Air Ejectors And DC Heaters Exam Questions And Answers 2024 LATEST VERSION
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Course
BOILER
Institution
BOILER
With the steam control valve wide open during normal operation, the rate of steam flow
from the auxiliary exhaust steam line to the DC heater is actually a function of
__________.
a. rate of condensation in the DC heater
b. spring pressure of the spray valves
c. water level in the DC heater re...
Air Ejectors And DC Heaters Exam
Questions And Answers
With the steam control valve wide open during normal operation, the rate of steam flow
from the auxiliary exhaust steam line to the DC heater is actually a function of
__________.
a. rate of condensation in the DC heater
b. spring pressure of the spray valves
c. water level in the DC heater reservoir
d. rate of evaporation in the DC heater - Answer A
In order to test the lifting pressure of the deaerating feed heater relief valve, you would
__________.
I. close the auxiliary exhaust dump valve to the main and auxiliary condensers
II. increase the set point of the make-up steam regulator to the auxiliary exhaust system
a. I only
b. II only
c. Both I and II
d. Neither I nor II - Answer C
The DC Heater functions to __________.
a. store, heat, and deaerate feed water
b. chemically treat feed water to remove carbonic gas
c. ensure recirculation in the feed water system
d. remove the major amount of non-condensable gases from the main condenser -
Answer A
If the DC heater relief valve lifts frequently, the cause can be excessive __________.
a. condensate supplied to the DC heater
b. auxiliary exhaust steam pressure
c. feed water recirculated from the feed pump
d. makeup feed introduced to the system - Answer B
If the boiler water and condenser hot well levels are normal, but the DC heater level is
only 30% of full, you should __________.
a. increase the speed of the condensate pump
b. open the feed pump recirculating valve wide
c. open the makeup feed
d. bypass the vent condenser and third-stage feed heater - Answer C
, Condensate is pumped from the condenser to the DC heater instead of directly to the
boiler because __________.
a. boiler feed pumps must operate with a negative suction head
b. suspended solids in the condensate must be eliminated
c. condensate should be deaerated before entering the boiler
d. condensate at condensing temperature is too hot and will cause thermal stress in the
boiler - Answer C
If the boiler water level is normal, the main condenser hot well level is normal, and the
DC heater level is 40% full, you should __________.
a. prime the condensate pump
b. bypass the vent condenser
c. slow the main unit
d. open the makeup feed vacuum drag line - Answer D
In a DC heater, which source of steam is commonly used to heat and deaerate
condensate?
a. Root steam
b. Auxiliary exhaust steam
c. Main steam
d. Auxiliary steam - Answer B
In order to test the lifting pressure of the deaerating feed heater relief valve, you would
__________.
I. close the auxiliary exhaust dump valves to the main and auxiliary condenser
II. increase the set point of the reduced steam pressure to the auxiliary exhaust system
a. I only
b. II only
c. Both I and II
d. Neither I nor II - Answer C
Feed water is deaerated to prevent __________.
a. cavitation in the feed pump
b. corrosion in the boiler
c. loss of system vacuum
d. all of the above - Answer B
A high water level in a deaerating feed heater will cause the automatic dump valve to
drain condensate to the __________.
a. atmospheric drain tank
b. reserve feed tank
c. auxiliary condenser
d. main condenser - Answer B
In a modern high pressure steam plant, most feed water deaeration takes place in the
__________.
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