Think your weekend of diving sucks / Read this!

[primalchaos]

Ouch! That would be like manslaughter if you ask me. I mean, knowing that people might get sucked into your intake pipe and making sure that they have no way to get out?!

It *is* Consumers' Energy. Their representative seemed more concerned about the diver "had not made it into the facility, only the cooling pond" than the possible responsibility of the accident.

 

[diver_paula]

It *is* Consumers' Energy. Their representative seemed more concerned about the diver "had not made it into the facility, only the cooling pond" than the possible responsibility of the accident.

I very much doubt that he / Consumers was not concerned about the diver. They wouldn't be that callous. Perhaps what you heard was the Consumers' representative trying to relieve the fears of people afraid that a means for terrorists to get into the system had be uncovered.

 

[primalchaos]

I very much doubt that he / Consumers was not concerned about the diver. They wouldn't be that callous. Perhaps what you heard was the Consumers' representative trying to relieve the fears of people afraid that a means for terrorists to get into the system had be uncovered.

That could be. It just seemed that he was not really interested in the diver, other than the risk she posed.

 

[derwoodwithasherwood]

Bernouli - Total energy head is pressure related, velocity related and elevation (total head = pressure/(density*gravity)+(velocity^2/(2*gravity)+elevation) and if you are comparing to points (ie near the entrance and exit of a pipe) you can also add on a frictional loss in head which would be the difference between the two total heads.

The flow within the pipe can be described by the Hazen-Williams formula,

fl = 0.2083 (100/C)^1.852 Q^1.852/di^4.8655

Where: fl = friction head loss in feet of water per 100 foot of pipe
C = Hazen-Williams roughness constant
Q = volume flow (USgal/min)
di = inside diameter (inches)

and

H1 - H2 = el


Where H1 = head in feet of water acting on the intake, IE: surface height of the water in the lake.
H2 = head in feet of water acting on the discharge, IE: surface height of the water in the pond.
el = elevation loss (difference in pressure due to elevation changes)

Since there is no mechanical pumping action, therefore

fl = el

C varies with the type of pipe, encrustation, etc. A smooth walled pipe like copper or plastic has a high C value on the order of 150. Asbestos Cement is 140. New cast iron pipe is 130, Ductile iron pipe, 120 and riveted steel pipe 110. Let us assume a C of 100 in this case. Volume works out to 113,097usgpm (96" diameter pipe, 6 ft/sec). (Roughness of the pipe wall has the net effect of reducing the effective pipe diameter. Flow tends to be turbulent along the wall and laminar towards the centre. The thickness of this turbulent zone varies in proportion to both roughness of the wall and flow rate. Once in the pipe, I think the turbulent flow along the pipe walls would tend to buffer contact and she would remain within the laminar flow. )

In any event, if the report is accurate in it's details, and if the pipe runs straight with no elbows, the difference in elevation between the surface of the lake and the surface of the holding pond is only 2' 7 1/8". If the pipe runs level, then the pressure change on the diver would be equivalent to rising 2' 7 1/8". If the pipe rises or falls, then the pressure change on the diver would reflect the difference in elevation between the inlet and outlet. So if the pipe rises from 45' to 25' (relative to the lake surface) then she would experience the same pressure effects as rising straight up 20' during her 7 minute ride.

(Anyone else remember the film "The Seven Minutes"? I imagine the effect on the psyche would be somewhat similar...)

 

[ArthurGerla]

Here's another take on the matter:

Consumers spokesman Dennis McKee said Eddy was "jubilant" to be alive when he came upon her shortly after she walked out of the intake canal. She had been diving in about 40 feet of water 3,500 feet offshore with her husband and another couple when she suddenly disappeared, triggering a sizable search.

McKee confirmed this past week that a section of the utility's intake system at the bottom of the lake was damaged weeks earlier. Bolts holding a 42-inch section of pipe had sheared off, leaving a hole that large in an 8-foot diameter pipe about 3,500 feet from shore. Eddy was sucked through that hole, then drawn into an 18-foot diameter pipe, tumbling through the water at about 6 feet per second until she entered the canal.

 

[medical1]

Busch Gardens Tampa will be opening a ride like this. Must have been like being shot through a cannon backwords. :11:

Bolts holding a 42-inch section of pipe had sheared off, leaving a hole that large in an 8-foot diameter pipe about 3,500 feet from shore. Eddy was sucked through that hole, then drawn into an 18-foot diameter pipe, tumbling through the water at about 6 feet per second until she entered the canal.