Mechanical Engineering Technical Project Presentation - English
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EnglishVoice Age
Middle Aged (35-54)Accents
North American (US General American - GenAM)Transcript
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Hello, this is uconn's M B 01 team. Our group members are Jake Joe mckenzie, working along with our faculty advisor, Professor Carbone and in partnership with our sponsor Acme Machinery. Acme Machinery is located in Norwalk, Connecticut. They produce high quality foam spray proportions that are both affordable and reliable. Acme Machinery is proud to say that their proportions are made right here in America. They plan to expand into the foam spray market by developing a foam spray gun. Our project was to design a foam spray gun for their purposes. Uconn's M 01 team was taxed to design a low cost disposable foam spray gun, also known as the S F G spray foam is created by two chemicals as a sate and resin which need to be mixed in a specific ratio in order to produce a certain effect, soft foam forms a 3 to 7 mixing ratio or solved form forms a 1 to 1 ratio. The original design of the sponsor's S F G could not mix the two chemicals together to create foam. This led to our main requirement for this project to mix the two chemicals together for the desired 1 to 1 ratio we researched and designed a way to both achieve proper mixing and to enhance the spray atomization of the foam spray gun. The other requirements for the S F G were to be able to handle the operating pressures from 120 psi to 1400 P. Si The other goals were for it to be built under $100 utilize an air purge and produce a spray pattern similar to that of the Greco fusion spray gun to develop a low cost S F G that can achieve proper mixing and spray atomization. We design a static mixing chamber, this impedes the flow of the chemicals causing turbulence and mixing to occur. As recommended by our faculty advisor, we add an air assist atomizer that would provide a fine particle spray. While inserting simplicity in our design, we designed the, our S F G to be modular. The internal components can easily be changed out. We also made the Helix disposable and the nozzle can also be changed out to different types for testing purposes. The mixing chamber designed for the SFG comprises of the following component, an O ring a mixing chamber, two air fittings, a helix, a nozzle and a cap to enhance the spray atomization of the air blast show we determined the diameter of it by using the solar mean diameter SMD equation to capture how the air and chemicals were interacting. The S MD is a ratio between the volume and surface area of the droplets. We use the S MD to determine what the mass flow rate of air should be to achieve an S MD of 400 microns. Then we utilize the choked flow equation to calculate the area given as a diameter of an eighth of an inch. To optimize our design of the mixing chamber. We perform two simulations. One to determine the factor of safety and the other for the minimum length of the mixing chamber to achieve a 1 to 1 ratio at the max operating pressure of the S FT. The setup of the simulation has three loadings and fixed support. The stress analysis simulation of the mixing chamber shows that the max stress occurs from the longitudinal stress at 12,150 psi. Since the yield strength of aluminum, 60 61 is 35,000 psi, the factor of safety is 2.88 to determine the proper mixing, we utilize the transport concentrated species physics coupled with the Frix load diffusion model. We also modeled it as a turbulent flow using the K O maker model. Some of the assumptions were made that it was a fully developed flow, the average mixture density and diffusion coefficient. The system's being modeled is the internal flow of the system where there are two inputs and one outlet simulating the mass concentration across the length of the mixing chamber as a parameter shows that their outflow reaches 0.5 or that there was a 1 to 1 mixing ratio. When the over length of the mixing chamber is 3.4 inches to validate our results from the simulation. We test it with no air assistance. A fan nozzle and metal heli. In the video on the left, the two chemicals are mixed and become foamed within a few seconds of being on the ground. This shows that our design was a success and performed how any SFG show the pictures in the center and on the right of the screen are the aftermath of the SFG spraying. We expected this from the test and the other shown are to test the performance of our design. We later tested the existing air purge on the S F G. An air purge uses compressed air to clean the SFG after spraying to avoid any clogging. And that's shown in these two photos. The next test is with air resistance, a fan nozzle and Metal Helix. This image on the left is the gun with the air hoses attached. Whereas in the previous test shown, there is no air assistance. This test was performed at 800 P SI and 1200 P si to view the spray and the foam developed between the pressures. A typical foam spray gun uses a full con spray pattern. Therefore, the performance with the fan nozzle is irrelevant in this test. However, we can conclude that the gun could perform at high pressures. One of the requirements was to build the foam gun for less than $100. We redesigned the front of the original foam gun, the mixing chamber and the nozzle. So the total cost for our design is $93.70. This cost analysis is only for what is circled in red. It does not include the original handle section of the gun. So we plan to redesign it by using plastic material instead of metal with this redesign and that higher demand resulting in lower manufacturing costs. We believe that we can manufacture the foam gun for less than $100. The one team came up with a solution that allows the gun to achieve a 1 to 1 mixing ratio and enhance spray atomization while maintaining a competitive build price of less than $100. Our future design will reduce the cost to $86.73 by utilizing plastic components. Thanks for listening to M E O One's design presentation of a low cost disposal from spray gun.