4 replies to this topic

[Behzad_1981]

Hello everyone,

 

I need your assistance for the preparation of dimethyl ether. 

I have simulated the whole thing and it has converged. But for exporting to the dynmic simulation the pressure check is pressed.  Then I get a message like this.

 

 

Warning for inlet pressure drops:

The inlet stream pressure is not equal to the block pressure in the following blocks:

 

B11

B15 stage 15

B17 stage 18

 

For dynamic simulation, the inlet pressure change will be fixed to the steady state value. If you want the inlet pressure drop to vary with flowrate, change your simulation to use a Valve to model the inlet pressure drop.

 

 

Pressure Check completed with Warnings.

Attached Files

•  DME_05.03.2021.png   298.39KB   1 downloads

Edited by Behzad_1981, 05 March 2021 - 06:09 AM.

[pmoneysh]

you can manually change the inlet pressure equal to the stage pressure. Or you can export this file to dynamic mode since this is not an error but a warning which is fixed by aspen itself when exported.

[Behzad_1981]

Thank you for the answer, that is correct I have set the feed pressure equal to the stage pressure and the error is solved, but in another simulation it does not work so, I have reduced the weir height according to William Luyben, and still the error is there.

[pmoneysh]

Increase the  pressure drop along the column. There might not be enough driving force.

Edited by pmoneysh, 08 March 2021 - 11:18 PM.

[Behzad_1981]

Thank you