Chemicals That Tend to Crystallize?

[ohiowater]

We have a project feeding several traditional water treatment chemicals listed below:

Sodium Hydroxide (Caustic Soda) - 50%
Sodium Hypochlorite - 12.5%
Hydrofluosilicic Acid - 18%
Ferric Chloride (coagulant) - 25%

I am looking for a source of information to find out which chemicals tend to crystalize and at what temperatures? Caustic Soda seems to be a consistent concern, but have heard different things about the others, esp. Ferric Chloride. Any help? Also, is heat trace and/or insulation usually enough?

 

[DeltaCascade]

Try checking the material properties? Like freezing point (caustic freezes at about 10C or so??)? Solubility as function of temperature? I dont think there is much of a problem, that is why the concentrations are what they are sold at, as long as we are talking about pure chemical in a pipe. Regarding insulation or heat tracing, that depends on your environment ... +30C or -40C?? Try asking your supplier?
Good luck

 

[Buhsman]

In our waste water treatment facility we use ferric chloride and haven't had problems with it crystalizing. The temp inside the facility ranges from 40F to around 100F.
Now sodium hydroxide on the other hand is a different story.
We keep our storage tank at around 100F and we do use heat tape and insulation on the majority of our piping. If it is going to be in a cooler enviroment I would suggest on doing the same or the caustic lines will freeze up.