Hi all,
I'm looking for a turbo for a fusor and found one that's 20 l/s. But looking down the road if I were to use it on a different project, I was wondering if there would be any issues using this size pump on a chamber as large as 20 gallons other than taking longer to pump down? Thanks.
20 l/s good enough?
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David Kunkle
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20 l/s good enough?
If your experiment needs statistics, you ought to have done a better experiment.
Ernest Rutherford
Ernest Rutherford
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Alexandru_Calburean
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Re: 20 l/s good enough?
David,
Generally the only thing pumping speed will affect in terms of performance is pumpdown time so even a 1 L/s turbo could pull down to the same pressure as a 100 L/s turbo just in a longer time.
Generally the only thing pumping speed will affect in terms of performance is pumpdown time so even a 1 L/s turbo could pull down to the same pressure as a 100 L/s turbo just in a longer time.
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David Kunkle
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Re: 20 l/s good enough?
That's what I thought, but don't want any surprises.
Also, the inlet flange is ISO LF63. Just been looking at Leskers website, and now I'm wondering if that's a weird size to attach to the chamber? They don't seem to have a clamp for that. Thanks.
Also, the inlet flange is ISO LF63. Just been looking at Leskers website, and now I'm wondering if that's a weird size to attach to the chamber? They don't seem to have a clamp for that. Thanks.
If your experiment needs statistics, you ought to have done a better experiment.
Ernest Rutherford
Ernest Rutherford
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Alexandru_Calburean
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Re: 20 l/s good enough?
David,
If you cannot find a chamber with ISO LF63 connections the simple and obvious solution is to buy an adapter from one of the many sources possible. As you scrounge up vacuum gear you will sometimes run into these situations where you have to roll your own creative work arounds, or shell out a lot of money for someone else to figure out those work arounds for you. To give you an example, I have a daia dpf 3z diffusion pump with a Japanese Industry standard flange, so I just used a viton o-ring with a flat steel plate and it works great. Also check out LDS for your vacuum needs: (http://vacuumshopper.stores.yahoo.net) they are the best in prices and great deals.
If you cannot find a chamber with ISO LF63 connections the simple and obvious solution is to buy an adapter from one of the many sources possible. As you scrounge up vacuum gear you will sometimes run into these situations where you have to roll your own creative work arounds, or shell out a lot of money for someone else to figure out those work arounds for you. To give you an example, I have a daia dpf 3z diffusion pump with a Japanese Industry standard flange, so I just used a viton o-ring with a flat steel plate and it works great. Also check out LDS for your vacuum needs: (http://vacuumshopper.stores.yahoo.net) they are the best in prices and great deals.
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Dennis P Brown
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Re: 20 l/s good enough?
If you have a lathe, making an adapter isn't all that difficult - I made one for a similar sized TP to fit a KF 40 all out of brass... . I'm not exactly a machinist, either.
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David Kunkle
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Re: 20 l/s good enough?
No lathe, but I already plan on needing to get a little creative making things fit. Thinking of having my own chamber welded together- at least I can pick what fittings to use if I know what pump etc. I'm going to have available.
Thanks, that helps a lot. What kind of vacuum can you get with the viton in there? Seem to make any noticeable difference?Alexandru_Calburean wrote:David,
I so I just used a viton o-ring with a flat steel plate and it works great. Also check out LDS for your vacuum needs: (http://vacuumshopper.stores.yahoo.net) they are the best in prices and great deals.
If your experiment needs statistics, you ought to have done a better experiment.
Ernest Rutherford
Ernest Rutherford
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Alexandru_Calburean
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Re: 20 l/s good enough?
I just used an old steel plate I found around the house and cleaned it up with some acetone so as to not outgas as much. If you do what I did for any vacuum connection (viton o-ring to steel plate with bolts for added sealing pressure) make sure that the plate is thick enough so as to not curve and deform and break your seal. I believe it was a 180 mm by 180 mm plate so the total pressure from the air came in at around 300 pounds if I recall correctly, this added to some extra force from the bolts as well slightly deformed the plate but not enough to break any seals. As for my vacuum level, I am getting to 11 microns as my lowest with the diffusion pump on. Now there a few things to note, first, I am using a thermistor gauge so not the best accuracy but certainly reasonable. Second, out of all the fusioneers ever I think I have the most kludge built vacuum system, but it seems to be working for now (to some degree) although I do also have some poorly tapped npt holes with using gas teflon tape, a homemade viewport, a homemade electrical feed-through, and some homemade gas handling lines out of old copper pipe, so that is most likely the cause. If you want to be sure of seal like that, coat the viton in diffusion pump (or otherwise high vacuum) oil and then install it. Good luck in your efforts.
All the best,
~Alex Calburean
All the best,
~Alex Calburean