I like to know when applied loads

[SKJ25POL]

I like to know when applied loads from conveyor belt to structure (Truss), at the location of the drive pulley or tail pulley, are there any bending moments we apply from pulleys to the structure? How the pulleys (head and tail) in inclined Gallery conveyors attach to structure

Anybody has good details how Drive pulley and Tail pulley attached to structure? Are they separate from structure or they always attach to truss?

I appreciate if any references or pics or details you have to share.

Thanks

 

[r13]

The conveyor has its own support system, that shall be separated from the building frame, unless the truss is part of the conveyor system.

 

[SKJ25POL]

Is it better I post this in Mechanical Engineering groups?
Anybody structural has experience with belt conveyors?

Thank you

 

[bootlegend]

In my experience the conveyor pulley loads are transferred to the supporting structure through the bearings at the end of the shaft. Load path after that is dependent on the specific situation.

 

[SKJ25POL]

bootlegend (Structural)
Thank you for your response.
I am trying to understand and follow the load path from belt and idlers to structure and then to the ground.
Anywhere book, article, picture, a drawing, a sketch available? I have hard time just picturing words and statements.

Thank you

 

[phamENG]

It would probably be more useful for you to post a picture/drawing of your proposed situation for input.

Though for what it's worth, no - pulleys typically don't apply a moment to the supporting structure (at least not in any significant sense). They turn on bearings with a "theoretical" zero resistance. No rotational restraint means no moment on the structure. You just have to account for the weight of the pulley and the trib of the cable or belt running on it at its support. Motors are a different story - the anchors have to resist the torque they're generating.

What's your role here? Are you working for the conveyor manufacturer or the building owner/architect?

 

[Blackstar123]

I am trying to understand and follow the load path from belt and idlers to structure and then to the ground.

As phamEng said, pulleys typically don't apply a moment to the supporting structure because, "ideally" they are designed to rotate freely.
End pulley's are usually mounted on a shaft resting on a frame. These shafts are designed to resist vertical and lateral loads from belt conveyor. Vertical reactions are due to the dead load + weight on the belt. Lateral reaction is due to the friction force produced due to belt running over the end pulleys.

Most manufacturer are responsible for providing the design of intermediate frames for belt conveyor along with the frames to support the tail and discharge end pulley. Therfore, they will usually provide you the maximum reaction at location of end pulleys, the load on belt conveyor, and required base connection details with supporting structure.
Depending on these connection details, you can easily determined how these end reactions or forces will be transferred to your supporting structure.

Is it better I post this in Mechanical Engineering groups?
Anybody structural has experience with belt conveyors?

1. If you want to, definitely. A mechanical engineer may give you better response about the working of a belt conveyor and true mechanism of pulleys, than any of us.
2. Yes, I've designed various structures to support the belt conveyors.

 

[r13]

I suggest go visit a cement/concrete producing plant, or quarry, and have a close look at the conveyors on its structure, and how it works.

 

[Accumulated]

Usually, Discharge end and tail-end are supported on a different frame from the conveyor.
All the loads on the idler and conveyor will be dead vertical loads + weight of the material carrying.
Similar principal but different story when the conveyor is going around a curve. You would then need to take care of belt tension acting on the idlers.

 

[SKJ25POL]

Accumulated (Structural),
Thank you for your reply. "Tail end supported on a different frame" May I ask do you have a sketch or pic/drawing showing it and you can mark on it. I love to see how it is and how that get connected to rest.

Blackstar,
Thank you for your comment. "End pulley's are usually mounted on a shaft resting on a frame." May I ask do you have a pic or sketch /drawing showing it in detail?

Thank you guys
Skj

 

[phamENG]

SKJ25POL - I'm sure we'd all love to help you, but without knowing your configuration, there's not a lot we can do. Showing some random detail from a project we did in the past may help you and may set you up for horrible failure. Every project is different - typical details are typically wrong.

Please post a drawing of the project your attempting to design and maybe one of us can give you a nudge in the right direction (because I don't think anyone here is willing to design it for you outright).

 

[dhengr]

SKJ25POL:
Given where you are starting from, or where you seem to be at the moment in your understanding of this type of equipment, you would do well to get some literature and drawings from several conveyor manufacturers and study them in detail. Maybe some plans and specialties literature and drawings from a previous job. Each will have much in common, but also some details which are that supplier’s stds. and not the same as other’s details. There are many different possibilities dependent on each job, and we just can’t answer/determine these for you in this forum. We can try to answer specific questions, given enough initial engineering design info., but we really can’t teach structural/mech. engineering design from scratch. You should be asking these questions of your boss, so he/she can guide you along the way, and so they know what you know and what you don’t know, so they can keep you and the company out of trouble. You probably shouldn’t be doing this on your own, at this point in your development.

 

[SKJ25POL]

phamENG (Structural),
Thank you for your comment and question. I am not working on any conveyor design or project at the moment so I dont have a pic or a drawing to show or ask. I am trying to learn it and understand it. I am looking for a Gallery truss conveyor belt - inclined outdoor/ industrial environment.

dhengr (Structural),
manufactures are just thinking to sell soon they see you want it to learn they wont answer you.
They first ask your information to see if you are good piece of pie!!! How can I get something from sharks !!!
I am trying to learn it for my self my boss and work place doesnt do conveyors so I cant ask my boss!!!
And I am not deigning any conveyor just trying to understand and that even brings me tons of criticism !!!
Man learning is becoming pain in the neck people are so dominant of their industry !!!

Thank you all
Skj

 

[r13]

Skj,

Whether is getting better, and it is nice to walk away from the desk, have a field trip, and learn from your eyes.

 

[phamENG]

SKJ25POL - got it. In that case, I would say that in all of the conveyor systems I've been involved with (a few, not a lot), they have been "packaged deals." I get a general arrangement drawing to make sure it fits in, on, and/or around the building, and a drawing with connection points and resulting loads. The good ones give wind, live, dead, and snow breakouts at each point. Moments if applicable, but at least axial and shear. I apply those loads to the structure, and that's that. I don't have to worry about accounting for individual components (like pulleys or motors), and usually don't even have to worry about vibrations since the manufacturer typically takes care of them within the "package."

If you want to understand what's going on inside, you'll have to follow retired's advice if you can't get any manufacturers to send you information. Especially if your office has industrial clients. Let them know you'd like to come out and see some of their equipment and watch it operate. You'll (hopefully) have to sit through a safety lecture, and then start learning.

 

[Blackstar123]

I understand what you're going through.

The mecahnical suppliers I've worked with used to specify the max load on conveyor and reactions at discharge and tail ends and we were asked to calculate the load at support points by ourselves.

When I first started designing structures with belt conveyors, I used to search the web for hours looking for a belt conveyors similar to the one I was working on. At that time I'd no idea, how the tail and discharge ends actually look like, whether loads from tensioing tower will be transferred through pulleys to belt conveyor frames or not. Understanding the loads given at discharge end and motor&gear loads was extra difficult.
There were no senior engineers to help me make sense of the given loads. Whatever I learned, I learned from the web and brain storming with fellow colleagues who were working on this with me for the first time as well. Suppliers drawings helped alot. The ones I've worked with use to provide everything but reactions at supports.

I know that sharing official supplier drawings on web is not in my office policy. So I can't really help you in that regard.
I'll advise you to search the web, you can find everything on it these days or better yet show us the conveyor which is giving you trouble and we might help.

 

[Blackstar123]

If you want to understand what's going on inside, you'll have to follow retired's advice if you can't get any manufacturers to send you information. Especially if your office has industrial clients. Let them know you'd like to come out and see some of their equipment and watch it operate. You'll (hopefully) have to sit through a safety lecture, and then start learning.

I was disappointed in this regard. When we finally got to visit the plant with all the equipments in place, the belt conveyors were covered from the side by sheets.

 

[phamENG]

True. That's why I suggested going to an existing client. They'll have to remove machine guards for you to see it. If it's operating, that means additional personnel to act as human guards to keep people out (assuming the site has a reasonable level of safety awareness). It'll take a solid relationship to convince them to do that.

 

[r13]

A simple web search resulted in this. Wish it helps. Link