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the atmosphere, which is characterized by the following factors: temperature,
pressure, humidity, wind speed. Therefore, the smoke flow can change its shape
according to the changes of factors mentioned above. The modern method of
calculation of air pollution with toxic substances from a single source allows to
determine the maximum value of the near-surface concentration and distance,
where it is observed from the source of contamination. The highest concentration
of toxic substances at the near-surface layer of the atmosphere should not exceed
its maximum allowable concentration in the air (MAC):
C (max)  MAC , (4.1)

The calculation method of the pollutants’ dispersion is carried out under
conditions, when the wind speed reaches dangerous values. Dangerous wind speed
is the speed when the concentration of harmful substances at the breathing level
reaches its maximum value for a given atmosphere’s condition. The value of the
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maximum surface concentration mg/m , of harmful substances during the emission
of hot air-gas mixture from a single source with a circular cross section under the
unfavorable meteorological conditions at a distance Х is defined by the following
М
equation:
AMFmn
C  , (4.2)
(max)
h 2 3 V  T
g
where А – coefficient that depends on the thermally stratified atmosphere (for the
Carpathian region – 150);
M – massive release of toxic substances – total amount of harmful
substances into the atmosphere, g/sec;

– dimensionless coefficient, which includes the effect of the terrain (equals
to 1 with at a differential of 50 m/km);
F – dimensionless coefficient that takes into account the sedimentation rate
of toxic substances in the atmosphere (from1 to 3);
h – geometric tube’s height, m;
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V – volume of gas flowrate, that is released from the source, m /sec;
g
Т – difference between the temperature of the emitted gas and the average
temperature of the air (which refers to the average temperature of the warmest
month of the year) ,С;
m, n – dimensionless coefficients that take into account the output of gas
mixture from the mouth of the emission source.
3
The volume flow rate of gas V m /s, is calculated by the means of the use of
g

values – speed of exit of gases from a pipe and D – diameter of chimney:
0
D 2
V  0  , (4.3)
g
4 o
The coefficients m and n are defined according to the following parameters:
V 
V  , 0 65 3 g  , (4.4)
M
h

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