Hi All
I need to run a test where I require 80C air at 100% RH at the input to my test piece. The air is flowing through a 1/2" shop air line (dried and filtered). I am planing to heat the air to over 80C (say 110C or something) introduce the water vapour, cool the air back down to 80C where the excess water will condense, ensuring 100% RH at the inlet. My question is What is the best way to introduce the water vapour into the air stream?
Thanks in advance, Dan W
My gut says a fine spray of warm deionized water. You will in any case need a droplet trap; some sort of baffle in the output air stream.
Jerry
You may be best off throttling some steam into your air. Pick out how much steam and how much air you need from the steam tables. You might want a mass flow meter on each stream. An alternative is to bubble air through 80C water.
I don't know how much air you need for all this, and what sorts of functionality you will require in the future. There are several other methods of doing it.
Michael
If the bubbling through 80C water would work, then I prefer that method, as I think I could get away with 1 mass flow meter. I could then figure out the mass of water added (W=(Rda/Rwv)*(Psat/(P-Psat)), W is mass ratio of water vapout to dry air, as this was I am not adding any additional 'dry air.' I guess the question becomes what mass of water I need at 80C to ensure 100% RH?
Herman Family wrote:
If you bubble through several inches of water at any temperature, you will have pretty close to 100% RH for that temperature. Make sure you have good bubble formation (little tiny bubbles...) and plenty of water. The taller the column and smaller the bubbles the closer you will be to the 100% RH.
All you really need to do is to keep enough water in the bubble column, pump in air, and keep the water hot. Measure the water temperature and air exit temperature.
Michael
Have something to add? Share your thoughts — no account required.
Ask the community — no account required