Wash (Generic)

General Description

Sometimes users have the need to introduce some material into a vessel in way that is analogous to the "Wash" operations in chromatography columns or filters. In other words, material enters the vessel, possibly interacts with its contents at the time, and then immediately exits. To simulate such a step, a generic “Wash” operation is now available in vessel and batch GBX procedures.

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 Fermentor

      Batch Vessel Procedure in a Seed Fermentor

      Batch Vessel Procedure in an Air Lift Fermentor

      Continuous Stoichiometric Reaction Procedure in a CSTR

      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 Tote Procedure

      Batch 1x1 Generic Box Procedure

      Batch 3x3 Generic Box Procedure

      Batch 5x5 Generic Box Procedure

      Batch 10x10 Generic Box Procedure

Wash (Generic): Modeling Calculations

Wash Time, Volume and Flowrate

The wash flowrate can be calculated by dividing the wash volume (per cycle, per unit) by the wash time (per cycle). Therefore, the user needs to specify only two variables at a time (i.e., time and flowrate, time and volume, or flowrate and volume). This can be done by choosing first one of the following specification options for the wash time (per cycle):

      Set directly by the user.

      Calculated based on the flowrate and volume (per cycle, per unit) of the wash inlet stream.

      Tied up to another operation or operation sequence by exploiting the Master-Slave relationship. If you introduce a master-slave relationship, the program will match the setup time, the process time and the turnaround time of this operation (the ‘slave’) with the corresponding times of the reference operation (the ‘master’ operation). For more details on how to setup a master-slave relationship, see The Scheduling Tab.

If the wash time (per cycle) is set by the user or set by a master-slave relationship, then you may choose to set either the wash flowrate or the wash volume (per cycle, per unit).

In addition, the following specification options are available for the wash volume (per cycle, per unit):

      The wash volume is available in the wash inlet stream. In that case, if the wash inlet stream is an input stream (not an intermediate stream), the user must visit the stream’s data dialog and set the stream’s flow.

      Set the wash volume (per cycle, per unit) on an absolute basis (in L)

      Set the ratio of wash volume (per cycle, per unit) to the liquid/solid volume of the equipment contents.

      Set the ratio of wash volume (per cycle, per unit) to the volume of the equipment.

Material Balances

By default, the wash inlet and outlet streams will have the same flow and composition. Optionally, if the equipment has contents, the user may specify that a fraction of the wash liquid’s mass stays in the equipment contents (“Wash Loss %”) and a fraction of the equipment contents for each component is carried away (Loss %”). Based on this, the program calculates the amount of wash that is added to the equipment contents and the amount of each component that is removed from the equipment contents and added to the wash.

Wash (Generic): Interface

The interface of this operation has the following tabs:

      Oper. Conditions, see Wash (Generic): Oper. Conditions Tab

      Contents Loss, see Wash (Generic): Contents Loss 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