One of the reasons that causes oil flowed from sludge outlet

One of the most common causes of reduction gear failure is gear wear caused by scoring as a result of

A.surface fatigue of the gears

B.an inadequate lube oil film

C.plastic flow of the gears

D.fretting corrosion from water

The core item in the Oil Record Book Part I is ____, and its main content is____.

A.Item A, BALLAST OR CLEANING OF FUEL OIL TANKS

B.Item B, DISCHARGE OF DIRTY BALLAST OR CLEANING WATER FROM FUEL OIL TANKS REFERRED TO UNDER SECTION(A)

C.Item C, DISPOSAL OF OIL RESIDUES(SLUDGE)

D.Item H, BUNKERING OF FUEL OIL

One of the reasons that causes oil flowed from sludge outlet of a self-cleaning purifier is

A.seal water supply be cut off

B.make-up water supply be cut off

C.oil outlet valve closed or not open sufficiently

D.the flow rate of oil is too much

The core(核心) item in the Oil Record Book Part I is______, and its main content is______.

A.Item A, BALLAST OR CLEANING OF FUEL OIL TANKS

B.Item B, DISCHARGE OF DIRTY BALLAST OR CLEANING WATER FROM FUEL OIL TANKS REFERRED TO UNDER SECTION(A)

C.Item C, DISPOSAL OF OIL RESIDUES(SLUDGE)

D.Item H, BUNKERING OF FUEL OIL

_______can cause oil flow from water outlet of the oil purifier.

A.Oil inlet valve opening too quickly

B.Oil temperature little higher than normal

C.Diameter of gravity disc too small

D.Viscosity of oil little lower than normal

Sludge may be formed in the oil in the crankcase of a reciprocating air conditioning compressor as a result of ______.

A.refrigerant bubbles in the lube oil

B.refrigerant reducing the lube oil viscosity

C.oxidation(氧化) of the lube oil from overheating

D.reducing the floc or cloud point of the oil

第二组

Displacement pumps are those where the volume of the pump chamber is alternately increased to draw the liquid in from the suction pipe and then decreased to force the liquid out into the delivery pipe. Centrifugal pumps are those wherein an impeller rotating at high speed throws the liquid by centrifugal force from the center to the periphery of the impeller where the liquid is discharged through the delivery outlet.

Gear pump consists of two or more meshing gears (spur, single or double helical teeth) enclosed m a close-fitted housing. These are used extensively for pumping fuel oil, lubricating oil and hydraulic oil. When gears are unmeshed on the inlet side, a pressure drop occurs that helps the atmospheric pressure acting on the surface of the oil in the reservoir to force it up the pipe to fill the void, the oil is then transferred around the periphery of the pump housing. As the gear teeth mesh again on the outlet side, they form. a seal that prevents oil from backing up to the inlet, the oil in the void is then be forced out into the discharge line.

All vane pumps have a rotor driven within a ring (cam ring) by a drive shaft coupled to a prime mover. A cylindrical rotor with sliding vanes, generally in radial slots, rotates within the ring. The center of the rotor is offset from the center of the ring. In a simple vane pump, as the rotor turns, the vanes are forced outward against the inner surface of the cam ring by centrifugal force. This outward radial movement of the vanes and turning of the rotor causes the chamber between the vanes to increase as the vanes pass further away from the inlet port. This increase in volume results in a lowering of pressure until the atmospheric pressure is sufficient to force oil from the reservoir into the inlet chamber. Oil from the inlet is swept away by the vanes toward the outlet port through a decreasing series of chambers until it is forced through the outlet port. A vane pump of balanced design has an elliptical cam ring so that two pumping chambers are formed. This pump is in hydraulically balance, since the two intake and two outlet ports are diametrically opposed to each other. Therefore the side loads exerted on the rotor cancel out, thereby increasing bearing lift and permitting high operating pressure.

According to the last sentence of paragraph 1, from where the liquid is discharged through the delivery outlet?

A.from the eye of the impeller

B.from passage of impeller

C.from the periphery of the impeller

D.from the impeller