Propane/Oxygen - from Cylinder to Oxy/Fuel cutting torch

AI Thread Summary
Calculating the total available gas in propane and oxygen cylinders involves understanding their respective volumes and pressures. For oxygen, nine interconnected cylinders with a 50-liter capacity at 150 bar yield approximately 67,500 liters of oxygen. Propane, stored as a liquid, has a volume of 1,080 liters at 10 bar from a 108-liter cylinder. Given the 4:1 consumption ratio, about 16 propane cylinders would be needed to match the oxygen supply. It's important to consider the phase transition of propane from liquid to gas and the variability in density due to temperature changes when making these calculations.
martijn_tholen
Messages
1
Reaction score
0
TL;DR Summary
How to calculate total gas volume for each cylinder based on the consumption ratio of oxy/fuel for cutting torches
For one of our projects we are at present using quite large amounts of gas & oxygen.
What I was trying to figure out was how to calculate the total available amount of gas in a cylinder (be that either Propane/Oxygen or Propylene (Propene)) and then to determine whether or not -given a certain number of cylinders of each- do we have sufficient gas in stock based on their relative consumption ratio.

For example:
we may have 1 oxygen quad (i.e. interconnected cylinders) with 9 cylinders, type: G/G2, with a 50ltr water-volume @ 150bar filling pressure.
we have propane cylinders, type: S/SE, with a 108ltr water-volume @ 10bar filling pressure.
Given that the oxy/fuel consumption ratio when cutting steel for oxygen vs propane is ± 4:1, how many cylinders of propane would I need to end up with an exact ratio between oxygen and propane?

Can I simply use normal gas laws here?
I.e. oxygen, 9 cylinders, each with a volume 50ltr @ 150bar = 67500ltr of oxygen?
and, subsequently for propane, volume 108ltr @ 10 bar = 1080ltr of propane?
i.e. in that case I would need 16 cylinders of propane?
(9 x (150 x 50)) = 67500ltr @ 4:1 = 16875ltr of propane required => 16875 / 1080 = 15.6 = 16 cylinders?

Would that be a correct approach or would I need to take into account a different volume for each gas based on the fact that the propane and oxygen go through a phase transition in the cylinder (i.e. they go from liquid to gas)
Any help would be appreciated.
 
Engineering news on Phys.org
Propane is stored as a liquid. The amount of propane is measured by weight in small tanks, typically less than 20 lbs or so. Larger tanks, at least in the US, are measured in gallons. A good search term to better understand the relationship is propane temperature pressure. Note that the density of liquid propane can vary by 10% over a typical range of ambient temperatures. The gas volume is calculated from the liquid volume.

You can measure the amount of propane by weighing the tanks if you know the tare (empty) weight of the tank. You can also measure the amount by pouring some hot water down the side of the tank. The tank surface temperature changes at the liquid surface level.

Pressurized oxygen tanks have a stated volume, with typical sizes being 80 or 122 cubic feet for welding oxygen. Oxygen at 150 bar is stored as a pressurized gas. The tank pressure tells how much is in the tank.
 
Thread 'What type of toilet do I have?'
I was enrolled in an online plumbing course at Stratford University. My plumbing textbook lists four types of residential toilets: 1# upflush toilets 2# pressure assisted toilets 3# gravity-fed, rim jet toilets and 4# gravity-fed, siphon-jet toilets. I know my toilet is not an upflush toilet because my toilet is not below the sewage line, and my toilet does not have a grinder and a pump next to it to propel waste upwards. I am about 99% sure that my toilet is not a pressure assisted...
After over 25 years of engineering, designing and analyzing bolted joints, I just learned this little fact. According to ASME B1.2, Gages and Gaging for Unified Inch Screw Threads: "The no-go gage should not pass over more than three complete turns when inserted into the internal thread of the product. " 3 turns seems like way to much. I have some really critical nuts that are of standard geometry (5/8"-11 UNC 3B) and have about 4.5 threads when you account for the chamfers on either...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
Back
Top