Snow Box Design

snow-box
#1

I am looking for articles, references, anything! on the design of a “Snow Box” or maybe a “Sublimation Box”.

This is a device with somewhat cooler surface areas to allow a component (which is usually susceptible to sublime) to solidify out of a air/gas/vapor stream and allow other components to go on to other downstream equipment, like a condenser. The device may cycle from cool to hot so the solids can melt and drain to another location, and then cycle from hot to cool to collect more “snow”.

Can anyone help?

#2

Wouldn’t this be similar to a physical vapor deposition process, but instead of a component being coated, you would coat the walls of the container itself? The wiki page has a lot of references to these processes; I would assume you could borrow and manipulate a lot of those design criteria to fit this “box” design.

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#3

Yes, excellent, I will go down that path and see what I can find and learn.

Has anyone gone down this path before me, and have a working “snow box”? If so, pictures, dimensional drawings, rates, capacities, and capabilities would be greatly appreciated.

#4

Investigate air driers for instrumentation air. In these the air passes through a heat exchanger into a cold chamber that may be 50 below. Any moisture is frozen out and the air them passes back through the heat exchanger to enhance efficiency.
These units are generally doubles, with one path melting and draining while the other is drying.
I hope this helps.

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#5

You seem to be describing a cold trap. This is pretty standard equipment in many chemistry labs. I have one that cools to -90C.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=lab+cold+trap%2C+savant&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=lab+cold+trap

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#6

Very neat! The video with cool music was a nice touch. Yes, a cold trap is half of it. I withheld this data, but I won’t need -100 degrees for phthalic anhydride. The idea is spot on tho.