High chemial resistant metal sought
High chemial resistant metal sought
(OP)
As electrical heating of electro-galvanising bathes is waiting for an accident to happen and burn the works down we will be using metal tubes on the bottom of our process bathes. Through these will flow fluid (water) from a heat-exchanger. Therefore a high grade plastic such as PVDF is out due to poor temperature transfer.
The problem is that the bathes operate at temperatures of minimum 85 degrees C up to about 100 deg. C and are quite aggressive chemically. The pH value shifts between 0.6 to 0.9 and the main acids are combi H2SO4/HCL and HCl. There are more complex compounds involved but this will have to do due to legal requirements.
Titanium will hold out quite well in the H2SO4/HCl environment but not too good in the HCl. Hastelloy B3 is equally dissapointing in both. The material erosion is not much but we would prefer not to have to renew everything if not needed. Cost factor does play a role however, so mabee a compromise must be made.
Question is: Is there a material we should look into that can meet our requirements? or have we done that with the Hastelloy?
The problem is that the bathes operate at temperatures of minimum 85 degrees C up to about 100 deg. C and are quite aggressive chemically. The pH value shifts between 0.6 to 0.9 and the main acids are combi H2SO4/HCL and HCl. There are more complex compounds involved but this will have to do due to legal requirements.
Titanium will hold out quite well in the H2SO4/HCl environment but not too good in the HCl. Hastelloy B3 is equally dissapointing in both. The material erosion is not much but we would prefer not to have to renew everything if not needed. Cost factor does play a role however, so mabee a compromise must be made.
Question is: Is there a material we should look into that can meet our requirements? or have we done that with the Hastelloy?





RE: High chemial resistant metal sought
RE: High chemial resistant metal sought
RE: High chemial resistant metal sought
RE: High chemial resistant metal sought
RE: High chemial resistant metal sought
Just a thought.
Bill
RE: High chemial resistant metal sought
Thank in any case, will look into all options offered.
RE: High chemial resistant metal sought
If your heating coil is of relatively simple geometry, e.g. a very loose serpentine with large radii, with the ends bent up and terminated above the liquid level, you could protect the coil with thin PP or PE tubing, slipped on from either end. If the tubing is thin enough, it doesn't have to fit the coil closely; hydrostatic pressure will push it into intimate contact with the coil.
Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA