Modern centrifuge designs enable continuous over a considerable period of timeThis is achieved by which is timed to discharge the sludge at regular intervals（）

相似题目

• The usual symptoms of cavitation in a centrifugal pump is （）.

  A . noise and vibration B . an increase in discharge pressure C . an increase in suction pressure D . lifting of the relief valve

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• Which of the following pumps belongs to centrifugal pump?（）

  A . Reciprocating pump B . Screw pump C . Diffuser pump D . Water-ring pum

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• A multistage centrifugal pump can be BEST described as having （）.

  A . two or more impellers housed together in one casing and mounted on a single shaft B . a single stepped impeller mounted in a progressively staged casing C . a large radial clearance between the impeller and casing to prevent overheating due to D . an increase in the discharge velocity of the liquid with a corresponding decrease in pressure through the stage

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• The function of a centrifugal pump double volute casing is to （）.

  A . reduce radial thrust to the impeller B . double the liquid velocity through the pump when compared to a single volute C . reduce hydraulic end thrust D . provide the effect of multi-staging

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• To maintain design discharge pressure from a centrifugal pump, the design clearance must be maintained between the （）.

  A . shaft and impeller B . motor and pump shaft C . casing and impeller wearing rings D . lantern ring and impeller

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• The simplest method to use for determining if a centrifugal pump is operating as designed, is to （）.

  A . closely observe the pump discharge temperature B . close off the discharge valve, and watch for a rise in pressure C . momentarily close off the suction valve, and watch for a rise in pressure D . use a clamp on ammeter and compare the readings to past record

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• The basic function of the centrifugal pump impeller is to （）.

  A . directly increase the pressure of the liquid being pumped B . directly increase the velocity of the liquid being pumped C . convert the potential energy of the liquid to kinetic energy D . separate air from the liquid being pumped

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• What is a characteristic of all centrifugal cargo pumps? （）

  A . They are self-priming B . Decreasing the speed of rotation will decrease the discharge pressure C . Opening the discharge valve wider will increase the discharge pressure D . All of the above

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• The project team members should also be aware of one of the fundamental tenets of modern quality management: quality is planned, designed and built in, not（）

  A . executedin B . inspectedin C . check-in D . look-in

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• When starting a centrifugal pump, the discharge valve should be （）.

  A . closed B . opened fully C . cracked open D . partly ope

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• On modern ships, centrifugal pump with a self-primer has replaced reciprocating pump as bilge pump because（）

  A . centrifugal pump is cheaper than reciprocating pump B . the size of centrifugal pump with same capacity is smaller than that of reciprocating pump C . centrifugal pump makes maintenance easier than reciprocating pump does D . all of the above

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• Heavy residual fuel oils are heated prior to centrifuging to （）

  A . reduce fuel weight B . increase specific gravity C . separate fuel from lube oil D . reduce fuel viscosity

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• A centrifugal bilge pump requires priming （）.

  A . primarily to lubricate the shaft seals B . due to the inability of this type of pump to lift water to cover the suction (eye) of the impeller C . to initially unload the pump by having its head pressure equal to discharge pressure D . in order to overcome the potential energy of water in the discharge line

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• Which of the following statements is true concerning centrifugal pumps?（）

  A . They are particularly suited for pumping high viscosity fluids B . They are started with the discharge valve opened C . The flow of liquid is developed by imparting energy due to the rotation of an impeller D . They are always mounted in a horizontal positio

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• density gradient centrifugation密度梯度离心

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• For many years marine centrifuges were designed for （） operation, that is the machines were run for a period during which solids accumulated in the bowlThe machine was stopped when the accumulated solids began to impair its performance.

  A、purifying B、batch C、long period D、temporary

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• differential centrifugation （差速离心）

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• Centrifugal pumps have what advantage(s) over reciprocating pumps?（）.

  A . They are less expensive B . They are smaller for equivalent pumping ability C . They pump more cargo in less time D . All of the above

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• A centrifugal compressor’s purge recovery unit（）

  A . reclaims water B . purges air without losing refrigerant C . purges air with some loss of refrigerant D . purges lube oil from the refrigerant

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• Centrifugal casting is suitable to produce ( ).

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• Modern centrifuge designs enable continuous over a considerable period of timeThis is achieved by which is timed to discharge the sludge at regular intervals.

  A.an injection process B.an ejection process C.a separation process D.a heating process

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• Which of the following statements is true concerning centrifugal pumps？

  A.They are particularly suited for pumping high viscosity fluids B.They are started with the discharge valve opened C.The flow of liquid is developed by imparting energy due to the rotation of an impeller D.They are always mounted in a horizontal position

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• Dynamic pumps are classified as centrifugal or axial. axial pumps operate on the principle of centrifugal force.（）

  是 否

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