Multi_R_Designer Tutorial

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1) Start a new project by selecting Start new query .

2) Apply the following problem specifications, namely the Liquid composition: 100% kerosene, Gas composition: 100% air, Pressure: 1 atm, Packing type: spheres, Packing material: Catalyst (Ni/Mo/Al ₂O₃) and Liquid hold-up measurement technique: Weighting.

• First, select the Hydrodynamics tab and check the box corresponding to Total liquid holdup, then Execute. It will extract 8650 data sets containing a total liquid hold-up value.
• In the same tab, check the box related to Liquid holdup measurement technique and select the corresponding Value field combo box. A choice is given to the user. In this case, it comprehends liquid holdup measurement techniques going from Conductance probes (RTD) to Weighting procedures. Select the latter choice (Weighting) and press Execute. A total of 3310 liquid holdup measurements were obtained via a Weighting procedure.

• In the Fluids tab, select the Add button in the Liquid phase section. Write kerosene in the Search box and activate the Search button. It will extract all components that contain this string. The exact component name will usually give the user one selection if it is available in the list. Press OK.
• Select (unspecified)  in the Liquid phase composition field. The following dialog window will appear. Highlight Kerosene (100%) associated with a gas composition of Air (100%) and press OK, then Execute. The data number is reduced to 241 from Midoux et al. and Morsi.

• Select the Operating conditions tab. Check the box corresponding the Pressure field. Change the unit from Pascals (Pa) to atmospheres (atm).
• Select the corresponding pen  in the Value field. It gives the min-max range for the 241 measurements, which were carried out at more or less 1 atm. Therefore, pressure specifications becomes trivial. Do not enter any values, and check the none option, then OK. The user may also deselect the Pressure field (optional).

• Select the Reactor tab and check the Packing type option. In the Value field , two packing types are presented to the user. Choose Spheres, then Execute.
• Check the Packing material box and choose Catalyst (Ni/Mo/Al2O3), then Execute. A total of 39 data sets from Morsi (1982) allow all the specifications established in this case problem to be fulfilled.

3) Save  the project as Case problem III.mr.
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4) Select the Plot button .
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5) Specify the X-axis as gas mass flow rate (In the Horizontal axis panel, click on the Operating conditions knob, and highlight Gas mass flow rate).
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6) Specify the Y-axis astotal liquid holdup (In the Vertical axis panel, click on the Hydrodynamics knob, then on Total liquid holdup knob, and highlight Experimental).
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7) In the Advanced tab, specify the discriminate value as liquid mass flow rate (Click on the Operating conditions knob, and highlight Liquid mass flow rate). Press OK.
 
 

8) Select the Discriminate series button.

9) In the Value discrimination panel, the min-max range for the liquid mass flow rate rests between 0.5 and 14 kg/m²s. Divide it into an infinite number of classes (i.e. 1000), and press OK. A new diagram with specific series in terms of liquid mass flow rate will be created.
 

10) Five distinctive liquid mass flow rates are exposed in the legend. The problem statement requests the evaluation of total liquid holdup at a liquid mass flow rate of 10 kg/m²s, which is located between the 9 and 14 kg/m²s series showcased on the diagram. To alleviate the diagram, unselect the series corresponding to liquid mass flow rates of 0.5, 1 and 5 kg/m²s. Right click on the legend and uncheck the boxes related to these series in the Draw field. Press OK.
 
CONCLUSION #1:  Based on the latter diagram, it can be concluded that the total liquid holdup for air-kerosene downflow through a bed of spherical Ni/Mo/Al₂O₃ catalysts at air mass flow rate of ca. 0.2 kg/m²s and kerosene mass flow rate of 10 kg/m²s should rest near 0.14 or 14% of kerosene volume per bed volume.

11) Select the Discriminate series button . Change the Value discrimination option for Code discrimination option, and choose General flow regime in the combo box. Press OK. The same diagram with a new discrimination will be created.
 
CONCLUSION #2:  By comparing the last two diagrams, it should be expected that the high interaction flow regime will pre-dominate based on the operating conditions established in the problem statement and experimental results given by Morsi.

12) For more precise information on the flow regime, select, in the Discriminate series  (Code discrimination), the Specific flow regime option. Press OK.
 

CONCLUSION #3: The exact flow regime operation in the high interaction region is the pulsing flow.

Multi_R_Designer Tutorial