Re the sulfur tank roof corrosion

[1906]

Recently, we experienced sulfur tank roof corrosion and considering installation of steam coil on the outside surface of roof because we think cause of corrosion is condensing of H2S and H2O.
Anybody who has comments about our countermeasure, please inform us.

 

[QMax1]

1906,

Most internal corrosion of sulfur tanks is due to wet sulfur corrosion on the inside wall of the tank (S trapping H2O). If the tank wall is not properly heated (which normally they are not), there will be areas of the tank (particularly the roof) that are below the freezing point of sulfur (247F). When sulfur particles come in contact with the wall the sulfur freezes on the tank wall. When the sulfur freezes on the tank wall, it traps moisture behind it (the air space in the tank is most likely full of moisture due to the sweep air and/or leaking internal steam coils). When the sulfur traps the moisture against the carbon steel, it creates iron oxides or worse, pyrophorics. The iron oxides eat the carbon steel until it can flake off and the process starts over again. I've seen sulfur tanks get eaten away after 5 years of use. Alberta Sulfur Research out of Calgary can back up this theory.

My suggestion is to design a system that maintains the tank side and roof walls above 260 F. There is a company out of Charlotte, NC that just presented a paper about preventing corrosion on sulfur tanks. They use an external coil design to do so.

http://www.csiheat.com

QMax1

 

[1906]

Thanks for your(QMax1) comments on this.
By the way, Can I get presented paper you mentioned ?

 

[QMax1]

1906, I think you are better served by contacting the author (CSI). I normally deal with Tom Perry who handles the Northeast.

 

[1906]

Many thanks !

 

[1906]

Re the strainers(60 mesh) at the inlet of ejectors for vacuum tower, please comment on following questions.

a) Reason of strainer installation at the inlet of ejector
b) Side effect in case of removing strainer
c) General Mesh size(if installation of strainer is general
practice).

We want to remove strainer and avoid any operational interuption by the plugging of strainer during normal operation. If you guys have good comments, please let me know.