Author Topic: Aspirator problem (Read 163 times)

Oerlikon · « **on:** July 31, 2010, 12:02:34 AM »

I don't know if this happens to everyone or my aspirator is defective but when I
pull strong vacuum I can't turn off water without flooding the whole apparatus.
This drives me nuts, It can't be controlled even while turning the water off very slowly.

Anyone has idea or even pictures of reliable rig!?

I had and idea to improvise "water trap" with glass jar attached on the middle but this
is to big and unreliable.

Feel free to delet this thread if you find it retarded and useless,but at least give me some link!

Vesp · « **Reply #1 on:** July 31, 2010, 01:10:20 AM »

Clamp off the hose to the aspirator, make sure it is an air-tight seal, and than turn off the aspirator. That should solve your problem.
You could even go as far as putting a valve onto the vacuum hose - I don't think that would be very difficult at all.

Oerlikon · « **Reply #2 on:** July 31, 2010, 12:22:39 PM »

Valve was my first idea, but unfortunately it is next to impossible here to find valve that can fit
hose at the both ends. How do you mean "clamp off the hose, make sure it is air tight"!?
You mean to plug it off while still under vacuum!? That is next to impossible since hose is
tightly screwed on it.

Vesp · « **Reply #3 on:** July 31, 2010, 05:06:53 PM »

well, if a valve isn't an option I suppose leave the aspirator running until the reaction is finished, and than pull the hose off of the reaction, than shut it off.

I was thinking you might be able to improvise a valve by bending or clamping the hose. Perhaps a Hoffman Clamp could work here? Seems like the tubing might be to rigid to deal with, since it does after all hold under a vacuum without collapse, I assume.

Oerlikon · « **Reply #4 on:** August 01, 2010, 12:27:18 AM »

Yes,first tubing was too soft and collapsed under vacuum, darn thing looked like road kill!
This one is extremely rigid.
Now I use it just for condenser water and only 2-3cm at the end of the rigid tube to fit
fragile glass.I can always puncture this 2-3cm of soft tube but this serves me only if everything else fails!
I can improvise something but I am only asking if someone had simple and original idea to fix this problem.

Regarding glass capillary and Hoffman Clamp...this part of apparatus is being constantly sucked in during vacuum.

I also tried to make pump to recycle the water and have eco and self containing system,
unfortunately good water pumps are extremely expensive and hard to find here.

lugh · « **Reply #5 on:** August 01, 2010, 01:09:20 AM »

Plumbing valves will work if that's all that's available, you have to get nipple adapters to attach to your vacuum tubing

You have to improvise solutions when the supplies are limited, but plumbing supplies are available everywhere

jon · « **Reply #6 on:** August 01, 2010, 01:10:19 AM »

put a pcv valve in line with the aspirator tubing

Satan · « **Reply #7 on:** August 01, 2010, 09:05:41 AM »

How about this idea:
If you want to stop your pump, close valve 1 then open valve 2, and stop water flow.

Oerlikon · « **Reply #8 on:** August 01, 2010, 12:29:09 PM »

Thanks Satan(lol,now this sound strange!

)
Had exactly the same idea but with 2 separate pieces!

jon · « **Reply #9 on:** August 01, 2010, 05:12:00 PM »

hail satan, oh prince of darkness!!
this good idea nobody said lucifer was a dummy.
but there are preessure fluctuations that cause water to backflow
barring a pcv or some type of check valve this has also been done sucessfully; run the tubing down and then back up to the vacum nipple run it 3 or more feet below and then back up.
what happens is if any water blows back, it runs downhill and gets trapped sort of like a j bend in a sink then it has to run uphill to get into your system, under a vacum this is'nt goint to happen.

Oerlikon · « **Reply #10 on:** August 01, 2010, 09:08:04 PM »

I don't understand it completely but j bend sounds like a good idea.
Please draw it if you feel like...

It is true that even under full vacuum pressure fluctuates and floods receiving flask.
Anyone uses vacuum capillary and hoffman clamp!?
I have them but you can barely control bubble flow and glass pipe is constantly being sucked in.

mumbles · « **Reply #11 on:** August 07, 2010, 07:35:59 AM »

I think jon might mean a U bend, you don't really need a pic just imagine a few feet of extra tube sagging towards the ground. Its a good idea.

Oerlikon · « **Reply #12 on:** August 07, 2010, 09:07:08 PM »

U bend doesn't work,but...
upside down 2m U bend does,along with one way gasoline valve!

Works great,thanks for inspiration!
Safrole comes over at range of 116-122°C with high to moderate water flow.

Author Topic: Aspirator problem (Read 163 times)

Oerlikon

Aspirator problem

Vesp

Re: Aspirator problem

Oerlikon

Re: Aspirator problem

Vesp

Re: Aspirator problem

Oerlikon

Re: Aspirator problem

lugh

Re: Aspirator problem

jon

Re: Aspirator problem

Satan

Re: Aspirator problem

Oerlikon

Re: Aspirator problem

jon

Re: Aspirator problem

Oerlikon

Re: Aspirator problem

mumbles

Re: Aspirator problem

Oerlikon

Re: Aspirator problem