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3
10  2 D
f  0 0 , (4.5)
h 2  
1
m  , if f<100, (4.6)
, 0 67  1 , 0 f  , 0 34 f
3

, 1 47
m  , if f  100, (4.7)
3 f
where V , f – factors that depend on the velocity of the exhaust gas.
M
The factor n is determined to the parameter V :
M
n , 1 if V ≥2, (4.8)
m
n , 0 532V M 2  , 2 13V M  , 3 13 ,if 0,5≤V <2, (4.9)
m

n  , 0 44V M , if V <0,5. (4.10)
m
Volumetric gasflow rate V is calculated by using the values ω – exit
g
0
velocity of the gas out of the pipe’s mouth and D – the diameter of the mouth of
0
the chimney. The maximum concentration of harmful substances at the near-
surface space under the unfavorable meteorological conditions located on the axis
of the plume emission (on average wind direction for the examined period of time)
at a distance, which is defined by the formula:

5 F
X   , h (4.11)
M
4
where φ – dimensionless value that is determined by the formula:
  , 2 48 1 (  , 0 28 f ), if V ≤0,5, (4.12)
3
m
  , 4 95V M 1 (  , 0 28 f ), if 0,5<V ≤2 (4.13)
3
m
 7 V M 1 (  , 0 28 f ), if V >2. (4.14)
3
m
The following formula is used for the determination of the concentration of
harmful substances at any distance X from the emission source:
C  S 1 C max , (4.15)
where S – dimensionless coefficient that is determined in accordance to the ratio
1
(Х/Х ):
m
. 1 13
S  , if 1< Х/Х <8, (4.16)
m
1  x  2
. 0 13   1


 x m 
 x  4  x  3  x  2
S 1  3   8   6   , if Х/Х ≤1, (4.17)





m
 x m   x m   x m 
Thus, after determining of the toxic substances concentration in the
breathing level it is necessary to compare the obtained value with the value of the
maximum allowable concentration (MAC) for this substance. If the obtained value
exceeds the MAC it is necessary to develop measures for the reducing of the
maximum near-surface concentration. One of the effective methods is to establish

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