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PF-126 · Verified method

Desiccant Dryer Purge Flow Calculator

Calculate purge flow from rated flow and purge percentage, or inverse.

Inputs

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ENGINEERING GUIDE

Use the Desiccant Dryer Purge Flow Calculator to calculate purge flow from rated flow and purge percentage, or inverse. The calculator uses Dryer rated flow and Purge percentage and reports purge flow; net delivered flow.

How to interpret the result

Read the result in the context of the selected units and pressure basis. For this tool, the primary outputs are purge flow; net delivered flow. Change one input at a time when comparing scenarios so the effect of each variable remains clear.

Formula and methodology

PneumaForge applies this verified method: Q_purge=Q_rated×purge fraction. The functional engine is shared with related tools in the dryer-flow family, while this page solves the specific intent represented by desiccant dryer purge flow calculator.

Q_purge=Q_rated×purge fraction

Variables and inputs

  • Dryer rated flow
  • Purge percentage

Worked example

Reproducible example: start with the calculator's default values (Dryer rated flow = 5000; Purge percentage = 15) and calculate the result. Then change the variable most relevant to your application and compare the new purge flow; net delivered flow against the baseline.

Assumptions and limits

Purge fraction comes from actual dryer data/user input, not a universal desiccant percentage.

Engineering tips

  • Use absolute total pressure in psychrometric calculations.
  • Compare moisture on a dry-air mass basis when pressure changes significantly.
  • Use correction factors from the actual dryer manufacturer rather than universal tables.
  • Keep the inputs used for desiccant dryer purge flow calculator on a consistent engineering basis before comparing alternatives.

Frequently asked questions

What does the Desiccant Dryer Purge Flow Calculator calculate?

It is designed to calculate purge flow from rated flow and purge percentage, or inverse. The reported outputs are purge flow; net delivered flow.

What inputs does the Desiccant Dryer Purge Flow Calculator use?

The calculator uses Dryer rated flow and Purge percentage. Only use values that represent the same operating condition or design case.

What formula or method is used?

The calculation follows: Q_purge=Q_rated×purge fraction. The page also states the assumptions that define where the method is valid.

Which assumptions can affect the result?

Purge fraction comes from actual dryer data/user input, not a universal desiccant percentage.

Can I use different units?

Yes. PneumaForge converts supported units through canonical engineering units. For compressed-air reference flows and pressure bases, the reference pressure and temperature must also remain consistent.

Technical sources