Chromatography Forum

I currently have a bit of a situation here. We had the disagreable surprise to see that for an unknown reason our hydrogen generator failed and started pushing liquid water into our hydrogen gas line. The resulting effect is that my inlet and two FID probably got liquid water in them (probably droplet). I was able to dry them but I still have two problem left:

- My split/splitless inless get underpressure (and keep it) but I have no flow at all (the split flow stays at 0).
- I can't seem to be able to turn on the flame on my FID.

My equipment is a 6890GC with 2 FID and EPC gaz control. Can it be that the water damaged the EPC? Is there a chance of salvaging the equipment?

... Can it be that the water damaged the EPC? ...

Very likely FID EPC has been damaged.

The "water" in a hydrogen generator is actually a concentrated solution of electrolytes, so if the fluid getting into the gas was due to a membrane failure you have probably suffered serious damage to the GC plumbing. The column is also probably damaged and you will need to clean or replace all the hydrogen lines.

Sorry !

Have you spoken to the supplier of the hydrogen generator about it ?

Peter

I fear too that the EPC has been damaged.

The FID EPC seems to indicate correctly the flow. I will try to clean the jet, it already had some difficulty maintaining it's flame (it seems that the make up gas put it off).

As for the inlet, I don't have any error code. It keep its pressure but I have zero flow in the split vent. I fear too that the EPC has been damaged and that we will need to have it repaired.

As for the H2 generator, it was a used part, hence not under warranty. I suspect an operator error, the dessicant cartridge was probably saturated and combined with the winter holyday created a bit of condensation in the line. When we restarted the GC it pushed water up in the EPC.

...The FID EPC seems to indicate correctly the flow. I will try to clean the jet, it already had some difficulty maintaining it's flame (it seems that the make up gas put it off).
...

Seems that it survived Another possibility is that restrictor plate in FID EPC is partially clogged and this changes real flows despite what is displayed. It would be good if you can check real flows with flowmeter.

As for the H2 generator, it was a used part, hence not under warranty. I suspect an operator error, the dessicant cartridge was probably saturated and combined with the winter holyday created a bit of condensation in the line. When we restarted the GC it pushed water up in the EPC.

What kind of generator is it ? - as far as I know those designed for GC produce pretty dry hydrogen, so having a moisture trap in the line would be superfluous. My knowledge on this might be out of date though.

What makes you think that you had/have water in the hydrogen lines ?

If the water is condensed vapour then it will be very pure and far less aggressive than the electolyte, so you might be able to salvage something.

Peter

One more thing. Do you deliver compressed air to FID from compressor or from gas cylinder ?

@dblux_: The air is from a compressor going through a Zero Air Generator.

@Peter Apps: The fact that I suspected water is simply the fact that there was water draining from the EPC when I removed the connection. Also, when I started the hydrogen generator without connection, I had about 2-3 ml of water expulsed from the outlet. I dried the dessicant in the generator that was pretty saturated. We recently acquired this system used and had not though of drying the dessican first.

@dblux_: The air is from a compressor going through a Zero Air Generator.
...

Yes. This combination may expell water when no moisture trap is installed after Zero Air Generator.
Wet air goes through Zero Air Generator and when the heater is not on water condense inside - (water from HC combustion neglected to simplify description).
When after sufficient amount of time Zero Air Generator is switched on, condensed water boils off and gets into FID EPC. Conclusion is that moisture trap is necessary after Zero Air Generator.

@dblux_: The air is from a compressor going through a Zero Air Generator.

@Peter Apps: The fact that I suspected water is simply the fact that there was water draining from the EPC when I removed the connection. Also, when I started the hydrogen generator without connection, I had about 2-3 ml of water expulsed from the outlet. I dried the dessicant in the generator that was pretty saturated. We recently acquired this system used and had not though of drying the dessican first.

That's pretty convincing evidence ! OIt does sound as if the water might be condensate, which is better than electrolyte by a long way. Try just running lots of dry gas through the system. NB that the gas coming through the gas line will be wet for quite a while, you can speed up drying the pipes by disconnecting form the GC aand heating them with a heat gun whith dry gas flowing through. The other more desperate measure is to rinse the whole thing with methanol, and then blow dry gas through it.