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#1
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making laminated glass tubes
Hi!
I have glass tubes filled with liquid CO2 at high pressure and need to make it safe in case the tube explodes. Currently I put it in a protective polycarbonate tube, but I'm worried the PC might not last long enough. Some of the tubes might be in use for 100+ years. They are meant to be viewed by students/pupils in schools and universities. There will probably be little UV exposure, but some tubes may be on display permanently, though still inside. So ... what would be the best material to fill the gap between 2 concentric glass tubes? Polyester, Epoxide, PU, Polycarbonate, Polyvinylbutyral, ...? It should be managable with low tech equipment. How opaque is (borosilicate) glass to UV? Thanks, Bernhard |
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#2
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making laminated glass tubes
Bernhard Kuemel wrote:
So ... what would be the best material to fill the gap between 2 concentric glass tubes? Polyester, Epoxide, PU, Polycarbonate, Polyvinylbutyral, ...? It should be managable with low tech equipment. Actually I first thought of filling the gap with a viscous liquid like glycerol or silicone oil. A test explosion of a 1 cm OD pressure tube shattered a 60mm OD borosilicate glass tube with 7mm wall to rather large pieces. I think, if the outer tube were not struck by the glass fragments of the pressure tube, the protective glass tube will withstand the shock wave. The pressure in the pressure tube (10mm OD, 5.5mm ID) may exceed 200bar. It was up to 240 bar without breaking. With a laminated glass tube, is there a possibility that the glass will crack from thermal expansion of the resin layer? The resin also should not separate from the glass as this would create additional optical surfaces which decrease optical transparency. Bernhard |
#3
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making laminated glass tubes
Bernhard Kuemel writes:
I have glass tubes filled with liquid CO2 at high pressure and need to make it safe in case the tube explodes. Really, in glass? What is the application? "Double bagging" seems a fool's errand. Things just cascade until the energy is absorbed. You must disperse the energy, such as through a stainless mesh. |
#4
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making laminated glass tubes
"Richard J Kinch" wrote in message
. .. Bernhard Kuemel writes: I have glass tubes filled with liquid CO2 at high pressure and need to make it safe in case the tube explodes. Really, in glass? What is the application? "Double bagging" seems a fool's errand. Things just cascade until the energy is absorbed. You must disperse the energy, such as through a stainless mesh. I'm a pretty adventurous soul, but I wouldn't keep those tubes anywhere near me.... |
#5
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making laminated glass tubes
In article ,
"SoundChaser" wrote: "Richard J Kinch" wrote in message . .. Bernhard Kuemel writes: I have glass tubes filled with liquid CO2 at high pressure and need to make it safe in case the tube explodes. Really, in glass? What is the application? "Double bagging" seems a fool's errand. Things just cascade until the energy is absorbed. You must disperse the energy, such as through a stainless mesh. I'm a pretty adventurous soul, but I wouldn't keep those tubes anywhere near me.... In the British Science Museum located in London, there is an exhibit using liquid carbon dioxide in a glass tube. It is used to demonstrate what happens when the triple point temperature is exceeded. As the tube is heated, the interface between liquid and gas becomes invisible. AFAIK that may have been around for over a hundred years. Why not find out what they do and how they protect the public? Bill -- Private Profit; Public Poop! Avoid collateral windfall! |
#6
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making laminated glass tubes
On Mar 18, 1:42*am, Bernhard Kuemel wrote:
Hi! I have glass tubes filled with liquid CO2 at high pressure and need to make it safe in case the tube explodes. 1. Substitute another liquid and tell the customers it's CO2. It can even be a fluorocarbon that will demonstrate the triple point, but at a lower pressure. 2. Use concentric PC tubes and test, test, test. (But visibility will be reduced.) 3. Embed in solid transparent polymer and provide a pressure relief at one end. 4. Use pressure rated steam boiler sight tubes and pass on the liability to the manufacturer. 5. Buy lots of liability insurance. DB |
#7
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making laminated glass tubes
Richard J Kinch wrote:
Bernhard Kuemel writes: I have glass tubes filled with liquid CO2 at high pressure and need to make it safe in case the tube explodes. Really, in glass? What is the application? To demonstrate the critical point. There's an image of one on http://de.wikipedia.org/wiki/Kritisc...(Thermodynamik) . "Double bagging" seems a fool's errand. Things just cascade until the energy is absorbed. The technology is applied in e.g. car windows. You must disperse the energy, I believe, a glass tube can take the pressure of the CO2 shock wave. Only the splinters that hit the tube make it break, and the pressure then drives the splinters away. But liquid or resin layer between 2 concentric glass tubes will prevent splinters hitting the outer glass tube and disperse the impact pressure evenly. Maybe it doesn't actually matter much, what middle layer I use. But if the device breaks from external force a simple (viscous) liquid filler would not hold the pieces together and then it might be dangerous if the pressure tube exploded. such as through a stainless mesh. The protective tube shall be completely clear to allow good vision of the critical point events. Bernhard |
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making laminated glass tubes
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#9
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making laminated glass tubes
Bernhard Kuemel wrote:
Thought of that. C2F6 has a slightly to low Tc. CFCl3 is unavailable s/to/too. s/CFCl3/CClF3 |
#10
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making laminated glass tubes
On Mar 24, 11:32*am, Bernhard Kuemel wrote:
I want to earn money, not pay. And the insurance probably would try not to pay if they could blame me. Also I want to avoid accidents. Sounds like you need to do some experiments. The pressure above liquid CO2 at room temp is about 850 psi, so if you had a tank of air or nitrogen at 2000 psi, you can pressurize the tubes until they explode, or don't. If they can take 2000 psi, good, but then you'll have to test for shock resistance, if only to cause the glass to fracture. This will test the ability of the PC shell to hold in the explosion. Finally, you have to get some information from the PC maker on long term performance of their products. Atlas Material Testing Co, of Chicago, IL, may be able to point you in the right direction. That's what they do for a living. Dangerous Bill |
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