Overview of Status of Analysis, Design, Fabrication, Tests, etc.
Problem encountered: When horizontal velocity is supplied to atomized droplets within nebulizer, the droplets instantly evaporate. As a result, we suspect nothing is actually being sprayed out from the nebulizer.
Possible solutions:
a 1/32 inch hole was drilled at the center of the baffle to attempt to make bigger droplets that will not instantly evaporate. The resulting droplets are between 20 and 50 microns, larger than we are looking for
a 1/78 inch hole was drilled at the same location in another nebulizer. We plan to test all version of nebulizer (no hole, 1/32, 1/78 hole) with glucose strips and glucose solution to determined if anything is being expelled.
Accomplishments from Previous Week
Velocity testing of nebulizer with hot wire anemometer
Testing of droplet size with horizontal air flow burst ("cough")
Fabricated 2 versions of nebulizer to compensate for horizontal air flow problem
Goals for Next Week (list names after each item). Use specific and measurable objectives.
Test 3 version of nebulizer with glucose solution and glucose strips
Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
In person:
Sponsor suggested that we could try humidified the horizontal air that we are blowing into the nebulizer. Right now the air is coming straight from the air compressor, so we would need to add a device between the compressor and back of the tee to humidify the air.
Also wanted to make sure that the pressure was not significantly dropping once the valve was actuated. This was tested, and while to regulator does adjust to the valve, there is no significant pressure drop.
Instructor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)
In person:
Looking into colormetric glucose strips: we have ordered these and expect delivery this week
Thinking about a water break or damping system for the door: with are continuing with the o-ring design, but we might need to add a damping component in the future
Comments from Other Students in the Class (indicate date of comments and if via email or in person)
N/A
Risks and Areas of Concern
If we do need to modify the nebulizer to make larger droplets, the disposability of the product becomes more difficult.
We lack the theoretical understanding of droplet size to baffle design that is necessary to predict droplet size before physically modifying the baffle
Resources or Information Required but not Available
High-speed camera
The team visited, emailed, and called Professor Nasser, he has replied that the camera is not available
Schedule
When glucose strips arrive: Test with glucose solution and strips for 3 versions of nebulizer
By Thursday (5/17): print new door, attach o-ring, test performance
Budget (list amount spent and amount remaining)
Nebulizer (5): $20.00
Vinyl tube: $3.25
Tee fitting: $2.49
Air hose repair kit: $3.89
Spray gun: $26.99
Nebulizer (10): $31.15
Glucose Powder: $6.99
Glucose Detection Strips: $15.97
Remaining budget: $6,388.89
Progress on Report and Webpage
Report: Theoretical predictions section underway
Webpage: progress report updated, new testing videos updated