9 replies to this topic

[chemks2012]

Hello all,

 

Please find the attached simple sketch.

 

I am sizing RV01 and wish to consider one of this scenarios please but not sure if this is a credible scenario and I want your opinion.

 

The reactor jacket is supplied with low pressure steam at 2barg.

Relief valve set pressure is 6barg

Jacket design pressure is 7barg

 

If control valve [CV01] fails and AV04 is closed as well as jacket inlet is blocked – the steam flow through failed control valve would be 1000kg/hr steam. Do you think RV01 will be activated at all as the steam pressure is 2barg?

 

I am bit confused and I need your help.

 

Thanks

Attached Files

•  sketch.PDF   140.66KB   11 downloads

Edited by chemks2012, 04 June 2014 - 06:49 AM.

[fallah]

Nothing attached...!

[chemks2012]

Hi Fallah,

Can you download the attachement now?

Thanks

[fallah]

Yes, thanks...

[fallah]

Hi,

 

Is the CV01 full open in failure position? At the same time what are the AV03 and AV02 situations? Is the steam pressure source 2 barg or this pressure is after CV01 in normal condition?

[chemks2012]

Hi Fallah,

 

Supplier confirmed when CV01 is 100% open it will pass 500kg/hr. I applied safety factor of 2 giving 1000kg/hr.

 

When steam is supplied, all valves will be closed except AV02.

 

Steam is supplied from a boiler which is locally protected by a relief valve at 2.5barg.

 

Yes, pressure drop through CV01 is 0.5bar when it is 100%. So let's say pressure at the CV01 downstream would be 1.5barg.

[fallah]

Hi,

 

No, this cannot be a credible scenario to overpressure the steam jacket with design pressure of 7 barg...

[chemks2012]

Thanks Fallah,

 

But I am just wondering what will happen to the blocked steam in that situation?

[fallah]

Hi,

 

If during CV01 failure the AV02 isn't closed, the steam isn't blocked. If AV02 is closed, the steam is blocked in the jacket with a pressure of 2 barg. Then...2 barg LP steam in a jacket with DP of 7 barg...appears nothing happens other than after a while having a flooded jacket with the steam condensate...and a reactor that cannot absorb adequate heat to do the reaction at proper rate...!

Edited by fallah, 04 June 2014 - 07:39 AM.

[chemks2012]

Thanks Fallah..

I believe, even if I consider that all the valves are closed, CV01 fully opens and the jacket nozzle itself is blocked [i.e. not letting steam flow in], steam will just condensate and hammering may occur but it will not cause a relief scenario?