Multi_R_Designer Tutorial

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The creation of a frame in which proprietary data will be stored, minimizes hardy manipulation during the simulation process. The frame is specific to the property (or properties) to be simulated and the selected models.

In this case, the frictional pressure drop in a trickle bed reactor () is the property to be simulated. Inputs are obtained from MultiRDesigner/sample/sample.csv (user's file) and the file with the specific frame created in this example is user1.csv.

The procedure consists of the following steps:

STEP 1:

• Select Simulation/Start new simulation from the bar menu or press .
• A Simulator: Trickle bed dialog window is opened. Go to Frictional pressure drop, choose the desired unit in the Unit field. At the bottom of the dialog window, a warning indicates that no model is selected. In the Model field, 0/16 means that none of the 16 available models are selected.

STEP 2:

In the Model field, select the pencil . Models available to predict are depicted in a Frictional pressure drop dialog window. All available models can be selected by pressing the Use heading, or specific models can be accessed with the check boxes.a

Informations about a model/correlation could be found by pressing the Info filed. In General panel, for Ellman et al.(1988) (example below), are depicted the Reference of the model, its Type (empirical correlation using dimensionless inputs), list of the model's Inputs in dimensional form (liquid density, gas density ...), and the Output in dimensional form also. In Applicability panel, a domain of validity for each model input is given in the unit of your choice. The range of validity is also indicated on the graphical representation of the simulated variable by open symbols. Some pertinent Comments on the formulation of the model are also presented.
 

STEP 3:

• In the Input tab of the Simulator: Trickle bed dialog window, the inputs required for the application of the selected models (STEP 2) are given.

 

• Some inputs necessitate codes. To know them, press(  )

 

Foaming property

General flow regime

• The presence of a pencil  in the Column index in file field means that the corresponding input can be simulated (corresponds toin the Summary models' input table)

a) if the general flow regime is available in the user's file(as a code), choose Value option.
 

b) if not available in the user's file, choose the Model/Conversion option. To select the desired model, click on its name (the performance of the model, in terms of and, on the Multi_R_Designer databank is given in parethesis).
 

When the specific flow regime is available in the user's file, Conversion from specific (to general) flow regime is a routine which converts the code of a specific flow regime to the general flow regime code (see Coded variables).

c) The Mixed option can be selected if the model input, general flow regime in this case, is known only for a portion of the database while the remaining are still unknown. It enables the user to determine the experimentally unknown general flow regime with a specified model.
 

As it is shown in the inputs table, Gas and Liquid mass flow rate are used instead of superficial velocities. If in the user's file, the superficial velocities are used, a converter to superficial velocities is available. Select what to be converted and press OX
 

STEP 4:

• In this example, Ergun constants, General flow regime and Total liquid holdup are not available in sample.csv (the user's file). They are estimated by the TB_ANN correlations. Therefore, they do not appear in the frame of the file to be used for simulation.
• If an input is not available, the corresponding model output will not be simulated. In this example, specific flow regime is not available in sample.csv. Thereofore, frictional pressure drop will not be computed for models involving the specific flow regime as an input.
• means that the input is available in the user's file,  means that it will be estimated using a model.

STEP 5:

• All inputs will appear in the frame of the user's file. If you want other variables to appear, such as experimental frictional pressure drop, click on the User tab at the top of the Input box.
• Click on Add. The Add user input dialog window appears.
• The output to be simulated appears in the Select box. This, if the experimental data is available to carry out comparison with the simulated one. If not, click on User definiton option, and identify  specifically the desired variable in the Name box. It can be used as a code (select the check box). Define its unit. Not specify means that it is in SI.
• Press OK. The identified variables will appear in the Parameter column and saved in the frame.
• Do not forget to assign the unit, if necessary.

STEP 6:

• Press Frame and choose the name and location of the spreadsheet in .csv format. In this example, user1.csv is assigned.

• Open user1.csv from any data processing software and fill the columns with the data to be simulated (from sample.csv). Do not forget to give to the coded inputs their corresponding number. Save the file (same name and format). Now the user's file: user1.csv is ready to be used for manual simulation.

Multi_R_Designer Tutorial