reports are this happen during the purge process
replace the hydrogen with carbon dioxide
replace the carbon dioxide with air
replace the hydrogen with carbon dioxide
replace the carbon dioxide with air
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ESKOM generator ka-boom 3
- Thread starter byrdj
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I'm guessing middle management MBA wannabies overruled the engineers who knew how to do it safely. Management cutting corners to save a day or two of downtime.
It happens more and more, but usually not with such dramatic results.
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Ohm's law
Not just a good idea;
It's the LAW!
It happens more and more, but usually not with such dramatic results.
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Ohm's law
Not just a good idea;
It's the LAW!
TugboatEng
Marine/Ocean
Seems to be a trend. We has one come apart recently, too. It threw debris 1/4 of a mile away.
electricpete
Electrical
dang, that's not good. I guess hydrogen mixing with air can result in either explosion or fire, but I'm not sure what determines which one occurs (explosion, fire or both). This looks more like an explosion than a fire from the photos. When we had a hydrogen event at our plant due to a hydrogen seal problem a few decades back, it was a fire (I guess seal oil might have been involved in the fire as well, I'm not sure)
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(2B)+(2B)' ?
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(2B)+(2B)' ?
That is a complete write-off. Hope no one was injured.
Keith Cress
kcress -
Keith Cress
kcress -
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1
- Thread starter
- #6
the HAYWARD, Calif article indicates the steam turbine malfunction during shut down.
I would guess a stuck steam valve and the breaker was open. being a combined plant the reporting was the combustion unit was put back in service (with out heat recover steam generator)
the other articles for ESKOM, said that 8 employess were "suspended" and a criminal investigation will be done.
as for doing a purge, I very rarely got involved, it was purely an Operations duty. (for commissioning I would watch closely and verify volumes used.
a plant I visited regualry had an event 10 years or so back. the Operations Shift Supivisor KNEW there was insufficent CO2. when mechanics open the bushing box to use fans to disperse, there was an explosion killing one mechanic. It has been a while, But I think the OSS was charged with manslaughter
I would guess a stuck steam valve and the breaker was open. being a combined plant the reporting was the combustion unit was put back in service (with out heat recover steam generator)
the other articles for ESKOM, said that 8 employess were "suspended" and a criminal investigation will be done.
as for doing a purge, I very rarely got involved, it was purely an Operations duty. (for commissioning I would watch closely and verify volumes used.
a plant I visited regualry had an event 10 years or so back. the Operations Shift Supivisor KNEW there was insufficent CO2. when mechanics open the bushing box to use fans to disperse, there was an explosion killing one mechanic. It has been a while, But I think the OSS was charged with manslaughter
This is the wrong disputant N2 rather than CO2.
The point is that hydrogen has wide ignition limits. and fairly wide detonation limits.
Video
Hydrogen-Air Mixture Explosion (43 Vol%, 1.4 m^3, Hydrogen mass: 49g)
The point is that hydrogen has wide ignition limits. and fairly wide detonation limits.
Video
Hydrogen-Air Mixture Explosion (43 Vol%, 1.4 m^3, Hydrogen mass: 49g)
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- #9
if a purge is done correctly, there is little delution of the h2 purity. the co2 is admitted at bpttom and h2 vented out top. given co2 is heavier
given its been 15~20 years since i worked, but I seem to recall seveal volume changes are needed with n2, only 1 if co2 is used n2 being lighter than co2
given its been 15~20 years since i worked, but I seem to recall seveal volume changes are needed with n2, only 1 if co2 is used n2 being lighter than co2
Looks like the end bells of the generator were blown clean off. I think those are for just H2 gas containment, the bearing housings are much beefier and probably still (??) intact. But good chance that generator is going to need to be replaced. Bunch of busted equipment with red pipes!! H2 for cooling.
I don't know what our plant used to purge, whether N2 or CO2. But it was taken seriously to be done right.
That Cali plant was just a steam turbine chucking blades. Sometimes just happens, sometimes due to an operational screw up.
I don't know what our plant used to purge, whether N2 or CO2. But it was taken seriously to be done right.
That Cali plant was just a steam turbine chucking blades. Sometimes just happens, sometimes due to an operational screw up.
TugboatEng
Marine/Ocean
The generator may be caput but look on the bright side, the lights are still on.
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- #12
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No, no, no, that's not the lights ON, it's 80% of the roof now missing.
Keith Cress
kcress -
I guess now we might get to see if the South African version of OSH has teeth Occupational Health and Safety Act 85 of 1993
Attached is a recent Safety and Health Information Bulletin
U.S. Department of Labor
Occupational Safety and Health Administration
Directorate of Technical Support & Emergency Management
Office of Science and Technology Assessment
Hazards when Purging Hydrogen Gas-Cooled Electric Generator
Attached is a recent Safety and Health Information Bulletin
U.S. Department of Labor
Occupational Safety and Health Administration
Directorate of Technical Support & Emergency Management
Office of Science and Technology Assessment
Hazards when Purging Hydrogen Gas-Cooled Electric Generator
The accident report should be circulated amongst the greenies that are pushing for a hydrogen economy, and apparently are unaware of the safety issues.
There have been a lot of major accidents in the ESKOM fleet over the last 20 yrs, I wonder what their insurance rates are.
"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick
There have been a lot of major accidents in the ESKOM fleet over the last 20 yrs, I wonder what their insurance rates are.
"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick
ESKOM has a record of industrial accidents and explosions ??!!!!
ESKOM has a reputation for management incompetence ??!!!!
Shocked, I am ..... SHOCKED I tell you !!!!
MJCronin
Sr. Process Engineer
ESKOM has a reputation for management incompetence ??!!!!
Shocked, I am ..... SHOCKED I tell you !!!!
MJCronin
Sr. Process Engineer
I think the correct description is that you may be " shocked, shocked", as spoken by Claude Raines in Casablanca .
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"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick
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"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick
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