Drawing the flowsheet

What it is for

Building the flowsheet: placing the units on the sheet, connecting them with streams and arranging the drawing. Each connected line is a stream, with its own number, and enters the balance.

Insert a unit

• Drag the unit from the palette and drop it on the drawing. It lands centered on the pointer and snapped to the grid.
• Or click the unit in the palette: it lands in the center of the view.
• Use the search at the top of the palette to find it by name ("cyclone", "thickener", "WHIMS").

New units come with typical values, so the balance calculates as soon as they are connected. Adjust the values in the side panel.

Connect two units

1. Hover over the source unit: the ports appear. Outlets are ● and inlets are ○.
2. Drag from an outlet (●) to an inlet (○) of another unit.
3. Release. The stream is created with the next free number (1, 2, 3…).

Connection rules:

• Each outlet has at most one stream. To split a line, use a Splitter, Distributor, trouser chute, splitter box, etc.
• Each inlet accepts several streams, which are added there. A cyclone underflow can go straight back to the mill without a drawn mixer.
• A unit cannot be connected to itself.
• Tanks, pump boxes and the stream junction have several inlet nozzles; drag to the nozzle you want.

Select

• Click a unit or a stream to select it; the side panel shows its properties.
• Shift+click adds a unit to the selection or removes it.
• Drag on the background to draw a selection box:
  • to the right (solid line) selects what is fully inside;
  • to the left (dashed) selects what the box touches.
• Shift+drag adds to the selection. Ctrl+A selects all units on the open tab. Esc or a click on the background clears the selection.

Move

• Drag the unit. It moves in steps of 8 units, on the grid.
• If a connection is almost straight, the unit snaps it straight on its own.
• The arrow keys nudge the selection one step (Shift: five steps).
• With several selected, dragging one of them moves the group.
• Dragging near the edge scrolls the view.

Moving, inserting, connecting and undoing do not change the zoom or the view position.

Pan and zoom

• Scroll: mouse wheel or two fingers on the trackpad; or the scroll bars.
• Pan the view: hold the space bar and drag, or drag with the middle button. On an iPad, dragging the background with a finger pans the view.
• Zoom: − and + buttons, Ctrl+wheel or pinch on the trackpad. Zoom follows the pointer. On a tablet, a two-finger pinch zooms around the point between your fingers, and moving both fingers pans at the same time; one finger dragging the background pans.
• Fit (Ctrl+0): shows the whole drawing.

Delete

Select and press Delete (or Backspace). The panel also has Delete unit and Delete stream. With several selected, the panel offers Delete the N units. Deleting a unit deletes the streams connected to it.

Reconnect a stream

Select the stream: both ends become visible. Drag the source end to another outlet, or the destination end to another inlet (including another tank nozzle). The number, the name and the values specified on the stream are kept.

An outlet that is already taken refuses the connection, with a warning.

Adjust the route of a line

Routes are automatic and orthogonal. To adjust one:

1. Select the stream. Each segment gets a handle in the middle.
2. Drag the segment perpendicular to itself. The neighboring bends follow.
3. To undo the adjustment, Ctrl+Z, or Back to automatic route in the stream panel.

Crossings: the horizontal line stays continuous and the vertical one is broken, as in engineering flowsheets and P&IDs.

Flip and rotate

• Flip horizontally (unit panel or H key): the symbol and the ports swap sides; the text stays readable.
• Rotate 90° (only on the Stream junction): the R key rotates clockwise, Shift+R counterclockwise.

Cut, copy, paste and duplicate

The same commands are in the Edit ▾ menu (with the shortcuts next to them). When you select units, a small bar shows up right above them with Copy, Duplicate, Mirror, Rotate (Stream junction only) and Delete, which also works on a tablet without a keyboard. The same buttons are in the unit panel; with something copied, the empty panel shows Paste here.

On copy:

• the new units have the same parameters, a name with "(copy)" and new tags;
• the streams between the copied units come along, with new numbers and whatever was specified on them;
• the streams that connected the group to the rest do not come along: the ports are left free.

On cut, the units stay the same, with the same numbers and connections. If pasted on another tab, the connections to what stayed behind become tab connectors.

Limit: copy and paste work within the same project, while it is open. Do not use them to take units from one project to another.

Stream number and name

In the stream panel:

• Number: given automatically when the stream is created (the next free number) and shown in the panel title ("Stream 8"). It cannot be edited: it is the stream's reference on the drawing, in the table and in the column order.
• Name: free text ("cyclone OF"). It appears in the Name row of the stream table. If blank, only the number is shown.

Common warnings and limits

• "That outlet already has a stream": the outlet already has a stream. Use a splitter or reconnect the existing stream.
• Projects saved long ago may show a small step in a line after a symbol update; drag the unit and the snap fixes it.
• A hand-made route is discarded if you reconnect the stream to another port.