"U" tube creation based on point cloud

[iogurt1]

I work in the heat exchanger industry and most of our designs have U-tubes in them. So far we've always created every tube separately and inserted them into our tube assembly. I've been playing around with iLogic over the last little bit and am now wondering if any of you have a good idea on how I could create these U-tubes automatically.

We always start off with a point cloud (see picture - the cloud is symmetrical around the blue center line) on a 2D sketch that shows the tube layout. We then use the hole feature the create tube holes in the baffles and other parts. Once the structure of the tube bundle is done, we create U-tubes.

Is it possible to use this point cloud to create these tubes automatically? A few things I have been thinking about so far:

- using iLogic, apply 2 circles (ID and OD of the tube) to every point in the cloud.

- In the bundle assembly, the only things I'd need are the center plane, the point where the tube starts and the straight length. With this information it should be possible to create the tube.

I haven't had any success as of yet and am looking for someone to give me that final nudge in the right direction 🙂

Thanks

[Jef_E]

Hi,

It's very interesting subject, I used to work in this industry and also played around with this a bit.

I have some questions before I can help you, to sketch the situation.

1) What creates the points cloud? Are these standard sketches or are they also created by i-Logic?

2) Are the tubes on the same row all the same length? (should you create a part for each tube or for each row?)

3) Is the tube bundle a U bend bundle only or are the outer tubes 3 bends?

[iogurt1]

Hi Jef_E

Thanks for taking the time to look at this. Here's the answers to your questions:

1) The point cloud is created either by hand in the sketch environment OR sometimes we get an excel sheet with coordinates we can import from the thermal engineering department.

2) Yes, tubes on the same row are exactly the same length (and therefore the same .ipt file)

3) They are all u-tubes. The only difference from the innermost tubes to the outermost is just the bend radius. Straight lengths are all the same for all the tubes.Over the weekend I have thought about some more options but still couldn't come up with a real solution (again, the following are just brain farts 🙂 ) :

a) it would be great if we could select a row of points and then it populates the entire row with tubes that are the same (same .ipt file)

b) If we could select all the centerpoints at once, could we let Inventor measure the distance to the center plane and for every different distance it finds, populate the points with the respective tubes (again, same .ipt for same row is crucial)

c) let's say we can't automatically create the tubes, we can still create them the same way we do now: They are iLogic components and when you go place->iLogic component and select a previously created tube, the configuration interface comes up right away where the user enters the bend diameter and row number (straight length is already populated since they are all the same) and it gives it the next number (automatically from Vault). This process only takes a few minutes even if there are 30 rows up tubes. The biggest time waste we have right now is to then insert these tubes into the bundle and constrain them to the tubesheet. On a 2-pass unit it's easy: you insert the 1st tube and pattern it accross the tubesheet and move on the next row of tubes. The problem comes in on units with more than 2 passes: The pass plate groves in the tubesheet create tube-hole distances that are not consistent anymore so you can only pattern the let's say first 4 tubes, before you need to insert another one and do another pattern. I hope it's understandable what I'm explaining here haha. If not I can always provide more pictures.

So if we could find a solution that places a tube on a row of selected points, even if they are not equally spaced, that would already help reduce our bundle creation time by a lot.

[Jef_E]

Why don't you just set the outer left or right hole for each row from the point cloud and then use a pattern to create the entire row of holes?

If you do this, then you can place 1 pipe into the plate for each row, and use pattern with feature recognition to follow the holes pattern?

This would save alot of time and still have no automation on it?

Edit: this doesnt mean it can't be fully automated.

[iogurt1]

I think the problem with that is the following: Let's say Tubes 1 to 4 in the same row have an equal spacing of 1in between them. But 4 to 5 have 1.5in because of a pass plate. 5 to 10 have 1in again and 10 and 11 have 1.5in. Since the point clouds are not created as a "feature", can it still recognize the pattern from the sketch? What if we have the point cloud imported from an excel sheet?