Sciencemadness Discussion Board

Low-flow reaction feeder

lysander - 16-1-2016 at 13:07

I need some means of feeding an aqueous solution into a reaction vessel at a very slow rate: like 500mL/hour.

What sort of mechanisms or devices might be suited to this?

The best I can come up with right now is to take a direct drip tube and repeatedly heat and compress its tip until I find a sufficiently low flow rate.

Magpie - 16-1-2016 at 13:23

Take a look at this peristaltic pump:
http://www.sciencemadness.org/talk/viewthread.php?tid=59870#...


http://youtu.be/jZZXV3DuTc4


The control circuit is the one shown at this website:
http://www.electronics-tutorials.ws/blog/pulse-width-modulat...

If you have any questions let me know.

[Edited on 16-1-2016 by Magpie]

[Edited on 16-1-2016 by Magpie]

lysander - 16-1-2016 at 14:08

That's very clever: Just use a screw clamp to control the output of a low-voltage peristaltic pump!

XeonTheMGPony - 17-1-2016 at 13:24

why not an addition funnel? pack the tip with cleaned fiber glass then fine tune the flow with the stop cock?

Bert - 17-1-2016 at 14:28

Quote: Originally posted by XeonTheMGPony  
why not an addition funnel? pack the tip with cleaned fiber glass then fine tune the flow with the stop cock?


From personal experience, a throttled down 500 ml addition funnel will vary rate quite a bit due to reduced head pressure as it empties-

There were made "constant addition funnels", the are heinously expensive and quite fragile. I would go with a pump/controller, if you have the option.