Salt bath

[lattar]

I hope here is someone who can advise me. This matter is really not my expertise.
We are planning a system where we are going to treat metal plates with molten caustic soda in 500 C temperature for couple of hours. Caustic melts somewhere around 400 C. Every once in a while the caustic should be changed. When it cools down it solidifies as one big mass which sticks to walls of the salt bath pot. What is good and safety method to take caustic out from the pot. Some ideas:
- put pipe and valve to bottom of the salt bath pot (we have not yet ordered bath) and drop it from the pot when it is molten
- buy a pot with pouring mechanism
- let it cool down and take the caustic mechanically out
- take for ex. 10 % of the caustic with pail or something quit often and replace that with fresh caustic

 

[unclesyd]

I would advise getting in touch with people that manufacture heat treating salt bath materials. You need to let them help you to the set up your salt bath system.
There are a lot of safety concerns that have to be addressed when using a salt bath.

Here are two companies that have been in the business for a long time.

http://www.kolene.com

http://www.heatbath.com/index.html