Main Propulsion Boiler Operation Flashcards
The number of pound of steam generated per hour at the pressure and temperature for all purposes to develop contract shaft horsepower of the ship divided by the numbers of boilers installed is defined as?
Boiler full power capacity
Boiler overload is normally what percentage of boiler full power capacity?
120%
A pressure specified by the boiler manufacturer as a criteria for the boiler design is termed as?
Design pressure
What is the minimum steam drum pressure on an operating boiler?
85% of boiler operating pressure
What type of circulation would installing the generating tubes at an increased inclination be?
Accelerated natural
What type of boiler consists of one or more water drums?
Drum type
Do header type boilers have a water drum?
No
The term high pressure boiler refers to a boiler operating at what pressure?
751 psi or above
What two sheets of steel make up the construction of the steam drum?
Wrapper sheet and tube sheet
What purpose do the generating tubes serve?
Provide the area in which most of the saturated steam is generated
What is the function of the waterwall tubes?
To protect furnace refractories, and allow a higher heat release
Water screen tubes protect superheater from what?
Direct radiant heat
What is installed between the inner and outer casings of the boiler to carry the downward flow of relatively cool water and thus maintain the boiler circulation?
Downcomers
