In early boilers, furnace walls were constructed of brick. Today this method has been replaced by the use of
a) baffles
b) steel casing
c) tubes to form the furnace walls
d) plastic insulation
e) block insulation
Answer: C
In early boilers, furnace walls were constructed of brick. Today this method has been replaced by the use of
a) baffles
b) steel casing
c) tubes to form the furnace walls
d) plastic insulation
e) block insulation