90.What is the function of dust collectors and what are the types of dust collectors are there? What are the limits of the precipitators? What is the environment limits?

Ash and unburned carbon will leave the furnace along with flue gas. These dusts shall not be left to chimney. To control pollution in the atmosphere, the dust shall be collected by some means before going to chimney. The equipment serves this function is dust collectors.

Mechanical separators, Electro static precipitator and bag filters are some of the dust collectors used commercially in boilers.

The finesse is the limit in the case of mechanical separators .

Electrical resistance is the limit for ESP

40 mg/M3 of dust burden is accepted in many countries. However dust burden specified is 20 mg/M3.