Cyclone separator Electrostatic precipitators Fabric filters
6 Chimney / Stack 1. The chimney should have a minimum height of 10 meters above ground level
and clear the highest point of the building by not less than 3 meters for all
roofs. The topography and height of adjacent buildings within 50 meters radius should be taken into account.
2. If possible the chimney should be visible to the operator from the feeding area.
3. The addition of dilution air after combustion in order to achieve the
requirement of these guidelines is unacceptable.
4. The minimum exit velocity should be 10 m/s and at least twice the surrounding wind speed (Efflux velocity = wind speed
x 2) whichever is higher to ensure no down washing of exiting gases.
5. Point for the measurement of emissions shall be provided.
7 Instrumentation Instrument for determining the inside wall temperature and not burner flame
temperature must be provided for both primary and secondary chambers.
2. An audible and visible alarm must be installed to warn the operator when the secondary temperature drops to below the
3. In addition to the above the following instruments may also be required.
A carbon monoxide and/or oxygen meter/recorder A smoke density meter/recorder
A gas flow meter/recorder
A solid particulate meter/recorder
Any other instrument or measurement that may be considered necessary
8 Emission Limits 1. Combustion efficiency:
Combustion efficiency (CE) shall be at least 99.00% The Combustion efficiency is computed as follows;
C.E= % CO 2 x 100
% CO2 + CO
2. The temperature of the primary chamber shall be 800 ± 50o C
3. The secondary chamber gas residence time shall be at least 1 (one) second at 1050 ± 50o C, with 3% Oxygen in the stack
4 Opacity of the smoke must not exceed 20% Viewed from 50 meters with naked eyes
5. All the emission to the air other than steam or water vapour must be odourless
and free from mist, fume and droplets.
6. The Authority may require that the certificate holder have tests carried out by an accredited institution to determine
stack and/or ground level concentrations of the following substances.