Boiler Operations Flashcards
- Adding Latent heat to steam results in a steam becoming super heated
a. True
b. False
b. False
Adding Latent heat to steam results in a steam becoming super heated
a. True
b. False
b. False
three element boiler feed water control will provide the quickest and smoothest return to set point. Adding the second element steam flow helps offset the control action due to shrink and swell. Adding the third element is most beneficial in systems where
a. steam drum level is frequently affected by shrink and swell
b. feed water temperature varies considerably
c. feed water flow varies considerably
d. demand for steam is relatively constant
- three element boiler feed water control will provide the quickest and smoothest return to set point. Adding the second element steam flow helps offset the control action due to shrink and swell. I think the third element is most beneficial in systems where
a. steam drum level is frequently affected by shrink and swell
b. feed water temperature varies considerably
c. feed water flow varies considerably
d. demand for steam is relatively constant
c. feed water flow varies considerably
Enthalphy is the measure of heat energy contained in a substance and stated in
a. degrees Celsius
b. Joules
c. degrees Fahrenheit
d. btus per pound
b. Joules
steam quality is a measure of which of the following
a. boiler efficiency
b. temperature and pressure of steam
c. mineral and particle content in steam
d. dryness of steam
d. dryness of steam
why is it important to have an initial flow through the superheater
a. the flow serves a coolant to avoid undue stresses to the tubes
b. this flow prevents high Steam drum level situation
c. this flow helps maintain a steady load condition
d. this flow helps maintain suitable output steam pressure
a. the flow serves a coolant to avoid undue stresses to the tubes
why is it important to have an initial flow through the superheater
a. the flow serves a coolant to avoid undue stresses to the tubes
b. this flow prevents high Steam drum level situation
c. this flow helps maintain a steady load condition
d. this flow helps maintain suitable output steam pressure
a. the flow serves a coolant to avoid undue stresses to the tubes
heat traps help improve the efficiency of a boiler. The two most common will do what?
a. Utilize steam flow to heat feed water and combustion air
b. utilize combustion chamber exhaust to heat feed water and fuel feed
c. utilize combustion chamber exhaust to heat feed water and combustion air
d. utilize steam flow to heat feed water and fuel feed
c. utilize combustion chamber exhaust to heat feed water and combustion air
purge time in a boiler is critical this is to ensure that
a. the boiler reach operating pressure quickly without causing undue thermal stresses
b. Boiler tubes are cleaned properly before startup
c. there is enough fuel in the combustion chamber for light off
d. there is no initial fuel in the combustion chamber before startup
d. there is no initial fuel in the combustion chamber before startup
a sudden decrease in steam demand or load in a boiler can have a drastic effect on boiler control. One of the main indications that this is occurring is a rapid
a. steam pressure build up
b. steam pressure loss
c. rise in steam temperature
d. drop in steam temperature
a. steam pressure build up
how many BTU’s are required to raise the temperature of 110 pounds of water from 120 degrees Fahrenheit to steam at 212 degrees Fahrenheit (Latent heat of vaporization is equal to 970 btus per pound)
a. 98.5
b. 316 460 btus
c. 106 700 BTU’s
d. 18,400 BTU’s
c. 106 700 BTU’s
how many BTU’s are required to raise the temperature of 110 pounds of water from 120 degrees Fahrenheit to steam at 212 degrees Fahrenheit (Latent heat of vaporization is equal to 970 btus per pound)
a. 98.5
b. 316 460 btus
c. 106 700 BTU’s
d. 18,400 BTU’s
c. 106 700 BTU’s
in a fire tube boiler, wet back design is what advantage over a dry back design?
a. Have less heat transfer surface area therefore providing better efficiency
b. Wet back design uses more btus per pound of water than a dry back
c. Wet back design will have greater heat transfer surface area therefore providing better efficiency
d. there is no advantage
c. Wet back design will have greater heat transfer surface area therefore providing better efficiency
the ratings for large and medium boilers express capacity in terms of?
a. Boiler horsepower
b. percentage of rating
c. pounds of steam per hour
d. total heating surface
c. pounds of steam per hour
