Hello everybody.
Today I would like to talk about 3 main points for compressor selection and give you one general tip.
It refers to industrial screw compressors, high pressure piston or diaphragm compressors for nitrogen, helium, methane, hydrogen and others.
Each week I get similar requests:
I need a 200-bar compressor for helium. Please give me a solution
or
I need a compressor to suck the gas from 200-bar tanks
and fill high pressure tanks till 400 bar
or
I have a 40 Nm3h capacity nitrogen generator and I need to get 200 bar,
please give me a solution for compressor
Do you understand the general mistake?
Is it possible to select a compressor if we have these requests?
Of course, NOT!
All compressors have three general points for selection. It’s point «0», it’s point START.
That are:
- Inlet pressure
- Outlet pressure
- Capacity
Inlet pressure will be atmospheric if you select a compressor for air. For all other gases you have to check inlet / outlet pressures and capacity.
For inlet pressure you have to remember that it must be only one point. You can’t take the range from 0… till 10 bar, from 0…till 5 bar or others – compressors have only one point for calculation.
If your gas source is a generator with range, for example, from 4 till 6 bar, it’s better to take 5 bar inlet pressure for compressor calculation.
If you have gas source 2….15 bar, it’s better to take 2-3-4 bar inlet pressure for compressor calculation and use the pressure reducer.
Don’t forget that all compressors have the working range +/- 1…2 bar.
That means that compressor with 5 bar inlet pressure will work with the inlet range about from 3…3.5 bar till 6…7 bar inlet pressure depending on the compressor type or manufacturer.
I know a lot of cases when mistakes with inlet pressure selection made compressor like a piece of nothing. It was impossible to use it.
This topic about inlet pressure is quite interesting and if you have any doubts, please leave the comment below this video and I will help you.
Outlet pressure is simple. All compressors have outlet pressure, which is limited by pressure sensors or pressure switches depending on manufacturer and also by safety valves.
So if you take a 300 bar compressor, you can fill your tanks in the range from 1 bar till 300 bar, in some cases till 305 bar.
Capacity selection is another huge topic.
There are different cases depending on gas source, gas generator capacity, your tanks and your technology.
So my general tip is – don’t forget to use these three points.
inlet pressure / outlet pressure / capacity
I hope everything is clear for you.
But anyway If you still have questions or doubts feel free to leave the comments below. I will answer within a couple of days.
See you next time, good luck.
Regards,
Konstantin Shirokikh
