Orifice for Soap Dispenser/Spirit

Go high tech...

http://www.amazon.com/Lysol-No-Touch-System-Dispenser-Refill/dp/B0035HIGGA

http://fritteritter.hubpages.com/hub/Lysol-No-Touch-Hand-Soap-System-Review-Guide

http://fritteritter.hubpages.com/hub/DIY-Soap-Refill-Lysol-No-Touch

The orifice is probably fine. You need to find a way to slow down the flow. I'm assuming that spirits are rubbing alcohol. Your dispenser will never work for both soap and spirit. One is thick and the other is thin.

You could probably design something that would allow you to adjust the flow, but I think you would better off with two separate dispensers.

"I guess that it could be due to backflow effect"

Whats that? Never heard of it. How can there be back-flow when all the flow is forward?

Limit the travel so it doesnt reach the end and cause the problem.

I don't know if this would be convenient to your situation, but the sanitizer dispensers we use have interchangeable orifices that can be switched when a different fluid is dispensed.

So, the major point here is that it's better to have two orifice one for sanitizer/spirit dispenser and the other for soap dispenser.

Back flow effect is the back suction of liquid that occurs during the 'press' process , where the left over liquid flows backwards due to pressure difference and cause the surrounding of 'orifice' to get dirty (liquid smudges).

Due to economical reasons, manual dispensers are preferred hence the research.

If an orifice had to be designed for 'sanitizer dispenser' would a short downward tapering orifice be better with round/soft end ??

One more thought. Why not simply switch to the gel type hand sanitizer? It still contains the spirit/alcohol, but it has the same consistency as the soap.

Ya but anyhow the reason for this sputter needs to be known..

I tried limiting the end of the piston during measurements and the sputter of the liquid was reduced (not present) but not the smudging. But this cannot be used in real time as the leftover liquid would anytime flow out and cause dirt in the area (spill out)

The reason for the sputter could be that a vacuum is created in the container when the product is dispensed. At the end of the piston travel, the unit is attempting to push out product and suck in air at the same time. Sounds like a reasonable explanation for the sputter. Pictures would help, but I'm guessing that a small tee in the outlet, with a simple spring loaded check valve above and behind the piston may alleviate the sputtering.

can you display a few pictures for better understanding ? Nozzle clean and dirtied. May be from the video one showing the flow.

If your problem is what I think it is, consider the design of teapots. Their spout rises up from below, when operated the liquid flows up and over a curve in the spout. When the supply is stopped, the remaining fluid stays in the spout.

In the case of your spirit, I don't think you would get too much evaporation, because a very small surface would be exposed to the air.

Also look carefully at the tip of the teapot spout, it sometimes has a little pointed lip to reduce dripping and sputtering.

This design is also used in creamers, for the same reason.

Liquid Sanitizer smudges after the process.

I hope it is not an infringment in any case.

Looks like you just need to incorporate a small cone shaped piece with a secondary orifice over your flat hole.

The spirits will be thin enough to run completely out when used, and the soap will be thick enough to stay put until the next use.

I did react with a delay because I was out of the net access.

I think it is due to the fact that the fluid "wets" the "nozzle". When the fluid interacts with the material the angle at the drop limit is such that the drop spreads over the surface. This is, on my opinion, what happens. The geometry has to be changed to avoid this phenomenon. To make a similitude years ago we had on CR4 a discussion about water flowing from a cup why did it follow the wall ? It is the same try to find the "chat". I do not know how it was called any more. However I have the feeling it will not be easy to find a correct geometry. I shall think it over and keep you informed. It could be necessary to make a few tests with different solutions till the good one will be obtained.

As of now, the measurements will be done with few designs of the orifice like conical, long necked and end flower shaped.

Will inform when there are results..