Particle Size

[cdrras]

Ok, this is a stab in the dark. Does anybody know the typical droplet size of generic spray bottles or those pump sprays (like found in hair product stuff or perfume)? I'm trying to find something out there that could simulate in the 1-20 micron range, but something tells me a spray bottle's droplets are much bigger than this. If anybody has any info or might know something I could put together around the house or put together really cheap...pass it along. Thanks!

 

[zdas04]

I recently did a talk that included some research on droplets. An "aerosol" is 1-50 microns, a "mist" is 51-100 microns, and a "fine spray" is 101-200 microns. Pressurized spray cans (hair spray, paint, etc.) tend to give you drops at the upper end of "fine spray" and larger. Pump sprayers tend to be bigger than "fine spray".

To get to an actual aerosol you have to add considerable energy to overcome surface tension. The only houshold product I can think of that does this is a nebulizer that people use for asthma relief.

David

 

[Cockroach]

Neat stuff, very interesting information!

I once used a nozzle off my wife's perfume bottle to feed a V1 rocket motor combustion chamber inlet. It worked rather well for a while, but started melting with increasing thermal outputs. Then the Reed Valves gave out. I was interested in the "fuel mist" because of air/fuel ratios and tried to make an electrostatic generator to suspend the particles against gravity. I think Milligan Oil Drop Experiment comes to mind in my university days. Nothing ever developed from that.

But nebulizers for asthma relief would be an interesting application for the design.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[m777182]

There are some manufacturers of spraying nozzles that give you data about the droplet size distribution of their products.I believe that with ultrasonic nozzles you can get very fine droplets.
m777182

 

[cdrras]

Thanks for the very helpful information. I am trying to simulate a mist that will be a part of a small test for a mist elimination pad used in a gas-liquid separator. I don't have a particle analyzer so I was at least trying to get an idea on the particle size by comparing it to various household products until I can get the correct equipment. I tried to contact some manufacturers of spraying nozzles, but they won't release that information to me. They claim that the information is proprietary. At least now I have some useful information to go by. Now...just gotta wait for the equipment. Thanks

 

[IRstuff]

Depends on how your question was framed. Determine the particle size you need, ask them if they can meet the requirement and how they prove it.

TTFN