3 replies to this topic

[bob789]

I was wandering if I could get some advice regarding nitrogen storage and use a as drying gas within my batch tray dryer, I am currently a 4th yr student. What I am doing is drying a granular powder down to 10% with nitrogen to provide an inert inviroment and also to prevent contamination as the powder is being used as a food additive. The dryer is being operated at 0.5 Bar also.

I had completley forgotten that nitrogen is stored as a compressed gas at high pressures. I noticed on the Air products website:

'Industrial grade nitrogen gas is available in a variety of cylinder sizes from 10 to 47 litres (water capacity) and filled to 200 bar.'

As I will not be requiring that much due to process running as a batch operation I have selected the nitrogen utilitity as coming from canisters.

As my dryer is operated at 0.5Bar,

how would I supply this nitrogen?

Would I have to reduce the pressure?

thanks,

Edited by bob789, 10 March 2011 - 05:01 AM.

[Profe]

Hi Bob.
About your inquire, all you need is a gas pressure regulator between the pressure range of nitrogen storage vessel and the use of nitrogen to the dryer.

You can buy this device at any provider of gas handling equipment for pressure.

Good luck

Edited by Profe, 10 March 2011 - 09:49 AM.

[bob789]

Hi Bob.
About your inquire, all you need is a gas pressure regulator between the pressure range of nitrogen storage vessel and the use of nitrogen to the dryer.

You can buy this device at any provider of gas handling equipment for pressure.

Good luck

Hi,

thanks for your reply, I have been reading up a bit more since the original post and am having issues in relation to working out the temperature the nitrogen may come out of the canister. The reason I need to know this is because I am using nitrogen gas at 60 degrees going into my dryer, so I need to work out the heating duty required to get my temperature of the gas out of the canister up to 60. At the moment I have assumed I am raising the temperature from 10 deg, however this is because i am unsure as to what temperature it will come out of the canister.

If you drop it through a regulator or expansion valve it'll probably be an isoenthalpic expansion, so there may be a drop in temperature - joules thomson effect

how would I calculate the change in temperature? any guidance would be great.

Do 10 Bar nitrogen gas canisters exist

or are they all around 200 bar? I feel a drop from 200 to 0.5 bar will provide a very large temperature drop so thats why a 10 bar canister would be better?

any assistance would be great,

thanks
bob

Edited by bob789, 10 March 2011 - 05:16 PM.

[bob789]

any guidance would be great,

thanks
bob