The only concern I have to the inner insulation is that we are dealing with some steam (water vapor) in the reaction and I am unsure how the <castable> liner would handle that. That if the temperature dropped and pressure was maintained and the steam condensed ?
BTW: the operating pressure of...
I agree. I was thinking the space between the outer shell and the inner shell could be filled with a castable insulating refractory material.
As long as the refractory shrinkage isn't too great, as soon as the inner shell gets pressure on it, it will press on the refractory, which will push on...
It is true that one needs very thick walls to use 316 or 316H. I've looked at other materials but have yet to find one that allows a more economic vessel. While other materials have marginally better design stresses, their incremental cost is way higher than their incremental pressure.
The...
Further to this point, what about cooling the shell ?
What if we put a pressurized water jacket around the shell and kept the exterior temperature of the shell at 1000F. (Say we ran the process at 1600F). One could even go so far as to make the water jacked pressure the same as the internal...
We have a reaction that we would like to occur at high temperatures, preferable around 1000C. This creates a problem in that most (all ?) alloy design pressure must be derated due to creep rupture issues.
Is there a spec or has anyone designed an internally insulated pressure vessel wherein...
Thanks for the reply, James. I got copies of Table 1A and I now understand why there is a difference.
As far as 316H and 316, I've been told that we can safely substitute some 316s for 316H, it depends on the composition. Care to comment on that ?
The 1999 Addenda, Secion VIII, Division1 Table 1A lists the maximum design stress for 304H and 316H to be 1400 and 1300 PSI at 1500F. We will lower our vessel temp to 1500F and stick with stainless steel.
Some of the super alloys will go to higher temperatures, but the cost doesn't seem...
This webpage says that 316H has a "short time" tensile strength of 120MPA at 900C.
It also says that for a creep of less than 1% in 10,000 hours at 800C the pressure should be kept below 20 MPA.
http://www.askzn.co.za/tech/tech_grade_316.htm
Could someone explain the relevance of these...
We need to build a small (250ml) test vessel that holds steam at 2000 PSI and 1600F or thereabouts. On first look, we are thinking of using 316H stainless.
a) what is the best guide to the stress/temp abilities of various steels, such as 316H.
b) what ASME documents should we be using to...
