If Your Saved File

MCH.apw is

Displayed

If Your Saved File

MCH.apw is not

Displayed

Getting Started Building and Running a Process Model Creating a Process Flow Diagram 6-3

Switching to PFD Mode

Simulation mode is the Aspen Plus default mode that you use to

model a process or perform calculations. PFD mode is used to

create a graphical representation of your process for a report or for

display purposes. Use PFD mode to do the following:

Add equipment icons and streams that were not explicitly

included in the simulation.

Display stream data.

Display a results table.

Add a title.

To toggle between Simulation Mode and PFD Mode, use either of

the following methods:

Select View | PFD Mode.

Press F12.

The check mark next to PFD Mode in the View menu and the

status bar at the bottom of the main window indicate that PFD

mode is on. Also, the process flowsheet workspace has a thick

colored border when you are using PFD mode.

When you select PFD mode, Aspen Plus creates a new graphic

identical to the original flowsheet. This new graphic is independent

of the original. Making changes to streams and blocks in either one

and toggling modes will show that these changes do not cross over.

Note: If you change the original process flowsheet model and you

wish to start over again with a new PFD style drawing that contains

these changes, select View | Reset PFD while in PFD mode. Your

old PFD will be deleted and it will be replaced by a new drawing

identical to the process flowsheet from your revised simulation

model.

6-4 Creating a Process Flow Diagram Getting Started Building and Running a Process Model

Adding a Pump to the Diagram

In the MCH simulation, you did not model the feed pump to the

column; instead, you simply specified the pressure in the feed

stream. However, you may wish to include a feed pump in a

drawing used for a report or display.

Place a pump in your diagram and split Stream 1 into two streams

– one entering the pump and one leaving the pump and entering

Block B1. Follow the directions below.

1 Enter PFD Mode by selecting View | PFD Mode if you have

not already done so. Look for the colored border on the process

flowsheet and the words PFD Mode in the bottom status bar to

ensure you are in PFD Mode.

2 From the Model Library, click the Pressure Changers tab.

3 Click next to the Pump unit operation model.

4 Hover over the icons to see their labels and select ICON1.

5 Drag (click and hold) the selected icon to the Process

Flowsheet window to create Pump block B2.

6 Place the pump icon in the middle of Stream 1.

7 Select Stream 1 and right-click.

8 From the shortcut menu, select Reconnect Destination.

Stream 1 is now disconnected from Block B1 and you are ready to

reconnect it to the pump.

9 Move the cursor arrowhead to an inlet port on the pump and

left-click.

Stream 1 is now enters the pump and you are ready to create a new

stream from the pump to Block B1.

10 Click once on on the left side of the Model Library.

11 Move the cursor (now a crosshair ) to an outlet port on the

pump and click once.

12 Move the cursor (now an arrowhead ) to a feed port on

Block B1 and click once to create a fifth stream.

Note: To cancel connecting the stream at any time, press ESC.

To Add the Feed

Pump to the PFD

Diagram

To Insert the Pump