Francois,

I used to make large quantities of immobilised cells from carrageenan. For these several nozzle techniques are available. These techniques could work fr this too. Do you want to know more..you know how to contact me!

Francois - this may be entirely inappropriate for your requirement, but you might try contacting Whittier Canada who are experts in snowmaking technologies.  They may be able to help you. 

http://www.whittiercanada.on.ca/techsupport/applications.htm

See this article "Making Artificial Snow for Laboratory Use by Richard A. Sommerfeld and Tara L. Freeman" It can be downloaded in the first 2 links below:

https://ia802702.us.archive.org/30/items/IND89028551/IND89028551.pdf

https://archive.org/details/IND89028551

https://books.google.com/books?id=Rnlc-4qWqxwC&pg=PP2&lpg=PP2&dq=making+ice+droplets+in+the+lab&source=bl&ots=dQ_cL2AacV&sig=zU3toDKMGGDMY8hKqQLiKjScjao&hl=en&sa=X&ved=0CDgQ6AEwBGoVChMI1Znk5t_qyAIVi5UeCh1kjAFS#v=onepage&q=making%20ice%20droplets%20in%20the%20lab&f=false

http://www.atmos-chem-phys.net/4/1997/2004/acp-4-1997-2004.pdf

http://www.nrc-cnrc.gc.ca/eng/solutions/facilities/wind_tunnel/altitude_icing.html

http://webs.wichita.edu/?u=icing&p=/sld/

http://www.smithsonianmag.com/science-nature/the-art-and-science-of-growing-snowflakes-in-a-lab-180949243/?no-ist

In addition , if you are into making large snowmaking as already here is a interesting and fun article link:

http://pubs.acs.org/cen/whatstuff/stuff/8203snow.html

Hi Francois,

One of my old contacts in Thames Water R&D did his PhD on ice pigging. I could put you in contact with him if that would help you?

Regards,

Charlotte

Hi All,

thanks for the suggestions, I'll sort them out and do some experiments. @ Charlotte: it would be great if you've contact details of that person at Thames water for me.

best regards

Francois

OK, I will get back to you after I have contacted him.

Regards,

Charlotte