box to the soot collecting tank and prove it to be clear. Using waterproof material cover the inlet from the engine to prevent water from running down to the turbochargers. Open the drains from the turbocharger exhaust outlet casings and prove them to be clear.
b) Using either a fresh water lance or a sea water hose commence washing the tubes through the inspection door in the outlet side of the boiler. The water jet should be directed at the smoke tubes and should be between 4.0 and 6.0 kg/cm2 pressure.
WarninG
When the smoke tubes are water washed there is the risk of generating steam. ensure that protective clothing including visors and gloves is worn and that the operators body remains outside the inspection door.
c) Constantly check the drain from the bottom of the inlet space to prevent any accumulation of water. Stop washing and clear the drain whenever it becomes blocked.
note: Once washing has commenced the process has to be completed and all deposits removed. Some types of deposit will become more difficult to remove if exposed to water and then allowed to dry.
d) When washing is complete, indicated by clean water at the drain, flush away all remaining residue from the bottom of the inlet box. If using sea water it is preferable that the final rinse is done with fresh water.
e) If available, neutralise any remaining acidic residues with a 10%
washing soda solution.
f) Remove the waterproof material from the exhaust gas inlet and close the drains on the turbochargers. Ensure that the drain valve is closed and the inspection doors are closed on completion.
g) The boiler should then be heated and dried out by use of the steam heating coil in the water space.
h) Clean the soot collecting tank on the drain system before the residue dries and compacts.
The boiler is now ready for service.
2.3 Condensate and feed Water systems
2.3.1 Condensate system 2.3.2 boiler feed Water system
2.3.3 Water sampling and treatment system
2.3.4 distilled Water transfer and distribution system
Maersk Seletar Machinery Operating Manual
PX PIAHMC
PC
Illustration 2.3.1a Engine Room Condensate System
From Fuel Oil Service Line Tracing Steam
Feed Filter TC ( 2mTank3 ) Inspection Tank
V20
From Starboard Passageway Exhaust
Gas Boiler (3000kg/h x
6kg/cm2) Heating
Coil
Reefer Cooling Water
Heater
Main Engine Cooling Water
Preheater
LubricatingMain Oil Settling
Tank
Calorifier
T-105V T-198V T-111V T-108V T-116V
T-149V T-156V
T-132V T-130V T-134V T-136V T-153V T-166V T-162V T-159V T-172V T-174V
T-188V T-192V T-178V T-176V T-180V
T-126V T-139V T-120V T-124V T-184V T-144V T-145V
T-102V T-38V
T-39V
T-28V
AccommodationFrom Air Conditioning
Room
Oil Fired Auxiliary Boiler
(4300kg/h x 6kg/cm2)
Heating Coil
No.1 Fuel Oil Heater No.2 Fuel
Oil Heater
LubricatingMain Oil Separator
Heater No.1 Generator
Engine Lubricating Oil Separator Heater No.2 Generator
Engine Lubricating Oil Separator Heater
No.1 Heavy Fuel Oil Separator
Heater No.2 Heavy
Fuel Oil Separator Heater No.3 Heavy
Fuel Oil Separator
Heater Boiler Waste
Oil Heater
Boiler Fuel Oil Heater
T-26V T-36V T-37V
Low Sulphur Heavy Fuel Oil
Settling Tank Low Sulphur
Heavy Fuel Oil Service Tank Heavy Fuel Oil
Settling Tank Heavy Fuel Oil
Service Tank Sludge Tank Boiler Waste
Oil Tank Heavy Fuel Oil
OverflowTank
Oily Bilge
Tank (Clean) Oily Bilge Tank (Dirty) T-25V
Key
Saturated Steam Condensate Control Air
Fuel Oil FilterAuto To Steam
System
From Port Passageway
Accommodation Heating Water
Heater
Dump Condenser/
Drain Cooler
Steam Dump Valve Set 6.6kg/cm2
Main Engine FO Tracing
Steam
Main Engine Lubricating Oil
Sump Tank T-23V
T-21V T-24V
T-22V
Maersk Seletar Machinery Operating Manual
2.3 Condensate and feed Water systeMs
2.3.1 Condensate systeMGeneral description
Condensate returns from the steam services are brought back to the feed filter tank, via the dump condenser/drain cooler and the inspection tank. The condensate is then returned to the feed water system. As there is a possibility of contamination from hydrocarbons from oil heating services the condensate is checked in the inspection tank, both visually and by the oil detector, before returning to the system.
The condensate from the dump condenser/drain cooler is transferred to the inspection tank, and thence to the feed filter tank, by means of gravity. The dump condenser also acts to condense excess steam from the steam system in order to maintain the desired steam system pressure. Condenser water level is maintained by a weir in the outlet line.
There are two inlets to the dump condenser/drain cooler, one from the steam dump valve and one from the condensate returns. The line from the steam dump valve is direct but the line from the condensate drain is via a three-way valve. The three-way valve at the drain line entry to the condenser allows the dump condenser to be bypassed and allows the condensate to flow directly to the inspection tank. This arrangement can be used when the dump condenser is being serviced, or when it is defective. However, the main purpose is to control the temperature of the water in the observation tank by allowing warm condensate directly into the observation tank. The valve is temperature controlled with a temperature set point at the inspection tank of 90ºC. Water flows from the inspection tank to the feed filter tank which is provided with a steam heating coil in order to heat the boiler feed water should that be necessary. Heating the feed water increases operating efficiency and reduces the risk of dissolved oxygen which is a major contributor to boiler corrosion.
The level in the feed filter tank is maintained by a make-up valve which allows make-up water from the distilled water tank into the feed filter tank; the make-up valve is manually operated and should normally be open. After this valve the inlet line has a float operated valve inside the filter tank.
The inspection tank is fitted with observation windows and an oil detector.
Should any oil be detected an alarm will sound and steps can be taken to prevent the pumping of oil into the boilers. There is a large reserve of water in the inspection tank and the flow from the inspection tank to the feed filter tank is from the bottom of the inspection chamber via a syphon tube. This reduces the risk of oil carry over to the feed filter tank and hence to the feed pump suction. Any floating sediment or oil in any part of the inspection tank may be removed through the scum line to the bilge holding tank. The inspection tank may also be drained to the bilge holding tank.
Water from the feed filter tank provides the boiler feed pumps with a positive inlet pressure head to the pump suctions.
The dump condenser is cooled by means of fresh water circulating in the low temperature central cooling system. The use of fresh water for cooling prevents contamination of the boiler feed water with salt water should there be a condenser tube leak.
oil Contamination
If oil contamination of the drain system occurs every effort must be made to avoid pumping oil into the boilers. The oil detection alarm will be activated and the operator should ascertain the quantity of oil, close the valve (T-1V) to the filter tank and open the scum valve (T-2V). This will raise the level in the inspection tank and direct the oil and condensate through the scum hopper to the bilge holding tank.
The temperature in the inspection tank should be maintained in order to assist in the oil removal operation. As the condensate drain is directed to the bilge holding tank it is important to check that the make-up system is operating in order to maintain the correct level. The steam heating system for the feed filter tank should be operated in order to maintain the correct feed water temperature.
The drains from on the steam traps on all the steam services should be checked until the defective service is located and isolated for repair.
After repair, the condensate line and steam trap from the defective service must be cleaned and all traces of oil removed. The inspection tank and the oil content monitor probe will also require thorough cleaning.
After the system has been repaired and all traces of oil removed the valve (T11V) from the inspection tank to the feed filter tank may be opened and the scumming valve (T-2V) closed
More frequent checks must be made on the boiler water by testing in order to determine if the condition has changed due to the presence of oil in the feed water system.
Condensate system
The following services return to the observation tank through the dump condenser/drains cooler:
• HFO storage, service and settling tanks
• Calorifier
• Accommodation heating water heater
• Steam tracing
• Accommodation air conditioning unit
• Oil fired and exhaust gas boiler systems
• Waste oil tank
• Engine room bilge and residue tanks
• FO and LO sludge tanks
• Main engine LO tanks
• Oily bilge tank
• HFO and LO separator heaters
• Main engine FO heaters
• Boiler FO and waste oil heaters
• FO overflow tank
• Main engine cooling water heater
• Reefer containers cooling water heater