Auxiliary Machinery. Test 4 – Online Maritime Tests

After obtaining permission from the duty Deck Officer, under what conditions would the process of sootblowing the boiler tubes be most beneficial?

When the boiler is firing on high rate.
When the boiler is firing on low rate.
When the boiler is standing idle.
When the boiler is firing on medium rate.

The thermo-expansion-valve is a part of the refrigeration system. What is the thermoexpansion valve doing?

Regulating the cargo hold temperature.
Regulating freon liquid flow to the evaporator.
Regulating the suction pressure.
Regulating the cooling-water temperature.

What is the main purpose of bottom-blowing a boiler?

To check that we do not have any leak of smoke and gases in the combustion camber.
To control that water is present in the water chamber, when the boiler is in active operation.
To get rid of sludge in the water chamber.
To adjust steam pressure when the burner capacity is excessive.

Correct start up procedure of an oil fired boiler is that the air fan is running for some time, before oil is supplied and ignition occurs. What is the reason for this?

To ensure enough air to ignite the fuel.
To allow the heavy fan to reach normal operation speed before load is put to the boiler.
To allow the funnel and air system to cool down by the air before heating is supplied.
For safety reasons, to ensure that all explosive atmosphere inside the boiler is removed.

You are going to start firing a boiler. Which of the below mentioned alternatives do you consider as most important?

Opening the main steam pressure outlet valve.
Activating the main safety valves.
Bottom-blowing the boiler to be absolutely convinced that water is present in the boiler.
A thorough ventilation of the combustion chamber before the ignition takes place.

What could be the reason if the lub oil viscosity decrease?

Low lub oil temperature.
Wrong lub oil pressure.
Diesel oil leakage to the lub oil system.
Heavy fuel oil leakage to the lub oil system.

After closing the drain during the blowing procedure for a glass water gauge, the water cock is opened and the water flows to the top of the glass. Then the steam cock is opened and the water flows down and out of the glass; Which of the following statements are correct?

The water level is above the steam cock connection of the boiler. There is a danger of priming the boiler if any additional feed is put into it.
The water level is between the water cock connection of the boiler, and the bottom of the gauge glass. It is safe to put feed water into the boiler.
The water level is normal, but it requires time for the gauge glass to stabilise. It is safe to put feed water into the boiler.
The water level in the boiler is below the water cock connection of the boiler. It is unsafe to put feed water into the boiler.

Most boiler design incorporate external 'downcomers'. For what purpose are those 'downcomers' primarly incorporated?

Directional control of steam bubbles.
Provide extra support for furnace tubes.
Ensure adequate circulation in all conditions of steaming.
To increase heating surface area.

Review Answers