MPure™ Design for Web Help

Creating a new project

• Select the New item from the  File menu.

  You might be prompted to save your previous work.

• Fill the forms in the following pages:

  • Feed water specification

  • Product quality specification

  • System specification

• Check the calculated operating parameters and product quality in the Results page.

• Check the automatically generated comments in the  Comments page.

• Select the Download project file item from the File menu to download a project file.

• Select the Download project report (*.tiff) item from the  File menu to download a project report. The project report is downloaded in the multi-page TIFF file format.

• Select the Download project report (*.xlsx) item from the  File menu to download a project report. The project report is downloaded in the Excel file format.

Notes:

• The current version of the web application does not implement state management. Reloading the website, navigating out from the website, navigating to the  account management section of the website (routes beginning with https://mpure.mega.cz/Account/), longer inactivity or an unhandled exception will result in complete loss of data in all cases. Unhandled exceptions may occur due to specification of a number out of the range of its data type or due to computational errors.

• Input errors are reported via messages at the bottom part of the website.

• No specific file type is associated with the program.

• It is recommended to save the project files with the  *.dat extension.

• The project files are saved in a binary format that cannot be edited in another program.

• If the program reports input errors, no calculation will be performed. In addition, it will not be possible to download a project report.

Opening an existing project

1. Click the Choose File button.

   The Open file dialog will appear.

2. Browse for the project file you want to open, select the file and then press the Open button.

3. Click the Upload button.

Feed water specification

• Select the Feed water specification page.

• Enter the feed water temperature in the given unit in the Temperature text box.

• Enter the feed water pH in the pH text box.

• Check the Enable dissociation equilibria check box if you want the program to support dissociation equilibria in  the feed water. If it is checked, concentration of only one of the  conjugate forms or the sum of concentrations of all conjugate forms of a  component can be entered for systems of conjugate acids and bases such as NH₄⁺ and NH₃ or CO₂, HCO₃^- and CO₃^2-. Equilibrium concentrations of other conjugate forms are then calculated automatically. If you want to enter the concentrations of all conjugate forms manually, simply uncheck the  Enable dissociation equilibria check box. Water dissociation is always considered regardless of the setting of the check box.

• In the Unit columns of the  Cations and Anions tables, select the  unit of concentration for each component, whose concentration in the  feed water you are going to enter.

• Enter the concentration of components in the feed water in the selected unit into the Concentration columns of the Cations and Anions tables.

The program also offers several useful tools to  modify or change the composition of the feed water:

• The Balance button ensures the  electric neutrality of the feed water by adding either a cation or an anion from the selected model electrolyte, see the Adjust cond./TDS/TEC/TEA button.

• The Adjust cond./TDS/TEC/TEA button sets the conductivity/TDS/TEC/TEA of the feed water to the  desired value by adding electrolyte selected in the  Conductivity/TDS/TEC/TEA adjustment settings group box into the feed water (the  Electrolyte addition item is checked) or by proportionally increasing the  concentration of all components in the feed water (the Proportional item is checked).

• The Calculate pH button ensures the electric neutrality of the feed water by changing its pH.

• The Sum conc. button converts the concentrations of components in the feed water into the sums of  concentrations of all their conjugate forms. Press the button if you want to preserve the sum of concentrations of all conjugate forms of the  component, such as before changing the feed water pH.

• The Reset button sets the  concentration of all components in the feed water to zero and sets the default temperature and pH. After pressing this button, the feed water composition corresponds to the pure water at a temperature of  25 °C.

Notes:

• The chemistry of water used in the program holds for  aqueous solutions with a very low ionic strength only.

• If you have entered the concentrations of  conjugated forms of a component manually and then check the  Enable dissociation equilibria check box, the program will first convert the concentrations of components in the feed water into  the sums of concentrations of all their conjugate forms and then apply dissociation equilibrium conditions.

• If the concentration unit is changed, the  concentration will be automatically converted into the new unit.

Product quality specification

• Select the Product quality specification page.

• In the Product conductivity/resistivity group box, select the right option button to specify the type of  conductivity/resistivity you are going to enter.

• Enter the target (cation) conductivity/resistivity into the respective text box in the Product conductivity/resistivity group box.

• You can dynamically add one or more conditions for  the product composition to the project. To do so, select the Add condition item from the Tools menu. This will add a new panel with a few controls on it into the Product composition group box. Select an ion or another parameter such as TDS from the Ions/parameters drop-down list and then click the (+) button to add the item into the  Selected ions/parameters list box. You can add one or more ions/parameters into the list in this way. If you want to remove a certain ion or parameter from the list, just select it in the  Selected ions/parameters list box and then click the (-) button. Enter the target sum of concentrations of ions and parameters listed in the  Selected ions/parameters list box into the  Sum of concentrations text box. Select the appropriate unit of  concentration from the Unit drop-down list. The ppb unit represents a mass concentration, the μmol/l unit represents a molar concentration and the ppb as CaCO₃ and μeq/l units represent an equivalent concentration (normality). The condition is ignored by the program if the Selected ions/parameters list box is empty or if the check box in the given condition is unchecked. If you want to remove the condition from the project, click the ✖ button.

Notes:

• The cation (acid) conductivity/resistivity is a  measure of water quality frequently used in the power generation industry.
  It expresses the conductivity of the water that has passed through a column filled with a strong cation-exchange resin in the H⁺ form.

• If you have correctly specified at least one condition for the product composition and you don't want to consider the  target conductivity/resistivity in the projection, you can uncheck the  Consider product conductivity/resistivity check box.

System specification

• Select the System specification page.

• In the System specification group box, select the stack series and type from the respective drop-down lists.

• If you want to enter the number of stacks manually, uncheck the Calculate number of stacks box in the  Calculation basis group box and enter the number of stacks into the Number of stacks text box in the  System specification group box.
  If you want the program to determine the number of stacks, check the Calculate number of stacks box in the  Calculation basis group box. This will disable the  Number of stacks text box in the System specification group box.

• In the Hydraulic conditions group box, enter the total product flow rate in the given unit into the  Product flow rate text box.

• In the Hydraulic conditions group box, optionally enter the total concentrate flow rate in the given unit into the  Concentrate flow rate text box.

• In the Hydraulic conditions group box, optionally enter the total electrode outlet flow rate in the given unit into the  Electrode flow rate text box.

• In the Hydraulic conditions group box, optionally enter the minimum product outlet pressure in the given unit into the  Minimum product outlet pressure text box.

• To specify operation in the countercurrent mode, check the Operation in countercurrent mode box in the  Hydraulic conditions group box. Otherwise (for the co-current operation) leave the box unchecked.

Notes:

• The program will automatically correct the  concentrate and electrode flow rates either to the minimum or the maximum limits under the given conditions if values outside these ranges are set in the respective text boxes.

• If the feed water flow rate is known instead of the  product flow rate, iteratively subtract the concentrate and electrode flow rates from the target feed flow rate and set the result into the  Product flow rate text box until the result is constant. For the  maximum water recovery, set the concentrate and electrode flow rates to 0 after each iteration and let the program correct these values.

• The concentrate may flow through MPure™ stacks in  either the co-current or the countercurrent direction to the  dilute flow. Operation in the countercurrent mode increases the  feed water hardness tolerance and reduces the frequency of chemical cleaning, but it may also have negative impact on demineralization performance of the stack, especially on silica and boron removal. Operation of the concentrate in  the countercurrent mode is recommended in case the feed water hardness is greater than 0.1 ppm as CaCO₃.

Results

• Select the Results page to view the results.

Comments

• Select the Comments page to view the  comments automatically generated by the program.

Settings

• Select the Settings page.

• Select the desired options for the physical units and other settings from the available drop-down lists or other controls.

• The recommended DC current limit is 75 %. A lower DC current limit increases the number of EDI stacks needed, thus increases the investment costs, but provides better design margin. A higher DC current limit reduces the number of EDI stacks needed, thus reduces the investment costs, but provides worse design margin.