Pull In

General Description

Use this operation to bring an amount of material into a vessel via an process input stream when you don’t know the amount of material to be transferred in but instead the amount depends on some criterion (e.g. to achieve a certain volume level or concentration in the vessel). Note that the material is not modelled to be transferred from another vessel but instead it is a direct process input. If you need to move material from one vessel to another then use a Transfer In operation. If you know the amount and composition of material to be transferred in then use a Charge operation instead.

This operation may result in VOC emissions if volatile compounds are involved; for more details, see Chapter 10  (Emissions).

Unit Procedure Availability

      Batch Vessel Procedure in a Reactor

      Batch Vessel Procedure in a Seed Reactor

      Batch Vessel Procedure in a Bioreactor

      Batch Vessel Procedure in a Seed Bioreactor

      Batch Vessel Procedure in a Disposable Bioreactor

      Batch Vessel Procedure in a Disposable Seed Bioreactor

      Batch Vessel Procedure in a Fermentor

      Batch Vessel Procedure in a Seed Fermentor

      Batch Vessel Procedure in a Disposable Bioreactor

      Inoculum Preparation Procedure in a Rocking Bioreactor

      Inoculum Preparation Procedure in a Roller Bottle

      Inoculum Preparation Procedure in a T-Flask

      Inoculum Preparation Procedure in a Shake Flask

      Inoculum Preparation Procedure in a Test Tube

      Batch Distillation Procedure

      Batch Storage in a Blending Tank Procedure

      Batch Storage in a Flat Bottom Tank Procedure

      Batch Storage in a Receiver Tank Procedure

      Batch Storage in a Horizontal Tank Procedure

      Batch Storage in a Vertical-on-Legs Tank Procedure

      Batch Storage in a Drum Procedure

      Batch Storage in a Drum Procedure

      Batch Storage in a Disposable Generic Container Procedure

      Batch Storage in a Disposable Large Bag (on a Skid) Procedure

      Freezing-Thawing Procedure

      Batch 1x1 Generic Box Procedure

      Batch 3x3 Generic Box Procedure

      Batch 5x5 Generic Box Procedure

      Batch 10x10 Generic Box Procedure

Material Inputs / Outputs

The Pull-In operation combines the material present in the host vessel at the end of the previous operation (if any) with the material from a designated pull-in stream. The resulting mixture remains in the equipment as the final contents after the operation.

Pull In: Modeling Calculations

A Pull-In operation is essentially an enhanced version of the Charge and Transfer In operations, with additional options. The specific calculations depend on the selected Amount Option:

      Available in Input Stream: The operation behaves exactly like a Charge or Transfer In operation.

      If the selected pull-in stream is an input stream, calculations follow the Charge model.

      If the pull-in stream is an intermediate stream, calculations follow the Transfer In model.

Pull In Model Description for the remaining options

For the remaining Amount Options, the material quantity is not specified in the input stream. Instead, it is either set directly by the user or determined during simulation. When computed during simulation, the model behaves uniquely. Most SuperPro Designer models combine variables from input streams and the unit procedure’s initial state with operating conditions to calculate the unit procedure and output stream states after execution. The Pull-In operation works in reverse: it examines the current state of the unit procedure and the user’s target for the final state, then adjusts the amount of material in the pull-in stream to achieve the design objective. This approach is useful in process design when the user needs to transfer material into a vessel (via an intermediate stream) or charge a vessel (via an input stream) to meet specific final mixture requirements, such as a desired total mass or volume. In such cases, the required pull-in quantity is not known in advance but is determined during simulation. If the pull-in stream is a process input stream, its composition must be defined before simulation.

Pull In Model Targets

a)     Amount is set in the input stream (like in Charge / Transfer In Operations)

b)  Pull-in mass

c)   Pull-in volume

d)  Properties of the final mixture

For case (d), the following specification options are available:

      Ratio of pull-in mass or volume to the initial amount

      Final Mass or Volume of the mixture (after the pull-in) operation

      Concentration or mass fraction of a specific component in the final mixture

      Final Temperature of the mixture

      Final pH of the mixture

When targeting final mixture properties, the pull-in flow is determined iteratively, performing heat and mass balances to calculate the final mixture composition, pull-in stream flow rate, or final temperature.

The required pull-in flow, whether user-specified or computed, is propagated backwards through the process network. If the user sets an unachievable target, the model may fail to determine a suitable pull-in flow. In such cases, a warning is displayed, explaining why the goal cannot be met and suggesting possible solutions.

If the Scalable option is selected, the user-specified pull-in mass/volume or final vessel mass/volume is automatically adjusted based on overall throughput changes.

Duration

If the duration of this operation is matched up to another operation (master operation), then the setup time, process time and turnaround time are simply derived from the master operation. For more details on how to setup a master-slave relationship, see The Scheduling Tab.

Equipment Sizing

See Batch Vessel Operations: Equipment Sizing.

Vacuum Pump Power Consumption

See Vacuum Pump Auxiliary Equipment Calculations.

Pull In: Interface

The interface of this operation has the following tabs:

      Oper. Cond’s, see Pull In: Oper. Conds Tab

      Volumes, see Batch Vessel Operations: Volumes Tab

      Vent/Emissions, see Vessel Operations: Vent/Emissions Tab

      Labor, etc, see Operations Dialog: Labor etc. Tab

      Description, see Operations Dialog: Description Tab

      Batch Sheet, see Operations Dialog: Batch Sheet Tab

      Scheduling, see Operations Dialog: Scheduling Tab