A unit operation (aka, an operation) represents the simplest physico-chemical transformation step that can be modeled by SuperPro Designer. It can represent a simple activity, such as ‘Charge’ or a ‘Mix’, or a more complicated activity, such as ‘Distill’ or ‘React’. Operations are strung together to form a unit procedure and unit procedures are put together to make up a process (or a recipe).
Sometimes a unit procedure may simply include only one operation. This is actually the norm in continuous processes. In that case, a unit procedure is equivalent to a unit operation. In batch processing however, most unit procedures include more than one operations. In order to add or remove an operation from a unit procedure, you must use The Operation Sequence Dialog that appears when selecting Add/Remove Operation from the procedure’s command menu. Remember that this dialog is only available if the unit procedure is in batch (or semi-continuous) mode. Not all operation types supported by SuperPro Designer are available in a given unit procedure. The actual list available depends on the type of unit procedure and the type of equipment resource used to host the procedure. The operations available for the procedure are listed on the left pane of The Operation Sequence Dialog. The right pane shows the actual operations that have already been assigned to execute currently in the procedure.
A typical unit operation has many attributes; some are very specific to the nature of the operation and some are common to all operations. For example, a ‘Heat’ operation has as one of its attributes the temperature target for the heating or the heating rate; these are attributes akin to this operation type alone. A ‘Heat’ operation also has attributes related to its scheduling. For example, it has a specification that dictates when the user expects the operation to start. Also, there may be some labor resources tied up when the operation is being carried out. These last two sets of attributes (and a few others) are common to all operations. All the attributes of an operation can be viewed and edited (if allowed) by its input/output (i/o) simulation dialog. Since the operations themselves do not have a direct iconic representation on the flowsheet, in order to bring up the i/o simulation dialog of an operation in a unit procedure, right-click on the procedure’s icon and then select Operation Data (if only one operation is in the operation sequence). If several operations are included in the operation sequence, you must select the name of the operation that you want to view from the submenu under the Operation Data entry.