Introduction

The objective of this tutorial is to calculate the exit concentration in a mixer in which a slurry stream is mixed with a solution stream.

The concentrations that are of interest are the concentrations in the solution phase and the percentage solids in the stream.

During this tutorial you will practice the following functions within Cycad Process:

• Drawing the flowsheet
• Adding components to the balance
• Changing stream compositions
• Using the Goal Seek function
• Calculating the balance
• Interpreting the results displayed in Convergence Form
• Examining the results.

In following this tutorial you will go through the following five steps:

Step 1: Draw the flowsheet

The first step is to draw the flowsheet, as shown in Figure 1.

To draw the flowsheet use the same techniques you used during the Challenge. Figure 1. The flowsheet for Tutorial 1.

Step 2: Add components to the mass balance

Add Fe2O3 (s), HCl (aq), H2O (l), FeCl3 (aq) to the list of components.

This is achieved as follows:

Press the "Add Components" Button on the Setup Balance Toolbar, which is illustrated in Figure 2, to launch the Components Selection Form. Figure 2. The Add Components Button on the Process Toolbar.

The Components Selection Form is shown inFigure 3.

To select a component find it in the list and then double click on it. This will add the component to the selected components list. Should you wish to remove an accidently selected component, simply double click on the component in the selected list.

After selecting all the required components, click the “OK” button to send the components to the Stream manager.

Click the Stream manager to check if all required components have been selected. Figure 3. The Component Selection Form.

Step 3: Setup the stream compositions

Select the feed stream in the Page Viewerand in the Stream manager make the flow rates:

• Fe2O3 (s) = 1 t/hr,
• H2O (l)= 10 t/hr.

Select the solution feed stream and make the flow rate:

• H2O (l)= 6.4t/hr
• concentration of HCl (aq) =10 g/L.

This is achieved in the following way:

Right-click on the sheet to expose the context menu.

Select Goal Seek from the menu shown in Figure 1. This launches the Goal seek form

Select the cell that displays the concentration of HCl (aq)

Then type “10” in the middle box of the Goal Seek form, and then select the cell that displays the flow rate of HCl (aq).

Then press "Run". Figure 4. The Goal Seek functionality in the Stream Manager.

Step 4: Calculate

Press one of the Run buttons on the process toolbar.

The Calculate Process Toolbar is shown in Figure 5. Figure 5. The Process Toolbar, with the cursor hovering over the Run button.

Once the project has run the Convergence form will be displayed.

This is shown in Figure 6. Figure 6. The convergence form.

The main thing to examine in this form is the mass balance error for each of the elements.

Since there is no error for any of the elements, the results can be accepted.

Press ‘”Accept Values” button.

Step 5: Examine results

Select the exit stream (Stream 30) and then select the Stream Manager to view the results of the calculation.

The exit stream should have the values shown in Figure 7. Figure 7. Results from the tank mixer operation.

Select the "All Streams" tab to display the results of all the streams in a single view.

This is shown in Figure 8. Figure 8. All Streams tab of the Stream Manager.

The results of the "All Streams" tab of the Stream Manager allow the results to be easily compared.

It is clear that the exit stream is a sum of the two input streams.