After which ONE of these stages should the hot water inlet and outlet valves be opened during start-up?
After there is a 90 % vacuum.
After opening the ejector pump overboard valve.
After there is a 30 % vacuum.
After closing the hot water bypass valve.
From which ONE of these is the feed-water taken in a fresh water generator?
The jacket water cooling system.
The seawater inlet to the condenser.
The seawater outlet from the condenser.
The seawater inlet to the jacket water cooler.
How is the fresh water produced in a fresh water generator delivered to the storage tank?
Using a fresh water ejector.
Using the attached fresh water pump.
Using a stand-alone fresh water pump.
Using gravity.
What is the FIRST step when stopping the fresh water generator? Select ONE answer:
Stop the hot water supply to the evaporator, after opening the bypass valve.
Stop the feed water supply.
Stop the ejector pump.
Stop the fresh water discharge pump.
What is the LAST step when stopping the fresh water generator? Select ONE answer:
Close the overboard valve for the combined air/brine ejector.
Stop the feed water supply.
Stop the ejector pump.
Open the air valve.
What should the pressure be before the ejector when starting the fresh water generator? Select ONE answer:
0,28-0,30 MPa.
0,20-0,25 MPa.
0,06-0,08 MPa.
Over 1,0 MPa.
When should the air valve on the top of the fresh water generator (FWG) be open? Select ONE answer:
During vacuum creation at start-up.
While the FWG is stopped.
Never.
Never – except during maintenance.
Which ONE of these actions would be best to increase the flow of jacket water to the fresh water generator while it is running?
Adjust the by-pass valve until the desired inlet and outlet temperatures are reached.
Open the jacket water inlet valve fully.
Open the jacket water outlet valve fully.
Start a second jacket water circulating pump.
Which ONE of these best describes the function of the sight glass on a fresh water generator?
It enables the brine level to be seen.
It enables the evaporated steam to be seen.
It enables the flow of feed water to be seen.
It enables the flow of condensate to be seen.
Which ONE of these best describes the process of “vacuum distillation”?
Seawater is boiled at low pressure and temperature before being condensed into fresh water.
Fresh water is boiled at low pressure and temperature before being condensed into alcohol.
Fresh water is boiled at low pressure but high temperature before being condensed into alcohol.
Fresh water is boiled at low pressure but high vacuum.
Which ONE of these best describes the purpose of a fresh water generator is?
To convert seawater into AC electricity.
To convert fresh water into DC electricity.
To convert seawater into drinking water.
To convert seawater into fresh water, for drinking and for use in ships systems.
Which ONE of these best describes the purpose of the air valve, fitted to the fresh water generator?
It allows the vacuum to be broken when shutting down.
It allows air to be removed, so that a vacuum can be created.
It prevents overpressure in the unit.
It allows vapour samples to be taken for analysis.
Which ONE of these best describes what is supplied by the fresh water generator ejector pump?
Condenser cooling, feed-water for evaporation and driving water for the brine/air ejector.
Only the driving water for brine/air ejector.
Only the feed-water for the evaporator only.
Only the feed-water for evaporation and driving water for brine/air ejector.
Which ONE of these best describes what takes the heating medium into the fresh water generator?
An integral hot water circulating pump is fitted.
A thermostatic valve controls the flow of heating medium.
The steam pressure drives.
It is pumped around by the jacket water circulating pump.
Which ONE of these best describes why fresh water disinfection equipment is often fitted with fresh water generators?
To prevent corrosion inside the unit.
Because the titanium heat exchangers leak poison.
To improve the taste of drinking water.
Because boiling water at low temperatures not kill all harmful bacteria.
Which ONE of these best describes why fresh water generators are more reliable than they used to be?
They use a different working principle to older designs.
They use steam for heating instead of jacket water.
They have fewer moving parts.
They use seawater resistant materials, rather than coatings.
Which ONE of these best describes why fresh water generators can be used in an unmanned engine room?
They are designed with continuous monitoring of the fresh water quality.
They have no moving parts and therefore do not go wrong.
All of their systems have remote control.
They are built with no local indicators or gauges.
Which ONE of these best describes why modern fresh water generators are simple to install?
They have fewer moving parts.
They can be assembled in place.
They use steam for heating instead of jacket water.
They can be folded for transportation.
Which ONE of these best describes why re-hardening filters are sometimes fitted with fresh water generators?
To prevent corrosion of the hot water circuit.
To improve the taste of drinking water.
To prevent corrosion of the cooling circuit.
To prevent corrosion inside the unit.
Which ONE of these best describes why spring loaded valves might be fitted in the fresh water discharge line?
They dump the fresh water when the tank is full.
They prevent air being sucked in.
They dump the fresh water when the salinity is too high.
They enable the reciprocating discharge pump to work.
Which ONE of these best describes why two similar fresh water generators might have a different number of plates in their heat exchangers?
They have been designed to fit different spaces on board.
They have been designed to operate with different heating or cooling water temperatures.
They use different vacuum levels.
One is designed for greater condenser throughput, to improve ejector performance.
Which ONE of these creates the vacuum inside the fresh water generator?
The fresh water pump.
The water powered ejector.
The compressed air powered venture.
The rotary vacuum pump.
Which ONE of these describes why the sea suction for fresh water generators is often separate from other suctions?
Because it is installed by the fresh water generator manufacturer, not the shipyard.
So it is away from any anti-fouling chemical injection systems.
Because the suction line will be made of titanium.
So it never takes water from the low suction.
Which ONE of these does the vapour generated in the evaporator pass through?
The condenser only.
The demister and condenser.
The demister only.
The brine pool, the demister and the condenser.
Which ONE of these explains why the ejector has a suction from the lower part of a fresh water generator?
To keep the ejector wet.
To prevent the brine level from rising too high.
To remove the incondensable gases.
To help remove salt water from the vapour.
Which ONE of these explains why we create a vacuum inside a fresh water generator?
To increase the boiling point of the feed water.
To decrease the boiling point of the feed water.
To draw in the feed-water.
To help discharge the fresh water output.
Which ONE of these happens to the feed water when it enters a running fresh water generator?
It all evaporates.
It partially evaporates.
It partially condenses.
It all condenses.
Which ONE of these vacuums will result in an evaporation temperature of 40-50 °C in a fresh water generator?
60-70 %.
70-80 %.
90-95 %.
95-100 %.
Which TWO of these are potential causes of high salinity in the water output from a fresh water generator?
Répondre
Which TWO of these are potential causes of loss of vacuum in a fresh water generator?
Répondre
Which TWO of these are potential causes of low fresh water output from a fresh water generator?
Répondre
Which TWO of these help remove drops of seawater from the evaporated water?
Répondre
Which of these is the minimum heating medium temperature above which an anti-scale chemical dosing system is recommended?
75 °C.
95 °C.
85 °C.
50 °C.
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