6 replies to this topic

[Ghasem.Bashiri]

Dear All
Refer to attachment you can see a closed drain drum equiped with a heater.
Previous design was Electrical heater but it was proposed to use steam heater.
But I think condensate accumulation in coil (as Drum is underground) may cause some problem. Major concern for shift from Electrical to Steam heater was maintenance. Is there any good practice for this issue?
What is your proposal for optimum design for this issue?
Ghasem.Bashiri@gmail.com

Attached Files

•  Electrical Heater for Closed Drain.doc   85.5KB   52 downloads

[Zauberberg]

In 100% cases so far I used to see electrical heaters employed in such service. They are reliable, accurate, self-regulating, you name it. And I don't understand the maintenance issue - having steam tracing will call for more maintenance for sure.

[Ghasem.Bashiri]

Our client stated that:
We have bad bad experince with Electrical Coil within such drums!
But you said that in 100% cases you used Electrical heater.
Assume that I want to explain this issue to our client. What is your proposal. He had bad experince with electrical heater that I dont know it.
But also I dont know bad issues for steam heater.
I dont know but is there any Design practice for this item from well known companies.
Ghasem Bashiri

[Zauberberg]

You can ask the client where is the problem with electrical heaters, and what was done wrong before. Perhaps the manufacturing quality was poor, or there were some other issues unknown to us. How can we answer that question without knowing any details?

[Art Montemayor]

What I do know is that it will be exceedingly difficult and practically impossible to automatically drain a submerged coil with a steam trap that is located at an elevated position.

How do you intend to ensure that the steam trap is:

1) initially 100% filled with liquid condensate?
2) kept functioning as a liquid trap - i.e., draining only the formed condensate?

This submerged steam coil is an un-workable design unless you place the steam trap (or any other condensate removal device) at or below the coil itself. You can make it work - but with constant purging and priming of the coil and trap involved. The only way I've seen this system work is by continuously purging a % of the introduced steam out to atmosphere through the condensate discharge. Otherwise, the coil will flood and the coil will stop heating.

[fallah]

In 100% cases so far I used to see electrical heaters employed in such service. They are reliable, accurate, self-regulating, you name it. And I don't understand the maintenance issue - having steam tracing will call for more maintenance for sure.

I agree with Zauberberg,but i have seen the cases with steam heater also.

Indeed,we had some drums with steam heater were converted to electrical type based on HAZOP study.The reason was simple:Potential of steam condensate freezing due to auto refrigeration during incoming fluid expansion!

[breizh]

Hi ,
On the market you can find cabinet where you can bring a pallet or more of drums for heating .
Electrical heater or steam heater are available.
Breizh