By specifying a pressure drop we're accounting for a "natural" pressure drop in the system or a valve used to obtain a specific pressure. The pressure is important because equilibrium curves change based on pressure. A pressure drop doesn't always improve separation, but we account for it in practice because that's how actual equipment operates.
The problem is under specified if you only have one property. You can use Temperature/Pressure, Temperature/Vapor Fraction, or Pressure/Vapor Fraction. If you don't have the Vapor Fraction then use Temperature and Pressure instead
what if my feed pressure is 200 bar and seperaor I want to operate it at 10 bar. How to model do in this case. When I put dp 190j bar error message comes as negative pressure in the sepertor. Please can you help thanks a million
Make sure the units for DP are correct and try to use a lower number to make sure it's doing what you intend for it to do. If there's a convergence error with the flash drum you can try to use a valve to expand the stream before it enters the flash drum to see if that works better.
When you specify a pressure in that box it is the Pressure decrease across the Flash Drum. In this example, by specifying a pressure drop (delta P) of 5 kPa the outlet pressures are 5 kPa lower than the inlet (96.32 kPa vs 101.32 kPa)
what should i do to make Hysys calculate the proper vessel design parameters, as i can see u ignored the flash drum design parameters in this tutorial which will affect the results for sure.
Because the flash drum calculates everything at equilibrium the size isn't an issue here. Most things in process simulators ignore sizes unless you're costing the equipment or running a dynamic simulation. If you use the costing tool it should give you some basic dimensions for the vessel one the problem is solved.
thanks I wish if you had more Aspen videos you are really helpful!
Hello
so how do you calculate that pressure drop for a flash tank.
Please make a video on lpg flash drum calculation which has flow of 60 GPM
Shoooooow!
Hey, so by specifying a pressure drop are we naturally decreasing system pressure, resulting in better separation? Please if u can clarify
By specifying a pressure drop we're accounting for a "natural" pressure drop in the system or a valve used to obtain a specific pressure. The pressure is important because equilibrium curves change based on pressure. A pressure drop doesn't always improve separation, but we account for it in practice because that's how actual equipment operates.
hi can i get the software
what if I have my temperature but not the vapor fraction
The problem is under specified if you only have one property. You can use Temperature/Pressure, Temperature/Vapor Fraction, or Pressure/Vapor Fraction. If you don't have the Vapor Fraction then use Temperature and Pressure instead
what if my feed pressure is 200 bar and seperaor I want to operate it at 10 bar. How to model do in this case. When I put dp 190j bar error message comes as negative pressure in the sepertor. Please can you help thanks a million
Make sure the units for DP are correct and try to use a lower number to make sure it's doing what you intend for it to do. If there's a convergence error with the flash drum you can try to use a valve to expand the stream before it enters the flash drum to see if that works better.
What does the delta P function do at 4:06? What does that mean?
When you specify a pressure in that box it is the Pressure decrease across the Flash Drum. In this example, by specifying a pressure drop (delta P) of 5 kPa the outlet pressures are 5 kPa lower than the inlet (96.32 kPa vs 101.32 kPa)
Ok, Thanks! :)
what should i do to make Hysys calculate the proper vessel design parameters, as i can see u ignored the flash drum design parameters in this tutorial which will affect the results for sure.
Because the flash drum calculates everything at equilibrium the size isn't an issue here. Most things in process simulators ignore sizes unless you're costing the equipment or running a dynamic simulation. If you use the costing tool it should give you some basic dimensions for the vessel one the problem is solved.
Hehehehe