Week 6 Cont. - Initial and Final Filter Designs.

 

Figure 21. Side view of preliminary filter design

 

Figure 22. Direct view of preliminary filter design



During week 6, Preliminary designs were created and a final design was chosen for the filtration system. The first filtration design is shown in figure 20 and 21. This design is called a mat pattern. There are many benefits to a this design but there are also some faults which became clear after extensive research about filters. The mat design of the filter consists of alternating vertical and horizontal nanofibers. This causes water to easily pass through the nanofibers while the bacteria will get caught in the matted net design. Through research that was conducted, it seems that the specific bacteria have the capability to pass through this pattern because the openings have a possibility of being too large (diagonally). This pattern creates little squares which can fit bacteria through and continue with the flow of water. As shown in figure 21 on the left, the pattern leaves openings big enough for water, as well as unwanted bacteria to pass through.  



Figure 23. Final filter design top view



Figure 24. Final filter design showing layers of nano fibers



After realizing that this design was faulty, the filter was redesigned into a spiral or helix shape. This design is seen in figures 22 and 23 to the left. The final filter designs have approximately 250 nanofiber sections in the cylindrical tube that turn at 5 degrees and move 20 μm inside the filter every section. This makes the filter a total of 5cm in length. This design is ideal for letting liquids pass through the filter and leaving any unwanted particles stuck in the filter. The design of this filter will also spin the nanofibers at a slow speed to insure that no unwanted particles will pass through the cracks. The bacteria that resides in the water or other liquid will not be able to pass through due to the small openings in the filter. The initial filter design was a static design only made as a net that would trap particles and bacteria. With this filter design, The nano fibers are perfectly aligned with each other and the separation between each nano fiber is approximately less than 0.6 μm due to the movement and alternating fiber displacement of the filter. These values were outputs that Pro/E measured in the filter design.This number was chosen because it is the smallest size of the bacteria in cubic μm. This filter is the ideal chosen to block bacteria such as  E. Coli and Giardia cysts.