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

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

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

(OP)
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).

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

Brookstone is selling a quad-rotor toy helicopter for a couple hundred bucks that would make a stable camera platform.  I have no idea if it has enough endurance to climb that far while carrying a camera and transmitter, but it's cheap enough to just go ahead and try.

 

Mike Halloran
Pembroke Pines, FL, USA

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

(OP)
we don't know yet, but probably the answer to your question is yes.

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

(OP)
the balloon is not a bad idea, but there are sharp edges (e.g., bolts) that would probably pop the balloon.

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

If the stack has draft, you could hack up a small steerable balloon, tethered and controlled by multiple fishing lines, like a 'control-line' model airplane with more bellcranks.

If the flow is particularly turbulent, that won't work well at all.



 

Mike Halloran
Pembroke Pines, FL, USA

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

(OP)
one problem with the balloon idea is that the balloon would have to enter through the top.  there is no entrance from the below the top with the stack operating.

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

Ok, if you're entering from the top anyway, can you not just lower down a 'camera' on a wire?

You could have some structure around it to stop it smacking things or getting caught up on them.

Do you have person access to the top of the stack?   

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

Sorry; I was assuming a manhole near the base for cleaning out bird crap and stuff.

So the UAV has to carry lights too, and climb over the top to get in.  ... and your RF has to go through the stack.

You may have to climb the stack.

 

Mike Halloran
Pembroke Pines, FL, USA

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

(OP)
We are trying to avoid sending the workers up to the top of the stack.  There is an existing step iron ladder system, but it was built in the 1940s.  It should be ok, but we want to avoid sending workers up to the top of the stack (or up the stack at all).  Typically, in the industry, a climbing inspection is typically what it performed, but we are looking for options to see if there is any other way to perform the inspection.  An interesting website that has an option we might use is found at http://www.thawkmav.com/demos.php

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

I have a bad feeling any UAV you try putting down there will get bounced around pretty severely.

I accidentally flew over (or near) the stacks of a power station when I was pilot training and it was pretty bumpy!

Now of course this wasn't in the stacks, where the airflow may be more directional etc. but still, I have my doubts as Meryl said.

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

(OP)
the purpose is to perform an internal inspection of the stack.  it has not been inspected in over a decade.

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

(OP)
what do you think about the uav with the stack off?  do you think it would still be hard to keep stable?

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

if the balloon idea fails 'cause you only have access from the top, what about a long piece of rope ?

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

There are a number of gas powered R/C helicopters out there that can carry a light weight camera - also quite available.

You might have to do a bit of cobbling together to get it all worked out.  Like keeping the exhaust from clouding your lens.  All together - it should cost less than a grand!!

I have even seen "services" offered that use RC planes or helicopters to do exactly what you are asking.

Not sure how to find them - but I am sure a "Google" would.  Maybe "inspection services" or "RC helicopter"+"camera"

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

Stack off would be better but, there may still be quite an updraft from the 'venturi' effect of wind blowing past the top of the stack.

Plus, MikeHalloran may have a point about RF issues.

If there are folk offering this service as MiketheEngineer suggests then it sounds like it would be worth talking to them.

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

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...

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

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

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

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?
 

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

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.

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

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 ...

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

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

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

(OP)
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.

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

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 ?

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

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

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

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

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

(OP)
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.

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

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

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

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

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

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.

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

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 ?

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

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

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

Camera cart, light rig  and a few flip HD's or similar. Direct illum on the way down, sidelight on the way up.

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

Bungee cord and high-speed video camera, falling behind a magnesium flare.

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