Solid state hydrogen storage experiments

Every fusor and fusion system seems to need a vacuum. This area is for detailed discussion of vacuum systems, materials, gauging, etc. related to fusor or fusion research.
Post Reply
User avatar
Rich Feldman
Posts: 1470
Joined: Mon Dec 21, 2009 6:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

Solid state hydrogen storage experiments

Post by Rich Feldman »

New title here. This is to continue a discussion that Corby Dawson, Rex Allers, and got into under "Any Swagelok Gurus out there?" viewtopic.php?f=10&t=11123

It's not the first time metal hydride storage came up on the forums, usually in connection with storing and transporting deuterium.

Like Rex, I got some "Hydrogen cores" sold under the Brunton brand. They go with a hydrogen fuel cell gadget that has a USB port for charging devices in the field. This consumer product system might not be made much longer. In the the other thread I reported picking up a Hydrogen Reactor and some cartridges at clearance prices. Get 'em while they last!

Brunton cores come filled with 10 liters of H2. That increases the weight from about 90 to 91 grams. Hydrostiks by Horizon Energy, sold for lab use, are compatible but are shipped empty. My inquiry last week brought a response including this advice: "Our HYDROSTIK is evacuated before shipping and there is a little bit of H2 to begin with." and this drawing:
stik.png
I'm planning to follow Rex's lead, and make instead of buy a Stik adapter fitting. The thread is a M6 x 1.0 mm, and the hole in the end admits a 0.071" round pin but not 0.072". The valve is held shut by an internal spring, that needs more than a few pounds of force from the mating device's "opener pin".

My fuel cell ran for the first time last night. It hosted a USB-A cable whose wire leads were broken out for a voltage logger and a load. Following directions, I inserted a full "core" and screwed it into place. Red LED flashed, there was a puff of gas sound, and blue LED came on. USB output, unloaded, had 5.00 volts on it. That dropped to about 4.95 V when 100 mA constant current load was connected.

I noticed occasional, momentary (100 ms?) voltage dips. My watch said they happened every 15 seconds. The voltage logger had been set up to sample every 5 seconds, so maybe it would catch some dips during the overnight run. The 100 mA load was left on for a bit more than 6 hours, theoretically using up about 1/7 of the hydrogen (core rating is 4500 mAh).

Logger was disconnected and plugged into computer USB port to upload the numbers. Sure enough, the voltage dip period was aliased from 15 seconds to 4 hours.
usb3a.PNG
Here is a detail of the second dip in that log.
dip2.PNG
Funny thing is, _both_ dips were caught on samples at 0, 15, 30, and 45 seconds after a whole minute, according to the voltage logger's clock, which is designed to keep time for many months. Must resist the temptation to give the Hydrogen Reactor's time base more attention than it needs. :-)
All models are wrong; some models are useful. -- George Box
Corby Dawson
Posts: 41
Joined: Mon Nov 23, 2015 9:31 pm
Real name: Corby Dawson

Re: Solid state hydrogen storage experiments

Post by Corby Dawson »

Rich,

Do you know if you can refill the Hydrocores via a compressed gas bottle?
I have the instructions to do that with the Hydrostiks.

Cheers,

Corby
Last edited by Corby Dawson on Mon Nov 14, 2016 8:08 pm, edited 1 time in total.
User avatar
Rich Feldman
Posts: 1470
Joined: Mon Dec 21, 2009 6:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

Re: Solid state hydrogen storage experiments

Post by Rich Feldman »

Why would that not work? They use an AB5-class storage alloy, I bet the same as in Hydrostiks.

The Brunton product launch literature gives two ways to refill empty cores.
1. Exchange for full ones at the store. (which refills them in back room?)
2. Fill them at home with electrolyzer, which consumes distilled water and electricity, and can work at ~ 400 psi. I think Rex has one of those.

I have some parts on hand to make a little piston compressor. Then electrolysis or chemical reaction could run at atmospheric pressure, with temporary H2 storage over water or oil in inverted flasks, or in mylar balloons. H2 cartridge literature says the recharging gas should be very dry; any moisture degrades the storage alloy.

As I said before, the low cost cartridges and fuel cells might not be available a year from now,
so get 'em while they last. "Reactor" is on sale for $59 here, for example:
https://www.bhphotovideo.com/c/product/ ... ellow.html
Last edited by Rich Feldman on Mon Nov 14, 2016 2:25 pm, edited 1 time in total.
All models are wrong; some models are useful. -- George Box
User avatar
Richard Hull
Moderator
Posts: 14992
Joined: Fri Jun 15, 2001 9:44 am
Real name: Richard Hull

Re: Solid state hydrogen storage experiments

Post by Richard Hull »

The core post here was the kind of post that is so rich and informative. Thanks to Rich Feldman for this exposition on the H2 storage and fuel cell operation with extensive data.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Rex Allers
Posts: 570
Joined: Sun Dec 30, 2012 3:39 am
Real name:
Location: San Jose CA

Re: Solid state hydrogen storage experiments

Post by Rex Allers »

Glad Rich is getting into this too. I think it was Corby that brought up the idea of using these about a year ago.

I've been planing to write up details of what I've done so far, but haven't got to that yet. Since Rich seems to be ready to make his own adapter fitting, I thought I'd share a few quick pics and notes now.

The original designers and sellers are (I think) Horizon Fuel Cell. They are the same people who sell the small plastic-cased PEM fuel cells that others here have used to make D2 from D2O. There are other posts here that have covered that.

This page shows the basics of the products Rich has described.
http://www.horizonfuelcell.com/minipak
As mentioned Brunton also sells a version of this stuff. On the top of the Horizon site pages there is a link to their Online Store. There are old and new versions of their Stiks and Chargers. The newer versions have a little more capacity but I think the old ones will be fine for our purposes.

The prices on their store page are scary high. The cartridges both new (Pro) and original are $39. The new Pro charger is $729 and the older charger is $419. Almost a year ago (Dec 1015) I bought one of the Hydrofills, I think from Jameco, and I think I paid about $230 for it. The store also shows the small inline adapter/regulator for $130.

I plan to use my own home-made fittings and I have a small standard regulator for low PSI out.

Until Rich's post, I hadn't realized the original Hydrostiks don't come filled. That certainly explains why the one I connected to my valve had zero pressure. Glad I also had a 4-pack of the Brunton Hydrocores; these measured in the vicinity of ~280-290 psi.

Here's a sloppy drawing I made of the cartridges for planning my fittings.
Hydrostik dimensions
Hydrostik dimensions
And another sketch of the dimensions of the fitting I turned to screw onto the Stiks. I used an 010-sized o-ring to seal between the adapter and the Stik.
Stik adapter connector
Stik adapter connector
Here's a close pic of the Stik output end.
Hydrostik output end
Hydrostik output end
The solid "plug" in the center of the opening is the valve. I made a little button with a thin rod to press into the valve. On the empty Stik, I measured about 60 oz force to open the valve. I didn't try to measure it on a full cartridge; I assume the force would be higher.

I made my own adapter fitting with a homemade valve that presses a pin to open the Stik valve. Without going into much detail, here's a pic of my valve.
My adapter and valve
My adapter and valve
The "body" of the valve started out as a brass 1/4" compression fitting. A bit of lathe work was involved. Turning the knob on the top, pushes a 1/8 rod with the end turned down to fit in the stik opening. Here's a view of what's in the valve I made. I'll try to write up a more detailed version later.
Internals of my valve
Internals of my valve
My next plan was to try to learn about the charging cycle of the Hydrofill I bought. I plan to turn an adapter that I can screw into the Hydrofill so I can have a Y and monitor the pressure during a charge cycle. Looking into the charger unit, I don't see any pin that would press the valve in the stik. I assume the as the pressure gets up to or above 300 PSI, that the gas just forces past the valve.

OK, enough for now. Hope some of this helps.
Rex Allers
Corby Dawson
Posts: 41
Joined: Mon Nov 23, 2015 9:31 pm
Real name: Corby Dawson

Re: Solid state hydrogen storage experiments

Post by Corby Dawson »

I've been looking at the pictures of and the user manuals for the Brunton Hydrolyzer and the Hydrostik Hydrofill Pro Hydrogen generators. These are used to recharge the Hydrocores and Hydrostiks, as well as to provide Hydrogen for other uses.
The Hydrolyzer runs $250.00 and the Hydrofill Pro runs $600.00.
It sure looks to me that they might be identical inside !
The Hydrofill manual says it produces 99.95% purity and the Hydrolyzer manual says 99%.
They both use PEM electrolyzers.
The Hydrofill Pro mentions using Malic acid powder to regenerate the PEM unit if needed.
Since the Hydrocores are shipped full and one in my application should last years it's probably cheaper not to invest in a refilling unit!
Just wondering what the difference in cost gets you?
Cheers,

Corby
Jim Stead
Posts: 94
Joined: Wed Aug 19, 2015 11:44 pm
Real name: Jim Stead

Re: Solid state hydrogen storage experiments

Post by Jim Stead »

The Hydrocores contain Hydrogen, not Deuterium. If you plan to use them for a Fusor, you will need to evacuate the supplied Hydrogen and replace it with Deuterium.
Rex Allers
Posts: 570
Joined: Sun Dec 30, 2012 3:39 am
Real name:
Location: San Jose CA

Re: Solid state hydrogen storage experiments

Post by Rex Allers »

Jim,
I thought the H2 vs D2 in these things was obvious so no one has mentioned it recently. I think Corby's current application is other than Fusor -- Hydrogen Maser? (am I right)? I think both Rich and I are hoping we can use them for a bunch of Fusor runs from one cartridge charge. I've thought, if nothing else, maybe the cartridges could be a way for someone who gets a D2 tank to share by filling some of these cartridges and thereby sharing and dividing the cost of purchase. This assumes many who get a tank of D2 will have more than they really need and might be willing to share some for a price, if we can come up with a workable design and procedure.

Corby,
The recharger device I got is one of the Horizon Hydrofills (not the Pro). I do not know, but I would guess the Horizon and Brunton versions are nearly identical. I don't know how different the Pro vs. original versions are. As I recall from the specs, the PRO runs to higher pressures. I wasn't aware of the reconditioning (my term) option you mentioned. That could add complexity to the design.

I've never seen any other unit than the Hydrofill I bought. Of course, as a certified nerd, the first thing I did was open it up to see what's in there. The PEM cell is a little bigger and much sturdier that the blue plastic fuel cells we have seen posted on this forum before. I looks to me that all the pressure (>300 psi I think) comes from the electrolysis -- no pump in there. The plumbing is mostly ~1/16" OD stainless tubing. The path from the cell passes through two cylinders about 1" dia and 3" long. They are not the same. The first one has a low pressure plastic tube coming out the bottom. It seems to go to a solenoid valve that gates into a (?) small water expulsion tank on top of the unit. (My best guess so far.) The second cylinder just has a simple 'in' on the bottom and 'out' on the top. Both are with the stainless plumbing.

I don't know exactly what is in these two cylinders but I assume it is probably to get water out of the gas. In the long run of trying to convert from H to D, I'm a bit concerned how hard it will be to purge the H and keep the D pure. Then, so far, I'm not sure if the design is willing to waste some H2 in its water expulsion. That would be bad for our precious D2. I still need to look closer and try to figure out how this thing works, in detail.

So the design is fairly sturdy and complex. For a low-volume custom design, I don't think the ~$200 price I paid is out of line. The other higher prices for most sellers now, and the very high premium for the Pro versions seems a bit too much for me.
Rex Allers
User avatar
Rich Feldman
Posts: 1470
Joined: Mon Dec 21, 2009 6:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

Re: Solid state hydrogen storage experiments

Post by Rich Feldman »

Nice work there, Rex.

My first cartridge ran out of gas during fuel cell load test, after 2300 mAh at about 5 volts. Almost 11½ watt hours -- not bad IMHO. Test loads were a 100 mA current source, a 100 Ω resistor, and current source modified for 280 mA. All probably accurate within 5%.
first_gas.JPG
Estimates in small-fuel-cell literature are in the same ballpark.
15 Wh here. http://resources.arcolaenergy.com/docs/ ... TW0719.pdf
13.3 Wh here, from the fuel consumption spec: http://www.fuelcellstore.com/edustack-junior-fcsu-32
Horizon Minipak http://www.horizonfuelcell.com/minipak claims "1 watt for 10 hours", and says most AA primary cells last less than 1 hour at 1 watt. Not really a fair comparison, because 1 watt is a very heavy load for a single AA alkaline cell, even more so for a single LeClanche.

Here are my figures from fundamentals.
Hydrostiks and Cores are supposed to hold "10 normal liters" of H2. Depending on whose Normal temperature they follow, that's about 0.89 or 0.83 grams. The FAQ link above implies the former, in cartridge lifetime discussion -- weight change dropping below 0.72 grams. I bet the capacity value does _not_ follow the lecture bottle convention, where nominal content includes residual gas at atmospheric pressure, accessible only to apparatus that sucks.
gas_works.JPG
gas_works.JPG (30.24 KiB) Viewed 9974 times
Coulometrically, there's about 23 ampere hours of fuel. 16 watt hours at 0.7 volts per cell. Lossless DC:DC conversion could deliver 3200 mAh at the 5 volt USB output. I see no way to match Brunton's 4500 mAh claim, for charging mobile devices, except to use 3.7 volts -- the nominal voltage of mobile device battery. Need to neglect conversion losses, and actual Li-ion battery voltage during charging (4.1 to 4.2 volts).


Last night I bought a compact digital scale with resolution of 0.01 gram, that came with a 100 gram reference mass. Didn't need a Mettler or other fine brand. Real shopping is better and faster than online shopping, so I visited Monsters of Rock on the way home from work. It's a smoke/vape shop and body piercing parlor, and the most prominent display shelves are loaded with exotic glass pipes. They have a whole cabinet full of compact digital scales. :-)

[edit] Guys, here's a pic the so-called reactor & core. Also a close-up of the parts where they conjugated.
DSCN0059.JPG
DSCN0068.JPG
All models are wrong; some models are useful. -- George Box
Rex Allers
Posts: 570
Joined: Sun Dec 30, 2012 3:39 am
Real name:
Location: San Jose CA

Re: Solid state hydrogen storage experiments

Post by Rex Allers »

Rich,

Good details. Using the hydrogen for fuel cell for electric energy isn't what we really want, but I do get that how much they hold is important. I hadn't really thought about getting the last little bit out of them. It remains to be seen if that will be something to care about.

I do have a couple of the small plastic electrolysers too. If I used them, I had planned to use a small mylar balloon as the intermediate, room pressure reservoir for D2. I might try that too, eventually.

I also recently bought a small digital scale, but mine was from ebay china seller. Unfortunately, the one I bought only goes to .1 g resolution. I guess not good enough to trust any difference due to gas in the cartridge. I weighed the 5 cartridges I have here and the total weight seemed to be about 105 to 107 g.

Nice pictures you took. There seems to be three lines of info etched on the bottom of the cartridge. I assume they are: serial number, mfg date, use-by date. I looked at the 5 I have here and they all seem to have exactly the same dates as yours; no difference between the Bruntons and the Horizon one. So, if I am interpreting right, they must have all been made in a big batch on Dec 20, 2013 and are rated for 10 years of use. Out of curiousity, I compared that first number (S/N ?) on the 4 Bruntons that came in the same box; they were far from sequential. Not important, I just found it interesting.

You got a nice clear picture of the port that the cartridge screws into. It looks very much like the output port in my Hydrofill recharger, except on yours the pin that opens the valve on the cartridge is easy to see. As I mentioned earlier, the Hydrofill doesn't have a pin.

Here's the output port in the Hydrofill...
Hydrofill output port
Hydrofill output port
The white gasket looks the same. I pried the gasket out and made a sketch of it and the port dimensions, as best I could.
Hydrofill gasket and port
Hydrofill gasket and port
I've never seen a gasket like that, not a simple shape. I assume it is a custom design. The material is white and pretty soft "rubber". I'm not well versed on plastics but it seemed a lot softer than something like Viton, more like vinyl.

Oh, BTW, that picture you got from Horizon of the cut-away view of the cartridge was nice to see. Too bad it didn't include any of the internal valve. Looks like it could have been there originally, but that area was erased before sharing.
Rex Allers
David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 12:43 pm
Real name: David Kunkle

Re: Solid state hydrogen storage experiments

Post by David Kunkle »

Rex Allers wrote: I've thought, if nothing else, maybe the cartridges could be a way for someone who gets a D2 tank to share by filling some of these cartridges and thereby sharing and dividing the cost of purchase. This assumes many who get a tank of D2 will have more than they really need and might be willing to share some for a price, if we can come up with a workable design and procedure.
I still have most of a 100L tank of D2. In the past, I've been willing to share some, but found it illegal to ship a cylinder of compressed gas, and prohibitive to set up to do it legally. I got your same thought reading this thread. It appears to be legal to ship these cartridges. Amazing you can get 10L in there, but of course when you go from gas to solid....

On ebay I found refill fittings for about $25 that do the same thing you constructed for yourself. Allows a refill of a Hydrostik from a compressed hydrogen source. 1/8" tube lets you hook up to a compression fitting. Not bad if you don't have a lathe.
Rex Allers wrote:In the long run of trying to convert from H to D, I'm a bit concerned how hard it will be to purge the H and keep the D pure.
As far as purging, my first thought was to make a "Y" set up and valves. One end connects to the Hydrostik, one to the compressed D2 bottle, and the third to the vacuum chamber or pump. Open the Hydrostik to vacuum to evacuate it, close off vacuum source, open regulator and fill Hydrostik.
If your experiment needs statistics, you ought to have done a better experiment.

Ernest Rutherford
Rex Allers
Posts: 570
Joined: Sun Dec 30, 2012 3:39 am
Real name:
Location: San Jose CA

Re: Solid state hydrogen storage experiments

Post by Rex Allers »

David,

Using vacuum to clear H from the cartridges prior to D fill is the same thing I was thinking. Perhaps a little heat on the cartridge while under vacuum too, to help it along.
Rex Allers
User avatar
Rich Feldman
Posts: 1470
Joined: Mon Dec 21, 2009 6:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

Re: Solid state hydrogen storage experiments

Post by Rich Feldman »

We might have to plow some new ground if we want reasonably pure D2 in cartridges that used to hold H2. Will it take multiple cycles of evacuation, heat, and flushing with deuterium?
How can one measure protium concentration in deuterium, without a mass spectrometer? Qualitative optical spectroscopy? Assay by fusor would certainly get to the point. :-)

Here is a report from some big boys at the Savannah River Site. http://sti.srs.gov/fulltext/ms2001247/ms2001247.html They investigated design aspects of a compact (50 lb) vessel to store up to 1600 liters of tritium adsorbed in metal powder. Working temperature runs into the red-hot range. It helps if the hydride medium is also good at co-adsorbing the decay product, helium-3.

Near the bottom, they discuss disposal of these containers at the end of their life. Need to reduce the residual activity to less than 1000 curies, "a 0.00038 T/M inventory. Desorption levels are not near this level and isotopic exchange will be needed to meet waste acceptance criteria for disposal."
3h.PNG
All models are wrong; some models are useful. -- George Box
David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 12:43 pm
Real name: David Kunkle

Re: Solid state hydrogen storage experiments

Post by David Kunkle »

I'd assume Hydrostiks can withstand a vacuum and not implode. Would be very easy to heat such a small cartridge, but to what temperature can they withstand?

If I read it right, these cartridges hold the equivalent of 300 psi? If allowed to come to atmospheric pressure of about 15 psi, wouldn't that still leave them with about 5% of the maximum amount of H2 they can hold? A fair bit stuck in there to mix with your D2. Just my gut feeling/guesstimate, but I think if held under vacuum with heat for some amount of time, 95%+ of the remaining H2 would be expelled. That would make a D2 refill 99.75% pure.

Short of having a mass spec, someone would have to be the guinea pig and measure neutron output of Hydrostik vs. their known supply of D2. I'm betting you'd have a hard time demonstrating the difference.


Anybody want to take a shot at converting 1000 curies of tritium to liters, then vs. 1600 liters total storage?
"Desorption levels are not near this level" Does this mean at atmospheric pressure inside the vessel?
If your experiment needs statistics, you ought to have done a better experiment.

Ernest Rutherford
Peter Schmelcher
Posts: 228
Joined: Sat Nov 13, 2010 1:56 am
Real name: Peter Schmelcher

Re: Solid state hydrogen storage experiments

Post by Peter Schmelcher »

I think the cartridges should be used and refilled thread end up.

Years ago a fellow at Ballard (a poster child company for the hydrogen economy) told me about the storage of hydrogen in metals, allegedly better than liquid H in the same container volume. The container is filled about 80% with metal chips and then with repeated cycling the metal expands to fill 100% of the volume. My thinking is that the expansion process might create some metal dust that would be bad for any valve seats.

For drying the deuterium the best solution I have found is:
http://www.ebay.com/p/supelco-20619-mol ... 7675.l2644
The result should be about 200ppb residual water.

Just my 2 cents
-Peter
Rex Allers
Posts: 570
Joined: Sun Dec 30, 2012 3:39 am
Real name:
Location: San Jose CA

Re: Solid state hydrogen storage experiments

Post by Rex Allers »

Peter,

The Hydrofill unit has the Stik cartridge horizontal during charge. I don't recall seeing anything in the datasheets about preferred orientation. I do get what you are saying about powdering, though. The paper that Rich just posted a link to, mentions this issue of powder as the metal hydride goes through cycles of use and they have a filter to block the powder. So, I would guess the Stiks may have a filter inside between the storage media and the valve.

The ebay link to the seives for water removal looks good but it is pretty big. The listing says it has a volume of 200 cc. I've been trying to think in terms of minimizing volume in the plumbing to avoid wasting gas.
Rex Allers
User avatar
Rich Feldman
Posts: 1470
Joined: Mon Dec 21, 2009 6:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

Re: Solid state hydrogen storage experiments

Post by Rich Feldman »

>> Anybody want to take a shot at converting 1000 curies of tritium to liters, then vs. 1600 liters total storage?

OK, David, I'll bite. 1000 curies in the form of radium-226 would be about, uh, 1000 grams. Specific activity of tritium is greater by factors of 75 (atomic mass ratio) and 130 (half-life ratio). Combined factor is v. close to 1e4, so we are talking about 0.10 grams of tritium. That's 0.4 liters, or 0.025% of the TSV's nominal capacity. Activity inside a full tank would be 4 MCi. All according to this unreviewed analysis. I think that paper says they couldn't empty the container to the 1 kCi level with just vacuum and heat. Would need to displace the last of the T with some D or H.

That residue requirement is clearly stricter, by a couple orders of magnitude, than fusioneers would need for making Deuterostiks or Deuterocores.
Anybody want to read the paper more carefully & find their actual desorption methods and numbers?

Here a different maker's hyped presentation of a little cartridge for 10 normal liters of H2, that has a different plumbing connection: http://www.pragma-industries.com/produc ... ride-tank/ Their page for a broader product line has this chart:
PCI_curve.jpg
PCI_curve.jpg (30.98 KiB) Viewed 8065 times
Text explains the typical "plateau" curve in terms of a shift between two solid-state phases. Maybe they mean plateaus when viewed sideways. The charge/discharge hysteresis amounts to a pretty substantial pressure ratio. The storage medium in Horizon products might be different, but I bet its PCI curves are qualitatively similar to the ones in this chart.

Literature for this tritium-storage unit, made for bio labs, touts the benefits of its hydride medium: depleted uranium metal. :-) http://lablogic.com/life-sciences/instr ... tri-sorber
All models are wrong; some models are useful. -- George Box
User avatar
Rich Feldman
Posts: 1470
Joined: Mon Dec 21, 2009 6:59 pm
Real name: Rich Feldman
Location: Santa Clara County, CA, USA

Re: Solid state hydrogen storage experiments

Post by Rich Feldman »

On a rainy Saturday, I took one Brunton hydrogen core and reactor on a visit to John McMaster's shed, to be x-rayed. John is registered at this forum and has posted a thing or two.
Letting the pictures speak, here are primitive fluoroscope images of the storage cell and the fuel cell USB charger unit.
fluoroscope.jpg
fluoroscope.jpg (7.22 KiB) Viewed 8029 times
fluroscope.jpg
Next we took close-up images using a USB-connected dental sensor. First the "stik" valve area:
capture_010.png
The valve head seems to be screwed into the cylinder body, I think with an O-ring seal and some radio-opaque stuff on the threads. Same image after "enhancement" makes it easier to see that stiks have balls.
capture_010e.png
Our oblique view, actually taken first, seems to show more space between ball and the externally visible pusher.
capture_002e.png
Who among us will be first to sacrifice a 'stik for destructive inspection?
Reactor images to follow.
All models are wrong; some models are useful. -- George Box
David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 12:43 pm
Real name: David Kunkle

Re: Solid state hydrogen storage experiments

Post by David Kunkle »

Rich,

I think I finally gleaned the relevant info from the paper: http://sti.srs.gov/fulltext/ms2001247/ms2001247.html
I don't think the results are so good for us. Figure 7 is the most relevant. Q/M is the ratio of atoms of H,D, or T to atoms of Ti. 2.0 is maxed out. Comparing absorption and desorption Q/M ratios tells the story. They start at 0 Q/M, and reach about 1.9 after absorption. After 2 days of vacuum and 700C, they reach about .2 Q/M after desorption. That leaves about 10% of the original H still stuck in the Ti.

"Here a different maker's hyped presentation of a little cartridge for 10 normal liters of H2, that has a different plumbing connection: http://www.pragma-industries.com/produc ... ride-tank/"
This 10L cartridge seems closer to what we'd be using. Their chart that you posted seems to show the room temp desorption line getting down to .1% by weight which would be acceptable. Do you read the same thing off that? I realize there are probably large differences between the two, but why would the T storage unit, after 700C even, show such a large remnant compared to the 10L cartridge?

I'm not sure either gives us any decent info to go off of for what we'd be using and doing.
My last thought is that it would be great if we could get cartridges from the factory line that were never filled.
If your experiment needs statistics, you ought to have done a better experiment.

Ernest Rutherford
Rex Allers
Posts: 570
Joined: Sun Dec 30, 2012 3:39 am
Real name:
Location: San Jose CA

Re: Solid state hydrogen storage experiments

Post by Rex Allers »

David,

If you look back through this thread, the Brunton Hydrocores come filled but the Horizon Hydrostiks come empty. Maybe we will have to only use clean Hydrostiks for D.
Rex Allers
David Kunkle
Posts: 284
Joined: Thu Apr 17, 2014 12:43 pm
Real name: David Kunkle

Re: Solid state hydrogen storage experiments

Post by David Kunkle »

I've read the whole thread, but that part didn't stick at the time I guess. Just starting with a new Hydrostik would be the easy winner then.

Why were we talking about vacuum and heat, and charts and graphs to get the old H out of there again? :)
If your experiment needs statistics, you ought to have done a better experiment.

Ernest Rutherford
Post Reply

Return to “Vacuum Technology (& FAQs)”