I need a method to remove an impure form of sodium stearate from a
clogged flat plate heat exchanger which is 6" w x 10" l x 4" d.  That
the material is sodium stearate has been confirmed analytically, but
is impure because it probably has dirt, rust, and other impurtities
mixed in. This coagulated material is preventing steam at 30 psi from
passing thru the heat exchanger. The heat exchanger cannot be taken
apart, so a mechanical method is not acceptable.  The method should
involve using a liquid to be poured into the heat exchanger to
"dissolve" or "loosen" the material.  Soaking the internals with both
Tide detergent, an orange industrial citrus cleaner/degreaser, and a
non-ionic surfactant with sodium metasilicate, with subsequent
backflushing with 40 psi water dislodged some material but not all.

Have you tried repeated flushes with boiling water?

The water used for backflushing has been 50 F.  However, the clogged
heat exchanger when in use has steam at 30 psi travelling in the
normal (forward) direction. I would think that 30 psi steam (which, if
saturated, is at 274 F and fairly abrasive in its own right) would be
more effective than boiling water, travelling foward or backward. It
would be difficult, ie more expensive than the posted reward for this
answer, to backflush with steam.

I hear ya.  I think NaSt is also partly alcohol-soluble.  Is that an option?

Yes, alcohol would be an option.

Hi -

Completely different application, but, we use ethanol to clear
stearate from glassware before it can be used with neurons.  Ethanol
seems to clear it away pretty well, but then again, we're using glass
that's already pretty clean, not a heat exchanger with all sorts of
other stuff in there...

synarchy