API Tank Design For Agitator Load 1

[GURURAJCN]

HI Good morning every one

I am designing API650 Storage Tank Of Diameter 4000mm x 9000 mm Long with cone Roof Cone & Bottom Plate thk=8mm & Shell is of 6mm thk. MOC SA 240 Gr.304. On the cone platform installed & A Agitator is installed at centre agitator loadings & Platform Loadings are as follows.

Roof Design information (Loading Data)
- Uniform Live Load : 120 kg/m2 (per Platform)=1,404kg
- Platform Dead Load : About 1,700kg
- The nozzle load on the roof : 628kg + Allowable force and moment
- Connecting Pipe : About 500kg
- Agitator : 4,300kg(Dead load), 10,750kg(Dynamic load)
- Live load of Urea unloading for IBC Tank Weight : 1,000kg

Therefore ;
 Dead load = 1,700kg + 628kg + 500kg + 4,300kg = Min. 7,128kg
 Live load = 1,404 kg + 1,000 kg = Min. kg 2,404
 Dynamic load = 10,750kg

Can Anybody please help me or send me excel sheets for checking agitator & platform load on top cone.


Thanks
Gururaj
Design Engineer (Static Equipments)

 

[MJCronin]

I am not sure that I understand your posting, but for a thin walled API-650 type tank with a center mounted agitator, a "bridge" is a common solution.

The "bridge" is simply two rails that distribute the agitator loads and attach to the tank shell.

Usually a flat topped tank is selected....... The cone roofed tank designer is not doing you any favors.

http://www.cfmworldwide.com/images/equipment/5423_1.JPG

Bridge rail analysis is no challenge for a structural engineer.

MJCronin
Sr. Process Engineer

 

[GURURAJCN]

Thanks Mr.MJ Cronin

I have a API Tank Of 4000 mm ID x 9000 mm Lg (MOC SA-240 Gr.304)

Roof is self supported Cone type of 8 mm thk on which 20" Nozzle at centre & Agitator is mounting on that 20" Nozzle.

Agitator Loads which acts on Roof as follows

Roof Design information (Loading Data)
- Uniform Live Load : 120 kg/m2 (per Platform)=1,404kg
- Platform Dead Load : About 1,700kg
- The nozzle load on the roof : 628kg + Allowable force and moment
- Connecting Pipe : About 500kg
- Agitator : 4,300kg(Dead load), 10,750kg(Dynamic load)
- Live load of Urea unloading for IBC Tank Weight : 1,000kg

Therefore ;
 Dead load = 1,700kg + 628kg + 500kg + 4,300kg = Min. 7,128kg
 Live load = 1,404 kg + 1,000 kg = Min. kg 2,404
 Dynamic load = 10,750kg


My Question is how can i check loads that withstand cone.

if possible plz help me on this if u have any reference or excel sheet plz provide me

hope u understand the post now

thanks in advance.

Regards
Gururaj
Design Engineer (Static Equipments)

 

[IFRs]

MJCronin had it 100% right, in my experience the agitator is supported by steel I-beams that span the tank and have vertical I-beams that go down the tank shell. The loads are easily taken by the tank shell. This is easy to design and economical to install. The roof nozzle connects to the agitator but is not designed to take any load. A self-supporting cone roof is unlikely to support these loads ( which are probably quite a bit more than the tank ) unless it was expressly designed to do so which based on its thickness it was not. If you insist on analyzing the roof, plan on a lot of FEA, and probably strengthening the nozzle, roof, roof-to-shell junction and possibly the tank shell itself. With that much weight up high, also check seismic stability - you may need anchors ( the tank is more than twice as high as it is wide ). Good luck and let us know how it turns out!