Thermal Oxidizer Regulation Norm 3

[MenInBlack777]

Hello to all and thanks in advance for your attention,

There is a project i'm working on that requires a flexibility test to be conducted in the piping system and also in the nozzles of a incinerator, the incinerator is meant to treat tail gas (from a sulphur recovery system), which is why a termal oxidizer has been chosen. I have been looking every where for a norm that regulates maximum loads in nozzles for this kind of equipment but have failed, in first instance i thought API 560 could be used in this case, but after deeper research, i found out it can't, for example this article:

http://www.zeeco.com/pdfs/zeeco-q2-2013.pdf

As you may see, i'm not experienced with thermal oxidizers, i can only think of the manufacturer providing this data for the nozzles of its equipment. If you have any info you could share that'd be great.

Kind Regards.

 

[georgeverghese]

Section 9 of API 560 (Aug 2007 edition) discusses permissible loads on convection and radiant bank external connections, which would not be relevant in the case of a TO. For other external conns, it makes reference to ISO 15649, which is stated to be equivalent to ASME B31.3 - see if there is some guidance here for permissible loads on burner nozzles.

 

[MenInBlack777]

@georgeverghese thanks for the help here, i will check this. I also was thinking ASME VIII, Div I could have some information about it.

 

[mk3223]

TO is a pressure vessel per ASME BPV Code. May check the thread794-57906 for nozzle load discussion. hope it helps.

 

[MenInBlack777]

@mk3223 Thanks a lot for the input, since it is a preassure vessel, then ASME/BPVC SEC VIII-1 / ASME/BPVC SEC VIII-2 should have the information required for this, correct?

 

[mk3223]

Correct.
Also, see the Pressure Vessel Handbook by Eugene F. Megyesy for quick reference.

 

[MenInBlack777]

@mk3223 thanks will check it out too. Ive reading ASME SEC VIII-1, it doesnt have like a table with permisible loads for nozzles as far as i can see, is there a maximum allowable stress in the nozzles stated in the norm?. Need to get really into the norm.

Edit: I guess depending on the material of the nozzle i could refer to table 5A in ASME SEC II

 

[mk3223]

@MIB777, the allowable load of the nozzle is to be "calculated" per many design factors and is different from one vessel to the other. Instead of the BPV Code, the PV Handbook as mentioned above provides a simplified method to calculate the allowable forces and moments of the nozzle.

You may search the similar topics as discussed in the "Boiler and Pressure Vessel Engineering" forums.

 

[MenInBlack777]

@mk3223 yes i reviewed the procedure in the book, makes sense and its really simple. However i´m trying to validate that with a statement in the norm, like a maximum or a rule that suggest having the stress below something, because the norm obviously is not going to mention that book.

 

[mk3223]

Sorry, not too clear what you mean...
"like a maximum or a rule that suggest having the stress below something,"

The allowable load is calculated according to the maximum allowable stress of the material as listed in the BPV Code. The simplified method is developed from the BPV Code. If wanted, you may search the detail references in the book for its origins of the BPV Code.

 

[georgeverghese]

Pardon me if I sound ignorant on this, but given that a burner nozzle is anchored in refractory tiles (rather than welded on to a metal shell with a repad included), mean that permissible loads would be much lower than those for other nozzles ?

 

[MenInBlack777]

@mk3223 you are right, the calculated stress from a FEA is to be compared with maximum allowable stress as stated in UG-23 depending on the material of the nozzle.

@georgeverghese (I think i'm the ignorant in this discussion, are you talking to me directly?) - In my case i'm focusing on the inlet tail gas nozzles attached to the shell, neck material SA-516-70.

 

[georgeverghese]

If the inlet tail gas feed were not tied into the burner nozzle ( maybe it ties into some special tangential mixing nozzle in the radiant combustion chamber of the TO), this nozzle would also be anchored in some refractory brick ??

 

[MenInBlack777]

If the inlet tail gas feed were not tied into the burner nozzle ( maybe it ties into some special tangential mixing nozzle in the radiant combustion chamber of the TO), this nozzle would also be anchored in some refractory brick ??

@georgeverghese well from what i can see in the plans, it doesn't seem like so, would you like me to share them with you in private?

EDIT: I've checked again and yes, it seems like it is anchored to refractory brick.
EDIT 2: It seems like, the tail gas pipe connects into another pipe, which is kind of a distribution system that the equipment has to then deliver the tail gas to each of it's 3 burners, then the 3 burners are connected to the shell as the main connection, but also have anchor points to refractory bricks. It also has a "sulphur pit vent connection" which is located in the shell, I checked and seems to be anchored as noted in Edit 1, but the main connection is with the shell tho.

 

[georgeverghese]

Ok that seems clear enough, so for these tail gas tie ins to these premix burners, surely the permissible loads on these burner nozzles partially buried in refractory would be low, given that, in addition, the shell wall is thin and probably has a design pressure close to atmospheric.

 

[MenInBlack777]

Ok that seems clear enough, so for these tail gas tie ins to these premix burners, surely the permissible loads on these burner nozzles partially buried in refractory would be low, given that, in addition, the shell wall is thin and probably has a design pressure close to atmospheric.

Yep it does look pretty thin and yeah its open to the atmosfere via a stack., so the piping where the tails gas tube is connected to the incinerator and then distributes the tails, should be modeled as part of the piping system and then have the burner nozzles checked in the interconnection with the body?

Is there a specific section of the norm in ASME VIII Div 1, that tackles problems like this? Since you mention that the loads are going to be lower than expected in a regular vessel.

 

[StoneCold]

I would bet if you talk to Zeeco, the allowable load from piping is zero. Piping must be self supporting and must have an anchor point within 20 ft of the nozzle so absorb piping loads. Just my guess, I worked a short time for one of their competitors. I will end this by saying I am not an expert on this.

Regards
StoneCold