Design Solutions Considered

The Layered Dome

Figure: layer dome

The Layered Dome is a design that would entirely replace the previous dome that is currently in use. The Layered Dome involve’ creating a product with the same functional requirements as the previous dome, but with the 3D CNC Machine. This would be done by cutting the dome shape, manifolds, and water channels into three pieces of acrylic and fixing them together.

The bottom piece of the Layered Dome is 3” thick, and contains three internal components: the inlet manifold with 4 dome inlets, the 6 dome outlets, and the dome structure. The middle piece, is ¾” thick, and contains the outlet manifold with the 6 dome outlets, and the primary inlet (into the inlet manifold). The top piece is also ¾” thick and contains only the primary inlet and primary outlet.

The Shielded Dome

Figure : Shielded Dome

The Shielded Dome design (shown in Figure 2 of the appendix)  involves using the previous dome structure and simply protecting it with a cover. Covers considered include a half-sphere, or a cylindrical shape. Polycarbonate was the primarily considered material.

Because this design is simply covering the pre-existing structure, it also contains the features of the old design. While this includes a fully functional dome, it also includes the awkward position of the

manifolds, the unequal length of inlet and outlet channels, and still the possibility of fracturing the weak joints by vibration if the dome is dropped.

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Auto-Sampling Tray

Figure : Circular Sampling Tray

The auto-sampling tray is a design concept to automatically switch the containers for the samples. The idea behind this design was  to create a circular sampling tray with five or six extruded holes to place the sample tubes. Similar to a turntable, the auto-sampling tray would rotate every time water sample is collected. Thus, after the one hour mark, there would be 5 to 6 samples of water ready for testing. However, this idea does not provide any solution to how we are going to be able to extract water from the closed looped system. None the less, the auto-sampling try is a systematic method to organize water samples.

5-Valve System

Figure : 5-Valve Sampling System

The 5-valve system is a design concept to collect 5 individual samples at allocated time intervals. All solenoids are controlled by a user interface.  Each solenoid corresponding to one sample at its specified time. Thus, every solenoid will be corresponding to each water sample. Whenever the time is complete, a solenoid valve will open and enable water sample to flow through the valves and into the sample test tube. After reaching the amount of water that is need for the metal concentration testing, the user interface will electronically close the valve and maintain a closed loop system.

Peristaltic Pump water extraction

Figure : Peristaltic Pump

The original sampling method was to switching on/off between two clip valves. One clip valve is the outlet, which enable water to flow out of the system. The other clip valve to to restrict the water flow in the closed loop system, and redirect the flow towards the outlet clip valve. In order to automate the water sampling process, a peristaltic pump can be inserted into the closed loop system. The goal of the pump is that, it is going to be turned on every time a water sample needs to be collected. Instead of the manual two clip valves method the anti-fouling dome had before, the peristaltic pump can be controlled through microcontroller, and eliminate some physical labor.