Cool first, then separate
In the aftercooler some of the water vapour may condense. The separator collects the resulting liquid, which accumulates at the drain. Without a working drain, water may be carried over again. Efficiency also depends on droplet size and flow rate; it is not constant at every operating point.
Where its role ends
Downstream of the separator, the air may still contain a considerable amount of vapour. Further cooling produces more condensate. To achieve the specified dew point drying is therefore required. Fine aerosols may also require a coalescing stage rather than relying on the cyclone alone.
What to check in practice
- Check the operating flow range and pressure drop.
- Ensure correct placement, flow direction and liquid drainage.
- Protect the downstream dryer in line with its inlet air requirements.
Example scenario
Water is separated downstream of the cooler at 30 °C. If the pipework later cools to 10 °C, more water may form from the remaining vapour. This alone does not mean the cyclone has failed; lowering the dew point to 10 °C was not its purpose.
What to watch out for
- Treating a cyclone as a substitute for a dryer.
- Sizing solely by the connection diameter.
- Forgetting to account for drain failure.
Is a larger separator always more efficient?
Not necessarily. Inertial separation has an operating range. If the flow through an oversized unit is too low, efficiency may change. Check the performance characteristics of the specific design.