1 reply to this topic

[mlai]

I am sizing a vent for fire relief for an 80,000 gallon atmospheric storage tank. More specifically,the tank is existing and I am checking the size of an existing vent. The content of the tank is edible oil with between 100 and 1000 ppm water. The edible oil has a B.P. of 1550 oF, so with no water in the system, no vaporization would occur before the failure temperature of the metal is reached. This, I believe, was the original assumption for specifying the tank vent ( 4 inch diameter conservation vent), although the design calculations are not available.

The introduction of water into the calculation (soluble in the oil at these concentrations) results in a lower bubble point (approximately 680oF) and a fire venting rate that is twice that which the existing vent can handle. Because I am checking an existing installation, I am interested in getting input regarding the treatment of trace impurities in storage tank contents. Is there a lower limit ( partial pressure, perhaps) below which they do not typically get addressed?

Thank you in advance for any assistance.

[ankur2061]

mlai,

Have a look at the following links about various safety considerations for Atmospheric Storage tanks:

http://www.wermac.or...nks_safety.html

http://www.process-s...tanks-fire.html


Regards,
Ankur.