4 ms·

Why not mount engines on the top of chimney itself? It looks more logical and effective than trailer on a ground. Though, I'm still skeptical as this is not a s

by kbart 10y ago

Why not mount engines on the top of chimney itself? It looks more logical and effective than trailer on a ground. Though, I'm still skeptical as this is not a solution to a problem, but more a cover up of it. Coal in XXI century is not an acceptable power source.

ohitsdom 10y ago
I'd guess that the airflow through the engine is greater than the output of the chimney. So if you put it directly over the chimney, it'd draw more from the chimney than the power plant is designed for, throwing off efficiency. With the jet away from the chimney, it will naturally draw from surrounding air without messing up the exhaust flow.
VLM 10y ago
I've stood a few hundred feet downrange (downwind?) from small bizjet engines and its noticeable but hardly overwhelming, which makes the whole discussion very strange in that the inversion must not be broken mechanically or fluid dynamically or it must be incredibly close to the ground. Clearly concentrated heat from the exhaust doesn't crack the inversion of the chimneys would "naturally" take care of the problem. My immediate assumption is this has gone thru the journalist filter too many times... decades ago we were able to make catalytic converters that ate hydrocarbons so effectively that car exhausts were cleaner on average than California air. Heck its even been run thru a particulate filter before the carburetor. Now I'm not sure this is the case as cat conv are only a little better and California air is so much cleaner its nearly transparent, so I'm told. Anyway, jet engines usually run pretty lean so I figured somewhat more CO2 could be traded for zilch hydrocarbon leading to zero to no smog if you blew all the air in a city thru an operating jet engine.
stuckagain 10y ago
Why not just design the chimney properly in the first place? Chimneys are supposed to have enough updraft to do this by themselves.
- Johnny555 10y ago
  To do what? Blast emissions at 900mph through a temperature inversion? The world's highest chimney is just over 400m, I don't know if that's high enough to get above the inversion layer. In any case, the pollution is not just coming from power plants and other industrial uses with chimneys: The widespread use of festival fireworks, the burning of rubbish by the city's poor, plus farm waste from around the city, vehicular emissions and construction dust, all contribute to the city's thick "pea-soup" fogs.

by kbart 10y ago

ohitsdom 10y ago

I'd guess that the airflow through the engine is greater than the output of the chimney. So if you put it directly over the chimney, it'd draw more from the chimney than the power plant is designed for, throwing off efficiency. With the jet away from the chimney, it will naturally draw from surrounding air without messing up the exhaust flow.

VLM 10y ago

I've stood a few hundred feet downrange (downwind?) from small bizjet engines and its noticeable but hardly overwhelming, which makes the whole discussion very strange in that the inversion must not be broken mechanically or fluid dynamically or it must be incredibly close to the ground. Clearly concentrated heat from the exhaust doesn't crack the inversion of the chimneys would "naturally" take care of the problem. My immediate assumption is this has gone thru the journalist filter too many times... decades ago we were able to make catalytic converters that ate hydrocarbons so effectively that car exhausts were cleaner on average than California air. Heck its even been run thru a particulate filter before the carburetor. Now I'm not sure this is the case as cat conv are only a little better and California air is so much cleaner its nearly transparent, so I'm told. Anyway, jet engines usually run pretty lean so I figured somewhat more CO2 could be traded for zilch hydrocarbon leading to zero to no smog if you blew all the air in a city thru an operating jet engine.

stuckagain 10y ago

Why not just design the chimney properly in the first place? Chimneys are supposed to have enough updraft to do this by themselves.

Johnny555 10y ago
To do what? Blast emissions at 900mph through a temperature inversion? The world's highest chimney is just over 400m, I don't know if that's high enough to get above the inversion layer. In any case, the pollution is not just coming from power plants and other industrial uses with chimneys: The widespread use of festival fireworks, the burning of rubbish by the city's poor, plus farm waste from around the city, vehicular emissions and construction dust, all contribute to the city's thick "pea-soup" fogs.