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Ray Rogers
12-07-2008, 02:48 PM
Ray - when you say hiccups - what do you mean? Your syringe pump stops? Is it something you think is specific to your syringe pump?

I doubt it is specfic... I think they all suffer this problem to greater or lesser degree.

Someone somewhere might have invented a more pefect device but the "hiccup" comes IIRC, at the point where a "withdrawn" plunger becomes "depressed"... psychological puns intended.

Pretty hard to eliminate the last tell tale signs completly, I would imagine.
It is really only a very very tiny amount, but nevertheless, it is not perfectly continous.

Ray

Photo Engineer
12-07-2008, 02:53 PM
We never had any problems with syringe pumps at EK, but then with our budget, IDK how pricey they were compared to yours Ray.

PE

Ray Rogers
12-07-2008, 03:35 PM
We never had any problems with syringe pumps at EK, but then with our budget, IDK how pricey they were compared to yours Ray.

PE

I was sort of expecting you would say that! :p

Like I said, someone might have made a better system and if anyone had the means AND the will power, it would have been Kodak.

I stress however, my hiccup is very small and momentary....

Just to be sure we are ccompasring Mac to Fuji apples
and not apples and oranges,
is the device you describe
delivering unlimited continous flow using 2 syringes per reactant,
or a was it single syringe having a limited, maximum capacity?

Ray

Photo Engineer
12-07-2008, 03:45 PM
It could deliver continuous fixed or ramped flows, and had a source "jar" size that was based on scalability. It could be unlimited, but then would be unscalable and there were provisions in the software and hardware for an unlimited supply.

There were 2 syringes with separate computer controlled flows, Salt and Silver, and the salt could be varied to control vAg. They were called AgS and XS respectively in the software and hardware monitoring panels. Pumped delivery systems were the same in all regards but were Aga, Agb, Agc and Xa, Xb and Xc etc... denoting pumped delivery and the following letters referred either to source jars (several could be used of varying concentration) or could refer to ILD (In Line Dilution) systems which could take one silver and deliver a varying concentration to the kettle using an ILD system.

There, more than you ever wanted to know. I doubt if anyone could engineer that at home.

PE

Ray Rogers
12-07-2008, 03:59 PM
It is only when you tell me more than I want to know, that I really begin to learn!

Ray

Kirk Keyes
12-07-2008, 04:53 PM
So Ray, your syringe pump takes, as example, a disposable plastic syringe, and it depresses it to dispense until you stop it or it bottoms out, right?

The hiccups are due to the flexing of the plastic plunger head momentarily catching the walls of the syringe and then releasing abruptly? Glass with teflon plunger head syringes could be use and they should have less of this catch/slip action. Even glass syringes with glass plungers could be used. If you can find the size you wanted, but they may be more costly and hard to find.

Kirk Keyes
12-07-2008, 04:56 PM
...delivering unlimited continous flow using 2 syringes per reactant,
or a was it single syringe having a limited, maximum capacity?


A dual "syringe" arrangement with unlimited puming volume like I image you are talking about here seems to me to be more of pump - a dual piston pump. I don't really call them a "syringe" pump, but I suppose they could. If so, why use syringes for them, instead of fixed, permanent pistons?

Kirk Keyes
12-07-2008, 04:59 PM
When someone says "syringe pump", this is what I think of:
http://www.syringepump.com/

OK, I they have "continuous cycle" or "continuous flow" syringe pumps that use at least two syringes. As one is dispensing, the other is being with-drawn and filling so that it's ready to dispense when the first one is done. As I said, it's a dual pistion pump that uses syringes.

There's some benefits over peristaltic pumps, like not haveing to prime the peristaltic pump to get it running.

Ray Rogers
12-07-2008, 05:18 PM
[QUOTE=Kirk Keyes;718727]So Ray, your syringe pump takes, as example, a disposable plastic syringe, and it depresses it to dispense until you stop it or it bottoms out, right?

The hiccups are due to the flexing of the plastic plunger head momentarily catching the walls of the syringe and then releasing abruptly?
QUOTE]

no, its all glass.
hiccups are due to change in pressure when direction is reversed.

Kirk Keyes
12-07-2008, 05:21 PM
Ray, what volumes and rates can your syringe pump do?

Kirk Keyes
12-07-2008, 05:22 PM
no, its all glass.
hiccups are due to change in pressure when direction is reversed.

So it's a continous flow one then?

Ray Rogers
12-07-2008, 05:22 PM
A dual "syringe" arrangement with unlimited puming volume like I image you are talking about here seems to me to be more of pump - a dual piston pump. I don't really call them a "syringe" pump, but I suppose they could. If so, why use syringes for them, instead of fixed, permanent pistons?

The design uses syringes.
I guess there may be other reasons, but one good one is that replacement is reasonable.

They were engineered with what people had in front of them at that time, I guess.

Ray Rogers
12-07-2008, 05:25 PM
Ray, what volumes and rates can your syringe pump do?

I will have to check.

I am out of town to attend a conference for the next two days.

When I get back I will check.

Ray Rogers
12-07-2008, 05:28 PM
So it's a continous flow one then?

Yes.

Photo Engineer
12-07-2008, 05:32 PM
Ours were kinda like the NE1000 on the page that Kirk posted, but they were larger. I forget the flow rate range and the volumes for research and production scale, but as I said, the research syringes could be pretty big but then the scalefactor was off. Remember, scale factor was a big bugaboo for us. Every pump had to have the same allowed multiplier in a complex equation relating to scaling of each type of emulsion. The software had to keep track of all of these and warn the engineer during design phase. He could override everything, but then the emulsion could not be scaled up or down properly.

I imagine one of us will run into this problem someday as well.

PE

Ray Rogers
12-07-2008, 05:34 PM
A dual "syringe" arrangement with unlimited puming volume like I image you are talking about here seems to me to be more of pump - a dual piston pump. I don't really call them a "syringe" pump, but I suppose they could. If so, why use syringes for them, instead of fixed, permanent pistons?

What is the difference between a syringe and a pistion?

Kirk Keyes
12-07-2008, 07:51 PM
What is the difference between a syringe and a pistion?

Well, really none in this kind of setup.

But there are machines like High Pressure (sometimes called performance) Liquid Chromatography pumps that use ruby rods for pistons that are about 1.5 inches by 0.2 inch diameter and they cycle in and out to make a pump. They typlically can only pump one liquid stream, but they often can mix up to 4 difference solutions at variable ratios to make up that one liquid stream. They usually cycle back and forth from a few times a second to once every few seconds, depending on the flow rate needed. They can pump very low flows - from a 1/10th of a ml/min to 10 ml/min. The catch is the pumps usually need some backpressure to run. And by packpressure, they can handle 100 psi up to 4,000 or more psi.

Ray Rogers
12-10-2008, 12:38 AM
Ray, what volumes and rates can your syringe pump do?

I am back now.

Ok, well, I checked. Without giving you a copy of the spec sheet, allow me to be creative and make you struggle:p

It seems I am able to deliver, approximately, as little one cup per day to as、well, more beer or expresso than you can drink in an hour, and live to tell about, for more than a couple of hours!

Kirk Keyes
12-10-2008, 10:48 AM
I typed "convert 1 cup/day to ml/min" into google and it didn't have an answer...

Ray Rogers
12-10-2008, 12:58 PM
I typed "convert 1 cup/day to ml/min" into google and it didn't have an answer...

"What's in a name? That which we call a rose
By any other name would smell as sweet."

Ray