Depressurization using blowdown utility in Aspen HYSYS

Following topics are covered in this video:

a. What is depressurization?
b. Why to depressurize?
c. What is 50%/15 minute Old API rule?
d. What is 50%/15 minute New API rule?
e. How sizing affects due to these Old and New rules, is exemplified in Aspen HYSYS?
f. Adiabatic depressuring problem is solved in Aspen HYSYS.

This video should help you learn about blowdown utility in HYSYS.

Thanks and regards.
Ajay S. Satpute
M.Tech. (Chemical), I.I.T. Madras
Managing Director
Converge Engineering Pvt. Ltd.
[phone]
F109, Eastern Business District, Neptune Mall,
Bhandup West, Mumbai 400078

[altafjasnaik]

The EDPV or BDV is the most crucial part of any high pressure separator used in Oil & Gas industry maybe in EPF or main production facility. Great video showing how to use HYSYS to simulate and obtain results according to old and new API 521. Very helpfull for all the Chemical Engineers both experienced and new.

[aruncs]

Thanks a lot, sir 🙏 It is very informative. I hope to learn more from you and use them to find solutions in real plant studies.

[rameshcheppali]

Your videos are very nice. Your explanation and the way you present is awesome. I love your lectures so much and i never missed anyone. Thanks for sharing such a valuable information.

[bilauabdulwaheedademola]

Very well explained. Thank you for always.

[Truth_stings]

Thank you for the explanation. This helped me!

[pravinsivasankar]

Hi Sir, first of all thanks for the excellent contribution. Kindly clarify the following doubts without any hesitation pls

1. How do u fix the vapor fraction for inlet stream as 0.5 & Why dont we provide temperature rather than vapor fraction for fire case scenario ? If we can provide temperature what shall be taken as basis ?
2. What is the source of value for orifice co-efficient?
3. How do we determine the volumetric flow rate (For both pipeline & vessel) to run the simulation ?

Your positive reply will be highly helpful sir .


Thanks once again.

[anweshaghosh]

Can you please show a example isochoric depressurization?

[JayPrajapati-pc]

For a adiabatic case, calculated depressurization time is 3 hours. Is not too much? Can share your thought on it?

[rushikeshshinde]

Thanks a lot sir 🙏 It is very informative.
I want to know there are three options available in Hysys in blowdown and depressuring section
1) Blowdown
2)Depressuring
3) Staggered blowdown
Which one is use for which case?
Beacause we can do Adiabatic or fire depressuring in 1 as well as 2 case also.

[arman]

Hi Ajay, Thanks for the video. I just wanted to ask that for fire case depressuring why do you take the max operating temperature for dynamic depressuring utility and not the fire case temperature. Kindly respond

[RafiqMalino]

hello sir, for adiabatic case you use PAHH as inlet pressure to vessel. what basis do you use for inlet temperature? can we use TAHH as the basis?

[heitor]

Dear Sr, why at the minute 13:30, we cannot see the temperature at the Orifice? Is it possible to calculate? Can you explain us, how to do? Thank you!

[shabrazk]

please put up a video on PSV sizing for blocked, overfilling and fire case scenario

[gayathriK-bqrj]

Hi sir, Good morning. I am newer to use Aspen hysys. I have one doubt sir. U said that about wall thickness and length. How should we consider it sir

[UsmanAli-yehm]

Sir, for adiabetic case why PAHH pressure is used? Why not operating pressure?

[muhammadfitrahribin]

Hello sir. How about if we want to do BDV on pipeline? Meaning that the BDV is not attached to the vessel

[huyphan]

I can not find the requirement about how large of Vessel need to be depressurized. Could you help me?

[rishikeshsawant]

Which property package is used for this problem?

[vinodyadav_]

The statement about vapor depressuring rate as per new API rule as on date is not correct in the video. As per API Standard 521 seventh edition(June 2020, Errata 1, Nov. 2022) section 4.6.6 " For pool fire exposure, this generally involves reducing the equipment pressure from initial conditions to a level equivalent to 50 % of the vessel’s design pressure within approximately 15 min. This criterion is based on the vessel wall temperature versus stress to rupture and applies generally to carbon steel vessels with a wall thickness of approximately 25.4 mm (1 in.) or more. Depressuring to a gauge pressure of 690 kPa (100 psi) in 15 min is commonly considered when the depressuring system is designed to reduce the consequences from a vessel leak or failure. This criterion is also commonly applied for both fire and leak scenarios." Please check and confirm.