Wood chips in the cooling water ( condenser issues)

[f1ori]

I work with a small packed column ( 3ft x 45ft), which normally runs under 125 mmHg vacuum and a O/H condenser cooled by water. Last week, we steamed the O/H condenser line to the steam jets and we found wood chips, which are coming from the cooling tower. Since then, the dist. tower is pressurizing to 160 mmHg. We are steaming the lines constantly, but the only way I know to drop the pressure to 125 mmHg is to torn apart the O/H pipe and do a real clean up.

Does it have any other way, besides shutting the tower down to make the pressure under control?

PS: The cooling water line to the O/H condenser does not have strainer neither booster pump prior it.

 

[Compositepro]

Caustic can dissolve wood if you think that will be easier than opening the condenser. Obviously you need a strainer in the cooling water line.

 

[sshep]

Your story doesn't say this, but we guess that you have wood chips getting trapped on the CW tubesheet of the CW inlet, restricting water flow. The normal online action would be to backflush the consenser to grade. You would have to have an inlet block valve and a drain valve. The drain valve could be hot-tapped, in which case you make it large enough to accomidate the full reverse flow.

If you can afford a <1hr shutdown, you could install a cone start-up strainer on a flange (even the inlet nozzle). A back flush arrangement would allow the strainer to be cleaned online, and would work better than backflushing off the tubesheet (i.e. some chips could get by into downstream channels of a multipass exchanger, which cannot be easily backflushed).

best wishes,
sshep