How can a vaporizer fail?

[ris2]

At our facility we vaporize liquid nitrogen from a storage
tank with an ambient air vaporizer. How can this vaporizer fail and allow liquid nitrogen into the gaseous notrogen header. Are there any site to check for vaporizer failures.

 

[weeeds]

What you may be experiencing is not a failure of the vaporizer but an overload condition. A vaporizer is sized to process a certain amount of liquid under certain ambient conditions. Often an increase in the demand for gas results in liquid being pulled from the storage tank and not vaporized as the heat exchanger is too small. The result is liquid coming out of the vaporizer and into the system. Has your gas demand increased sigificantly recently? Check this first.

 

[Montemayor]

ris2:

What you bring up is an important topic because almost all chemical process plants require and have Liquid Nitrogen storage and vaporization utility facilities in order to operate. However, you don't state one of the most important basic data: is the installation your own or do you purchase "across-the-fence", from a contracted supplier who owns the storage tank, vaporizer and instrumentation?

If you are buying the regulated gas supply from a contractor, then you have an easy problem. I have always received detailed training and hazop performance from such suppliers as Air Products, Air Liquide, PraxAir, etc. They will explain and go over all the details about how the system works, how it can fail, and how it safely will alarm, shut down and prevent any downstream hazards. They do this all the time - they have to, according to OSHA and PSM (Process Safety Management).

If you own the Liquid Nitrogen facilities and operate them, then you have the obligation of furnishing all the above information -including the hazop- to your operators. If this is the case, you should have all the safety and operational information known and understood well before you got into the business. Which of the two situations do you find yourself in?

Art Montemayor
Spring, TX

 

[ris2]

Montemayor

Our system is bought from Praxair. I will email them for some information. Thanks for your help.