Slug Catcher Forces
Slug Catcher Forces
(OP)
I am designing a foundation for a finger type slug catcher consisting of 36 in diameter pipe. I have done these in the past by using typical friction forces on the support but I have had one client say that a slug catcher moved quite a bit on startup. Prior to design he insisted that there were no unusual forces associated with this type of equipment. Is there a method to predict any lateral forces on these that should be accounted for in the support design?





RE: Slug Catcher Forces
Most likely the dynamic effect of an incoming liquid slug impact ?
RE: Slug Catcher Forces
RE: Slug Catcher Forces
RE: Slug Catcher Forces
If you can post what your inlet pipework configuration looks like then you may get some more informed comments.
However as noted in onother psot somewhere, slug catcher diesign and loadings are more art than calcualtion. You can get it a magnitude out if you calculate it wrong....
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Slug Catcher Forces
RE: Slug Catcher Forces
Independent events are seldomly independent.
RE: Slug Catcher Forces
When it comes to forces I agree that Purdue has nothing to do with it. I usually go for a change of momentum calc for forces on a bend based on the additional flow that arises during a liquid surge event (aka slug). Be careful about the velocity you use and mass of the surge volume. For piping, there are some increases in load which can be significant to move pipe which is only simply supported, but there's no way it's 15 tonnes force if you've only got an inlet velocity of less than 5 m/sec. Moving the inlet vertical is a good idea.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Slug Catcher Forces
RE: Slug Catcher Forces
Independent events are seldomly independent.
RE: Slug Catcher Forces
RE: Slug Catcher Forces
And ...
Within a typical pipe racks only 10% of the weight of the pipe is used (refinery design practice of major EPC companies) as a net thermal load in the longitudinal direction, because it is assumed that 45% of the pipe is moving one way and 55% of the pipe is moving the other, thus cancelling out 90%. Not 100%
Thermal is not live or transient, unless it is the result of a diurnal heating of the pipe, or something similar. But that is not the only criteria used to determine the load factor. The degree of accuracy to which the load can be calculated is also a consideration. For example, water loads can be live loads, yet a factor of 1.2 is applied to those, yet wind is 1.6 due to the relatively unknown maximum velocity and buffeting effects. Pipe stress from plant starts and stops is generally considered a dead load. Furthermore it is usually a self-limiting load, that if reached may impart some damage, but probably would not cause the collapse of the structure. Usually by that time the pipe had buckled anyway. Calculate that buckling load first. 1.6 seems high under those circumstances. This reference, and IMO ACI318 itself, suggests 1.2 http://faculty.delhi.edu/hultendc/AECT480-Lecture%...
Independent events are seldomly independent.