Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in

PRV Design issue as process getting crystallization.(solid) 1

Status
Not open for further replies.
Mussha

Mussha

Mechanical
May 5, 2021
37
0
0
SA
In our storage Terphenyl Product tank, we are facing issues with Emergency Vent cover & Breather valve.

The Emergency vent cover pops up within 100 mmWC while its set pressure is 150 mmWC and process crystalizes & cause continues passing.

While Breather valves is not even passing and popping up. During overhauling, we observed the process crystallization.

To prevent the crystallization of process in the valve seats during operation, we provided electrical heat tracing cable over the valve bodies. But not effective.

Anu suggestion for suitable Breather valve and Emergency Vent cover for our process material Terphenyl with Melting point 200-220 DegC.

 
Replies continue below

Recommended for you

Sort by date Sort by votes
Hi,
Consider breather valve and emergency vent steam Jacketed!
Make sure your steam supply is reliable. I had bad experience on a phenol tank.
Pierre
 
Upvote 0 Downvote
Yes Sir, it is well insulated but only covering body, material getting pop up in the form of crystal, refer photo. Thanks for feedback.
 
Upvote 0 Downvote
@Pierreick
Actually, we don't have in our faculty high temp. steam, because required temp. is 200-220degC. we are having steam upto 160degC.
 
Upvote 0 Downvote
Mussha said:
Electrical tracing set point is 180degC.
Click to expand...

But, that is below "process material Terphenyl with Melting point 200-220 DegC". Do you see the problem? Does the Terphenyl form "whiskers" during it's deposition from vapor to solid?

Good Luck,
Latexman

 
Upvote 0 Downvote
What is the opening system of the emergency valve? It is quite a low pressure, but shouldn't be opening at 2/3 of its set pressure.

What is the set pressure of the "breather " valve?

What temp is the rest of the tank maintained at?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Upvote 0 Downvote
Mussha,
You cannot have an electrical tracing supplying a temperature below the freezing point of your product!
You need a heating source above the melting point of Terphenyl.
How is managed the temperature in the storage tank (hot oil?)?

Pierre
 
Upvote 0 Downvote
@Latexman Yes sir, below 200degC it is getting crystalized, we know that Electrical heating set point is not sufficient, that's why we want to look for another suitable option. For more detail pls refer
@LittleInch Sir, can you pls go through the thread where i attached P&ID with other detail and also photo. i m getting issue uploading photo here.
@Peirreick Yes Sir, that what we want to search suitable option hence i came here for expert opinions. Tank is having steam coil inside with N2 blanketing. pls refer
 
Upvote 0 Downvote
Hi,
You said in a previous reply that the steam temperature is below 200 C and your freezing point of your product is above 200-220 C!
This is totally wrong. Your heat source must be above the melting point of your product, to keep your product in liquid form.
Is your tank blanketed?
You must address this with your process engineer and safety manager.
Pierre
 
Upvote 0 Downvote
@Pierreick, steam coil inside the tank which keeping TP in liquid form. But only we are facing issue in PRV/ERV. where we can't be able to provide the high temperature steam jacketing. Because we don't have high temperature steam in our facility. Manufacturer of PRV/ERV recommending for high temperature steam jacketing.
Regarding the blanketing we have N2 blanketing for the tank.
 
Upvote 0 Downvote
@Shvet, Yes, we are looking solution to avoid crystallization at PVRV/ERV.

@LittleInch, Sir difficulty is providing high temperature steam as we don't have facility in our plant. And manufacturer provide option for steam jacketed solution only. They are not giving option other than steam jacketed PVRV/ERV. we went to KSPC, korea who is OEM for our other PVRVs. we didn't approach as of now what you mentioned, Thanks for the name we will approach them.
 
Upvote 0 Downvote
The "normal" HT cable only goes to about 200C. They might not be aware of this higher temperature cable.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

therunningbruce
  • Question
Retube process key steps 3
Replies
5
Views
17
chicopee
chicopee
sentenza
  • Question
Air removal before thermal process
2
Replies
28
Views
35
shvet
shvet
EEENGRX
  • Locked
  • Question
SRU FLAME SCANNER ISSUE
Replies
5
Views
6
mk3223
mk3223
Rubbman
  • Locked
  • Question
Vacuum pump - cooling plugging issue
Replies
1
Views
2
EdStainless
EdStainless
Said92441322
  • Locked
  • Question
Aspen EDR Design & Simulation Mode Difference
Replies
6
Views
7
georgeverghese
georgeverghese
Back
Top