A. water B. voltage C. fuel pressure D. steam pressure
38. The advantages of flash type evaporators, as compared to submerged tube type evaporators, include ______.
A. less internal corrosion because of lower brine density
B. higher temperature evaporation for lower salinity of the distillate produced C. less scale formation in a flash evaporator
D. less feed-water required for a flash evaporator
39. Distilled water from an evaporator may be discharged into a drinking water tank ______.
A. through a detachable hose connection
B. after passing through an activated charcoal filter
C. after chemical analysis shows it is fit for consumption D. through a solenoid operated three-way valve
二. 关联题（关联题题干下有4个小题，每小题4个选项）
With many small package boilers, the automatic control sequence usually ensures that the boiler fire is initially ignited from a diesel oil supply, and changed over to the usual source when ignition is completed. With good management, to facilitate subsequent starting from cold, the fuel system of large boilers will have been flushed through with diesel oil when the boiler was on light duty immediately prior to being secured. When burning such diesel fuel it is essential for safety that only the correct (small) burner tip should be used. It should be kept in mind that if fire does not light, immediately shut off fuel and vent furnace.
Complete ignition of fuel in the furnace is essential. The burner flame, the smoke indicator and the funnel should be frequently observed. With satisfactory combustion, the flame should appear in candescent （白热的）with an orange shade at the flame tip, and a faint brownish haze should show at the funnel. If on first ignition the flame is uncertain, badly shaped and separates from the primary swirler, momentary opening or closing of air register may correct.
1. Small package boilers will use _______ while being lit up.
A. the usual source of oil B. fuel oil
C. diesel oil D. mixture of fuel oil and diesel oil
2. After large boilers being secured, the fuel in the feeding line will be____.
A. the usual source of oil B. fuel oil
C. diesel oil D. mixture of fuel oil and diesel oil 3. If large boilers were not lit up, _____.
A. feed water to normal level B. stop fuel supply immediately and purge the furnace
C. light the boiler again D. reset the burner 4. An indication for a good combustion is ______.
A. white smoke B. brown haze in the funnel C. orange flame tip D. swirl oil spray
Lesson 17
Boiler Management
单项选择题：
1. You should frequently compare drum-mounted and remote-reading water level indications. ________ between these have contributed to failures because of overheating through shortage of water, when a boiler was being oil-fired. A. Descriptions B. Discrepancies C. Different D. Deflections
2. Water level controllers of the boiler must be kept operable to protect external steam-using plant from water “_______” danger. A. carry off B. carry down C. carry on D. carry over
3. The soot blowers are operating in the oil fuel boiler the air / fuel ratio must ______ throughout the action, and blowers greased after use. A. be increased B. be decreased C. remain constant D. either be increased or remain constant
4. The water in an auxiliary boiler should be tested daily for ________. A. dissolved oxygen B. chlorides C. sludge D. dissolved nitrogen
5. Before an auxiliary boiler is shutdown for an extended period of time, the water in the boiler should have a pH value of ______.
A. 10 B. 7 C. 4 D. 1
6. Excessive alkalinity of the water in an auxiliary boiler can cause ______. A. caustic embrittlement（脆化） of the boiler metal B. acidic corrosion of the boiler metal
C. hard scale deposits on the boiler tubes D. etching （腐蚀）of the heat exchange surfaces
7. Because of the reduced ______in the vacuum boiling evaporator, some of the sea water boils as it flows through the tubes.
A. temperature B. water level C. pressure D. rate of flow
8. Prior to lighting off a cold automatically fired auxiliary boiler, you should ______. A. check and regulate the water level B. close the air cock once fires are lit C. blowdown the gage glass D. crack the steam stop to assure protective steam flow
9. Improper maintenance of an automatic auxiliary boiler oil burner could result in ______.
A. fuel pump failure B. fan motor failure
C. increased feed-water consumption D. decreased boiler efficiency
10. For proper operation, auxiliary boiler feed water must have which of the following characteristics?
A. High oxygen concentration. B. Low pH. C. Proper alkalinity. D. All of the above.
11. If an operating auxiliary boiler has a water pH reading of 7, you should ______. A. bottom blow the boiler
B. treat the water with caustic soda
C. treat the water with chemical scavengers
D. reduce the water alkalinity to recommended readings
12. The most common cause of scale formation in an auxiliary boiler is ______. A. concentrations of calcium sulphate in the boiler water B. fuel oil in the feed water
C. improper treatment of the feed water with calcium sulphate D. excessive feed water alkalinity
13. In motor ship, ______is often used to recover some of the heat carried in the exhaust gases from the main engine. A. an diesel oil heater B. a waste heat boiler C. a fresh water generator D. a donkey boiler
14. An exhaust gas bypass is installed on a waste heat boiler in order to ______. A. bypass exhaust gas at high loads to prevent excessive back pressure B. bypass a portion of the exhaust gas at peak loads for better efficiency C. recycle exhaust gas to the turbocharger
D. minimize moisture condensation in the boiler gas passages at low loads
15. Prior to lighting off a cold automatically fired auxiliary boiler, you should ______. A. check and regulate the water level B. close the air cock once fires are lit C. blow down the gage glass D. assure protective steam flow 16. Flame failure in an automatically fired auxiliary boiler can mostly result from a/an ______.
A. incorrect electrode setting B. incorrect nozzle position C. clogged fuel nozzle D. broken high tension lead 17. Waterside scale in a fire-tube boiler may cause ______. A. increased heat transfer B. fireside erosion C. high steam demand D. overheated tubes
Lesson 18 Steering Gear
单项选择题：
1. In a hydraulic system, ________ are used to protect the system from over pressure. A. stop valves B. check valves C. safety valves D. reducing valves
2. Two rams of the hydraulic gear are linked at their outer ends to _______ by a crosshead and swivel block. A. the piston rod B. the tiller arm C. the connecting rod D. the rudder
3. _______ connected to the moving tiller will bring the floating lever pivot and the lever into line at right angles to the screw shaft axis. A. A cut-off lever B. A swivel block C. A crosshead D. A driving gear
4. If a heavy sea strikes the rudder, the shock is transmitted through ________ to the rams, this cause a sudden increase in oil pressure in one of the cylinders. A. the control rod B. the hunting gear C. the floating ring D. the tiller arm
5. The control rod of a steering gear pump is attached at its outer end to _______. A. the hunting gear B. the rudder stock C. the rudder controller D. the feedback unit
6. The control spindle operates the slipper ring or _______ of the variable delivery pump, which controls the suction and discharge of the oil. A. servo-motor B. swash plate C. plunger D. cylinder
7. According to the way the steering gear is operated, the steering gear may be divided into: hand-steering, ________ and automatic steering. A. hydraulic steering B. follow-up steering C. remote control steering D. air controlled steering
8. If a heavy sea strikes the _______, the shock is transmitted through the tiller arms. A. propeller B. rudder C. bow thruster D. stabilizer
9. If a heavy sea strikes the rudder, the shock is transmitted through the tiller to _______.
A. the tiller arms B. the swivel blocks C. hunting gear D. the rams 10. ______the moveable plate and floating ring inside the pump is very difficult. A. Having adjusted B. Being adjusted C. To adjust D. Adjusted
11. If a hydraulic pump is overheating, the cause may be ______. A. excessive internal leakage in the pump B. low discharge pressure and fluid flow
C. excessive fluid level in the hydraulic reservoir D. operation of the pump at 100% efficiency
12. The auxiliary steering gear must be capable of being brought speedily into operation and be able to put the rudder over from 15 degrees on one side to 15 degrees on the other side in no more than ______with the ship at its deepest service draught and run ahead at the greater of one half of the maximum service speed or ______.
A. 28 seconds/7 knots B. 28 seconds/14 knots C. 60 seconds/7 knots D. 60 seconds/14 knots
13. If a radial piston hydraulic pump fails to deliver rated fluid volume, the cause can be ______.
A. contaminated fluid B. pitted thrust rings C. worn pintle bearings D. obstructed suctions passage
14. The hand steering is a method by which the motion of the rudder is controlled with ______.
A. a motor-driven steering wheel B. a pneumatic steering wheel C. a hand-driven steering wheel D. an electric steering wheel
15. With reference to rules governing steering gear, which one of the following rules is incorrect ?
A. It is required that all ships are provided with two independent steering gear systems that is
one main and one auxiliary.
B. The auxiliary gear could be power operated in passenger ships.
C. The auxiliary gear must be of adequate strength and sufficient to steer a ship at navigable speed.
D. All moving parts of the steering gear must be guarded against any possible damage.
16. Steering gears can be arranged with hydraulic control equipment known as a \
A. telemeter B. telemanometer C. telemotor D. telemometer 17. In the hydraulic system, _____ is the power unit.
A. oil pump B. control valve C. hydraulic motor D. fittings
18. Compensated flow control, or constant flow valves are used in hydraulic systems to ______.
A. compensate for major leaks in the system B. maintain the original fluid viscosity
C. allow for changes in pressure and temperature within the system D. assure constant fluid temperature
19. It is important with all hydraulic systems to ensure that interlocking arrangements provided for pump or motor control levers are _______before the pump driving motor can be started.
A. in the port position B. in the starboard position C. in the neutral position D. to be dismantled 20. What type of valve is used to direct the flow of hydraulic fluid? A. relief valve B. direction control valve C. stop valve D. pressure control valve
21. In a radial piston pump, reversal and control of fluid flow are accomplished by moving the ______. C
A. central valve B. radial plunger C. floating ring D. cylinder body
22. Dual (双的)electro-hydraulic steering units usually operate ______. B
A. with both pumps on line at the same time B．with one pump on standby C．with the follow-up gear disconnected D．only when the rudder is moved amidships
二、关联题（每组关联题题干下有4个小题，每小题4个选项） 第一组：
The electrical remote control system is commonly used in modern steering installations since it uses a small control unit as transmitter on the bridge and is simple and reliable in operation.
The control box assembly is mounted on the steering gear. Movement of the bridge transmitter results in electrical imbalance and current flow to the motor in the control box. The motor drives, through a flexible coupling, a screw shaft, causing it to turn. A screw block on the shaft is moved and in turn moves the floating lever to which a control rod is attached. The control rod operates the