Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*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.

Students Click Here


will a sloped 8" pipe freeze?

will a sloped 8" pipe freeze?

will a sloped 8" pipe freeze?

Hello all,

As you can see I'm not a civil, but I've been tasked with designing a drain system for a coal power plant. My issue is, do I need to heat trace the drain line for winter use? Here's some points about the drain:

- 8" diameter carbon or stainless steel pipe; still haven't decided on material
- 20-30 degree slope down a coal conveyor belt enclosure
- About 700 feet long
- Will be a coal dust and water slurry; not sure of the coal dust to water ratio
- Belt enclosure is not heated
- We get down to the single digits or negatives (in Farenheight) for several days at a time, and stay below freezing for weeks in the winter
- Will use the system once a day; approx. 200 gallons over two hours each use

I can't tell if the slurry will build a small layer of ice each use until it clogs and bursts without heat trace, or if it will be ok. Any thoughts are welcome and thank you in advance!

RE: will a sloped 8" pipe freeze?

it will form ice and the rate of ice accumulation will be directly related to the weather and the flow rate, one of which you cannot control. but 200 gallons is not much so it is a risk you need to evaluate

RE: will a sloped 8" pipe freeze?

Unless you're putting boiling water down it it will freeze and block after the first or second day, especially as it is basically dribbling down it. Even boiling water will probably freeze by the end of the third day.

Yes you need to trace it.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: will a sloped 8" pipe freeze?

Waterfalls freeze in weather like that. Your pipe will also freeze unless you trace it.

RE: will a sloped 8" pipe freeze?

Im glad all previous posters gave you the same advice because I agree 100%. But I would also note that the flows you allude to are less than 2 gallons per minute and at that flow I would think that a 2 inch pipe would be more than adequate. Smaller diameter means higher velocity, means less weight of steel, less surface area to lose heat , all of which reduce the liklihood of freezing.

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.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


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:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close