1. Advanced Air Pollution Engineering
Control of Smoke and odors
Learning Outcome
Analyze the effect of process change in air pollution control

2. Objectives
1- sources of smoke. 2- measurement of smoke, smoke and public health. 3- Smoke prevention and control. 4- Sources of odors, measurement of odor and odor control.

3. sources of smoke Automobiles domestic heating plants
industrial power plants
railway engines
ships
refuse incinerators
oil burnt in diesel engines
The amount of smoke varies considerably and it depends on the type of fuel and the efficiency of combustion device.

4. smoke and public health
Smoke may effect public health through:
Irritation of the eye membranes.
Irritation of the respiratory tract.
infection of the ear.
increase morbidity rate through diminished resistance to disease because of decrease of sunlight.
increase of nervous and psychological disorders because of SMOG formation.

5. Smoke prevention and control
Following are some of the methods which can be adopted for smoke prevention and control:
Use of low volatile fuels such as bituminous coal and anthracite coal.
use of smokeless fuel (coke).
strict regulations regarding smoke emissions.
proper design and maintenance of stacks.
use of particulate control equipment such as scrubbers, ESP.
use of proper combustion equipment's ( proper deswign of furnaces). For smokeless combustion of the fuel:
a- proper air fuel ratio.
b- sufficient mixing of air and fuel.
c- sufficient ignition temperature.
d- sufficient space to permit time for proper burning.

6. measurement of smoke
There are many methods for estimating the density of smoke as it emerges from the stack. The most commonly used is the Ringelmann Chart. Associate measurements of the smoke density (smoke quality) is essential for the enforcement of ordinances regulating smoke emissions.

7. measurement of smoke
The Ringelmann Chart is a scheme where graduated shades of gray vary by five equal steps between white and black. The Chart as shown below, has four grades of gray, as well as pure white and an all black section.

8. measurement of smoke
Details about the width of black lines, width of white spaces and percentage of black is given in the following tables: Several conditions should be followed while using this method:
Ringelmann Chart No.
Black (mm)
White (mm)
Percent of black
All white 1 9 20 2
2.3
7.7 40 3
3.7
6.3 60 4
5.5
4.5 80 5
All black -
100

9. measurement of smoke
1- chart should be used under daylight condition. 2- held of fixed facing observer in a vertical plane. 3- chart should be in line with the top of chimney. 4- chart should be at a sufficient distance from the observer for the lines to appear to merge until each square forms a uniform shade.

10. measurement of smoke
The observer glances from the smoke, as it issues from the stack, to the chart and notes the number most nearly corresponding with the shade of the smoke. A clear stack is recorded as No. 0, and 100 percent black smoke as No. 5. There is very little value in making a single observation. A series of observations should be made, preferably by two or more observers, over an extended period, at regular intervals.

12. Sources of odors solid , liquid, or a concentrated gas. garbage dumps
sewage works
agricultural activities
exhaust from motor vehicles
decaying vegetation
The odor threshold for acetone is 100 ppm, acetic acid 1 ppm and for pyridine 0.02 ppm.

14. Measurement of odors
Measurements of odors falls into two categories: 1- determination of the threshold concentration of odoriferous gasses. 2- determine the type and intensity of atmospheric odors. 1- threshold concentration: minimum identification level , generally the odor intensity increase with the odorant concentration. P= klogs Where: P: Odor intensity K: constant and S: odor concntration