Length of distillation column segments

[Dinber]

My first question here, so let's give it a try...

We construct the distillation column, for example 50m long. Because of the transport we have to make it in a few segments. What i want to know is, are there any (standard) advices/restrictions on how long these segments should/must be? Also, are there any advices on how they should be connected, welded or in some cases it can be a flange?

In some literature i found that max length of one segment can be 12m, but there are no any explanation about it. I asked some engineers, they said it's because of the length of trucks trailer.

I'm young engineer, so please have some understanding.

Thank you in advance!

 

[hokie66]

This depends almost entirely on transport restrictions. Transport companies should be able to advise you as to local requirements and availability of haulage equipment.

 

[Dinber]

@hokie66

Thank you sir for a quick answer.

 

[KootK]

This thread provides some interesting discussion (and a great paper) on the theoretical aspects of column splicing: Link. I might look to monopole design guides for precedent.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[moltenmetal]

Asking a shipping company what dimensions they can ship usually ends up with an answer like "we can ship anything"...because you're asking the wrong question. What you really want to know is what is practical to ship, and that depends on vehicle dimensions, which in turn depends on the required modes of transport, the diameter and weight of the column segments in question, the routing taken from source to destination etc.

Some over-dimension shipment issues are minor, such as obtaining permits, route optimization, restricted travel hours or days through certain cities etc. Others some add cost- special trailers and/or tractors, pilot cars, escorts, police escort etc. If you need to start relocating utility wires, leaving the highway at every overpass, or switching modes of transport to get around certain obstacles (tunnels etc.)

 

[JoshPlumSE]

Not much to add here. I have always been told that standard semi-trucks can transport a max length of approximately 36 ft. That's not exact, but it's merely my recollection. Give it +/- 10%.

But, in cases where you require specialty transportation (which is expensive) you can get twice that.

 

[jayrod12]

Maybe it's me but I see a lot of 53 foot trailers. Wouldn't that mean it could be closer to 50 foot pieces?

One way or the other, every 2 1/2-3 1/2 storeys is where I've seen typical splices.

 

[moltenmetal]

OK, assuming it's a small enough diameter to fit on a flatbed, you can easily ship pieces which are two full random lengths of pipe welded together, i.e. 38-42'. We routinely receive truckloads of 48' lengths of HSS here and there's no special trucking required for that. It gets more complex when diameters and weights get larger. The rules and costs for longer lengths depend on routing. Over length vehicle permits and escort requirements vary from province to province and state to state in Canada and the US.

 

[dhengr]

Dinber:
We have to know much more about your fabricated vessels to have a meaningful discussion. What weights, diameters, lengths, structural strength of the vessels themselves, max. dia. at flanges, nozzles, and the like for clearance studies? Your company must be shipping these types of vessels now, how are they doing this? Talk with some transport people within your company or contractors who might do this function for you. They can help you understand clearance and size issues. They can explain the various transport equipment available, travel routes available, etc. If the vessel won’t fit on a std. flatbed or low deck (lowboy) trailer, you are almost automatically in a special transport realm. If the vessel is strong enough it can be placed on a low level dolly up at the tractor and another steerable dolly in the rear, and hung only a few inches above the pavement to improve topside clearances. 150' is not an impossible length for this type of movement. The transport people will have to do a clearance study to determine the route of transport, but those people do this for almost every load they move, so this isn’t new to them. This special transport and its added costs comes into play when field assembly cost become very high, such as the need for post weld heat treatment, in the field, or things like that. Take a look at You Tube, Google ‘High, Wide and Heavy Load Transport,’ ‘Heavy load transport,’ or some such, to see some of what can be done.