5 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   12 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.