SaintCyril (Hive Bee)
07-26-02 06:10
No 337221
      Quartz glass flasks  Bookmark   

I have noticed alot of posts about hydrogenation, both with H gas, and with the microwave CHT method.  I have noticed one of the main dangers or concearns with the use of this method is the explosion of the reaction flask, and accordingly the hydrogen within.  My solution top this, and I asume a professional labs solution is to use some thing that has little likely hood of exploding, is quartz glass flasks.  For the microwave method it appears there would be a better transference of microwaves anyhow here is something I found on quartz glass that may help out in your decision.  Also they make almost every piece of lab glassware from quartz, and it bearly costs more.


Cy

PROPERTY: 
Density                         2.2 gm/cm3      
Hardness                        5.56.5 Mohs Scale    
Design Tensile Strength         7,000 psi     
Design Compressive Strength     160,000 psi          
Bulk Modulus                    5.3 x 106 psi
Rigidity Modulus                4.5 x 106 psi 
Youngs Modulus                 10.5 x 106 psi
Poissons Ratio                .17       
Coefficient of Thermal Expansion  5.5 x 10-7 cm/cm C(20C 320C)   
Thermal Conductivity (20 C)      3.3 x 10-3 gm cal
Specific Heat (20)               .16gm cal/gm      
Softening Point                   1683C      
Annealing Point                   1215C     
Strain Point                      1120C     
Electrical Resistivity            7(107) ohm cm 350C
Dielectric Properties             (20C and 1 MHz)           Constant                          3.75      3.75
               Strength       5 x 107 volts/mil      
               Loss Factor   Less than 4 x 10-4      
               Dissipation Factor      Less than 1 x 10-4      
Index of Refraction      1.4585      1.4585
Velocity of Sound-Shear Wave      3.75 x 105 cm/sec     
Velocity of Sound-Compression Wave      5.90 x 105 cm/sec    
Sonic Attenuation      Less than 11 db/m MHz     
Permeability Constants      (cm mm/cm sec cm of Hg 700C/973K
       Helium      210 x 10-10
       Hydrogen      21 x 10-10
       Deutrium      17 x 10-10 

     


We are the people that your parents warned you about.
 
 
 
 
    terbium
(Old P2P Cook)
07-26-02 06:23
No 337227
      References please.  Bookmark   

My solution top this ... is to use some thing that has little likely hood of exploding, is quartz glass flasks.
I don't follow your reasoning.

Also they make almost every piece of lab glassware from quartz, and it bearly costs more.
That is news to me.
 
 
 
 
    SaintCyril
(Hive Bee)
07-26-02 07:49
No 337267
      Okay let me rephrase that  Bookmark   

The likely hood of explosion would not be reduced, however, if it were to occur it would be contained, also I have seen alot of expression of concearn for explosion of a flask under pressure, this definately cirumvents that problem.  As far as the cost although it is about twice as much, I guess in my opinion an extra $100-200 per flask is not much more, other bees may have differing opinions on that.  As usual I was just \telling you what works for me, take what you want and leave the rest.

Anyhow,
Cy

We are the people that your parents warned you about.
 
 
 
 
    terbium
(Old P2P Cook)
07-26-02 08:27
No 337282
      Still nonsense.  Bookmark   

if it were to occur it would be contained, also I have seen alot of expression of concearn for explosion of a flask under pressure, this definately cirumvents that problem.
That is what I thought. So, you somehow think that a quartz flask is going to be orders of magnitude stronger than a glass flask. I don't think so. Why do you think this?

As far as the cost although it is about twice as much,
Just twice, eh? Again, where do you get this number?
 
 
 
 
    SaintCyril
(Hive Bee)
07-26-02 09:12
No 337296
      quartz prices  Bookmark   

A quick orice comparison:

Borsilica Round bottom flask:
500ml   $73
1l      $106
2l      $209

Quartz RBF:
500ml   $169
1l      $246
2l      $426

Don't know what you are talkng about.

Cy


We are the people that your parents warned you about.
 
 
 
 
    Barium
(Hive Bee)
07-26-02 09:50
No 337318
      Hmm  Bookmark   

So you think/assume that a quartz reaction flask of the the same size and wall thickness as a regular borosillicate reaction flask will hold an eventual hydrogen/oxygen detonation.
I dont think so....Instead of trying to figure out what material can withstand a explosion, focus that energy towards issues such as not allowing oxygen coming into the reaction system.
 
 
 
 
    hypo
(Official Hive Approximator)
07-26-02 09:54
No 337321
      uh!!  Bookmark   


> Borsilica Round bottom flask:
> 500ml   $73

these are _not_ US$, are they!?
for that price you should get a whole distillation apparatus
with column from your local friendly glasblower!

official gene trash
 
 
 
 
    SaintCyril
(Hive Bee)
07-26-02 10:53
No 337333
      should have specified  Bookmark   

Heavy walled borsilica

We are the people that your parents warned you about.
 
 
 
 
    Osmium
(Stoni's sexual toy)
07-26-02 10:55
No 337335
      Hypo, that might very well be US-$.  Bookmark   

Hypo, that might very well be US-$. There seems to be a huge conspiracy among all the US glass blowers, they all charge at least 2-3 times the money over there compared to european prices.

If it wasn't for incompatible joint sizes I already would have set up an glassware export business.

I'm not fat just horizontally disproportionate.
 
 
 
 
    Barium
(Hive Bee)
07-26-02 12:13
No 337351
      Hmm again  Bookmark   

There is a huge diffrence between being able to withstand a pressure of 7000psig  being genersted by opening a gas tube slowly and being able to withstand a detonation..... 
 
 
 
 
    SaintCyril
(Hive Bee)
07-26-02 12:57
No 337357
      A huge differnce  Bookmark   

You think a quartz flask could stop this?



I understand the physics of it, but I still think i was at least a good idea wasn't it. . . .

Cy
Cy

We are the people that your parents warned you about.
 
 
 
 
    Osmium
(Stoni's sexual toy)
07-26-02 13:29
No 337365
      > Design Tensile Strength 7,000 psi > ...  Bookmark   

> Design Tensile Strength         7,000 psi
> Design Compressive Strength     160,000 psi   

This has NOTHING (well, almost nothing) to do with how much pressure your vessel can endure. These are merely values characterising the physical properties of quartz as a material for comparison to other materials. There is a BIG difference!    

I'm not fat just horizontally disproportionate.