Add units to a flowsheet

Add a still to a flowsheet

A still is a generic distillation unit representing a distillation step in a refinery or laboratory.

Click the New Tower button to create a new unit in the flowsheet

A still unit requires:

• A name used to refer to the still.

• A pressure used to calculate the true boiling point of the still's products. It is only possible to enter a single bulk value for the still pressure: pressure drop over a distillation column is not modelled by the flowsheet.

• An input source, either whole crude or the product of another flowsheet unit.

• The feed stream of the input source connected to this still. Not available if the input source is Crude Feed.

• Names for the still's product streams.

• Cut points for each of the still's product streams.

• Stripping and rectifying fractionation indices used to describe the efficiency of each stage of the still's separation.

Product names, cut points and fractionation indices can be entered directly on the Flowsheet page in the relevant textboxes for the still. Each flowsheet also has an associated separation model which can be chosen from the drop-down menu (Enter flowsheet parameters).

Whole crude is used as the feed source for the first still. Whole crude can only be used as a source for a single still within the flowsheet. Any other stills are fed by the product of another flowsheet unit. For example a flowsheet may contain two stills representing an atmospheric and a vacuum distillation.

Whole crude is used a feed for the first atmospheric still. The second still must be fed by a product of the first separation, in this case the atmospheric residue remaining after the first distillation.

Add a splitter to a flowsheet

Splitters can be included in a flowsheet topology to divide the flow in a stream. When configuring the splitter you must enter the number of outputs from the splitter, and the split ratio between the different outlets.

Click the Add Splitter button to create a new splitter in the flowsheet

In the Flowsheet enter the name of the Splitter unit, and using the Input Unit menu select the process unit used to feed the splitter. If the process unit used as a feeder has more than one output use the Feed Stream menu to select the stream from the feeder unit used as source for the splitter.

Also enter names for the output streams from the splitter in the Output Name textboxes.

For each splitter output stream enter the fraction of the input which is split into the stream. The fraction should be entered as a decimal, and the total of the individual streams fractions should sum to 1.

Add a mixer to a flowsheet

Mixers can be included in a flowsheet topology to blend two product streams together. When adding a mixer on the Flowsheet page it is possible to blend any number of input streams, which are assumed to mix perfectly.

Click the Add Mixer button to create a new unit in the flowsheet

In the Flowsheet enter the name for the mixer and choose the input process unit for each of the streams used to feed the mixer. If the process unit used as a feeder has more than one output choose the stream used to feed the mixer using the Input Stream menu.