Black smoke coming out of the chimney of a furnace is an indication of
the use of __________ in the furnace.
(A) Low amount of excess combustion air
(B) Large quantity of excess combustion air
(C) Hydrocarbon fuel
(D) Pulverised coal as fuel
the use of __________ in the furnace.
(A) Low amount of excess combustion air
(B) Large quantity of excess combustion air
(C) Hydrocarbon fuel
(D) Pulverised coal as fuel