Dear all: what type of evaporatir should be used for caustic soda concentration up to 50%? Forced circulation or falling film? 4

[Librianus]

Dear all
What tupe of evaporator should be used for caustic soda concentration up to 50%?
What construction materials should be used?

 

[EdStainless]

There are a number of people out there with experience building these.
Steam heated.
There are only two material options, Ni200 or 26-1S (E-Brite) superferritic SS.

 

[pierreick]

Material should be Nickel, based on my experience. Regarding operation, should be forced circulation due to the viscosity of caustic at high concentration.

Forced Circulation Evaporator

Ideal for highly viscous liquids or with a tendency to fouling. Optimal for saline solutions among other applications.

www.gea.com

Check physical properties of caustic solution. Pierre

 

[Librianus]

Falling films could be considered as well or forced circulation is better?

 

[georgeverghese]

There is a detailed discussion on this topic in Perry Chem Engg Handbook, chapter on heat transfer equipment , subsection on Evaporators.

 

[pierreick]

Another resource:

Caustic soda evaporation

Get compact and energy-efficient caustic evaporation systems from Alfa Laval. Low operation temperatures and corrosion-resistant design means higher reliability and longer service lifetime.

www.alfalaval.co.th

You may want to contact them, both GEA and Alfa Laval
Pierre

 

[Librianus]

Thank you so much, Pierre!
In my case, I need to project / specify a tubular unit.

 

[EdStainless]

I believe that Graham Mfg also makes these.
I have made a lot of E-Brite for this service, and have seen tubes with more than 40 years of service.
The issue with Ni200 is that it will erode from the excess salt in the solution.

 

[Librianus]

Thks for the very valuable tip!

 

[Librianus]

Thks for the very valuable hint

 

[pierreick]

Hi,

Material for high temperature caustic vessels - Boiler and Pressure Vessel engineering

Hi Guys, I'm designing a pressure vessel with 250 C temperature and 20 barg for caustic soda 50%. Do you have any idea about material selection? I have read a couple of references like "Alloy selection for caustic soda service" and "NACE SP040315" but not applicable for this temperature. Thanks

www.eng-tips.com

Pierre