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Emulsion
04-05-2008, 05:56 PM
Kirk,

Yes the rate is slow :-(

A couple of options might be to:

1) make a bracket to support multiple syringes (may overload the motor/mechanism)
2) Use a couple of syringe driver units at a time (easiest...cheapest)
3) use a much larger syringe (hard to get >60ml syringes though, there are some on e-bay, once again it may overload the device and a modified bracket would have to be made)
4) make a syringe driver from scratch ...here is a massive design, not for this use though :-)
http://www.maths.manchester.ac.uk/~ajuel/pipe1.JPG

Option 2 is the easiest though. By using two syringe drivers the the rate would be doubled.

Emulsion



Emulsion - that's interesting about the syringe drivers. After spending some time recently visiting my mother, I thought about those instead of a peristaltic pump. The first issue I see is that the fastest one of the pumps you list can deliver is 200 m/hr. That's milliliters per HOUR... Not very fast. That's 3.3 mls/min. But that should work - I used my peristaltic pump to deliver 2.8 ml/min on the last emulsion I made.

Kirk Keyes
04-06-2008, 12:50 AM
Nice pump there!

Also, have you notcied the difference in price between USA and UK for the syringe drivers? Models like you list in the UK for a quid or so are starting at $200 or more in the US!

I bought a lab grade peristaltic pump (one with 8 rollers) for under $100. But then I work in a chem lab and I knew what to look for in a pump so I got sone that is suitable and quite flexible for making emulsions.

Neanderman
04-06-2008, 11:20 AM
I bought a lab grade peristaltic pump (one with 8 rollers) for under $100.

Will you share the make and model number?

Ed

Photo Engineer
04-06-2008, 11:26 AM
Ed;

You might try looking at Masterflex pumps. This would give you a starting point with lots of information.

PE

Kirk Keyes
04-06-2008, 02:30 PM
Will you share the make and model number?

Ed

I bought an Isco "Wiz" - yeah, stupid name. But it's a really nice pump. There's on on eBay right now with a buy it now - it looks like it will be about $150 with shipping.

http://cgi.ebay.com/Isco-Wiz-Pump-Diluter-Dispenser-Laboratory-Digital_W0QQitemZ350043784159QQihZ022QQcategoryZ78 220QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I have no connection with this auction, but it looks like a functional unit. it has 2 of a possible 4 tubing holders (cassette assembly), and that would be enough to make a double run emulsion even.

You can get pump tubing from www.smallparts.com.

If anyone is looking for a pump and needs help picking one out, I'd be more than happy to give an opinion.

Photo Engineer
04-06-2008, 02:38 PM
Make sure that you use Tygon tubing of the right outside diameter to fit the roller set. There are 3 sizes of roller set gaps and guides made. Make sure you change the tubing after every 3 or 4 runs, and remember that it will not take high temperature or pressure well. A peristaltic pump can refuse to 'peristalt' :D if you run it with high pressure and temperature. The tubing turns to sausage.

Don't ask. The company said the tygon tubing could take up to 80 psi and 120F. This is WRONG.

Do not use PVC tubing or any hard tubing in the rollers. It can damage the pump or the tubing and leave a mess on the floor. That one I didn't do. I know that from years of experience at EK. The other was from the company and I believed them. Shame on them.

BTW, for high temperature and pressure, we used web reinforced tubing at EK. I should have guessed the company was wrong from that information alone, but I believed them.

PE

Kirk Keyes
04-06-2008, 03:23 PM
Ed;

You might try looking at Masterflex pumps. This would give you a starting point with lots of information.

PE

Ron - could you give the model of pump and heads you are using?

Photo Engineer
04-06-2008, 03:28 PM
Since my model came from another company, the model # is an oddball, but I'm using a #16 head. That may not be optimum.

PE

Neanderman
04-06-2008, 03:39 PM
Thanks Kirk & PE.

Ray Rogers
04-06-2008, 04:22 PM
I belive that if you check you will find that there is more than one kind of Tygon tubing...there are quite a few formulas for various tweaks.

Ray

Photo Engineer
04-06-2008, 04:36 PM
I belive that if you check you will find that there is more than one kind of Tygon tubing...there are quite a few formulas for various tweaks.

Ray


Ray;

There are pages of Tygon tubings. I used the one recommended by the company that said up to 80 PSI at up to 120F was acceptable. They also said that the tubing was optimum for their pump.

It didn't work. I'm looking at other options.

PE

Ray Rogers
04-06-2008, 08:29 PM
Ray;

There are pages of Tygon tubings. I used the one recommended by the company that said up to 80 PSI at up to 120F was acceptable. They also said that the tubing was optimum for their pump.

It didn't work. I'm looking at other options.

PE

That is unfortunate.

Might you have had better luck asking the manufacturer of TYGON directly?

You do have to watch your back however.
When I purchased mine, I asked for Tygon specfically, but was sent an immitation... I paid THAT company a visit and got things straightened out.

In the end, I examined a few formulas and came to the conclusion that POSSIBLY, a cheeper immitation MIGHT work, but I was not willing to do the proofing needed to Ok it.

I'm a Tygon Man.

Anyway, it is a shame that the pump mfg. gave you poor advice!
Perhaps they only check the flow rate... and take most other specs from a table.

Ray

Kirk Keyes
04-07-2008, 12:07 PM
I'm a Tygon Man.

Yes - at least when you have genuine Tygon brand tubing, you have the grace of Saint Gobain with you...

Kirk Keyes
04-07-2008, 12:18 PM
Since my model came from another company, the model # is an oddball, but I'm using a #16 head.

Would that be this one?
http://www.masterflex.com/catalog/product_view.asp?sku=0701620

Photo Engineer
04-07-2008, 12:25 PM
That is the 16 head. You can stack 3 heads of this general type with 3 different flow rates at the same time or three identical flow rates.

PE

Ray Rogers
04-07-2008, 08:28 PM
Yes - at least when you have genuine Tygon brand tubing, you have the grace of Saint Gobain with you...

Thats the one!
"Performance Plastics" for those in need of uh, flexible... tubing!:p

Kirk Keyes
04-07-2008, 11:45 PM
That is the 16 head. You can stack 3 heads of this general type with 3 different flow rates at the same time or three identical flow rates.

PE

Did you notice that the specs on that pump head say it has a max pressure of 25 PSI continuous?

Photo Engineer
04-08-2008, 08:39 AM
And the specs of that page said 40 - 80 PSI depending on flow rate and tubing.

I measured it at 60 PSI with a pressure guage and at 40 ml / min with a pump setting of 1.0. I repeated this over a period of 3 days. As I increased flow rate to 2, pressure went down as the rollers slipped.

Of course, during my shopping, the VWR pages changed 2x during that week and prices went way up also. The site was unavailable for a day or so, probably while they made all of these changes. However, I did get the pump from another source.

PE