Design and Analysis of a Bottle Washer for Reusable Bottles
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Final Report – Masters Capstone Design ProjectApril 22, 2015, Miami, Florida, USA
DESIGN AND ANALYSIS OF A WASHER FOR REUSABLE BOTTLES
Akpejiori EthasorDepartment of Mechanical Engineering
University of MiamiCoral Gables, Florida, USA
Diaz DanielDepartment of Mechanical Engineering
University of MiamiCoral Gables, Florida, USA
A project was defined to create a mechanism to wash reusable squeeze bottles. Using a case study was done on the University of Miami their use of disposable bottles is to be eliminated due to cost and pollution of the environment by dumping the plastic waste. The school saves about $540 to $680 by using reusable bottle instead of the disposable ones. Different designs for a prototype were done until a final prototype was chosen due to favorability in cost, and ease of manufacturability. To meet the FDA standard for cleaning a bottle, the food and public health standards were researched and met, using pressurized water at a temperature greater than 66oC. Calculations were made for the flow rate through the mechanism to optimize the flow through the channels of the washers in the assembly. A drainage size had to be calculated to eliminate flooding of the mechanism during its operation. 8 drain holes of 0.75” diameter were used to eliminate the flooding problem. The prototype
worked perfectly well in achieving the goal of cleaning Gatorade bottles it specifically is designed for. The mechanism can be used in cleaning other types of hollow kitchenware with a dimensional reevaluation to fit whatever it is designed to wash. The design also pushes the University positively towards a green status.
TABLE OF CONTENTS
1. Abstract 1
2. Introduction 2
2.1 Statement of the project 2
2.2 Literature Review and Background 2
3. Preliminary Considerations and
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3.1 Timeline 3
3.2 Constraints 3
3.3 Assumptions Made Along with Rationale 5
4. Design Methodology 5
4.1 Other Possible Designs 5
4.2 Why the Chosen Design is the Most Appropriate 7
5. Design and Analysis 7
5.1 Interpretation of Results 7
5.2 Error Analysis 8
6. Steps Towards the Prototype12
6.1 Cost Analysis 9
6.2 Assembly, Sub-Assembly, And Parts-Drawing 9
6.3. Discussion on how the Prototype is Done 11
7. Conclusions 13
7.1 Discussions 13
7.2 Lessons Learned 14
7.3 Suggestions for Improvements 15
8. References 15
9. Appendices 15
9.1 Data 15
9.2 Material 18
In the presentation of this report, the modeling of a reusable bottle washer will be explained. Each component is modeled, assembled, and analyzed using Pro-Engineer Wildfire. The design process is explained for the production of the prototype. The final prototype dimensions and workings is also explained. The FDA food code is research to obtain information on properly cleaning a Gatorade squeeze bottle. Upon obtaining the parts for the final prototype, the parts are machined, the holes and drilled to the designed dimensions for the exit of the fluid in the spry, and the assembly is welded togethter to obtain the working prototype.
The prototype is then tested and observed to any faults or failures. Drain holes are made on the prototype to eliminate flooding of the mechanism while in operation. The flow through the mechanism is improved by making fillet on the entrance into the outer washer. The final prototype is obtained in T6-6061 aluminum and will be viable in meeting the green status due to the elimination of plastic waste into the environment.
4.1. STATEMENT AND BACKGROUND OF THE PROJECT
The goal of this project is to model and create a mechanism that can efficiently clean reusable bottles en masse. The bottle specification for this design is a 32oz reusable Gatorade squeeze bottle. The idea for this project originated from observing a typical University of Miami football practice session. During every break and rehydration period, the players drank Gatorade from 12oz disposable plastic bottles instead of from available 32oz squeeze bottles. The Athletic training staff employed to administer the Gatorade to the players explain that the problem with using the squeeze bottles is the rigorous and time consuming process it takes to clean them after every practice. As a result, it became the scope of this project to model and create such a device that could assist the University of Miami athletic program in cleaning their reusable bottles after football practices and
Design and Analysis of a Washer for Reusable BottlesPage 2
competitions, and take a significant step in efforts of achieving a ‘Green’ status for the University.
Fig.1 Reusable Gatorade bottles set out to be washed
As stated, this mechanism will assist athletic trainers to rapidly clean these 8in deep hollow bottles without the need for industrial dish-washers. Also, by creating this mechanism, we eliminate the waste and cost associated with the consumption of commercially produced 12oz Gatorade disposable bottles. Wastes eliminated include both plastic wastes to the environment (landfills, bodies of water), and also waste of space and energy in storing these packs of 12oz Gatorade bottles. Aside from making a device available for the athletic department to clean their 32oz squeeze bottles, with further improvements to its design and physical structure we can apply the utilization of this mechanism for culinary practices, and home/kitchen appliances.
Prior to embarking on this project, a timeline was set for its completion. Adhering to this timeline was a priority but due to unforeseen circumstances adjustments were made. A Gannt chart for this timeline was created:
Fig.2 Chart Showing the Timeline of the Project
Economic Impact: Using the University of Miami football team as a case study, 40 - 50 cases of Gatorade are used in a given football practice. Each case contains 24 120z disposable plastic bottles, costing $15 a case. A reusable squeeze bottle is capable of holding 32oz in volume of liquid contents.
For the utilization of the squeeze bottles, it was assumed that the athletic department would purchase and use pre-mixed Gatorade powder to produce their own Gatorade for practice and competition. It costs about $75 for a case of 14 Gatorade pre-mixed powders. 1½ packets is required to be mix into 10 gallons of water for the equivalent of an 8oz disposable Gatorable bottle. Making the cost calculation, the ability to wash and utilize these squeeze bottles will save the athletic department about $540 to $680 per football practice.
Fig.3 10-gallon storages for mixed Gatorade
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Fig.4 Pre mixed Gatorade powders
Environmental Impact: Eliminating the use of disposable bottles will eliminate dumping of plastic wastes to the environment. The pollution of the oceans, landfills, and the effect of contamination of wildlife with plastic would be significantly reduced.
Fig.5 12oz unused cases of disposable Gatorade bottles
Manufacturability: The final working prototype was designed for ease of manufacturability. Upon obtaining the proposed final CAD design of the prototype, T6-6061 aluminum materials were bought with the closest dimensions to the final design. These parts were then cut, machined, and welded together to
obtain a prototype nearly identical to the CAD designed prototype. The final dimensions of the holes were selected with considerations to standard drill diameters.
Standard pipefitting, plugs, caps, and hoses were used in the configuration of the prototype. These were obtained from local hardware stores, and fitted to the assembly. The manufacturing process of the final prototype took a week of consistent machining, drilling, and welding respectively.
Health and Safety:
The use of this mechanism will pose little or no chance of bodily harm or injury to the user. With the major constraint of the project being the breach of health and safety standards, the material selection had to be no-porous material with ease of cleaning. Aluminum was the most viable material available for these criteria. It presented little to no health risk and the cleanliness of the squeeze bottles would be determined by codes and standards set aside by the FDA (Food and Drug Administration).
In order to remove any residue (sugars, dyes,…) the tested bottle was put through a cycle of wash in the washer and then theoretically completely submerged in a tank of hot water maintained at a temperature of at least 77ᵒ C (171ᵒ F) for at least 30 seconds. Based on our design, falling under the category of “Manual Warewashing Equipment”, according to FDA food code 2013 this would be the appropriate measure for using hot water as a method of sanitation. The hot bath tub is used strictly as a means for sanitation and all other residue that should be cleaned off the surface of the bottle is done so by the bottle washer. The sec-tion out of the FDA food code handbook may be found in the next section.
Codes and Standards: We adhered strictly to the Codes and Standards set by the FDA in cleaning Kitchen Utensils and Food Handling Equipment. The clauses obtained from the “FDA Food Code 2009: Chapter 4 - Equipment, Utensils, and Linens” and from the “Food Code U.S. Public Health Service 2013 U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service” were strictly adhered to, and are provided below:
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Materials that are used in the construction of UTENSILS and FOOD-CONTACT SURFACES OF EQUIPMENT may not allow the migration of deleteri-ous substances or impart colors, odors, or tastes to FOOD and under normal use conditions shall be:
(B) Durable, CORROSION-RESISTANT, and nonab-sorbent;
(C) Sufficient in weight and thickness to withstand repeated WAREWASHING;
(D) Finished to have a SMOOTH, EASILY CLEANABLE surface; and
(E) Resistant to pitting, chipping, crazing, scratch-ing, scoring, distortion, and decomposition.
4-501.111 Manual ware washing Equipment, Hot Water Sanitization Temperatures.
If immersion in hot water is used for SANITIZING in a manual operation, the temperature of the water shall be maintained at 77o C (171o F) or above. P 134 4-
Several assumptions were made prior to the start of the design process for the working prototype. The prototype was tested with the threshold of these assumptions:
1. A pressurized flow of water at the washing temperature will be used to provide a flow rate of water into the washing equipment.
2. An inlet valve will be used to control the fluid flow into the mechanism at any given instant.
3. Liquid solutions used as the cleaning fluid, running through the mechanism are FDA health standard approved for sanitization.
4. Techniques for cleanliness are to be designed to meet the parameters set by FDA food codes.
4.1. OTHER POSSIBLE DESIGNS
Prior to embarking on the project, various designs were sought out for the mechanism. First, dimensions for a standard 32oz Gatorade squeeze bottle were obtained from the training room of the University of Miami athletic department. Every design constraint and dimension was made to the dimensions of the bottle. Dimensions for the bottle washer are given below:
Length – 9.0625in Diameter – 3.120in Neck – 2.455in Inner Diameter – 2.120in
Many ideas for the design of a bottle washing mechanism were thought out and considered. Most of them were struck out due their infeasibility, as one of the goals was to create a totally mechanical mechanism and eliminate any use of electricity on the working prototype. This decision was made to eliminate any risk of electrocution, as the working fluid (water) has a high conductance.
Other proposed designs considered were seen as too expensive to achieve a cheap financial budget. One of the fore-proposed designs was one that contained multiple divided chambers across the length of the washing cylinder, each having oscillatory motions relative to the axis of the cylinder. The motion of each chamber was to have the same oscillatory frequency but move opposite to the preceding or proceeding chamber. This design proved to be complex, as the means of producing an opposing oscillatory motion for each chamber while obtaining a fluid flow though all chambers was not feasible.
Another proposed design included a cylindrical washer with helical profiles for divided chambers but the design did not pose much of a challenge and
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problems did not differ much from that obtained with the divided oscillating chambers. Another design proposed involved the ability to wash both the interior and exterior of the bottle by a means of rotational motion. To translate a rotational motion of the internal cylinder produced by thrust obtained from the exiting fluid though the orifices of the inner chamber (inner washer), producing a torque to create a rotational motion of the inner washer about its axis, to an outer chamber (outer washer) a cam-follower system, coupled with a crank slider was the best option partially due to its simplicity, and mostly due to its feasibility for the design idea. The design also had a base connection, responsible for splitting the flow to the outer and inner washer, which housed the inlet connection.
This design idea was chosen after carefully studying the mechanics and workings of an electric toothbrush, a pressure washer, and a lawn sprinkler system. In comparison to initial designs, adding bristles to the outer washer would create complexities to the design, and would pose problems with replacements and cleanliness. It was decided that spray techniques in washing both the inside and outside of the bottle would be the best option. Inverting the bottle during the spray-washing process would also assist in fluid drainage.
The prototype was developed and is shown below:
Fig 6. 3-D model of initial prototype
Fig 7. Final Model of Initial Prototype
Due to the immense cost of having this design made, a full-scale model of this prototype could not be obtained. In order for the design to be made the original was scaled down by 50% which threw off all the flow rate and dimension calculations that had been done earlier. While testing this initial prototype, it was concluded that the inner washer could not generate enough force to drive the outer washer in an oscillatory motion through the cam-follower-crank system. This design also did not pass for manufacturability, as it could only be made in 3-D print, which is a virtually expensive means for creating a product and any leading competitor could undercut the design’s cost by designing something simpler. The prototype was also created in a less-dense ABS plastic with faults in leaking and does not meet the FDA food code for handling manually warewashing food and beverages.
Despite not obtaining the final prototype from the previous design ideas, these prior designs paved way for the final design and prototype.
4.2. WHY THE CHOSEN DESIGN IS THE MOST APPROPRIATE
The final design was chosen mostly in part to the working failures of the initial prototype, cost, and lessons learned in manufacturability. Referring back to the failures of the previous prototype, the assembly of the mechanical system and nozzles created on the inner washer for rotational motion were eliminated.
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The use of ABS plastic was eliminated and replaced with aluminum. The base connection was eliminated and holes were made directly on the bottom plate for pipefittings.
The final design was exponentially less expensive, much simpler, more effective, projected less wear and tear in the long run due to the elimination of moving parts, and simplified the design and design process. The new prototype also passed the non-porous and non-adhesive criteria for a sanitation equipment standard set by the FDA by using an aluminum material.
DESIGN AND ANALYSIS
5.1. INTERPRETATION OF RESULTS
In testing the prototype, various calculations had to be made. The total inlet (0.4418ft2) and outlet area of the fluid in each washer (0.1584ft^2 and 0.4224ft^2 for the inner and outer washer respectively) was calculated. The flow rate of water (outer washer exit flow rate: 0.0232ft3/s, inner washer exit flow rate: 0.0106ft3/s, assembly exit flow rate: 0.0300ft3/s, and assembly flow rate with bottle: 0.0307ft3/s) to operate the mechanism was obtained by measuring the time it took the fluid to fill up an empty bucket of known volume (5 US gallons: 0.6684ft3). This was done for a total of 15 times to obtain an accurate value for the volumetric flow rate. The total inlet area and total outlet area (77 total holes) were obtained. The pressure of 60psi and temperature of 143OF of the hot water outlet was measured. These obtained values were used in calculating the velocity of the inlet and outlet.
To solve the problem with drainage, the total flow rate (0.0338ft3/s) of the outlet orifices were calculated. This was set as the flow rate of the drainage. To minimize flooding a flow rate greater than the inlet flow rate is picked. A flow rate of 0.05ft3/s is picked as the flow rate of the drainage
outlet. The total drain outlet area is then obtained using the flow continuity equation:
A1V1 = A2V2
Using this equation, for a safe value of the outlet flow rate of 0.05ft3/s, and a drainage inlet area of 0.8642ft2, the value of the drainage outlet area (0.5848ft2) is obtained. This area is divided into 8 parts to obtain the minimum diameter of each hole. The calculated value of the minimum diameter of the drainage hole is 0.3051in. a safety value of 0.75” diameter is used for the drainage holes to nullify any fluctuations in the increase in pressure or flow rate through the assembly.
5.2. ERROR ANALYSIS
To calculate percent error of the volumetric flowrate and average outlet velocity, a theoretical and actual value of each is required. Those values would then be plugged into the equation,
to obtain a percent error.
The theoretical values were calculated using a combi-nation of the continuity equation along with the mea-sured flowrate of the inlets and areas of the outlets:
Q1 = Q2 = 0.0338ft3/s = A2V2
= (0.5848ft2)* V2
V2 = 0.0578 ft/sec = 0.0176 m/s
The actual values that were measured for the flowrate and average velocity of the water through the outlet of the washer were:
Q2 = 0.0307 ft3/s (mean of measured flowrates)
Q2 = 0.0307 ft3/s = A2V2
= (0.5848ft2)* V2
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V2 = 0.0525 ft/s = 0.0160 m/s
Therefore for the flowrate of the bottle washer, there was an error of,
For the average velocity of the outlet flow, there was an error of,
With such a small error in the volumetric flowrate and average velocity of the fluid, we can assume there is a change in energy within the system.
5.3. OPTIMIZATION OF DESIGN AND SELECTION OF FINAL DESIGN PARAMETERS
Given the fact that there was an error of about 10% of the resulting flow rate and fluid velocity tested, some things may be said about further optimization to the design of the bottle washer. Since due to the restriction of the design having to be able to be manufactured en masse, that meant that the design had to me be limited in the amount of rounding to allow for the most optimal fluid flow through the bottle washer. Flow through the chamber of the outer washer is currently not as uniform throughout as it ideally was intended to be. Given these restrictions, adding more inlets for the outer washer would help improve the volumetric flow rate throughout. That of course would cost more in labor and materials seeing as the price in adapters and connecting parts would double. However, seeing as the error was only 10%, further optimizing the design would not be necessary for the results obtained. Optimizing would only cost more and possible competitors would simply go with the simpler design to undercut the price.
STEPS TOWARDS THE PROTOTYPE
6.1. COST ANALYSIS
Prototyping the initial design took the brunt of the cost of the entire project. Despite obtaining a scaled down model of high grade ABS material with low density, the total cost of 3-D printing the half scaled model of the prototype with a discounted price, and obtaining pipe and fitting amounted to about $1000.
For the final prototype, a 1/8” aluminum plate and a ½” aluminum plate both with dimensions of 10X10, an 8” OD rod, a 6065”ID rod, and a 0.824” ID rod was purchased; all with a length of 12”. The total cost of these material and all other unused aluminum parts cost $135.32. The machining, drilling, and welding, of the prototype was done with assistance from a faculty member of the University.
6.2. ASSEMBLY, SUB-ASSEMBLY, AND PARTS DRAWING
In modeling the parts for the final prototype, Pro-Engineer Wildfire was used to create a CAD drawing and analyze the placements and feasibility of the elements in the parts. As stated earlier, each part was created with strict consideration to the dimensions of the 32oz Gatorade squeeze bottle. After obtaining the aluminum materials with standard dimensions (dimensions closest to the proposed sketches), the 2-D sketch was updated to account for the materials obtained.
The sketch and detailed explanation of each of the parts is shown below:
The Inner Washer
The inner washer, the most important part of the design, is tasked with washing the inner part of the bottle. The inner washer stands at 10.5”, welded to the plate at 8” from the top to the top of the plate. The ID of the inner washer is 0.824” with a thickness of 0.113” (standard ¾ pipe). Three holes of diameter 0.098” are drilled horizontally across the curved surface of the cylinder. This horizontal layer of holes is then patterned for 6 vertical layers, 1” apart. The top of the inner washer is then threaded to fit a brass cap on to be closed off. Holes of the same diameter
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are drilled 30o to the horizontal on the edge of the brass cap. The purpose of drilling the hole at this angle is to enable the mechanism in washing the internal edges of the bottle. The bottom end of the inner washer is also threaded to fit a pipe fit on for connection to the hose. The sketch of the inner washer is shown below:
Fig 8. 2-D Front Orientation of Inner Washer
The outer washer is responsible for washing the outer surface of the bottle. The dimensions of the outer washer were carefully selected for feasibility reason in fitting a standard human hand greater than 5” to place and remove the bottle after washing. The cylinder with an 8” OD and 1/8” thickness is coupled with the cylinder with a 6.065”ID and 0.28” thickness to form the outer washer. The outer washer stands at 12” long in the vertical direction, having 8-layers of holes of 0.081” diameter, 45o apart on the same axis. The holes are placed on the inner cylinder (6.065”ID), with this layer of holes patterned for 6 vertical layers, 1.5” apart, with the first layer of holes at 0.5” from the top of the plate. The top of the cylinder is welded to a 0.125” thick donut shaped plate, cut to fit the outer washer assembly (with an ID of 6.065” and OD
of 8”). The 7th layer of holes of the outer washer assembly is placed 2” from the sixth layer. It is also inclined at 30o from the horizontal to enable the outer washer in washing the bottom and bottom edge of the bottle. The sketch of the outer washer is shown below:
Fig 9. 2-D Front Orientation of Outer Washer
Plate (Pipe Connections)
The plate is responsible for holding both the inner and outer washer in place. A 0.5” thick, 10”X10” plate is used to achieve this purpose. A hole in the middle having the inner washer dimensions is drilled to fit through. Two holes of 0.37” were drilled 3.69” each from the center of the plate. These drilled holes are the entrance of the water into the outer washer. The dimensions of the holes were obtained from the exit dimension of the purchased fitting adapter used in connecting the pipe to the assembly.
The plate also served the purpose of draining the assembly of water after washing the bottle. The drain consists of 8 holes, 45o apart and on a 2.45” radius, modeled to fit on the opening diameter of the bottle. The diameters of the holes were calculated considering the flow rate water exiting the assembly. The diameter of the drain holes had to be big enough
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to eliminate flooding of the assembly during washing. The minimum diameter of the holes to accomplish proper drainage was 0.5634”. A diameter of 0.75” was chosen for the drain holes to for safety. The sketch of the plate is shown below:
Fig 10. 2-D Sketch of the Plate
The parts were assembled in Pro-Engineer and checked for any assembly errors before being sent out for manufacturing.
A model assembly for the prototype is shown below:
Fig 11. A sketch of the Assembly showing the Internal Parts
Fig 12. A model of the assembly showing the Bottom View
6.3. DISCUSSION ON HOW PROTOTYPING IS DONE
After the CAD design and assembly was obtained, the sketches were sent out for manufacturing. In piecing the parts together, all the holes were first drilled on
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the plate. The dimensions of the hole were carefully marked and precisely drilled. The cylinders were then cut to the desired lengths, and then machined to obtain a smooth and orthogonal surface in preparation for welding. About a 1/10” between necessary surfaces was kept in order to account for welding.
The holes were then drilled on the 6.065”ID cylinder and the inner washer. To achieve a feasible weld of the assembly, the inner washer was fit into its drilled fitting and welded around the plate. The 6.065” diameter cylinder was then placed on the plate and welded on the outside edges, as it was impossible to place a weld to achieve an internal weld for the parts. The weld was machined off to obtain proper clearance for the hole, so that the weld would not interfere with the incoming water. The 8” cylinder was then welded to the plate to create flow area for the outer washer. This was done on the edges of the outer washer.
To obtain a closure of the outer washer, the donut shaped plate; initially cut to fit and cover up both cylinders was welded on the surface of the cylinder, creating a perfect seal for the outer washer. Prior to welding the external washers, the drilled holes were de-burred and a fillet was created for each hole to improve the flow of water out of the orifices. The two entrance holes to the outer washer were tapped to screw on a ¼ adapter, which in subsequence was converted to allow a hose of ¾ to be connected by means of adapters. An adapter was also screwed onto the inlet of the inner washer. After all the welding and machining was done, the mechanism was cleaned and prepped for testing.
The images of the final prototype are shown below:
Fig 13. Top view of the final prototype showing the inner washer and drain holes
Fig 14. Top view of the Final prototype showing the spray from the inner and outer washer
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Fig 15. Front view of the final prototype showing all the pipe connections and draining of the working
Fig 16. Top view of the prototype while the bottle is being washed
Fig 17. Placing / removing the bottle fro the prototype while the bottle is being washed
Fig 18. Bottom of the prototype showing all the welded pipe connections and fittings
The project definition was to design and create a mechanism that can wash reusable squeeze bottles. A case study was done on the University of Miami
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football team, when noticing that Gatorade was being consumed from disposable 12oz Gatorade bottles instead of their 32oz squeeze bottles. Upon further investigation, it was observed that the problem with using reusable squeeze bottles was due to the tedious and time-consuming process of washing and cleaning them. Further calculations proved that the school would save about $540 to $680 daily by using the reusable bottles in place of the disposable ones.
The design process started with discussions on the possible designs. Many designs were proposed, but the final design chosen involved a spray type washing process, modeled after a pressure washer. The process had to have the capability of washing the inside and outside of a bottle. The bottle’s dimensions were taken to obtain the possible dimensions and constraints of the proposed bottle washer.
The FDA and Public health food code was adhered to obtain a standard for the cleanliness of the bottle. It was concluded that in order to obtain a clean and sanitized product, the bottle would have to be run through the bottle washer and then completely submerged in a hot water tank at a temperature of 77o C (171o F) or above.
At the first attempt of design a mechanism consisting of an inner washer rotating about its axis was created, driven by thrust forces developed at the exit of the fluid, with an outer washer oscillating on its own axis. The motion of the outer washer was intended to be driven from the rotating motion of the inner washer, connected by a cam-follower-crank system. A base connection, which contained the inlet port for the mechanism, was responsible in separating the flow into each washer. Manufacturing this prototype proved to be immensely expensive, which then forced the manufacturing of a ½ scale model; which then wasn’t helpful in being able to wash a bottle. The material of production, (ABS plastic), did not meet the FDA standards for ware washers. After this design was discarded, a new design was created in its place.
Aluminum was used chosen for the material. The use of aluminum material met the FDA code for the material properties used for standard washing equipment. A new design was made with just an inner
washer, outer washer, and a base plate that had connections to the hoses connected to the hot water outlet. The mechanical system was eliminated, as it proved to be too complex and unnecessary for the design. Materials were sourced from the local aluminum supply store, with a re-dimensioning done of the entire assembly done after obtaining the materials of standard dimensions. After obtaining the materials, the holes on the washer were drilled, machined to cut away excess materials, and the outer washer was welded off to create a seal on the top. Pipefitting adapters were drilled on the bottom of the plate to connect the hoses to the inner and outer washers, while a brass cap was put on the top of the inner washer to seal off the top. A hole at 30 degrees was drilled on the inner washer for the water to reach the inner edges of the bottle.
Calculations were made to obtain proper flow through the mechanism. The total outlet area of each washer was slightly smaller than the inlet area so as to create some acceleration though the exit orifices, but not too small to reduce stagnation pressure in sections of the mechanism. Drainage holes were created to prevent flooding of the assembly during washing. The drainage holes were calculated by assuming a higher value of the flow rate of drainage exit compared to the total flow rate from all the orifices. The diameter of each drainage holes was set at 0.75”, which worked perfectly in draining the used water in the mechanism.
In testing the prototype, flow rates were measured and used in calculating the error of the mechanism. As for potential improvements to the prototype, it was observed that a rise in length and increase in angle of the top layer exit orifices for the outer washer could be made to get a better outside clean for the bottle. The design being an open-ended prototype could also be redesigned for cleaning cups, and other hollow plates and kitchen equipment. It could also be redesigned, with the mechanism connected together in multiple rows, which would deem viable for washing multiple bottles at the same time.
The design and prototype worked perfectly well, while achieving all the set out goals. The cost of the redesigned prototype made with aluminum was far less than the cost of the previous design made out of ABS material. In relation to the expenses of the
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athletic department, the cost of manufacture and purchase of this mechanism would be insignificant in comparison to the daily cost the department incurs in utilizing disposable bottles. This design also eliminates the cause of plastic waste into the environment, contributing to a more green University.
A great deal was learned from this project. This project got us familiar with the design process. The major lesson learned was in product manufacturability. Upon switching to aluminum as the material for the final prototype, we had to adjust the dimensions of the prototype to conform to the aluminum parts readily available. We also learned to always have a detailed design sketch and look into all the constraints before setting out to manufacture to eliminate overhauling the project due to unrealized faults that could have be eliminated from the start. This was also seen in the many unnecessary and unused parts we bought that amounted to a waste of resources.
From the failed prototype, we learned a lot about improving the flow through channels by providing a fillet radius on flow bends to eliminate flow separation, and hereby, reduce or eliminate pressure drops. Despite being a failure, improving the mechanical system consisting of the cam-follower connection, taught us a lot in that aspect. The failed prototype also taught us a lesson in manufacturability. The prototype could not be manufactured on a large scale as a result of 3-D printing due to the complexities in the design. We also learned to always make every mechanism design as simple as possible to cut cost and improve its ability to be manufacture en masse.
Suggestions For Improvement:
Being an open-ended project, the washer can be improved in many ways. The washer can be made in an assembly, connecting more washers in order to washer more Gatorade bottles all at the same time. For this to be achieved, we would need to obtain a
larger flow rate of water at a much larger pressure than 60psi.
Also, the spacing of the holes can be altered to obtain a more even wash across all the segments of the bottle to be washed. The angles of the inclined hole can also be altered to obtain a better wash on the inside and outer edges of the bottles, while a hole or series of can be drilled on the top of the inner washer to obtain a wash on the top of the bottle.
A wide range of improvements can be done for sizing the prototype to any bottle dimension desired. The size of the initial prototype can also be reduced immensely, cutting down cost and reducing the weight of the mechanism. To improve portability, risk of minor cuts and injuries, and durability, the sharp edges of the plates can be machined of to obtain a circular base, while a stand can be made for the prototype, with the pipe openings made parallel to the curved surface of the cylinder, to allow for an easier connection from the hot water outlet.
 Specifications, Design, and Kinematic Analysis of an Electric Toothbrush using CATIA V5R19 http://e-archivo.uc3m.es/bitstream/handle/10016/13019/Specification,%20design%20and%20kinematic%20analysis%20of%20an%20Electric%20Toothbrush%20using%20CATIAV5R19.pdf?sequence=2
 How do toothbrushes work?http://www.explainthatstuff.com/electrictoothbrush.html
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 Singheresu Rao. “Mechanical Vibrations”. 5th
Design and Analysis of a Washer for Reusable BottlesPage 14
 Robert E. Sanders, Jr. (2001). "Technology Innovation in Aluminum Products". JOM 53 (2): 21–25. Bibcode:2001JOM....53b..21S. doi:10.1007/s11837-001-0115-7.
 Plastic Properties of Acrylonitrile Butadiene Styrene (ABS) Small table of ABS properties towards the bottom. Retrieved 7 May 2010
Matlab Code for Flow rate calcultaions
clearclc inlet_pipe_dia = 0.75inlet_area = pi*inlet_pipe_dia^2/4 inner_n = 21;inner_dia = .098;inner_area = inner_n*pi*inner_dia^2/4 outer_n = 56;outer_dia = .081;outer_area = outer_n*pi*inner_dia^2/4 buck_vol = 0.66840278 %ft^3 outer_washer_flow_rate_exit = buck_vol/28.76 inner_washer_flow_rate_exit = buck_vol/63.08 assembly_flow_rate_exit = buck_vol/22.26 assembly_flow_rate_bottle = buck_vol/21.75 % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % Drainage %%%%%%%% drainage_inlet_flowrate = outer_washer_flow_rate_exit + inner_washer_flow_rate_exit drainage_inlet_area = outer_area + inlet_area % % % % for a flow rate greater than 0.0338, assume the flow rate to more% (0.05) drain_outlet_area = drainage_inlet_flowrate*drainage_inlet_area/0.05 % % % % for 8 holes, the radius is calculated drain_8holes_dia = sqrt((drain_outlet_area/8)*4/pi)
% we need hole of diameter >> 0.3051% % we picked 0.75 to be on the safe side
WASHER CAM SVAJ
function [s,v,a,j] = svajexample(t) b1=pi/12;b2=11*pi/12;b3=pi/12;b4=11*pi/12; h1=0;h2=1.72125; if t>=0 && t<=b1s=0;v=0;a=0;j=0; elseif t>=b1 && t<=b1+b2s=h2*(35*((t-b1)/b2)^4 - 84*((t-b1)/b2)^5 + 70*((t-b1)/b2)^6 - 20*((t-b1)/b2)^7);v=h2/b2*(140*((t-b1)/b2)^3 - 420*((t-b1)/b2)^4 + 420*((t-b1)/b2)^5 - 140*((t-b1)/b2)^6);a=h2/b2^2*(420*((t-b1)/b2)^2 - 1680*((t-b1)/b2)^3 + 2100*((t-b1)/b2)^4 - 840*((t-b1)/b2)^5);j=h2/b2^3*(840*((t-b1)/b2) - 5040*((t-b1)/b2)^2 + 8400*((t-b1)/b2)^3 - 4200*((t-b1)/b2)^4); elseif t>=b1+b2 && t<=b1+b2+b3s=h2;v=0;a=0;j=0; elses=h2-(h2*(35*((t-b1-b2-b3)/b4)^4 - 84*((t-b1-b2-b3)/b4)^5 + 70*((t-b1-b2-b3)/b4)^6 - 20*((t-b1-b2-b3)/b4)^7));v=-h2/b4*(140*((t-b1-b2-b3)/b4)^3 - 420*((t-b1-b2-b3)/b4)^4 + 420*((t-b1-b2-b3)/b4)^5 - 140*((t-b1-b2-b3)/b4)^6);a=-h2/b4^2*(420*((t-b1-b2-b3)/b4)^2 - 1680*((t-b1-b2-b3)/b4)^3 + 2100*((t-b1-b2-b3)/b4)^4 - 840*((t-b1-b2-b3)/b4)^5);
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j=-h2/b4^3*(840*((t-b1-b2-b3)/b4) - 5040*((t-b1-b2-b3)/b4)^2 + 8400*((t-b1-b2-b3)/b4)^3 - 4200*((t-b1-b2-b3)/b4)^4);end WASHER CAM SVAJ PLOTclear all;N=1000;for i=1:N+1 x(i)=(i-1)*2*pi/N; [s(i),v(i),a(i),j(i)]=svajexample(x(i));end
figure(1);plot(x,s,'b-');grid on;title('Displacement');xlabel('Angle (rad)');ylabel('Diplacement (in)');%axis([0,2*pi,0,7])%axis equal
figure(2);plot(x,v,'b-');grid on;title('Velocity');xlabel('Angle (rad)');ylabel('Velocity (in/rad)');
figure(3)plot(x,a,'b-');grid on;title('Acceleration');xlabel('Angle (rad)');ylabel('Acceleration (in/rad^2)');
figure(4)plot(x,j,'b-');grid on;title('Jerk');xlabel('Angle (rad)');ylabel('Jerk (in/rad^3)');SIZING WASHER CAMclear all;N=1000;Rp=.73725;Rf=.175;
x(i)=(i-1)*2*pi/N; [s(i),v(i),a(i),j(i)]=svajexample(x(i)); beta(i)=atan(-(v(i)*sin(x(i))+(Rp+s(i))*cos(x(i)))/(v(i)*cos(x(i))-(Rp+s(i))*sin(x(i)))); dx=v(i)*sin(x(i))+(Rp+s(i))*cos(x(i)); dy=v(i)*cos(x(i))-(Rp+s(i))*sin(x(i)); if dy<0 beta(i)=atan(-dx/dy)+pi; elseif dy>0 beta(i)=atan(-dx/dy); elseif dx>0 & dy==0 beta(i)=-pi/2; elseif dx<0 & dy==0 beta(i)=pi/2; end%pitch curve coord_x1(i)=(Rp+s(i))*sin(x(i)); coord_y1(i)=(Rp+s(i))*cos(x(i));%Cam profile coord_x(i)=(Rp+s(i))*sin(x(i))+Rf*cos(beta(i)); coord_y(i)=(Rp+s(i))*cos(x(i))+Rf*sin(beta(i));%Pressure angle phi(i)=atan(v(i)/(s(i)+Rp))*360/(2*pi);%Radius of curvature rou(i)=((Rp+s(i))^2+v(i)^2)^(3/2)/((Rp+s(i))^2+2*v(i)^2-a(i)*(Rp+s(i)));end
figure(1)plot(x,phi,'b-');grid on;title('Pressure angle');xlabel('Angle');ylabel('Pressure angle (degree)');axis equal
figure(2)plot(x,rou,'b-');grid on;title('Radius of curvature');xlabel('Angle');ylabel('Radius of curvature (in)');axis equal
figure(3)plot(coord_x,coord_y,'b-',Rp*cos(x),Rp*sin(x),'g-',coord_x1,coord_y1,'y-');grid on;title('Cam profile');
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xlabel('x (in)');ylabel('y (in)');axis equal
MATLAB CALCULATION OUTPUT
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Seconds to fill 5 gallon bucket
Volumetric Flow Rate of Washer As-sembly (gal/
21.61 13.8824618221.56 13.9146567721.75 13.7931034521.96 13.6612021921.68 13.8376383821.95 13.66742597
21.9 13.6986301421.65 13.8568129321.61 13.8824618221.58 13.9017608921.83 13.74255612
22.6 13.2743362821.65 13.8568129321.88 13.71115174
Aluminum 6061-T6 was used as the material is manufacturing the prototype. 6061-T6 aluminum alloy is generally a cheap, and contains elements of silicon and magnesium. It possesses good mechanical
properties and is one of the most common alloys for general-purpose use. 6061-T6 is commonly available in pre-tempered grade, used in the manufacture of stressed frames, and aircraft components. This aluminum alloy is highly weldable with arc or any other form of welding, but loses some of its strength after the welding process. It is also a non-brittle material that is very machinable. On the other hand, the previously used ABS plastic material (Acrylonitrile butadiene styrene) is a polymer made by polymerizing styrene and acrylonitrile. It is a low hazard material that presents low risk to health and humans. It has desirable properties in toughness, impact, and low electrical conductance, while also being significantly lighter than aluminum.ABS plastic does not meet the criteria for the washer material set by the FDA, and thus was not used as the material for the final prototype. Water running throughout the mechanism made with ABS material might be contaminated with the inorganic compounds of the material.
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