Author Topic: Building a Fume Hood  (Read 16316 times)

Offline PekkaNF

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Re: Building a Fume Hood
« Reply #25 on: September 16, 2016, 08:03:42 AM »
Bugger.

I have a a friend that has wood clog under everything on his basement, office, lab....after a incident that had faucet to break at the middle of the night. There were maybe 20 mm of water on the floor, but that spoiled a whole lot electrics. Including one computer that was not exactly cheap at the time.

Hope it turns out well.

Pekka

Offline S. Heslop

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Re: Building a Fume Hood
« Reply #26 on: September 16, 2016, 08:29:34 AM »
Bugger.

I have a a friend that has wood clog under everything on his basement, office, lab....after a incident that had faucet to break at the middle of the night. There were maybe 20 mm of water on the floor, but that spoiled a whole lot electrics. Including one computer that was not exactly cheap at the time.

Hope it turns out well.

Pekka

That's pretty rough. The flooding isn't too bad for me since i've built everything to be a few inches off the floor, it's just a hassle waiting for it to dry so I can start sweeping up the sediment and get back in. Thanks for the concern though.

Offline S. Heslop

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Re: Building a Fume Hood
« Reply #27 on: September 28, 2016, 11:14:28 AM »
Haven't done anything on this the past week. I've been working on the slideshow parts of the video and it's become a real chore. I sort of want to continue that corny computer graphics vibe I went for in the title cards of my last video to hopefully make them somewhat interesting to look at, but i've been trying to find a system to make them easier to produce. I tried out Adobe After Effects but it turns out trying to draw a solid 1 pixel line in that is a damn chore since it wants to anti-alias everything. There's ways to prevent that but it was alot of jumping through hoops just to get a single line.

So i've been trying out some terrible software called Game Maker Studio, which was on sale for 1p a few weeks ago. It's designed for producing crappy 2d games so should be ideal for what I want to do. So i'm trying to freshen up on scripting, which I haven't done in years, and it's taking a while since the documentation for that software is really all over the place.

In other news, Rob Wilson dropped off that blower and it looks ideal. He said that fume hoods often use the venturi effect to pull the air through and I didn't realise what he meant till he was gone, but that's actually a great idea for keeping the blower out of the path of corrosive or explosive fumes.

RobWilson

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Re: Building a Fume Hood
« Reply #28 on: September 28, 2016, 03:27:33 PM »

In other news, Rob Wilson dropped off that blower and it looks ideal. He said that fume hoods often use the venturi effect to pull the air through and I didn't realise what he meant till he was gone, but that's actually a great idea for keeping the blower out of the path of corrosive or explosive fumes.

And I got that wee bit of info from Phil (hermetic) , something he pointed out wile we were discussing options for my coke forge hood  project .


Rob

Offline S. Heslop

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Re: Building a Fume Hood
« Reply #29 on: September 29, 2016, 04:56:33 PM »
I did it. Now I can make annoying animated text and get maths wrong with ease.



The program prompts you for text and then dumps each frame as a properly sized series of images (that's a lie, i need to trim the top off. I forgot why I made the letter sprites so tall). It's fairly easy to pull a series of images into the video editing software I use as frames. For special characters you prefix some regular characters with either a ^ or @. The program crashes if you input anything it doesn't recognise though. There's alot of problems in general but my code is so awful i've already lost track of what does what. I have no idea how professional programmers manage actual projects.


There's also a prompt for 3 colours; green, amber, and white. I'm not too concerned about the authenticity of this since it's supposed to be somewhat corny. I'm also going to heap bloom, blur, and maybe scanline effects over it in the video editor to make it look extra tacky.

Offline S. Heslop

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Re: Building a Fume Hood
« Reply #30 on: October 04, 2016, 01:54:23 PM »
I got a little too excited with the last post. I was thrilled I'd gotten something to work. Made some other programs for bounding boxes and the like and spent most of today trying to get to grips with After Effects. Still haven't got an effect i'm too happy with.

I also spent a bit of time thinking about the hood proper. I'm wondering how well this sort of arrangement would work as a venturi. I believe for a venturi to work well there needs to be a bit of a restriction and then the inlet just ahead of it.



If I get some time i'll have a go at building it tomorrow, but i'd appreciate any opinions on if this'll work or not.

Offline Manxmodder

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Re: Building a Fume Hood
« Reply #31 on: October 04, 2016, 02:59:28 PM »
Simon, that probably will give you the negative pressure you need for the extraction to take place,however you will probably need a bit of experimentation with the leading ramp and certainly watch out for vortices caused by sharp edges causing abrupt changes of airflow. The sharp corner you show on your lead ramp may actually cause some downdraught on the reverse side thus reducing your extraction flow rate. Maybe a slower and longer rate of ramp angle on the leading face will also help improve the efficiency.......OZ
Helixes aren't always downward spirals,sometimes they're screwed up

Offline Will_D

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Re: Building a Fume Hood
« Reply #32 on: October 04, 2016, 06:06:32 PM »
When checking a fume hood a cigarette is your only friend!

Just don't smoke it!!

Engineer and Chemist to the NHC.ie
http://www.nationalhomebrewclub.ie/forum/

Offline S. Heslop

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Re: Building a Fume Hood
« Reply #33 on: October 07, 2016, 10:26:51 AM »
I built it and gave it a test but the results are pretty disappointing. I played around with it for a bit trying to get a better airflow but didn't get anything too impressive.



So in all honesty I feel like the blower by itself produces about the airflow that I want. I really wasn't sure what sort of performance i'd get out of this venturi but I think even under ideal circumstances it won't ever be enough.

So my options are to either mount this blower directly in the fume path or go to back to the bouncy castle blower. I think the blower Rob gave me is really nice though, and I might have a use for it elsewhere. So it'd be a shame to potentially wreck it with a bunch of corrosive fumes.


Offline S. Heslop

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Re: Building a Fume Hood
« Reply #34 on: October 07, 2016, 06:55:18 PM »
Still fussing with this corny slideshow effect.



Not 100% on it but it's starting to look more like what i'm after. Each new effect layer really messes with the brightness and colours and it's a juggling act with various level adjustment layers to try keep the colours sane. There's more tweaking to go. It's tempting to add other stuff like the image warping, but it's already headache inducing enough.

The nice part though is that it's fairly quick to make the animation underneath it all, and once the effect is final I won't ever have to make it again.