Romix
Hazard to Others (Literally)
Posts: 483
Registered: 19-6-2015
Member Is Offline
Mood: No Mood
|
|
How to prevent pressure suck back
Hello Dear forum members,
I think I've seen it here on a forum, set up with pictures and videos on how to prevent pressure suck back during distillation and filtering the gases
through something...
Can you please direct me to that thread and explain how it works?
|
|
|
macckone
Dispenser of practical lab wisdom
Posts: 2168
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline
Mood: Electrical
|
|
there are two methods, the trap method and the funnel method.
With the trap method, you have an intermediate container that captures liquid during suckback.
With the funnel method, you have the funnel just below the surface of the liquid which will prevent suckback because it doesn't fill sufficiently
before air gets sucked back.
|
|
|
ManyInterests
National Hazard
Posts: 930
Registered: 19-5-2019
Member Is Offline
|
|
I had this problem with my first two nitric acid attempts. I might try that again, but I will use the absolute minimum of sodium hydroxide AND I will
move the funnel slightly out of the solution once I feel all the NO2 gasses are done.
|
|
|
draculic acid69
International Hazard
Posts: 1371
Registered: 2-8-2018
Member Is Offline
|
|
Quote: Originally posted by Romix  | Hello Dear forum members,
I think I've seen it here on a forum, set up with pictures and videos on how to prevent pressure suck back during distillation and filtering the gases
through something...
Can you please direct me to that thread and explain how it works? |
Buy a $3 plastic check valve off eBay and you will never have suckback happen again
|
|
|
Sulaiman
International Hazard
Posts: 3695
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
|
|
For an inverted funnel trap it is best if the funnel is of only slightly smaller diameter than the liquid container,
(eg 90mm diameter funnel in a 100mm diameter beaker)
this way, as the liquid is sucked up into the funnel the level of liquid in the container simultaneously drops significantly.
Clamp the funnel rather than letting it sit on the bottom of the container to allow the use of a large quantity of liquid,
enabling the use of a larger volume of liquid absorbent.
Test/play with water to get a feel for it.
With water you can use your mouth as a suction source.
CAUTION : Hobby Chemist, not Professional or even Amateur
|
|
|
Texium
|
Thread Moved
25-7-2022 at 12:52 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
