Stream geometry and process connections
A flowsheet describes both where material goes and how that relationship is drawn. Stream nodes help separate those two meanings.
The connection and its drawing have different roles
A material connection relates a source port to a destination port and carries the stream’s material data. The line on the canvas is the graphical representation of that relationship. When a route becomes difficult to follow, the drawing can be changed without changing the material connection.
A stream node is an intermediate routing point on an existing connection. It provides a bend in the line rather than another unit operation. This is why a node can help a recycle pass around the main circuit, but cannot divide material between products or combine separate feeds. A Splitter and a Mixer perform those process roles.
How a routing point belongs to a selected stream
A node is added to one connection, so the selected object matters. The toolbar’s Add stream node command places a point on the longest segment of the selected connection. The context command Stream → Add Node instead uses the position clicked on that stream. These are two ways of locating the same kind of graphical routing point.
The before-and-after views show the relationship clearly: the intermediate point appears on the existing connection, whose equipment endpoints remain the same. No new material stream is implied by the additional bend.
A route can become clearer without a new process relationship
Moving a point changes the path of the line through the canvas. The stream still belongs to the same source and destination ports and retains its identity. A recycle can therefore be drawn above or below the main path while keeping the underlying circuit unchanged.
Extra bends are useful only when they clarify the route. Too many points can make the drawing harder to read. Snap To Grid can help keep graphical spacing consistent, but alignment on a grid is not proof of a correct material connection.
Removing geometry is different from removing a stream
Stream → Remove Node removes a routing point near the clicked position. The toolbar’s Remove stream node command removes a point near the centre of the selected connection. The remaining line is then redrawn between its remaining points and endpoints.
The distinction matters when simplifying a drawing: removal of a point leaves the material stream present, while deletion of the stream removes the connection itself. If there are no intermediate points, there is no routing node to remove. Unavailable node controls can also indicate that exactly one stream has not been selected or connection editing is not enabled.
Exercise: identify what changed and what stayed the same
This exercise uses a saved flowsheet with a connected material stream. Its purpose is to change the readability of the route while retaining the process relationship; feed data and model parameters can remain unchanged.
- Select one material stream and identify its source equipment, source port, destination equipment and destination port. Note its stream identity.
- Add a point with Add stream node. Keep the stream selected and move the point so that the line clears an equipment icon. Compare the endpoints and identity with those noted before.
- For a specific bend location, right-click directly on the stream and use Stream → Add Node. Remove a redundant point with Stream → Remove Node, taking care to choose the routing-point command rather than stream deletion.
- For a recycle, arrange the route around the main process with only the bends needed to follow it. Save the project when the drawing is clear.