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Calculation of stack height
245
Calculation of Stack Height
A numari~ comparison is given in TABLE2 for postulated conditions. The critical windspeed (atween parentheses) is calculated by means of equation (20) in the CONCAWE paper.
TABLE2.
STACK HEIGHT FOR -‘IED
CGNDXKIONS, USING &JlTGN
VARIOUS PLUMI% RISE EQUATIONS (-CAL
WMD@EED
DXSPERSIONEQUATION AND
BETWEEN P-)
30
100
300
(&
122 (1)
146 (3)
159 (6)
Sutton equation + Sttimk8 II plume rise
: (:
(l”; t”3s
Sutton equation + Bosanquet plume rise
(Z
(i::
(2& 118 (4) 115 (13)
(235
:;
:;
(&
&
:; 131 (3)
(Z) 163 (9 183 (14) 121 (8) 111 (5) 301 (2)
10
Stack output (Nm3 set-‘) Sutton equation + Scorer-Barrett plume rise Sutton equation
f Oak Ridge plume rise
Sutton equation + Sttimke I plume rise
Sutton equation + CONCAWE plume rise Sutton equation + Lucas plume rise Sutton equation
+ Rauch plume rise
P. C.
Stichtiqq CONCA WE.
BL~KKER
REFERENCES BESTA. C. (1957) Maximum gas concentration at ground level from industrial chimneys. J. ht. Fuel, 30,329-338.
LUCU D. H. (1967) Application and evaluation of results of the Tilbury plume rise and dispersion experiment. Atmospheric Environment 1,421-424. THOMAS D. M, G. (1962) Air & Wat. Pollut. Int. J. 6,89-90.
Atmospheric Environment, Pergamon Press 1968. Vol. 2, pp. 245-246. Printed in Great Britain.
I VERY much appreciate the development of the Round Table at which some of the beat known international experts ~ticipated, and I was able to listen to an interesting discussion. Regarding the Round Table, I should like to tell you of our experiences in our power stations. The ‘Ente Naxionale per 1’Energia Elettrica Italiana,’ which controls the production and distribution of electric power in Italy, has faced the problem of atmospheric pollution for some years, bearing in mind the huge concentration of production of thermal power which is foreseen. For example, the Spexia Power Station at the present moment consists of two units of 320 and 335 MW and a third unit, of the supercritical type, of 600 MW. A fourth unit, of 600 MW, will be running in the first months of 1968. The total output will therefore be about 2000 MW. In addition the Piacenxa Power Station should have about 1300 MW, Vado Ligure about 2000 MW, of plant, etc. The Central Laboratory of the Thermic and Nuclear Construction Department, in agreement with the Department of Production and Transmission and with the Research Department, has been instructed to proceed with both chemical and meteorological tests, according to the following program.
246
v.
GIOVANARDI
(1) tests on the ground along the smoke plume with the aim of verifying the levels of pollution and comparing them with those calculated theoretically; (2) testing the average level of pollution in a locality adjacent to a power station; (3) testing the level of pollution existing in a zone where the installing of a new power station is foreseen ; (4) testing the conditions of diffusion at low levels concurrently with determinations of wind direction and speed and of air temperature at various heights and other factors which influence the diffusion of smoke. The results of these tests are available as internal reports. Ground level measurements of the concentration of SOs comprise short tests (30 mm-1 hr) and long periods (12-24 hr) with absorption instruments and also with continuous recordings. These instruments generally use an analytical selective method, West and Gaeke modified by Huitt and Lodge; other methods are also used. In addition, measurements are made of dust and other pollution caused by industry in the locality. Regarding the meteorological part, besides the “pilot” for the determination of the speed and direction of the wind at altitude, the Centre of Automatic Research of ENEL has developed a thermoelectric probe with transmission to the ground via radio impulses of the air temperature at altitude. From all these samples ENEL has been able to obtain the data for the determination of the most suitable height for the smoke stack bearing in mind the very different orographic and meteorological conditions of the Italian peninsula. To quote an example, the Spezia Power Station has four smoke stacks, of 125 m, 125 m, 180 m and 220 m; one for each unit. In Piacenza, where two new units of 320 MW each are planned there will be one smoke stack only, of at least 200 m. In reference to point 6,* on the necessity of carrying out tests, by means of photographic technique, on the elevation and diffusion of the smoke, the Laboratorio Centrale DCTN of ENEL, basing its work on its program of study, has been making these sort of observations for quite a long time. These observations are carried out at different times during the day to study the behaviour of smoke in conditions of stability, instability and thermic inversions. Obviously considered are the meteorological factors and also the conditions of practice. The study of the diffusion of a smoke plume is based, not only on photographic observations, but also on direct measurements, in good visibility, of the elevation by means of a theodolite. In reference to point 7* on the local meteorological conditions, our laboratory is provided with a mobile laboratory equipped with meteorological instruments for the determination of the strength and direction of the wind from the ground up to 1500 m altitude. The vertical gradient of temperature at low altitudes (up to 500 m) is measured by means of a captive balloon and the thermometric probe with radio impulse transmitter. As a general observation on the CONCAWE study, we agree with the statement in the introduction of the booklet that the CONCAWE formula is not applicable to the thermoelectric unit whose sizes are, in Italy, as we have already mentioned, from at least 150 to 300 MW. It would also be interesting to know the possibilities of application of the formula CONCAWE in the case of two or more smoke stacks side by side. For this we must await the continuation of the study. Ente Nazionale per I’Ettergia Elettrica. Piacenza, Ztaly. + Of the agreed statement.
V.
GIOVANARDI
Calculation of Stack Height
A numari~ comparison is given in TABLE2 for postulated conditions. The critical windspeed (atween parentheses) is calculated by means of equation (20) in the CONCAWE paper.
TABLE2.
STACK HEIGHT FOR -‘IED
CGNDXKIONS, USING &JlTGN
VARIOUS PLUMI% RISE EQUATIONS (-CAL
WMD@EED
DXSPERSIONEQUATION AND
BETWEEN P-)
30
100
300
(&
122 (1)
146 (3)
159 (6)
Sutton equation + Sttimk8 II plume rise
: (:
(l”; t”3s
Sutton equation + Bosanquet plume rise
(Z
(i::
(2& 118 (4) 115 (13)
(235
:;
:;
(&
&
:; 131 (3)
(Z) 163 (9 183 (14) 121 (8) 111 (5) 301 (2)
10
Stack output (Nm3 set-‘) Sutton equation + Scorer-Barrett plume rise Sutton equation
f Oak Ridge plume rise
Sutton equation + Sttimke I plume rise
Sutton equation + CONCAWE plume rise Sutton equation + Lucas plume rise Sutton equation
+ Rauch plume rise
P. C.
Stichtiqq CONCA WE.
BL~KKER
REFERENCES BESTA. C. (1957) Maximum gas concentration at ground level from industrial chimneys. J. ht. Fuel, 30,329-338.
LUCU D. H. (1967) Application and evaluation of results of the Tilbury plume rise and dispersion experiment. Atmospheric Environment 1,421-424. THOMAS D. M, G. (1962) Air & Wat. Pollut. Int. J. 6,89-90.
Atmospheric Environment, Pergamon Press 1968. Vol. 2, pp. 245-246. Printed in Great Britain.
I VERY much appreciate the development of the Round Table at which some of the beat known international experts ~ticipated, and I was able to listen to an interesting discussion. Regarding the Round Table, I should like to tell you of our experiences in our power stations. The ‘Ente Naxionale per 1’Energia Elettrica Italiana,’ which controls the production and distribution of electric power in Italy, has faced the problem of atmospheric pollution for some years, bearing in mind the huge concentration of production of thermal power which is foreseen. For example, the Spexia Power Station at the present moment consists of two units of 320 and 335 MW and a third unit, of the supercritical type, of 600 MW. A fourth unit, of 600 MW, will be running in the first months of 1968. The total output will therefore be about 2000 MW. In addition the Piacenxa Power Station should have about 1300 MW, Vado Ligure about 2000 MW, of plant, etc. The Central Laboratory of the Thermic and Nuclear Construction Department, in agreement with the Department of Production and Transmission and with the Research Department, has been instructed to proceed with both chemical and meteorological tests, according to the following program.
246
v.
GIOVANARDI
(1) tests on the ground along the smoke plume with the aim of verifying the levels of pollution and comparing them with those calculated theoretically; (2) testing the average level of pollution in a locality adjacent to a power station; (3) testing the level of pollution existing in a zone where the installing of a new power station is foreseen ; (4) testing the conditions of diffusion at low levels concurrently with determinations of wind direction and speed and of air temperature at various heights and other factors which influence the diffusion of smoke. The results of these tests are available as internal reports. Ground level measurements of the concentration of SOs comprise short tests (30 mm-1 hr) and long periods (12-24 hr) with absorption instruments and also with continuous recordings. These instruments generally use an analytical selective method, West and Gaeke modified by Huitt and Lodge; other methods are also used. In addition, measurements are made of dust and other pollution caused by industry in the locality. Regarding the meteorological part, besides the “pilot” for the determination of the speed and direction of the wind at altitude, the Centre of Automatic Research of ENEL has developed a thermoelectric probe with transmission to the ground via radio impulses of the air temperature at altitude. From all these samples ENEL has been able to obtain the data for the determination of the most suitable height for the smoke stack bearing in mind the very different orographic and meteorological conditions of the Italian peninsula. To quote an example, the Spezia Power Station has four smoke stacks, of 125 m, 125 m, 180 m and 220 m; one for each unit. In Piacenza, where two new units of 320 MW each are planned there will be one smoke stack only, of at least 200 m. In reference to point 6,* on the necessity of carrying out tests, by means of photographic technique, on the elevation and diffusion of the smoke, the Laboratorio Centrale DCTN of ENEL, basing its work on its program of study, has been making these sort of observations for quite a long time. These observations are carried out at different times during the day to study the behaviour of smoke in conditions of stability, instability and thermic inversions. Obviously considered are the meteorological factors and also the conditions of practice. The study of the diffusion of a smoke plume is based, not only on photographic observations, but also on direct measurements, in good visibility, of the elevation by means of a theodolite. In reference to point 7* on the local meteorological conditions, our laboratory is provided with a mobile laboratory equipped with meteorological instruments for the determination of the strength and direction of the wind from the ground up to 1500 m altitude. The vertical gradient of temperature at low altitudes (up to 500 m) is measured by means of a captive balloon and the thermometric probe with radio impulse transmitter. As a general observation on the CONCAWE study, we agree with the statement in the introduction of the booklet that the CONCAWE formula is not applicable to the thermoelectric unit whose sizes are, in Italy, as we have already mentioned, from at least 150 to 300 MW. It would also be interesting to know the possibilities of application of the formula CONCAWE in the case of two or more smoke stacks side by side. For this we must await the continuation of the study. Ente Nazionale per I’Ettergia Elettrica. Piacenza, Ztaly. + Of the agreed statement.
V.
GIOVANARDI