Purifiers & Centrifuges Flashcards
In order to obtain the best performance with a lube oil purifier, the lube oil inlet temperature should __________.
be maintained in a temperature range of 160F to a maximum of 180F
Which of the following statements concerning the operation of a lube oil purifier is correct?
A They should be operated at maximum design speed and recommended operating capacity.
B They should be operated as slowly as possible to ensure a long service life.
C They should not be primed with water when operated as a separator.
D They should be operated as clarifiers for optimum moisture removal.
A They should be operated at maximum design speed and recommended operating capacity.
Of the many impurities commonly found in marine lubricating oil, which of the following CANNOT be removed by a centrifugal purifier at normal operating speeds and temperatures?
diesel fuel oil
Which factor determines the size of the ring dam for a fuel oil centrifugal purifier?
The specific gravity of the fuel.
Various tests while conducting a fuel oil analysis can be performed on board to facilitate proper centrifugation. What test provides the key data for selecting the correct purifier gravity disk for fuel oil centrifugal purifiers?
density
The item shown in the illustration is commonly identified as a _________. GS-0124
bowl type purifier
Sludge tanks are used in an oil lubricating system to receive __________.
foreign liquid matter, discharged from the lube oil purifier or the stripping pump
The bulk of the solid material entering a centrifugal purifier with lube oil is __________.
trapped in the bowl
The dirty oil inlet on centrifugal lube oil purifiers is located at the __________.
bottom of the tubular bowl type
In a disk type centrifugal purifier, the bowl is mounted on the upper end of the __________.
bowl spindle
Excessive water in an operating lube oil system can be detected by __________.
the amount of water discharging from the lube oil purifier
A poorly cleaned lube oil purifier bowl may result in __________.
improper separation
During the routine inspection of an operating centrifugal lube oil purifier, you notice oil discharging through the water discharge port. Which of the following actions should be taken?
Add water to seal the bowl.
A centrifugal oil purifier should be shut down if the __________.
purifier is vibrating badly
In a disk type lubricating oil centrifuge __________.
deterioration of the bowl ring gasket will cause the purifier to lose its water seal
When water is removed from lube oil passing through a centrifugal purifier, the water removed will __________.
displace an equal amount of water from the bowl seal
One function of the disks, in a disk-type centrifugal purifier, is to divide the bowl space into many separate passages to __________.
minimize agitation of the oil-water mixture
The size of the discharge ring used for the efficient operation of a disk type purifier is dependent upon the __________.
specific gravity of the oil being purified
The disk stack and tubular shaft used in a lube oil centrifugal purifier is forced to rotate at bowl speed by __________.
the locating pin
In a disk type centrifugal purifier, the contaminated oil enters the centrifuge __________.
at the top through the regulating tube
Which of the following statements is true concerning the lube oil system shown in the illustration? Illustration SE-0011
The drains from lube oil coolers can be directed back to the main sump, the sludge tank or the lube oil purifier.
When the flow of oil admitted to a disk-type centrifugal purifier is in excess of its designed capacity, which of the following conditions will usually occur?
The oil will discharged through the heavy phase discharge port.
Which of the following problems will occur if a manually cleaned disk-type centrifugal lube oil purifier contains insufficient sealing water prior to admitting oil flow to the bowl?
Lube oil will discharge from the heavy phase discharge port to the sludge tank.
To determine the extent of lube oil system contamination you would __________.
inspect the purifier for separated foreign matter
If fuel oil were being discharged from the waste water outlet of a fuel oil disk type centrifuge, operated as a separator, you should __________.
re-prime the purifier with sealing water
If the bowl of a disk type centrifugal purifier when operated as a separator is not primed, the __________.
oil will be lost through the water discharge ports
As Chief Engineer of a slow speed diesel engine vessel equipped with an ALCAP fuel oil purification system. You note a definite increase in the rate at which the purifier sludge tank is rising. One of the first items to check on your system would be which of the following?
The opening water solenoid for leak through.
According to the illustrated diesel engine fuel treatment and fuel service systems schematic, what statement is true concerning the valves labeled “4” and “5”? Illustration MO-0077
Valves 4 and 5 are closed during normal operation, but when opened will allow one of the HFO purifiers to be used as a backup DO purifier, should the DO purifier become disabled.
According to the illustrated diesel engine fuel treatment and fuel service systems schematic, what would be the appropriate valve configuration for operating the two heavy fuel oil purifiers in series? Illustration MO-0077
Valves 2 and 3 CLOSED, and Valve 6 OPEN
What would be the primary indication that a heavy fuel oil purifier supply pump suction strainer needed cleaning?
An increased pressure drop across the strainer (more differential).
If two centrifuges are to be simultaneously used in series to treat residual fuel contaminated with both water and solids, how should the centrifuges be configured?
The first centrifuge should be set up as a purifier and the second centrifuge should be set up as a clarifier.
A motor vessel has three centrifuges to pre-treat the fuel which can be configured to operate in series, parallel, and series-parallel. A large quantity of water is determined to be present in the fuel. How would you configure the centrifuges to deal with this problem?
Run two centrifuges in parallel as purifiers discharging to the third one in series as a clarifier.
If the bowl of a centrifugal purifier is improperly reassembled with O-ring seals that have become hard and flat, the centrifuge __________ .
will begin to lose its water seal
In a disk type lube oil purifier, heavy impurities collect mostly __________ .
on the inside surfaces of the bowl
In a disk-type purifier which component is used to separate lube oil into thin layers and create shallow settling distances?
A series of cone- shaped plates
One of the most effective methods of improving purification in tubular and disk type centrifugal purifiers is to __________.
decrease the viscosity of the oil by heating
The maximum, safe, upper limit temperature of lubricating oil discharged from the purifiers is __________ .
180*F
When a lube oil purifier has been cleaned, but a small amount of sludge remains in one spot of the bowl side, the __________.
seal will be gradually lost after being placed into operation
Which of the following statements best describes the actions occurring to the oil as it flows through a disk type centrifugal purifier?
Most of the dirt and sludge is forced to accumulate on the vertical surfaces of the bowl.
Which of the following statements is correct regarding the selection of the proper size ring dam for a tubular-type lube oil purifier?
Satisfactory purification is obtained when the ring dam is the largest size possible, and no oil is present at the water discharge.
Which of the substances listed is satisfactorily removed from the fuel by a centrifugal oil purifier? A Carbon particles B Lube oil C Gasoline D Diesel fuel
A Carbon particles
Which of the following conditions is most likely to occur if oil containing moisture is continuously fed to a purifier operating as a clarifier?
The bowl will eventually fill with water.
When operating the HFO purifiers in “parallel”, as shown in the illustration __________ . MO-0077
valve “6” would be closed
Under what condition would valves “4” and “5”, as shown in the illustration, be closed? MO-0077
Operating in normal mode.
One engine manufacturer recommends heavy fuel oil should not be heated above 80°C to 95°C (176°F to 203°F) before purification. This upper limit should be observed to ensure against __________ .
operation within the explosive range of the fuel
In the past, the interior sides of most centrifugal purifier bowls were straight. However. the interior side of the bowl shown in the illustration, as compared to a straight interior vertical side bowl, is designed to __________ .
assist in the self- cleaning process
In the illustration shown, under what conditions would valves “2” and “3” be closed and valve “6” be opened? MO-0077
When the HFO centrifuges are being run as separators and clarifiers respectively.
A large fire has developed in the HFO purifier room accessed by door “E”. To combat this fire you should __________.
remotely de-energize the power to the purifiers and ventilation fans in the room and activate the fixed fire extinguishing system for that space
The Pollution Prevention Regulations (33 CFR) prohibit draining __________ .
lube oil purifiers into the bilge
The water seal in a centrifuge, operating at normal speed, prevents the lube oil from discharging from the water outlet. Another function of the seal is to __________.
provide an area for separated water to pass and create a path to remove the water from the bowl
Whether using a centrifuge or a simple filter, oil cleaning and filtration will be the most effective when the oil is at a __________.
high temperature and a low viscosity
Lube oil is preheated before centrifuging in order to __________.
improve purification
In order to maintain the effectiveness of the lube oil centrifuge to remove water, the engineer in charge should __________.
take lube oil samples each week and place in clear containers for inspection
Clean oil leaves the centrifuge illustrated through item __________. Illustration GS-0124
X
When an oil purification centrifuge loses a portion of its seal, the oil can then be discharged through the heavy phase discharge port. This is partly a result of greater __________.
centrifugal force being developed on the oil near the interface
A modern centrifuge, similar to the device shown in the illustration, is opened for periodic cleaning. The most common cause of operating failure after reassembling, is due to __________. MO-0012
not replacing the bowl O-rings that have taken a permanent set
The temperature of the contaminated fuel oil fed to the centrifuge shown in the illustration should be __________. Illustration MO-0012
203F to less than 212F
The greatest difference between the centrifuge bowl shown in the illustration and that of a tubular bowl, with straight, vertical, interior surfaces, is that the illustrated unit __________. Illustration MO-0012
is self-desludging
Which of the following statements describes “N” shown in the illustration? Illustration MO-0112
the centrifuge disc stack
If the separating temperature is to remain constant, what is the relationship between the specific gravity of the oil and the required size of the regulating ring? Illustration MO-0113
The larger sized regulating rings are designed to be used with oils of lower specific gravities.
While operating the fuel oil centrifuge shown in the illustration, the bowl fails to open for sludge ejection. The probable cause is that __________. Illustration MO-0012
the seal ring on the operating slide is defective
