experimentalbois (Stranger)
01-20-03 17:23
No 400035
      Temperature Problems  Bookmark   

A certain somebody was telling me that when distilling sassy, the temp wouldn't go above 80C under vacuum, even with the hotplate on high. (Using a 500mL RBF immersed in peanut oil in an anodized iron flat bottom pot on the hotplate.) He thought it was the used hotplate, but conditions didn't improve even with a brand new hotplate. The hotplate was tested to heat water in the iron pot and the temp of the water reached 100C so...any ideas as to why the setup with the peanut oil isn't doing the trick?
 
 
 
 
    Wargasm
(Hive Bee)
01-20-03 17:45
No 400039
      there is no actual max temp  Bookmark   

that the safrole will come over.  The temp you get your safrole will be dependant on how strong your vac pump is.  A good rotary vane can distill safrole lower than 80C, but a diaphragm pump may not.
A common way bees use to determine how strong there vac is is to distill H2O under vac and see where it comes over.  There is a table on Rhodium's site that will tell you how strong your vac is.
What kind of vac setup are you using?
I think you may need to do a little more reading.  Look up temp/pressure characteristic curves.


Worker bees can leave
   Even drones can fly away
      The queen is their slave
 
 
 
 
    hCiLdOdUeDn
(Hive Bee)
01-20-03 17:50
No 400042
      again  Bookmark   

Read this again and again and again and your problems will bee solved!

../rhodium /safrole.distillation.html

Sink or SWIM
 
 
 
 
    experimentalbois
(Stranger)
01-20-03 18:31
No 400052
      the kind of vac setup that someone said ...  Bookmark   

the kind of vac setup that someone said they're using is a water aspirator....i'm gonna tell someone to go to rhodium's site at a secure location
 
 
 
 
    experimentalbois
(Stranger)
01-20-03 20:53
No 400080
      one other little addition to this inquiry:...  Bookmark   

one other little addition to this inquiry: why, when the water pressure drops on someone's system (due to someone else in the building showering), does the temperature fall drastically?  Shouldn't the temp rise due to a decrease in the vacuum?
 
 
 
 
    goiterjoe
(Title on BackOrder)
01-20-03 20:59
No 400081
      nothing is touching the thermometer  Bookmark   

When the vacuum drops in your flask, the distillate stops boiling and your thermometer cools down because nothing is coming over.  Your distillate doesn't just instantly rise in temperature because the pressure increased a minute amount.

If at first you don't succeed, try, try again. Then give up. There's no use being a fool about it.