Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
37 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What is a water tube boiler? |
A boiler where tubes are filled with water and steam where heat is applied outside |
|
|
|
List advantages of water tube boiler |
Quick to start up Can handle high pressures Can handle super hot steam Better water circulation Tubes are flexible in design what’s |
|
|
|
List the disadvantages of water tube boiler |
Less heat reserve More expensive both buying and fixing Not good for high steam demand Complex design Needs high quality water |
|
|
|
What are the characteristics of a bent tuber water tube boiler |
Heat is carried through rapids water circulation Can be used for low or high steam/water pressure Is enclosed |
|
|
|
Describe the 2 waterfalls of bent tube boiler |
Inner walls = contain radiant heat Outer walls = has convection heat and passage for flue gas to travel |
|
|
|
True or false, all watertube boilers are bent tube design |
True |
|
|
|
Why are bent tube designs so popular? |
Can handle lots of steam High pressure High temperature |
|
|
|
What is natural circulation? |
Travels downwards through risers to create steam bubbles at Low density making it easier for heat absorption |
Does something to density |
|
|
What is a forced circulation |
Uses feed water pumps, and secondary pump to create circulation |
|
|
|
Between natural circulation and forced circulation is more common |
Natural circulation, doesn’t require power |
|
|
|
Between natural and forced circulation, which produces steam faster? |
Forced circulation, we don’t have to wait for it to cool down |
|
|
|
Which type of circulation would you use for critical conditions |
Forced |
|
|
|
What are components of a watertube? |
Internal feedwater lines, CBD, mud drum blowdown line, chemical feed pipe, cyclone separator, baffle, dry pipe, chevons, settling, water cooled walls |
|
|
|
What’s the purpose of the CBD? |
Remove dissolved solids |
|
|
|
What’s the purpose of the mud drum blowdown line? |
Remove suspended solids, but can create sludge |
|
|
|
What’s the purpose of the chemical feed pipe? |
Send chemicals to the boiler drum to remove scale |
|
|
|
What’s the purpose of the cyclone separate |
Separates dirt and water using rapid circulation to be brought back |
|
|
|
What’s the purpose of the baffle? |
Separate water in the steam drum to keep the natural circulation |
Something to do with natural circulation |
|
|
What’s the purpose of the dry pipe? |
Removes moisture from steam |
|
|
|
What’s the purpose of the chevons and scrubbers? |
Removes water from steam by changing its direction |
Does something with steam |
|
|
What’s the purpose of the settling? |
Is the foundation the boiler sits on |
|
|
|
What’s the purpose of the water cooled wall? |
Uses to tubes to form walls around the furnace |
|
|
|
True or false, watertube uses multiple burners |
True |
|
|
|
What are the 3 types of walls in a watertube boiler? |
Q type tangent tube flat stud |
|
|
|
What are the 3 types of water tube boilers |
Type O Type A Type D |
Ashwin Over Dosed |
|
|
Describe a type O boiler |
made up of 2 drums tubes are exposed to less heat furnace is at the centre Has a manhole on both sides |
|
|
|
Describe a type A boiler |
Has 3 drums: the largest is for seperation of water/ steam, 2 small ones as storage for dirt in water Furnace at centre |
View Boiler |
|
|
Describe a D type boiler |
has 2 drums Tubes are bent into a D shape Has back-walls to receive both radiant and convection heat Has manholes on both side |
|
|
|
What is the purpose of heat transfer equipment |
extract heat from flu gas and send it to another fluid |
|
|
|
True or false, efficiency relies on in extracting as much heat as possible |
True |
|
|
|
What are example of heat transfer equipments |
Boilers superheaters Reheaters Economizer Air heater |
|
|
|
what is the difference between convection and radiant superheaters? |
Convection heats in path of flue gas Radiant heats in the furnace |
|
|
|
Describe Superheat steam |
steam thats above saturation(100) |
|
|
|
why would you use superheat steam |
increases efficiency(energy absorption Lowers chance of condensation in steam turbine |
|
|
|
Describer a reheater and where its located |
adds superheat to the steam found near the furnace outlet |
|
|
|
Describe an economizers |
reduces shock of cool water to boiler by transferring heat in gas to feedwater |
|
|
|
whats the difference between natural and sub critical steam generating units |
Natural uses convection to move the water Sub criticial is only used at below critical pressure of water or steam at 22,000 kpa of density |
|
