Rapid Mix Tube Design Modifications

Agalteca Rapid Mix Tube Design Modifications

The Rapid Mix Tube designed during the Fall 2009 semester was installed in the new Agalteca plant this spring. The original Rapid Mix Tube design was very general, and certain modifications had to be made to customize the tube to the Agalteca plant. A second, modified MathCAD file was created for the Agalteca plant to serve a few different purposes:

1. We need to be able to adjust the total head loss through the entire plant to adjust for any extra head loss created in the plant. The easiest way to do this is to change the number of orifices in the Rapid Mix Plate: adding more orifices will reduce the total amount of head loss, and creating a plate with fewer orifices will increase the total head loss through the plant. The MathCAD file created allows the user to easily input the existing plant parameters such as plant flow and measured head loss, as well as the existing plate characteristics, including the number and diameter of the existing orifices. Using this data, the MathCAD file calculates the total head loss created through the current plate, as well as the target head loss through the plant, and produces the number of extra orifices that must be drilled or taken away from the existing plate to achieve the target head loss through the plant.

1. We also need to measure the head loss through the flocculator in the Agalteca plant, and the MathCAD file produced will also estimate that given the total measured head loss through the plant. Because the head loss through all other plant components can be measured or easily modeled, the head loss through the flocculator simply becomes the difference between the total plant head loss and the sum of the head losses of all other plant components.

1. The target head loss through the plant will change with varying flow rates, so to adjust correctly the number of orifices in the Rapid Mix Plate, we must know the target head loss through the plant at the time of measurement. This calculation was also added to the MathCAD file for greater accuracy.