ABSA 4A Unit 12 – Complete Exam Question Set with Verified Answers on Combustion and Draft Systems

ABSA 4A UNIT 12 questions with accurate answers
A characteristic of mechanical draft is that the draft:


Select one:
a. Varies with atmospheric pressure
b. Varies with chimney height
c. Varies with chimney temperature
d. Is properly regulated during all firing conditions Ans✓✓✓ d. Is
properly regulated during all firing conditions


A draft system with a FD and ID fan is ___________


Select one:
a. Forced
b. Balanced
c. Induced
d. Hybrid Ans✓✓✓ b. Balanced


A float operated level control:


Select one:
a. Will recognize swell and shrinkage and correct the feedwater flow
b. Will have the float in the boiler drum

, c. Is only used on small boilers
d. Is used on fire tube boilers only Ans✓✓✓ c. Is only used on small
boilers


A sudden drop in steam pressure causes


Select one:
a. a sudden increase in drum level
b. a rapid collapse of steam bubbles in the boiler
c. "shrinkage"
d. a single element feedwater control to immediately add water to the
drum Ans✓✓✓ a. a sudden increase in drum level


An induced draft fan handles:


Select one:
a. Air from the combustion chamber
b. Air going to the combustion chamber
c. Flue gases going to the combustion chamber
d. Flue gases from the combustion chamber Ans✓✓✓ d. Flue gases
from the combustion chamber


Boiler chimneys are commonly lined with: