6" adjustable vent

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zemlin
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Location: Indianapolis, Indiana

6" adjustable vent

Post by zemlin » Fri Sep 30, 2016 12:31 pm

This was a project for the day job and my most ambitious build so far. I design bottling machinery for a bottle cap company. We sometimes blow bottle caps through 6" stainless steel tubes to get them from point A to point B. In order to limit the speed of the caps at different points in the tube we want to test venting some of the air after the caps are part-way through the system. This is a 6-piece build with 42 stainless-steel rods creating the cage. The 6" tubing will (hopefully) slide into each end and we'll be able to open the vent to different amounts to see how it impacts the velocity of the caps downstream. I have a spring-loaded ball for a detent to give it 10 positions between open and closed.

This is all PLA. It's not for long-term and I felt more confident about getting straight, true builds from PLA than ABS. PETG wouldn't have been a good choice because sliding parts tend to be sticky with PETG.

video: https://youtu.be/mhnWkKlrkHY
I wanted the two inner sleeves to be orange, but I ran out of orange filament due to a failed build.
vent.png
Capture.JPG

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jamigas
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Location: Crawfordsville, IN

Re: 6" adjustable vent

Post by jamigas » Fri Sep 30, 2016 3:32 pm

I actually watched part of this build take place via the live feed link you posted in another topic. Very well done. You continue to inspire.

mgordeeva250
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Joined: Wed Sep 14, 2016 5:13 pm

Re: 6" adjustable vent

Post by mgordeeva250 » Thu Oct 13, 2016 3:09 pm

That is really very inspiring! Watched the video, at first it seems like magic (to me at least :) though then you start to understad what is going on. Geat job!

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zemlin
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Location: Indianapolis, Indiana

Re: 6" adjustable vent

Post by zemlin » Mon Aug 07, 2017 2:23 am

Some new visuals of my latest build.
Click on the thumbnail of the animattion - the preview looks bad from my end.
Vent.gif
KZ4_3252-Edit-1600.jpg
KZ4_3199-Edit-1600.jpg
2017-08-06-16.23.00 ZS PMax-Edit-1600.jpg
KZ4_3194-Edit-1600.jpg

jferguson
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Location: St Petersburg, FL

Re: 6" adjustable vent

Post by jferguson » Mon Aug 07, 2017 4:28 am

Really slick Karl. Very impressive design.

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willnewton
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Re: 6" adjustable vent

Post by willnewton » Wed Aug 16, 2017 1:02 pm

Just a comment that may or may not apply depending on how I interpreted your first post.

You say that you are looking to slow down the speed of the caps "at different points" by introducing venting. This says to me you are expecting to be able to increase the speed at some point after the vent. This solution will not do that, it will reduce ALL airflow after the vent.

You may have a good or better understanding of flow dynamics than myself, but I will lay out some basic info for those readers that may not understand the issue at hand.

The way fluid (including air) pressure in a pipe works is that everything after the vent(restriction) point will flow at reduced pressure after the vent (restriction). There will not be areas of reduced speed which then increase to a previous pressure at "X" feet after the vent.

Even if you reduce the pipe diameter after the vent to increase the velocity, you will increase the back pressure (restriction) which will send more air down the past of least resistance, which is out the vent. Sure you could increase the fan power to get back some of this lost velocity, but this will also create the need for further flow reduction at the vent to reduce speed, so you will need a larger vent, which will increase the pressure loss out of the vent.

Also this vent looks like a good place for bottle caps to get stuck. After all, the caps follow the airflow and gravity, so they may accumulate in your vent grate. This may not actually be an issue, just something I was thinking about. ;)

To slow down the velocity without venting air into a un-pressurized system (anywhere outside the pipe), increase the diameter of the pipe and speed will be reduced. You can the decrease the diameter back to the original size with no significant loss in flow in the rest of the system, since you have not created a smaller restriction point than the original pipe, nor lost pressure through venting.

This is how you would control speed "at different points". If you mean to only decrease speeds as the bottle travels along the complete pipe run, then your vent solution seems fine. If you expect to introduce a speed increase after the vent, well, you may have unexpected results. :)

Otherwise, that design and print is very, very cool. Your vent itself is obviously well thought out and is the kind of project that is the perfect application of 3dprinting. My post is not meant as a comment against your vent design itself or your CAD skills and ingenuity, which are quite awesome, but just commenting on how your design may perform when implemented in real life.
I'm finally back to where I started two days ago!

A thread with some stuff in it I update every once in a while. viewtopic.php?f=8&t=9
See some of my stuff http://www.thingiverse.com/willnewton/favorites

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zemlin
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Location: Indianapolis, Indiana

Re: 6" adjustable vent

Post by zemlin » Wed Aug 16, 2017 3:58 pm

willnewton wrote:This says to me you are expecting to be able to increase the speed at some point after the vent. This solution will not do that, it will reduce ALL airflow after the vent.
Nope. 1-2 vents in a line to slow the caps at transition points - once after going from vertical to horizontal - and potentially one more at the end of the line to blow off more air before they go into a cyclone-type decelerator.
willnewton wrote:Also this vent looks like a good place for bottle caps to get stuck. After all, the caps follow the airflow and gravity, so they may accumulate in your vent grate. This may not actually be an issue, just something I was thinking about. ;)
No issues with that in testing, but it was a consideration. The inertia of the caps and the air keeps things moving. If venting too much the issue was caps piling up further downstream.
willnewton wrote:To slow down the velocity without venting air into a un-pressurized system (anywhere outside the pipe), increase the diameter of the pipe and speed will be reduced. You can the decrease the diameter back to the original size with no significant loss in flow in the rest of the system, since you have not created a smaller restriction point than the original pipe, nor lost pressure through venting.
The problem is that nominal pipe sizes change diameter too dramatically. 4" -> 6" is a 225% increase in area. We need finer control than that.
willnewton wrote:Otherwise, that design and print is very, very cool. Your vent itself is obviously well thought out and is the kind of project that is the perfect application of 3dprinting. My post is not meant as a comment against your vent design itself or your CAD skills and ingenuity, which are quite awesome, but just commenting on how your design may perform when implemented in real life.
Your time and consideration is appreciated.

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willnewton
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Re: 6" adjustable vent

Post by willnewton » Sat Aug 26, 2017 2:10 am

Sounds like you got it under control! I was just excited about the novelty of bottle cap behavior in a duct, which says a lot for the quality of entertainment where I live.
I'm finally back to where I started two days ago!

A thread with some stuff in it I update every once in a while. viewtopic.php?f=8&t=9
See some of my stuff http://www.thingiverse.com/willnewton/favorites

billc
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Location: Ann Arbor, Mi

Re: 6" adjustable vent

Post by billc » Thu Oct 12, 2017 5:52 pm

Amazing work ! Educational and inspirational :)

jk42
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Re: 6" adjustable vent

Post by jk42 » Thu Oct 12, 2017 6:51 pm

Amazing! We love seeing the ingenuity of our customers; outstanding job!
~Jason from MakerGear
~Jason from MakerGear

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