Argon Gas requirement

[MADHU MADATHIL]

one of my machine required Argon Gas for the operations and the requirement is around 650 L/Min with 9 bar pressure. How will I determine the required Gas cylinders for 24 hour continuous operation. we have 40 liter cylinders available with 150 bar pressure. the normal outside temperature is 33 degree Celsius.

 

[GBTorpenhow]

Figure out how much mass needs to be taken out of one cylinder that is initially at 150 bar to get the pressure down to 9 bar (mass per cylinder).
Figure out how much Argon that 650 L/min is in terms of mass flow rate (mass per time).
Mass per cylinder and mass per time gets you cylinders per time.
Argon at 150 bar may not behave ideally.

 

[1503-44]

Why involve mass when you have volume as given information?

I assume you need 650 L/min at 33°C
Bottle volume of 40 L is at 20°C

650 x (9+1) /(273+33) / (150+1) x (273+20) =41 L/minute at 20°C

41 L/min estimate compressibility = 0.9 (that may be wrong, I don't know what it is)
41/0.9 = 45 L/minute

Ar is commonly supplied in 16m3 bottles at 400 barG
You may find those more convenient.


--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[pierreick]

Hi,
Your requirement: 936 m3/day
My answer:
1383 Cylinders/day
Hypothesis:
Argon @20C and 150 Barg >> EOS Peng Robinson: Z=0.9180 and Density = 267.83 kg/m3
Argon @33C and 9 Barg >>> Pen Robinson: Z=0.9919 and Density =15.82 kg/m3

You should consider bulk or larger cylinders, talk to your supplier.
Good luck
Pierre

 

[GBTorpenhow]

Why involve mass when you have volume as given information?

Because volume lies, but mass doesn't.

Or in other words, NIST REFPROP outputs density without extra mouse clicks.

 

[1503-44]

Please show us an example of how volume lies.

650L/min @ 33C 9Barg
@ STP = 650 X 10/1x 293/306 = 6223.8 L/min@20C 1 BarA

Bottle contents
40L @20C 150BarG
@STP
40 x 150/1 x 293/293 = 6000 L
Of Ar = 6000 /0.9183 = 6533.8 L of Ar

Number of bottles
6223.8/6533.8 = 0.952 bottles per min
1371.6 bottles/day

Within round off error of pierre's answer and not a gram in sight.
Pierre thanks for the z value.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[pierreick]

Hi,
The reason why I think it's better to use mass is to avoid mistakes!
In your calculation you are mixing absolute pressure and gauge pressure. It should be 151 bar Absolute.
Up to you to use what you are comfortable with.
Pierre

 

[GBTorpenhow]

Please show us an example of how volume lies.

I once tried to burn one cubic foot of propane with 24 cubic feet of air and the propane didn't burn right. I checked my propane tank and there was way less than a cubic foot of propane missing. Then the combustion products didn't add up to 25 cubic feet.

 

[MADHU MADATHIL]

according to the calculations the mass in 40 L / 150 bar cylinder is 69,996.07 and the mass for 650 liter gas at 9 bar is coming 9845. by this result, I need to have 202.5 nos cylinders for 24 hour operations.

is it possible to consider to get the Liquid Argon and convert it to Gas to reduce the cost of cylinders and reduce the risk of handling high pressure cylinders.

 

[pierreick]

Hi, Your calculation is wrong!
Requirement: 0.650/1'*24*60= 936 m3/day
936*15.82= 14807 kg/day
Mass per cylinder: 40*267.83 =10.7132 kg per cylinder

Number of cylinders per day: 14807/10.7132 = 1383 cylinders per day.

OF course, you can purchase liquid argon and use a vaporizer to convert liquid to gas. Let you contact your supplier for options.

Good luck

Pierre

 

[LittleInch]

First,

Are you absolutely sure about the flow rate. Is that 650 l/min actual litres or is someone giving you standard volume but then saying it needs to be delivered at 9 bar? Makes a big difference.

That's an awful lot of argon.

Liquid argon is cryogenic stuff though ; -186C so basically the same as LNG.

You'll need some pretty good levels of insulation and no idea how they transport it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

By Cryogenic Road Tankers of course.
Uni job was doing QA/QC certification for NASA's liquefied gas loads.
They were using a whole lotta' LOX back then.
Basically a whole LNG ship shrunk down into a road package.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."