Testing a peristaltic pump

[driga]

Hi all!

I have set up a simple flow line to test our peristaltic pump. It turns out to be that the flow rate is so small. I think it is even smaller than the one given by the manufacturer.

The pump was made by verder. Instead of using water, I am using glycerin-water mixture.

My flow line is: reservoir-tube(25.4mm inner dia.)-adapter-pump-adapter-tube(25.4 mm ID)-flow meter-reservoir

The adapter is self made by our workshop. The reason is that up to four heads can be installed on the pump.

Is it because I am choosing too big diameter for the tube? My adapter is also quite large.

It turns out that I can only use 3 out of 4 heads. If I use 4 heads then the motor's power won't be sufficient.

I have no idea why this is happening?

Any suggestions would be much appreciated.

Thanks!

 

[MikeHalloran]

If the peristaltic tube, the one within the pump head, is too thin, or the shoe against which it's squeezed is too distant from the rollers, the pump capacity is essentially zero.

Once you get that fixed, you might want to test the pump against a restriction representing the installed system head. If you make the restriction variable, you will find that the pump's capacity curve is not a straight vertical line on the Q-h diagram, and that it may not even be a straight slanted line.



Mike Halloran
Pembroke Pines, FL, USA

 

[driga]

Hi Mike!

How do I check the distance between the roller and the shoe? Have you ever used verder's pump? The shoe cannot be adjusted. For each head, I used 45-50 cm long tube. The tube inner diameter is 15.9 mm and the wall thickness is 3.2 mm, and that is in accordance with the manual.

Thanks

 

[MikeHalloran]

1. Maybe you can get a telescope gage in there.
2. No, I haven't used verder's pumps. I've bought a few of other brands, and had a hand in designing and/or fixing custom versions in half a dozen products. I know lots of ways to make a peristaltic pump that isn't quite as good as I think it should be.

It's beginning to smell like you're not using Verder's official tube. That may be your problem.



Mike Halloran
Pembroke Pines, FL, USA

 

[micalbrch]

Driga: Can you tell us the Verder pump model?

And can anybody tell me what "four heads" on a peristaltic pump mean?

 

[driga]

Hi Mike,

Do you think tube selection plays a big role here? What I use is Noprene A-60-F. I do have verderprene. I did call verder's representative but their response is quite slow.

What is telescope gage?

To mica,

Hmm.. four heads mean it has four channel. Four tube can be used simultaneously.

 

[micalbrch]

Verder's website tells me that the hose size of a Silicone hose is 16 x 3.2 mm while the Verderprene hose shall be 16 x 4.8 mm.

 

[CH5OH]

important is that the shoe seals off the hose
(check by trying to blow through it)

 

[driga]

What I had from the invoice is verderprene with an inner diameter of 15.9 mm and wall thickness of 3.2 mm.

The type of the pump is S30 L-series.

To CH50H: I will do your suggestion.

 

[driga]

I have checked by blowing air into the tube. The shoe perfectly seal the tube.

I changed our noprene tube with verderprene (same inner diameter and wall thickness).

I thought it is going to work but it is not. I have attached a short movie about the error.