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Discussion Starter · #1 ·
Does anyone have any slight knowlidge of "dynamics of flow"? :rolleyes:



This device has come up thanks to the experimentation of Charles T. McCullogh, described at www.steamup.info It's a "killer replacement" for chimneyfans, in my view. Even this initial crude design, provides more than double the suction provided by traditional chimneyfans. It will easily hold a 4x4 inch paperclipping. 



All parts are standard plumbing, and a beachtoy inflator. The inflator moves a lot of air, with only moderate pressure.



The air-inlet pipe must end in between the downward column (to the chimney), and the air outlet. It can even just go into the narrower outlet, as long as a small portion around it connects to the air behind and around the air-inlet blowing pipe.

The air-outlet can not be larger in diameter than the inlet blow-pipe - hence the reduction for the outlet, that make them exactly equal. I don't know what would happen, if the inlet blow-pipe was smaller than the outlet ;-)



I bought all the parts ready made yesterday, and was running the T&inflator suction device in 10 minutes! Some standard plumbing-parts, a snippet of hose, and the rechargeable inflator, everything just off the shelves. Total cost (in Sweden) about USD 30!


I would be grateful for any suggestions for further experimentation, because I know nothing about "dynamics of flow", so I have absolutely no idea in what direction to look / go :confused:
 

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Discussion Starter · #5 ·
RE: Help! Dynamics of flow & new killer suction device!

Yes Henner, that seems to be the case! :) Only, my injected airstream is in the center, not around the circumference. The inside of "my" T reminds a lot of a steam water injector.

Having spent the day thinking, I think I'll try with a smaller inlet blow-pipe. That ought to increase the pressure in the inlet jet-stream (and probably reduce it's velocity). That should increase the difference in pressure between the "chimney" air, and the through-put airjet = increasing suction.
- But what is the importance of the smaller outlet? Maybe, thefull size fitting was so big in diameter (and short length?), that it went over a critical maximum, killing the vacuum alltogether. Proportions maybe have to be within reason / limits?

According to Henners link, a 1:25 ratio of airflow amplification is possible. In that case I don't I'm achieving more than 1/50 of the effect I ought possibly achieve! /DesktopModules/NTForums/themes/mls/emoticons/wow.gif
 

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Discussion Starter · #6 ·
I finalized the design yesterday. Inlet is now 4mm diameter, compared to outlet 10mm. It does not go far into the "T", and placement is not that critical. The 4:10 diameter ratio is probably due to the characteristics of a beachtoy inflator = low pressure, lots of air. With a compressor = higher pressure = I would guess the inlet should be considerably smaller. The "T" is iabout 20mm diameter (inside threaded to fit a 1/2" pipe)

The whole thing actually works as an auxilliary locomotive chimney! Anyway, it seems to work great. :D



Unfortunately, Aster has made my chimney 9,8mm inside, so I had to turn and drill a fitting pipe! /DesktopModules/NTForums/themes/mls/emoticons/crazy.gif


I really did experiment with all sorts of modifications. Extensions, airstream as circumference, all sizes of pipes and... :rolleyes:
 

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