HCl Gas Diffuser

[Buster_Hymen]

These things work great:



Don't know what they're called (maybe someone out there will recognize and chime in), but I believe they are some kind of muffler used on small pneumatic switches found on industrial/manufacturing equipment.

Anyway, my buddy saw them at work, examined them, had one of those light-bulb-over-the-head moments, and took a couple home to try out. The opening on the end is threaded, and screws perfectly into the end of the tube on his 1L Nalgene gassing bottle.

Not sure what they're made of, brass or copper, but after 3 uses, the one on the right has held up pretty well. Some discoloration, but no corrosion.

Instead of having a single stream of big fat bubbles coming off the end of his tube when he squeezes the bottle, this thing breaks the stream up into like 15 or 20 smaller streams of teeny tiny little bubbles, causing a veritable blizzard of instantaneous satisfaction in his freebase whatever...

Gassing is over with very quickly. Less likely to overgas, or add product-robbing water into the mix.

Anyway, thought I'd share his discovery. If anybody knows what they are called, and where you can buy them, please tell.

[Jade]

Although, I can't tell you anything about what you have there, I can associate with the way you are describing the results.  Swim has used those air stones that go in a fish tank before and it gasses out in a fine spray like matter.  It's beautiful!  These stones, unlike what you have, will not hold up to the acid for long though.

[methyl_ethyl]

I believe they are some kind of muffler used on small pneumatic switches found on industrial/manufacturing equipment.

     Tonight is the first time I have ever seen such a thing.  But that does not really matter.  I think you are exactly right, this is some sort of diffusor, or muffler, primarily comprised of sintered bronze, or other metal.  A google search will quickly find what you are looking for if you enter sintered bronze muffler pneumatic etc...  I would post a link but you know how it goes.  Although I do not think the pneumatic muffling industry is under heavy attack from the clandestine chemist, do what I say and you will find what you are looking for.  Personally I think that any pourous, metallic, muffler used in the pneumatics industry would be of good use if thrown on the end of your gassing tube.  They seem to bee very cheap.....  Aw fuck it

http://www.valvestore.com/sinbronexmuf.html

.  Mods, if you really think this link will be the demise of your good source of pneumatic mufflers, go ahead and lock the fucking thread...
     This is just something I found whilst searching, it is up to you to determine the reactivity of the components of the muffler, with the solution it is sitting in, while your gas is bubbling.   I aint no kemist.....

[fierceness]

wont the HCl corrode the metal, thereby letting some of the corroded metal to get into whatever you're gassing?

[Buster_Hymen]

There you go! I knew somebody would either know or find them...



Anyway, they work great for our purposes.

He figured bronze would be highly suceptible to corrosion from the HCl, but that does not seem to be the case. Snow was white as can be, and post-snowed-tolly was same color as when he started. At least so far, it seems that as long they are rinsed thoroughly after use, they hold up well. In future I will post back to this thread if that changes for him.

Only problem is they work SO good they start to become clogged with snow after awhile, and it gets to the point where you have to squeeze that bottle real hard to get any output!

[abolt]

Although, I too, wonder about corrosion and impurities getting into the end product.

I was lucky enough to stumble across these beauties. If you have the means I highly recommend getting your hands on them. They are correctly known as "Dreschel Bottles", though I don't know what there true purpose actually is. (Maybe one of the big bees can tell us?).

The one on the left is hooked up to the gas generator and is filled with drying agent. The one on the right has a sintered head, offering excellent dispersal for the gassing of product. The bottle shape also helps to get more gas into contact with our goodies, so gassing is done in less time. The whole thing is connected up with a suitable "Tygon" HCl resistant hose and the extra outlet on the dispersaal bottle can be directed into a beaker of saturated Bicarb, or just vented outside for safety. The tops come off for easy cleaning and extraction/refill. I can't recommend this gassing glass highly enough.

[Rhodium]

Only problem is they work SO good they start to become clogged with snow after awhile, and it gets to the point where you have to squeeze that bottle real hard to get any output!

Remedy: Use more solvent to dissolve your freebase in.

[halfkast]

>>He figured bronze would be highly suceptible to corrosion from the HCl, but that does not seem to be the case.

I hope it's a good Aluminium alloy, can you find out B_H?
It's quite a handsome little ghetto bubbler too.



Technical article referring to chemical resistance of different Cu alloys in industry. (

http://www.key-to-metals.com/ViewArticle.asp?ID=16

)

Abstract about Aluminium-Cu bronze alloy:

Aluminum bronzes (C 60600 - C 64400; C 95200 - C 95810) containing 5 to 12% Al have excellent resistance to impingement corrosion and high- temperature oxidation. Aluminum bronzes are used for beater bars and for blades in wood pulp machines because of their ability to withstand mechanical abrasion and chemical attack by sulfite solutions.

In the most of practical commercial applications, the corrosion characteristics of aluminum bronzes are primarily related to aluminum content. Alloys with up to 8% Al normally have completely face-centered cubic structures and a good resistance to corrosion attack. As aluminum con tent increases above 8%, a-b duplex structures appear.

Depending on specific environmental conditions, b phase or eutectoid structure in aluminum bronze can be selectively attacked by a mechanism similar to the dezincification of brasses. Proper quench-and-temper treatment of duplex alloys, such as C62400 and C95400, produces a tempered (b structure with reprecipitated acicular a crystals, a combination that is often superior in corrosion resistance to the normal annealed structures.

Nickel-aluminum bronzes are more complex in structure with the introduction of the K phase. Nickel appears to alter the corrosion characteristics of the b phase to provide greater resistance to dealloying and cavitation-erosion in most liquids.

Aluminum bronzes are generally suitable for service in nonoxidizing mineral acids, such as phosphoric (H3PO4), sulfuric (H2SO4), and HCl; organic acids, such as lactic, acetic (CF3COOH), or oxalic; neutral saline solutions, such as sodium chloride (NaCI) or potassium chloride (KCl); alkalies, such as sodium hydroxide (NaOH), potassium hydroxide (KOH), and anhydrous ammonium hydroxide (NH4OH); and various natural waters including sea, brackish, and potable waters. Environments to be avoided include nitric acid (HNO3); some metallic salts, such as ferric chloride (FeCl3) and chromic acid (H2CrO4); moist chlorinated hydrocarbons; and moist HN3. Aeration can result in accelerated corrosion in many media that appear to be compatible.
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So, what do these pneumatic switches do exactly?