×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# Angle of Repose

## Angle of Repose

(OP)
Not sure if this is the correct forum to be posting, but is my best guess.

The angle of repose is basically the angle that from the conical incline (formed from an unconsolidated bulk solid falling freely onto a horizontal plane) to the horizontal.  I have learned that this is important in filling bins as it can create void space when the tip of the conical shape reaches the inlet of the bin.

Is it safe to assume that if the material flowing into the bin enters on a angle (or on the side) that the conical shape will follow the same pattern moving up its projected path?

Please see the picture for a better understanding.

So from the picture, the line with the arrow is the projected path of the material flowing into the bin.  The yellow material is the pile of material at say Time 1.  The orange and yellow is the pile at Time 2, and so on.  The light blue space is the void space.

Second question is about potash.  Is there available information on the angle of repose for this material?  What about a range of bulk densities?

Thanks!
Replies continue below

### RE: Angle of Repose

geotechnical engineers don't like the term "angle of repose."  We use the term "drained friction angle," which can be reflective of this pile slope, but not necessarily. . .

¡papá gordo ain't no madre flaca!

### RE: Angle of Repose

(OP)
Was my prediction for the conical or pile formation correct for the angled (projected) flow of material into the bin?

### RE: Angle of Repose

The angle of repose is achieved if the discharge point is close to the tip of the pile. The material could be piled at slopes shallower than the repose angle when there is a drop height. That is how I see the problem.

### RE: Angle of Repose

With silos, the "repose" angle might be affected by the proximity of the wall and wall friction - would not necessarily be that of an "open" or true repose of a pile (and dry vs moist would yet give different "repose" angles).  Silo earth pressures have been discussed in a couple of other forums.

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!