Auxillary Flashcards
What device transfers heat from one fluid to another?
Heat exchanger
What is the most common type of heat exchanger used in the Coast Guard?
Shell and tube
The fin and tube heat exchanger is an air cooled condenser in AC/R systems. What increases the surface area and aids in transferring heat?
The fins
How does a condenser work in an AC/R system?
It changes refrigerant from a vapor to a liquid as heat is transferred from the vapor to the surrounding water
Corrective maintenance is conducted conditionally on heat exchangers when?
Fluid is leaking from the heat exchanger or the system is not operating within normal parameters
Before draining, cleaning, and inspecting a heat exchanger that is part of an AC/R system who must recover the refrigerant?
AN EPA certified technician
What is generally the best method for cleaning tubes because it removes all soft fouling?
High-pressure water jet
Where can you find all the information you need about heat exchangers?
NSTM, Chapter 254
Backflushing is only required on what kind of plate type heat exchanger?
Seawater cooled
What do you never want to do on a plate type here exchanger while it is running?
Tighten or loosen the plate pack
Exercise extreme caution when handling plates because?
The edges can be extremely sharp. Always wear gloves
How do you want to remove the plates and a plate type heat exchanger?
Tilt them toward the rear of the unit until the top slot is free of the guide bar.
How do you want to clean the plates on a plate type heat exchanger?
With a fiber brush and clean water
What is the primary goal for expecting plate type heat exchangers?
To detect for leaks
Not more than how much percent of a heat exchanger can be plugged before it has to be replaced?
10%
How much time do you allow that he served here after you replace the gaskets?
12 hours
What are the two types of auxiliary boilers?
Fire tube and water tube boilers
Third vantage of fire two boilers are what?
Inexpensive to build
Simple to operate
And less maintenance
The disadvantages of the fire tube boilers is what?
Long warm-up time
And weight of the unit compared to the amount of steam produce
The advantages of the water tube boilers are what?
Les warm-up time in the ratio of size and weight to steam produced
The disadvantages of the water tube are what?
Requires more maintenance and are expensive to build
The temperature at which water boils is called what?
Boiling point or saturation temperature
As Steve gives up his he returns to its liquid state it is called what?
Condensate
What is used in the auxiliary boiler to produce a controlled fire in the combustion chamber?
The burner unit
