Stream Drawing

If you plan on drawing several streams, one after another, it is easier if you switched to Connect Mode. To enter the connect mode, click on the connect button  displayed on the main toolbar. Notice that the cursor changes into the ‘Connect Mode Cursor’, to remind you, that the system is now in connect mode:

: The Connect Mode Cursor.

Remember that when you draw a stream you always start from the source and then conclude the drawing at the destination of the stream. For input streams, without a source procedure, you start from an unoccupied area of the flowsheet. For output streams, without a destination procedure, you end at an unoccupied area of the flowsheet. After you start the process of drawing a stream, you can either add your own elbows to give a custom-appearance to all the stream segments, or you can directly end the stream by designating its destination point (and let the application auto-draw the stream segments.) For step-by-step instructions on how to draw an input, intermediate or output stream see below.

●      To draw an input stream...

1.   To draw an intermediate stream...

3.   To draw an output stream...

The system remains in connect mode after a stream has been created in order to allow you to create the next stream. When you are finished drawing streams, you should return to Select Mode by clicking on the select button  of the main toolbar. The select mode cursor will appear:

: The Select Mode Cursor

►    To draw an input stream...

5.   Make sure you are in connect mode (the button is pressed o the main toolbar).

1.   Since you are always drawing streams source-to-destination but input streams do not have a source procedure, move the mouse to an unoccupied area of the flowsheet (where you wish to start the drawing of the input stream) and click once to start the drawing the first segment of the input stream. The first segment can either be horizontal or vertical.

3.   Move the mouse to draw either a vertical or a horizontal segment for the stream. Do not hold the mouse pressed down as you are moving it to create the segment. Notice that you don’t have to be exact in your horizontal or vertical motion with the mouse as the system always draws either horizontal or vertical segments (approximating the exact location of the mouse to the nearest horizontal or vertical location).

5.   A single mouse click ends the current segment and starts another one. The next segment must alternate its orientation. In other words, if the previous segment was horizontal, then this segment must be vertical and vice versa.

1.   Repeat steps (2) through (4) to give the desired shape of the stream by adding extra segments (if so desired).

3.   End the stream by a single click on an unoccupied input port. Note that an input stream cannot end with a vertical segment.

►    To draw an intermediate stream...

5.   Make sure you are in connect mode (the button is pressed o the main toolbar).

a)  Since you are always drawing streams source-to-destination, move the mouse over an unoccupied output port (cursor changes to double direction arrow) and click once to start the drawing of the first segment of the stream. The first segment of an intermediate stream must be a horizontal segment.

c)   Move the mouse to draw either a vertical or a horizontal segment for the stream. Do not hold the mouse pressed down as you are moving it to create the segment. Notice that you don’t have to be exact in your horizontal or vertical motion with the mouse as the system always draws either horizontal or vertical segments (approximating the exact location of the mouse to the nearest horizontal or vertical location).

e)  A single mouse click ends the current segment and starts another one. The next segment must alternate its orientation. In other words, if the previous segment was horizontal, then this segment must be vertical and vice versa.

1.   Repeat steps (2) through (4) to give the desired shape of the stream by adding extra segments (if so desired).

1.   End the stream by a single click on an unoccupied input port of the destination procedure. Note that an intermediate stream cannot end with a vertical segment.

►    To draw an output stream...

3.   Make sure you are in connect mode (the button is pressed o the main toolbar).

Since you are always drawing streams source-to-destination, move the mouse over an unoccupied output port and click once to start drawing the stream. Notice that the first segment of the stream must be a horizontal segment.

Move the mouse to draw either a vertical or a horizontal segment for the stream. Do not hold the mouse pressed down as you are moving it to create the segment. Notice that you don’t have to be exact in your horizontal or vertical motion with the mouse as the system always draws either horizontal or vertical segments (approximating the exact location of the mouse to the nearest horizontal or vertical location).

A single mouse click ends the current segment and starts another one. The next segment must alternate its orientation. In other words, if the previous segment was horizontal, then this segment must be vertical and vice versa.

Repeat steps (2) through (4) to give the desired shape of the stream by adding extra segments (if so desired).

Since a single click will introduce an elbow, and an output stream must end on a point that is not an input port, you must double click on an empty area of the flowsheet to terminate the drawing of an output stream. You can end an output stream on either a horizontal or a vertical segment.

While in select mode, if you want to draw just one stream and then immediately go back to select mode, you may find it easier instead of switching to connect mode, to switch to the temporary connect mode. While in select mode, you can enter the temporary connect mode by holding down the Ctrl key and double-clicking with the mouse over an output port (to start an intermediate or output stream) or over an empty area (to start an input stream). Unlike what happens when ending a stream while in connect mode, this time, immediately after the stream is created, the system will revert to select mode.

NOTES

Every time a stream touches upon an icon’s port, its segment must be horizontal. Therefore the first and last segment of an intermediate stream must be horizontal; the last segment of an input stream must be horizontal; the first segment of an output stream must be horizontal.

Every icon’s port can only host one stream. You cannot start a stream from an output port that already has a stream attached to it, and you cannot end a stream on an input port that has a stream attached to it.

When starting to draw an stream from a bulk output port of procedure, the application assumes you are about to draw a bulk stream, and it will not allow you to end it on a discrete input port. Similarly, when you start drawing a stream from a discrete output port of a procedure, the system assumes that you are about to create an intermediate discrete stream, and it will not allow you to end it on a bulk input port.

You do not have to draw every segment of a stream. If the location of stream elbows is not important, you can simply initiate the drawing of the stream and then skip straight to the step that ends the stream. The application will automatically create the minimum number of segments needed to bridge the two points and insert the stream. A word of caution is necessary: the auto-connect algorithm may introduce stream segments that could cross over other streams or run over procedure icons. It is not recommended that you use this shortcut when drawing streams in a crowded flowsheet.

During drawing of any stream segment, while left click introduces a new elbow, a right click removes the last elbow of the stream. After a stream has been drawn, the location of its elbows can be edited (see Stream Elbow Editing).

During drawing of any stream, hitting Esc aborts the whole procedure.

►    To relocate a stream to a different port...

Click on the stream that you want to relocate and drag it near the new port.

Release the mouse button.

►    To delete a stream (or any other item on the flowsheet)...

Make sure you are in select mode (the button is pressed on the main toolbar).

Click on the item that is to be deleted in order to select it (notice how the items is now shown in red color). If you wish to delete multiple items, then either group-select them (by click-and-dragging a selection rectangle around them) or keep adding items to the selection group one-by-one by clicking on them while holding the Ctrl key down. Note that if you Ctrl+click on an item already selected it will be removed from the group of selected items.

Click on the Delete button () on the main toolbar, or hit the Delete or Backspace key on your keyboard. If procedure icons are part of your deletion group, you may be warned if their deletion (including their contained operations) may affect the settings of other operations in the process. If you refuse to proceed with the deletion (by click No on the warning dialog that appears) then the deletion of the selected items will be cancelled. If there was no warning or you allowed the system to proceed with the deletion by clicking on Yes in the warning dialog, then all selected items will be deleted from the flowsheet.

When a unit procedure icon is deleted from the flowsheet, all streams attached to it will also automatically be deleted as well.