Zeyu Yao's Individual Contribution Page

Spring '14 Contributions

I am working on the design team this semester, and our team's focus is on Chemical Dose Controller modifications

Stock Tank function

In order to simplify the stock solution mixing process, a function was created to take integer number of coagulant bags as input to set the coagulant stock solution concentration, and calculate the stock tank volume and dimensions. The function was written in a way that the dose selected by the CDC algorithm can continue to be used. It also allows for more accurate stock concentration since the plan operator is no longer required to weigh the proper amount of coagulant in order to achieve the set concentration. 

Chlorine viscosity equation

Currently the chlorine viscosity is assumed to be the same as water. Although this assumption does not generate significant errors due to the low concentration used in the plants, it is still meaningful to determine an equation for the viscosity of CaCl2 in order to improve accuracy in calculations.

CDC drawing updates

There are a few updates to the drawing that need to be done, including the drawing of flexible tubing, which requires FlexTubeF (work for the remainder of the semester).

Fall '13 Contributions

Chlorinator packaging for India

Prepared a setup manual for local personnel who are not familiar with chemical dose controller to aid the system assembling process. I also started to prepare a packaging spreadsheet because a large of the components need to be pre-assembled in lab since they cannot be locally sourced as well as easily assembled. This spreadsheet will be complete once Mathcad codes are embedded. 

Improving CDC design

Calculated using Mathcad the number and length of dosing tube for a low flow plant (plant flow rate = 2.4 L/s), and modified the manifold design based on the calculations. Changes I made to the setup include cutting the manifold to only two pairs, and eliminating or shortening unnecessary tubings and pipes. I also tested drop tube calibration and found that a ball valve can be attached so solution volume can be directly measured in drop tube. The added weight of ball valve may offset the balance of lever arm, but errors are negligible.

Researched on different types of constant head tank to replace the one that is not chlorine resistant. I found a Nalgene bottle and cap made of chlorine resistant materials, and also a chlorine resistant bottle with a regular cap with Teflon cap liner added. 

Designed a single lever for dosing one chemical, and made Sketchup drawings for the lever arm and drop tube group.