On the design of large powder silos
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May I ask about the design steps for a large powder silo? Design volume: 1350 cubic meters ； The bulk density of the material is 1650 kg/m³, the angle of repose is 32–35°, and it has good flowability ； Where should one start when performing the design calculations for the tank walls and bottom? In other words, where should I look for information? How to determine the location and number of support points for a grid structure supported by steel pipes? I earnestly ask fellow sailors to provide answers; the more detailed, the better! Thank you first!
It can be solved by checking standard NY4735.2.
JB/T 4735 Silos – calculations are possible; there are also calculation steps included
You’re not an expert in this field, right? Take a close look at JB/T4735
I would like to ask whether explosion protection needs to be considered for powders
It is said that JB4735-97 has many errors; you might also consider referring to sh3078-1996. Keep going – I’m also working on a 500-cubic-meter project...
Yes, it needs to be explosion-proof. There are requirements regarding protection and explosion-proof ratings
Powders have a lateral pressure that is different from that of liquids, and this needs to be taken into account
This calculation is quite complicated; it is recommended to follow the SH3078-96 \"Design Code for Vertical Cylindrical Steel and Aluminum Silos\" for the calculations, paying special attention to the calculations at the junction between the cylinder body and the hopper； Support can be provided using rigid ring lug mounts; a framework in the civil structure will suffice ； Recently, there was also a device of this type, with dimensions DN8500x15000 (it is still in the planning stage at present). I consulted experts on this matter, and they recommended considering the approach mentioned above.
I disagree a bit with the opinion above; in my view, for a silo of this size, skirt bases are more appropriate. It’s more complicated to calculate the rigidity of rings that support the structure at the waist level, whereas skirt bases, located at the junction of the lowest cylinder section and the hopper, make it easier to reinforce those areas locally. By the way, SH3078 is being upgraded, and **the calculations have undergone significant changes, as the height-to-diameter ratio of large silos generally does not exceed 5–10. The loads considered for large silos are different from those of containers; the operating pressure is probably only a few KPA. The main factor is the force exerted by solid materials on the silo walls. If there is a platform at the top to support the silo roof, this should also be taken into account. But from what the LZ says, it seems that the shape of this silo hasn’t been decided yet. Isn’t the \"bottom of the tank\" used for tanks with a flat bottom? Also, why does the bulk density of such materials have to be so high? . . ?
Ah, if it were a flat-bottomed pot, it would be much easier. Now, discharge is required from the bottom; the lower end cap is conical, and using a skirt would make it too high.