What happens inside the unit while it runs. Knowing this helps you read the measured values and understand why the vents must stay open.
- MethodTwin-tower · heater purge
- H2 used for regenerationapprox. 90 NL/h
First timeRead the process overview and the cycle.
Done this beforeGo to the measured values.
On this pageProcess overview
Process overview#
Wet hydrogen enters at H2 IN and passes through the separator, the online one of the two adsorber towers, and the filter and outlet pressure regulator before it leaves at H2 OUT.
| Stage | What it does |
|---|---|
| Separator | Collects water droplets carried with the hydrogen. An automatic valve empties it to DRAIN |
| Adsorbers A and B | Two towers filled with molecular sieve. One removes water while the other is regenerated |
| Filter and pressure regulator | Hold back dust from the adsorbent and keep the operating pressure of the system |
The regeneration cycle#
The two towers take turns. While one tower dries the hydrogen, the other is regenerated through the steps below. The step names match the status shown in the control app.
| Step | What happens |
|---|---|
| Heating (HEATING) | The tower, depressurised through DEPR., is heated by its internal heater to the regeneration temperature (150 °C by default) to drive the water out of the adsorbent |
| Cooling (COOLING) | A small flow of dry product hydrogen, approx. 90 NL/h, flows back through the tower, cools it and carries the water out through PURGE |
| Switching delay (IDLE) | Switching waits until the regenerated tower has cooled to 40 °C or below |
| Switching (SWITCHING) | The regenerated tower is brought up to operating pressure and the towers swap. Product gas keeps flowing during the switch |
The defaults and ranges for cycle time, heating time and regeneration temperature are under regeneration settings in the Operation chapter.
Operating states#
The Status field at the top of the control app shows the unit's current state.
| App shows | Meaning |
|---|---|
| STOPPED | The regeneration cycle is stopped. After a stop the system is depressurised |
| STANDBY | Inlet pressure has fallen below 8.5 barg and the unit is waiting. It carries on automatically once the pressure is back at 9.5 barg or above |
| HEATING | The tower being regenerated is heating |
| COOLING | The tower being regenerated is cooling with purge hydrogen |
| IDLE | Switching is held until the regenerated tower has cooled |
| SWITCHING | The towers are swapping |
| EMERGENCY | Emergency stop is active. Find the cause, then clear it with Release in the app |
| OFFLINE | The control app is not receiving data from the unit. Check power and Ethernet |
Measured values#
| Measurement | Used for |
|---|---|
| Inlet pressure | Checking the pressure arriving from the HXB-V1 units |
| Gas temperature at the adsorber inlet | Tracking the water load on the online tower |
| Outlet pressure | Operating pressure of the system |
| Tower temperatures | Heating and cooling progress |
| Separator level | Starting the automatic drain |
| Liquid leak sensor | Stopping the unit if liquid collects inside |
| Outlet dew point (option) | Product quality |
The dew point sensor is an option. If your unit has it, read the outlet dew point on the control PC; if not, use an analyser at H2 SAMPLE OUT. With the sensor fitted, the unit warns when the dew point rises above -70 °C and stops if it stays above -65 °C for ten minutes.
What this chapter is based on
- HXD-V1 datasheetPDF · 3.2 MB
- HXD-V1 outline drawingPDF · 368 KB
- First start checklistPDF · 61 KB
- Routine check sheetPDF · 66 KB
- Maintenance logPDF · 49 KB
- HXD-V1 user manualPDF · 2.7 MB
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