\[PR=\frac{P}{R}\]
Variables
PRpurge ratio
Ppurge flow rate (kg/s)
Rrecycle flow rate (kg/s)
Description
What is this formula?
The purge ratio measures the fraction of the recycle stream that is intentionally removed from a process to prevent the accumulation of inert compounds, impurities, or undesired by-products.
When to use it
Use this formula in recycle systems where certain components cannot be completely removed by separation equipment and would otherwise accumulate inside the process loop.
Example
A recycle loop returns 500 kg/h of material, and 25 kg/h is withdrawn as purge.
Formula:
PR = P / R
Substitution:
PR = 25 / 500
Result:
PR = 0.05
The purge flow corresponds to 5% of the recycle flow.
Applications
- Recycle reactor systems
- Ammonia production plants
- Hydrogen process units
- Gas treatment systems
- Control of inert accumulation