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Author: Subject: LET THIS SIGNAL THE END OF THE FRIDGE PUMP QUESTIONS!
peach
Bon Vivant

Posts: 1428
Registered: 14-11-2008
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LET THIS SIGNAL THE END OF THE FRIDGE PUMP QUESTIONS!

No need to UTFSE, I've done it all for you, and then some more. A lot more actually.

I can't imagine there's a whole lot more you'll need to know, but I'll add some more on the exotic ideas later, perhaps with the help of my arch nemesis, entropy...

Names dropped; entropy, bartlog, JohnWW, chief

{edit} some of the captions aren't popping up when I click these on here, so you may want to youtube them directly, as they contain corrections or extra information {/done}

[Edited on 6-9-2010 by peach]

psychokinetic
International Hazard

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Location: Nouveau Sheepelande.
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Mood: Constantly missing equilibrium

I have a question about fridge pumps....

*leaves*

“If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search.
I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor.”
-Tesla
Chainhit222
Hazard to Others

Posts: 138
Registered: 22-8-2009
Location: peach's mailbox
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Mood: grignard failing to start

my dad cut one of those pumps open once (using a band saw) and spilled it all over my moms roses lol

[Edited on 6-9-2010 by Chainhit222]

The practice of storing bottles of milk or beer in laboratory refrigerators is to be strongly condemned encouraged
-Vogels Textbook of Practical Organic Chemistry
peach
Bon Vivant

Posts: 1428
Registered: 14-11-2008
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 Quote: Originally posted by Chainhit222 what is that white band around your head

My dirty hippy length hair is now getting in my eyes all the time and I'm too busy sawing things open to get it cut, so I'm using this girly headband occasionally for an enhanced viewing experience of reality.

Chainhit222
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Mood: grignard failing to start

hang a air freshener off of it

but I enjoyed the videos, they are entertaining to watch. You need DMT to unlock the higher dimension spheres.

[Edited on 6-9-2010 by Chainhit222]

The practice of storing bottles of milk or beer in laboratory refrigerators is to be strongly condemned encouraged
-Vogels Textbook of Practical Organic Chemistry
peach
Bon Vivant

Posts: 1428
Registered: 14-11-2008
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 Quote: Originally posted by Chainhit222 hang a air freshener off of it

I also spilled the oil all over the grass when I drained one to measure the oil volume in there, and then walked away for a minute leaving it balanced on it's side.

There was a blast furnace near our house, back in the olden days. Rather than use expensive hardcore (which is always expensive), the builders bought all the clinker from the furnace.

That means the lawn is now laced with an under layer of fairly caustic crap. When I clean the glassware, I'll often purposefully spill the washes of sulphuric over the lawn. It loves it. And me taking the occasional wazz on there in the dead of night.

DJF90
International Hazard

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Really good job peach, very informative videos and I love the humour too!
smaerd
International Hazard

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Mood: hmm...

Amazing video's I learned a whole lot. Funny stuff too. I really appreciate the hard-work I'm sure that was.

Cheers

edit - this should be stickied

[Edited on 6-9-2010 by smaerd]
BromicAcid
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Mood: Anxious

This should be put into a full length feature and put into Member Publications, our first feature film starring Peach.

Shamelessly plugging my attempts at writing fiction: http://www.robvincent.org
denatured
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Mood: HCl 50%?

I second Bromic, this is really nice. thanks Peach.
psychokinetic
International Hazard

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Mood: Constantly missing equilibrium

Oh peach, I could listen to you all day *dreamy eyes*
Also, more males should wear headbands. There's something about them when worn correctly.

-ahem- yes, full length and publish.

“If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search.
I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor.”
-Tesla
Fleaker
International Hazard

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Mood: nucleophilic

"I suck very hard"--peach.

^ Just kidding. Kudos to him for actually showing his face. That should definitely convince us all of your good and honest ambitions.

Very nicely put together. Now I want a video tutorial on demethylation :-P

"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
peach
Bon Vivant

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Registered: 14-11-2008
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Thanks for all the nice replies. It did indeed take forever to make something that long on a 256mb computer, so I'd be happy if just one person got some use out it.

I think more of us should post videos. This is one of, well probably the best at home chemistry forum on the web. Yet youtoop is populated by unhelpful, kind of boring videos about acetone peroxide and pipe bombs. I think team science madness could do a little better than that (len and his sodium, the lead acid chambers, etc). It could also make the massive project threads a lot more productive. It's hard to have an unnecessary flame war when you can see the other person.

All of you will have cameras that record, and can click upload. I expect a lot of us have glassware and odd things the standard younoober will want to see or knowledge of SOMETHING others can learn from. None of us know everything, but I suspect some of your are downplaying your own ability versus the standard youtube viewer.

I troll Jeri Ellsworth's videos a lot, she does them for electronics and are a good example of what I mean.

First person to make a video with their face and voice in it gets an instant subscription from John.

Demethylation, I may do that since it's very pretty seeing all the purple and orange everywhere, it's an odd reaction (as it can seems to be able to do a very passable impression of tar and illustrates how there is a spectrum within the hard / soft definitions of lewis acids) and it'd give me a chance to whip out some fancy looking glass.

It's cost me a few thousand pounds in equipment and reagents to figure out the demethylation, and a few years, amongst other things. £1k per view?

[Edited on 8-9-2010 by peach]

spong
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Great video Peach
I need to get a metric nomograph, it would save me so much time using an internet calculator. I've gone and got one out of an old fridge now so I can join in the fun It's not pulling the best the vacuum (I could only get warm water to boil, no gauge yet) but as you said in the video, it could just be the refrigerant boiling off still. I'll have to make some videos on AlCl3 production, once I make a new youtube account with a user name I didn't pick when I was 13.
peach
Bon Vivant

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Registered: 14-11-2008
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I have to start getting some money together to pay for the things you see in the videos (being jobless and having £10+k's worth of student debt), so you can have a customized, hand written, all units and laminated nomograph for a £2 + p&p gift thru palpaid.

"But John... you have all those pumps! Why do you need MOAR money!?", I'm refitting them to sell them, not collecting them.

I checked that pump again just now, and the pressure had gone up a bit, indicating there's still refrigerant in it. I've flicked it back on, blocked the intake and will leave it overnight to go.

You should expect some level of nuncing around from the pumps when they first come out, they will take time to sit still.

You don't have to be doing something super novel to make a worthwhile video, you could just post up a reply to that one featuring you pulling one out and doing the same thing to show it in a different way. It may also raise questions I didn't cover.

[Edited on 8-9-2010 by peach]

aonomus
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Mood: Refluxing

I have figured out why my overheating issues were so bad with my rotary compressor, in order for the motor to fully come up to speed, there must be slight backpressure on the output side of the pump. Once it reaches full revs, current draw decreases, and it pumps slightly faster and to a lower vacuum (although it looks like both gauges I had were crap, and they broke, so I need new ones).

Once I have a nice unit set up with a digital vacuum gauge and such setup for fast/easy use, I'll probably film a short video.
peach
Bon Vivant

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Registered: 14-11-2008
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A pump that requires additional back pressure? Yikes.

Thanks for the update on these, and a video (with a bit of detail) would be great (once it's uploaded, click 'video reply' on mine and then link to yours, so it's all in one place), since I didn't have one to hand to take to bits and talk about in those videos. If I find one, or anyone would like to post me one, I'll do a video about those too.

I'd also like to look at and take apart the pumps from superfreezers. Donations welcome.

aonomus
National Hazard

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Mood: Refluxing

I've seen videos of 95kW (yikes) scroll compressors, wonder whats in there?

When I have it all pretty looking I'll do a video response; it won't contain anything of the disassembly, but I'll try to cover what I know. It is a old R22 new-old-stock AC pump, so it seems to be a pretty good way of getting new pumps without refrigerant if you can source them.
peach
Bon Vivant

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Registered: 14-11-2008
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I decided to leave these up in case you want to see inside a piston fridge pump more, but I strongly suspect the pressures on the gauges are wrong.

Actual pressure from distillation temperatures and nomograph, ~26mBar, ~20 Torr

[Edited on 14-9-2010 by peach]

aonomus
National Hazard

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Mood: Refluxing

A slightly boring take on rotary refrigeration/AC compressors, and the results.

psychokinetic
International Hazard

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Mood: Constantly missing equilibrium

Oh my virgin eyes!

I'll watch them when I have internet that's faster than a backed up mule.

“If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search.
I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor.”
-Tesla
peach
Bon Vivant

Posts: 1428
Registered: 14-11-2008
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HOLY MOLY, you've gone purple!

Excellent! To see another person helping on this.

I have a few annoying observations to make, which I don't really want to knowing how hard it is to make these videos but thought they'd be helpful in some way.

• I am now getting near rotary pressures (or possibly better) from pistons. But yep, they're 100% not going to do that without modification. ~15-10mBar is the lowest I've seen them go with two in series, unmodified.
• Piston fridge pumps also have a starter winding, it's hidden inside the can. If you pull the electrics off, you'll see the three terminals. The black cylinder stuck to the side is a starting relay. The thing I forgot to put back on whilst busying myself with my nipple and the pliers. You can see the relay hanging off those flying leads (the black and white bits of plastic) near the vice. Some of them also have a 5uF cap on there as well.

I also forgot to point out how the motor will burn it's self out if left in the 'hum' state.

Those filters are SO damn expensive from BOC. They're just a bit of material in a plastic can.

I also missed out what the oil in the pistons was. The oil bit is helpful.

73C YIKES in a few minutes! That's friction for you. Mine was at 51C after 3h+ none stop, with high vacuum grease on the piston. I can see why there are so many questions about cooling these pumps from the US / Canada guys. 150C, I could fry my breakfast on that after an all night distillation.

Subscribbled and ratified.

Thanks again for the video and trying to help!

[Edited on 14-9-2010 by peach]

Magpie
lab constructor

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Registered: 1-11-2003
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Mood: pumped

Very nice! Kudos to Peach for special comedic effects, and to aonomus for organization and conciseness.

I must say that Peach has tied axehandle in turning his living quarters into an industrial development laboratory.

The single most important condition for a successful synthesis is good mixing - Nicodem
aonomus
National Hazard

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Mood: Refluxing

The cooling issue is a tenuous one at best right now, I can do most things I need such as filtrations, distillations, etc, but keeping the pump at a reasonable temp is the problem, and thats when its running at full speed.

I toyed with over-filling the pump with oil so that the oil will act as a heat transfer fluid to the casing (which I could then add heatsinks to), but all that happens is an oil geyser out the top, that just goes straight through the filter. And the 150degC warning is if the thermal protection switch is installed, which for me it is not. The pump isn't meant for unattended operation.

Also, the small oil/water separator I bought for $10 failed, miserably. I made a few more modifications, using my 3 position switch to turn on a fan before the compressor (allowing me to run the fan without the compressor running to allow for cooldown periods before fully shutting down), and I need to build a trap, a brute force oil collector (maybe using something like a household water filter for sheer surface area), and a activated carbon trap for organics before they enter the pump (because I don't have LN on tap, or dry ice in a cooler stocked). As for the oil filters, I believe we have EMF20's fitted to our edwards pumps at work, but the filter inserts haven't been changed in.... [range-exceeded], and oil mist just sprays out the top because the filters are so badly clogged the pressure relief valve pops open. I think we would save more money properly maintaining the pumps vs spending more on vac pump oil.... I'll try to film a quick video once I have the pump traps built (trying to do so on a minimum/zero budget is hard!), but I'm trying to get it set up so I can just regularly maintain it so that I can flip the switch to 'on' and expect the pump to work reasonably well without being a hazard to my health. Edit:  Quote: and to aonomus for organization and conciseness. 13 minutes is concise?! I feel terrible about slapping that video together like that, but I didn't want to spend more time on the video than the pump itself. [Edited on 14-9-2010 by aonomus] peach Bon Vivant Posts: 1428 Registered: 14-11-2008 Member Is Offline @Magpie Darn right! I'm not letting go on those things until they a.) can't do any better, b.) explode. The way they are from the factory is just to make things simple for the home user who's never going to want to see it, let alone do anything to it. The R600a means they're essentially designed to pump from a butane cylinder, fairly flammable stuff. The severe lack of rubber based seals or vanes should make them fairly corrosion / solvent resistant also. And they're built to a standard inside where I seriously suspect they can do a lot better than they will straight out of the skip, with not much effort. I have honestly seen Edwards etc brand names that look worse inside, for thousands. @aonomus Could you bend a bit of sheet metal into a heatsink, or submerge the pump? If you remove the can, you may (like I found with pistons) be able to run it on it's own for better cooling? I don't know, those AC things never turn up at the tip round here. It's too cold most of the time to need one, but I love having cool fresh air around. I have all the windows open and heating off right now, and it's 5am in September. I know that you could theoretically run a lab rotary without the oil box on it, you'd just need to catch the oil in the exhaust and let the pump suck it back in through a bit of tube or something like that (there's a port on the bottom of the pump heads). Again, the box is there to make it look neater and make it easier for the normal users. But it may be worth the slight extra effort required in ripping it off to get it running cooler during 3-6h distillations. With the solvents thing, it's worth sticking some carbon in the way if only to trap the traces. But, as I say in the nomnomnomograph video, if the thing you're working on isn't particularly sensitive to heat, you can always raise the pressure a little to catch the solvent in the condenser. No need to buy the trap, or the nitrogen. Or even use such a low pressure in the first place. Remember, the Buchi V700 pump has a pressure of ~10mBar, dead on the piston fridge pump pressure range; 35-20mBar normal, 15-10mBar for two in series or one with vacuum pump oil squirted in. The Buchi V700 is$2,160!

When doing filtrations that I know are going to clog up (and so boil the solvent), I'll stick the flask in the freezer for a while when I know I'm getting close to needing it. Then wrap it in a microfibre cloth or two.

As soon as the solvent tries to boil on the way through, it's going to evaporatively cool it's self and stop (due to the insulation).

[Edited on 14-9-2010 by peach]

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