9 replies to this topic

[worrier]

Hello, the attached image shows the air flow data for gas filter. I'm looking for the unit suitable for my current job : Ammonia gas, inlet pressure 9barg, temperature 25degC, outlet pressure assumed to be 8.95barg (0.05bar drop across the filter), actual flow rate requirement is 100L/min. 

 

Supplier proposed the unit with 7micron pore size (39 std L/min at 0.34bar pressure different; 82 std L/min at 0.68bar pressure different; 130 std L/min at 1bar pressure different).

 

My question is, the actual pressure drop only 0.05bar, then i can only take the reference "39 std L/min at 0.34bar pressure different". To convert to ammonia gas actual flow rate =>using ammonia gas conversion factor, 39std L/min / 0.772 = 50.5 std L/min; and then apply real gas flow equation Qa = Qs(Ps/Pa)(Ta/Ts) or Qa = 50.5 (1/10)(298/293), Q actual =>5.13 L/min. The calculated actual flow rate only 5.13L/min. Does the calculation make sense? Or is there any other way to interpret the air flow data table below?

 

Thanks in advance.

 

 Gas filter air flow data table.pdf   333.33KB   27 downloads

Edited by worrier, 25 November 2025 - 10:43 AM.

[latexman]

The calculation makes no sense. Is the NH3 filter open to atmosphere? I doubt it. That’s the basis for the air data.

Use the lowest flow/dP air data point (less compressible effects) and determine a Cv (or K) for the filter, then use that Cv for your NH3 case. A Crane manual will be useful for this.

[breizh]

Hi,
Let you submit a process data sheet to reputable suppliers to get comparative proposals. Amongst them try Parker / Cuno/Donaldson/Filson. Many more using your favorite engine.

CAT_FNT_ Product Catalog 2024.pdf

Ammonia-Refrigerant-Filters-Datasheet-WFL1045-211129-Rev-A-UK-SM.pdf

Breizh

[worrier]

Nope, downstream of the filter the ammonia gas is routed into ½″ process tubing (not to atmosphere).

 

Thanks for the advice. I'll give a try.

The calculation makes no sense. Is the NH3 filter open to atmosphere? I doubt it. That’s the basis for the air data.

Use the lowest flow/dP air data point (less compressible effects) and determine a Cv (or K) for the filter, then use that Cv for your NH3 case. A Crane manual will be useful for this.

[worrier]

Appreciate it 

 

Hi,
Let you submit a process data sheet to reputable suppliers to get comparative proposals. Amongst them try Parker / Cuno/Donaldson/Filson. Many more using your favorite engine.

CAT_FNT_ Product Catalog 2024.pdf

Ammonia-Refrigerant-Filters-Datasheet-WFL1045-211129-Rev-A-UK-SM.pdf

Breizh

[latexman]

Nope, downstream of the filter the ammonia gas is routed into ½″ process tubing (not to atmosphere).

Thanks for the advice. I'll give a try.

Cool, show us your work and we’ll check it.

[worrier]

Sure, really appreciate it. 

 

There are 2 attachments : one for the ammonia gas piping and one for the acetylene gas piping. These are provided to verify that all components are suitable for the system, particularly in terms of flow rate. Would be grateful if you could kindly review them and advise. 

 

 Ammonia Pipes.pdf   3.28MB   11 downloads

 Acetylene Pipes.pdf   1.24MB   0 downloads

 

 

Nope, downstream of the filter the ammonia gas is routed into ½″ process tubing (not to atmosphere).

Thanks for the advice. I'll give a try.

Cool, show us your work and we’ll check it.

 

 

[breizh]

Hi,

Attached a link with a set of equation about AGA :

AGA Fully Turbulent Flow – Technical Toolboxes Knowledge Center

EDIT :I've prepared a spreadsheet for those interested with the calculation, there is a typo in the document above for the calculation of the velocity. it has been corrected in the spreadsheet .

Note 1

I believe AGA equations are related to gas pipeline crossing the countries, not hoses!

 

Microsoft Word - GasHydraulicsCourse R.doc

 

Note 2: Attached documents to support this type of calculation

Good luck

Breizh

Attached Files

•  Compressible Flow Refresher.pdf   372.48KB   2 downloads
•  CompressibleFluidFlowCalculationMethods-edited.pdf   1.23MB   1 downloads
•  AGA fully turbulent .xlsx   1.36MB   2 downloads

[worrier]

This is really helpful, thanks a lot Breizh. I’ll make time to go through and digest them.

 

Really appreciate them 

 

 

Hi,

Attached a link with a set of equation about AGA :

AGA Fully Turbulent Flow – Technical Toolboxes Knowledge Center

EDIT :I've prepared a spreadsheet for those interested with the calculation, there is a typo in the document above for the calculation of the velocity. it has been corrected in the spreadsheet .

Note 1

I believe AGA equations are related to gas pipeline crossing the countries, not hoses!

 

Microsoft Word - GasHydraulicsCourse R.doc

 

Note 2: Attached documents to support this type of calculation

Good luck

Breizh

[breizh]

Hi,

For those who want to refresh their knowledge about fluid mechanic, I encourage you to review tutorials from Dr Biddle on youtube.

incompressible and compressible flow. A set of 34 videos

fluid mechanics dr biddle - YouTube

 

Breizh