micro air vehicle or similar to perform internal inspection 300ft high 2

[carterav]

I am looking for ideas related to performing a video/camera type inspection of a ~300ft tall stack with ~8.5ft diameter at it's top with remote controlled equipment. I've seen the T-Hawk from Honeywell and I am looking into it, but I wanted to ask for help on this site about what other options might be available (besides physically climbing up the chimney/stack and dropping a camera down inside).

 

[SAITAETGrad]

Triz solutions: plumb in a line at the base and pump the stack full of water and check for leaks due to the head pressure on a low wind day. Why do you have to inspect from the inside? Could you use an infrared telescope at night from the ground to check for areas of heat concentration indicating cracks? Could you monitor the health of the stack by exciting it @ its natural frequency with sound waves and look for signs of response dampening over time?

Real World Solution: Get up there...

 

[rb1957]

agreed ... i don't think the high tech solution (UAV) will work well in the confines of a stack, unless we're dealing with something 10-30' wide. a small UAV (1' dia ?) would need to be very responsive to maintain control.

will the stack be in commission when you inspect it ? if not, cover the outlet to stabilise the interior airflow, then a UAV might work.

as asked above, what's the scale of the inspection ? visual, ultrasonic ? looking for small damage 1" or larger 1' ??

personally i don't think pumping the thing full of water is such a good idea ... i doubt it was designed to that pressure at the base ?? but there other ways, like suspending the camera on a rope

 

[monkeydog]

Sounds like a cool soultion to an unidentifed problem or better yet a pass/fail critera.

Problem:
Inspect smoke stake from the interior.
Pass/Fail criteria:
See how black the soot is?

 

[KirbyWan]

Dropping a camera on a rope sounds like the Occam's razor solution, and least likely to damage your camera if something goes wrong. The filling with water idea is funny. 300 ft stack means 150 psi water pressure at the base. I wonder how thick the Hover dam is 300 ft below it's rim?

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[rb1957]

maybe your inspection equipment (camera ?) needs to be controlled relative to the stack wall ...

if the stack ID is constant it would be easy to build a track (with a wagon wheel) so the camera position could be controlled and recorded and this could to lowered (carefully, so you don't drop and break it !) down the stack ...

 

[MikeHalloran]

I think the desire to not use a stair that probably hasn't been painted in 60+ years is a valid concern.

I'm wondering if a blimp or a helicopter could be fitted with the sort of precision station-keeping arrangement used on drillships. That would provide a relatively stable platform from which to lower a camera, etc.



Mike Halloran
Pembroke Pines, FL, USA

 

[KENAT]

I like it Mike,dangle the camera on a rope from the stabilized 'weather balloon'.

rb1957, that's what I was thinking when I first said lower the camera on a cable.

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[carterav]

regarding the question about how close do we need to get? Close enough to evaluate the condition of the internal brick liner and determine whether or not repairs are necessary. Hope that answers the question.

 

[rb1957]

if you find a problem with the liner, how are you goig to repair it ? with a gang of guys, no? i doubt they'll access the stack from a cable suspended below a blimp. where i'm going is, repair the external stairs, now you can access the top of the stack easily (confidently?) and the rest is easy. (easier)

if you really want to go the UAV route, could you access the base of the stack through the exhaust pipes feeding the stack ? this'd get round the problem of flying the UAV into the stack.

have you talked to people who inspect stacks for a living ?

 

[MiketheEngineer]

You could scaffold it and yes we have done that a number of times...

 

[rb1957]

whichever's cheaper ... refurbishing the stairs or erecting scaffold each time

 

[thruthefence]

Is the stack of large enough diameter for one of these?

http://www.youtube.com/watch?v=vRG4xfJcLF4

 

[carterav]

I'll have to watch youtube from my home computer, b/c i cannot access youtube from work. I'll see what you've suggested. thanks.

 

[berkshire]

There is quad rotor being developed in the UK for the military.
However it only has a duration of 15 mins, not much for getting a look at the inside of a stack.
I think you would be better off employing a steeplejack.
B.E.

http://www.theengineer.co.uk/1009931.article?cmpid=TE01&cmptype=newsletter&cmpdate=090911&email=true

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[KENAT]

Where is Fred Dibnah when you need him?

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[berkshire]

KENAT,
I thought he just blew them up.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[MiketheEngineer]

BTW -

There is a company that uses "climbers" - guys that actually rappel down buildings/structures and do inspections - minor repairs.

Again don't know their name but Google might find them.

Sounds like an exiting career for the "wild and crazy"...

How you get them to the top?? Big crane, chopper, I suppose.

 

[KENAT]

http://en.wikipedia.org/wiki/Fred_Dibnah

Blowing them up was the least favorite part of his job apparently.

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[rb1957]

what you rappel down, you have to climb up (before or after); unless you have helicopters/sherpas standing by.

but back at crazyj, ... can you insert a UAV into the inlet pipes ? is the chimney transparent to radio frequencies ?

 

[rb1957]

oops, that shouldn've been @ cartav ... getting my threads mixed up ...